This file is indexed.

/usr/lib/python2.7/dist-packages/pyqtgraph/graphicsItems/ROI.py is in python-pyqtgraph 0.9.10-5.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
# -*- coding: utf-8 -*-
"""
ROI.py -  Interactive graphics items for GraphicsView (ROI widgets)
Copyright 2010  Luke Campagnola
Distributed under MIT/X11 license. See license.txt for more infomation.

Implements a series of graphics items which display movable/scalable/rotatable shapes
for use as region-of-interest markers. ROI class automatically handles extraction 
of array data from ImageItems.

The ROI class is meant to serve as the base for more specific types; see several examples
of how to build an ROI at the bottom of the file.
"""

from ..Qt import QtCore, QtGui
import numpy as np
#from numpy.linalg import norm
from ..Point import *
from ..SRTTransform import SRTTransform
from math import cos, sin
from .. import functions as fn
from .GraphicsObject import GraphicsObject
from .UIGraphicsItem import UIGraphicsItem

__all__ = [
    'ROI', 
    'TestROI', 'RectROI', 'EllipseROI', 'CircleROI', 'PolygonROI', 
    'LineROI', 'MultiLineROI', 'MultiRectROI', 'LineSegmentROI', 'PolyLineROI', 'SpiralROI', 'CrosshairROI',
]


def rectStr(r):
    return "[%f, %f] + [%f, %f]" % (r.x(), r.y(), r.width(), r.height())

class ROI(GraphicsObject):
    """
    Generic region-of-interest widget.
    
    Can be used for implementing many types of selection box with 
    rotate/translate/scale handles.
    ROIs can be customized to have a variety of shapes (by subclassing or using
    any of the built-in subclasses) and any combination of draggable handles
    that allow the user to manipulate the ROI.
    
    
    
    ================ ===========================================================
    **Arguments**
    pos              (length-2 sequence) Indicates the position of the ROI's 
                     origin. For most ROIs, this is the lower-left corner of
                     its bounding rectangle.
    size             (length-2 sequence) Indicates the width and height of the 
                     ROI.
    angle            (float) The rotation of the ROI in degrees. Default is 0.
    invertible       (bool) If True, the user may resize the ROI to have 
                     negative width or height (assuming the ROI has scale
                     handles). Default is False.
    maxBounds        (QRect, QRectF, or None) Specifies boundaries that the ROI 
                     cannot be dragged outside of by the user. Default is None.
    snapSize         (float) The spacing of snap positions used when *scaleSnap*
                     or *translateSnap* are enabled. Default is 1.0.
    scaleSnap        (bool) If True, the width and height of the ROI are forced
                     to be integer multiples of *snapSize* when being resized
                     by the user. Default is False.
    translateSnap    (bool) If True, the x and y positions of the ROI are forced
                     to be integer multiples of *snapSize* when being resized
                     by the user. Default is False.
    rotateSnap       (bool) If True, the ROI angle is forced to a multiple of 
                     15 degrees when rotated by the user. Default is False.
    parent           (QGraphicsItem) The graphics item parent of this ROI. It
                     is generally not necessary to specify the parent.
    pen              (QPen or argument to pg.mkPen) The pen to use when drawing
                     the shape of the ROI.
    movable          (bool) If True, the ROI can be moved by dragging anywhere 
                     inside the ROI. Default is True.
    removable        (bool) If True, the ROI will be given a context menu with
                     an option to remove the ROI. The ROI emits
                     sigRemoveRequested when this menu action is selected.
                     Default is False.
    ================ ===========================================================
    
    
    
    ======================= ====================================================
    **Signals**
    sigRegionChangeFinished Emitted when the user stops dragging the ROI (or
                            one of its handles) or if the ROI is changed
                            programatically.
    sigRegionChangeStarted  Emitted when the user starts dragging the ROI (or
                            one of its handles).
    sigRegionChanged        Emitted any time the position of the ROI changes,
                            including while it is being dragged by the user.
    sigHoverEvent           Emitted when the mouse hovers over the ROI.
    sigClicked              Emitted when the user clicks on the ROI.
                            Note that clicking is disabled by default to prevent
                            stealing clicks from objects behind the ROI. To 
                            enable clicking, call 
                            roi.setAcceptedMouseButtons(QtCore.Qt.LeftButton). 
                            See QtGui.QGraphicsItem documentation for more 
                            details.
    sigRemoveRequested      Emitted when the user selects 'remove' from the 
                            ROI's context menu (if available).
    ======================= ====================================================
    """
    
    sigRegionChangeFinished = QtCore.Signal(object)
    sigRegionChangeStarted = QtCore.Signal(object)
    sigRegionChanged = QtCore.Signal(object)
    sigHoverEvent = QtCore.Signal(object)
    sigClicked = QtCore.Signal(object, object)
    sigRemoveRequested = QtCore.Signal(object)
    
    def __init__(self, pos, size=Point(1, 1), angle=0.0, invertible=False, maxBounds=None, snapSize=1.0, scaleSnap=False, translateSnap=False, rotateSnap=False, parent=None, pen=None, movable=True, removable=False):
        #QObjectWorkaround.__init__(self)
        GraphicsObject.__init__(self, parent)
        self.setAcceptedMouseButtons(QtCore.Qt.NoButton)
        pos = Point(pos)
        size = Point(size)
        self.aspectLocked = False
        self.translatable = movable
        self.rotateAllowed = True
        self.removable = removable
        self.menu = None
        
        self.freeHandleMoved = False ## keep track of whether free handles have moved since last change signal was emitted.
        self.mouseHovering = False
        if pen is None:
            pen = (255, 255, 255)
        self.setPen(pen)
        
        self.handlePen = QtGui.QPen(QtGui.QColor(150, 255, 255))
        self.handles = []
        self.state = {'pos': Point(0,0), 'size': Point(1,1), 'angle': 0}  ## angle is in degrees for ease of Qt integration
        self.lastState = None
        self.setPos(pos)
        self.setAngle(angle)
        self.setSize(size)
        self.setZValue(10)
        self.isMoving = False
        
        self.handleSize = 5
        self.invertible = invertible
        self.maxBounds = maxBounds
        
        self.snapSize = snapSize
        self.translateSnap = translateSnap
        self.rotateSnap = rotateSnap
        self.scaleSnap = scaleSnap
        #self.setFlag(self.ItemIsSelectable, True)
    
    def getState(self):
        return self.stateCopy()

    def stateCopy(self):
        sc = {}
        sc['pos'] = Point(self.state['pos'])
        sc['size'] = Point(self.state['size'])
        sc['angle'] = self.state['angle']
        return sc
        
    def saveState(self):
        """Return the state of the widget in a format suitable for storing to 
        disk. (Points are converted to tuple)
        
        Combined with setState(), this allows ROIs to be easily saved and 
        restored."""
        state = {}
        state['pos'] = tuple(self.state['pos'])
        state['size'] = tuple(self.state['size'])
        state['angle'] = self.state['angle']
        return state
    
    def setState(self, state, update=True):
        """
        Set the state of the ROI from a structure generated by saveState() or
        getState().
        """
        self.setPos(state['pos'], update=False)
        self.setSize(state['size'], update=False)
        self.setAngle(state['angle'], update=update)
    
    def setZValue(self, z):
        QtGui.QGraphicsItem.setZValue(self, z)
        for h in self.handles:
            h['item'].setZValue(z+1)
        
    def parentBounds(self):
        """
        Return the bounding rectangle of this ROI in the coordinate system
        of its parent.        
        """
        return self.mapToParent(self.boundingRect()).boundingRect()

    def setPen(self, *args, **kwargs):
        """
        Set the pen to use when drawing the ROI shape.
        For arguments, see :func:`mkPen <pyqtgraph.mkPen>`.
        """
        self.pen = fn.mkPen(*args, **kwargs)
        self.currentPen = self.pen
        self.update()
        
    def size(self):
        """Return the size (w,h) of the ROI."""
        return self.getState()['size']
        
    def pos(self):
        """Return the position (x,y) of the ROI's origin. 
        For most ROIs, this will be the lower-left corner."""
        return self.getState()['pos']
        
    def angle(self):
        """Return the angle of the ROI in degrees."""
        return self.getState()['angle']
        
    def setPos(self, pos, update=True, finish=True):
        """Set the position of the ROI (in the parent's coordinate system).
        By default, this will cause both sigRegionChanged and sigRegionChangeFinished to be emitted.
        
        If finish is False, then sigRegionChangeFinished will not be emitted. You can then use 
        stateChangeFinished() to cause the signal to be emitted after a series of state changes.
        
        If update is False, the state change will be remembered but not processed and no signals 
        will be emitted. You can then use stateChanged() to complete the state change. This allows
        multiple change functions to be called sequentially while minimizing processing overhead
        and repeated signals. Setting update=False also forces finish=False.
        """
        
        pos = Point(pos)
        self.state['pos'] = pos
        QtGui.QGraphicsItem.setPos(self, pos)
        if update:
            self.stateChanged(finish=finish)
        
    def setSize(self, size, update=True, finish=True):
        """Set the size of the ROI. May be specified as a QPoint, Point, or list of two values.
        See setPos() for an explanation of the update and finish arguments.
        """
        size = Point(size)
        self.prepareGeometryChange()
        self.state['size'] = size
        if update:
            self.stateChanged(finish=finish)
        
    def setAngle(self, angle, update=True, finish=True):
        """Set the angle of rotation (in degrees) for this ROI.
        See setPos() for an explanation of the update and finish arguments.
        """
        self.state['angle'] = angle
        tr = QtGui.QTransform()
        #tr.rotate(-angle * 180 / np.pi)
        tr.rotate(angle)
        self.setTransform(tr)
        if update:
            self.stateChanged(finish=finish)
        
    def scale(self, s, center=[0,0], update=True, finish=True):
        """
        Resize the ROI by scaling relative to *center*.
        See setPos() for an explanation of the *update* and *finish* arguments.
        """
        c = self.mapToParent(Point(center) * self.state['size'])
        self.prepareGeometryChange()
        newSize = self.state['size'] * s
        c1 = self.mapToParent(Point(center) * newSize)
        newPos = self.state['pos'] + c - c1
        
        self.setSize(newSize, update=False)
        self.setPos(newPos, update=update, finish=finish)
        
   
    def translate(self, *args, **kargs):
        """
        Move the ROI to a new position.
        Accepts either (x, y, snap) or ([x,y], snap) as arguments
        If the ROI is bounded and the move would exceed boundaries, then the ROI
        is moved to the nearest acceptable position instead.
        
        *snap* can be:
        
        =============== ==========================================================================
        None (default)  use self.translateSnap and self.snapSize to determine whether/how to snap
        False           do not snap
        Point(w,h)      snap to rectangular grid with spacing (w,h)
        True            snap using self.snapSize (and ignoring self.translateSnap)
        =============== ==========================================================================
           
        Also accepts *update* and *finish* arguments (see setPos() for a description of these).
        """

        if len(args) == 1:
            pt = args[0]
        else:
            pt = args
            
        newState = self.stateCopy()
        newState['pos'] = newState['pos'] + pt
        
        ## snap position
        #snap = kargs.get('snap', None)
        #if (snap is not False)   and   not (snap is None and self.translateSnap is False):
        
        snap = kargs.get('snap', None)
        if snap is None:
            snap = self.translateSnap
        if snap is not False:
            newState['pos'] = self.getSnapPosition(newState['pos'], snap=snap)
        
        #d = ev.scenePos() - self.mapToScene(self.pressPos)
        if self.maxBounds is not None:
            r = self.stateRect(newState)
            #r0 = self.sceneTransform().mapRect(self.boundingRect())
            d = Point(0,0)
            if self.maxBounds.left() > r.left():
                d[0] = self.maxBounds.left() - r.left()
            elif self.maxBounds.right() < r.right():
                d[0] = self.maxBounds.right() - r.right()
            if self.maxBounds.top() > r.top():
                d[1] = self.maxBounds.top() - r.top()
            elif self.maxBounds.bottom() < r.bottom():
                d[1] = self.maxBounds.bottom() - r.bottom()
            newState['pos'] += d
        
        #self.state['pos'] = newState['pos']
        update = kargs.get('update', True)
        finish = kargs.get('finish', True)
        self.setPos(newState['pos'], update=update, finish=finish)
        #if 'update' not in kargs or kargs['update'] is True:
        #self.stateChanged()

    def rotate(self, angle, update=True, finish=True):
        """
        Rotate the ROI by *angle* degrees. 
        
        Also accepts *update* and *finish* arguments (see setPos() for a 
        description of these).
        """
        self.setAngle(self.angle()+angle, update=update, finish=finish)

    def handleMoveStarted(self):
        self.preMoveState = self.getState()
    
    def addTranslateHandle(self, pos, axes=None, item=None, name=None, index=None):
        """
        Add a new translation handle to the ROI. Dragging the handle will move 
        the entire ROI without changing its angle or shape. 
        
        Note that, by default, ROIs may be moved by dragging anywhere inside the
        ROI. However, for larger ROIs it may be desirable to disable this and
        instead provide one or more translation handles.
        
        =================== ====================================================
        **Arguments**
        pos                 (length-2 sequence) The position of the handle 
                            relative to the shape of the ROI. A value of (0,0)
                            indicates the origin, whereas (1, 1) indicates the
                            upper-right corner, regardless of the ROI's size.
        item                The Handle instance to add. If None, a new handle
                            will be created.
        name                The name of this handle (optional). Handles are 
                            identified by name when calling 
                            getLocalHandlePositions and getSceneHandlePositions.
        =================== ====================================================
        """
        pos = Point(pos)
        return self.addHandle({'name': name, 'type': 't', 'pos': pos, 'item': item}, index=index)
    
    def addFreeHandle(self, pos=None, axes=None, item=None, name=None, index=None):
        """
        Add a new free handle to the ROI. Dragging free handles has no effect
        on the position or shape of the ROI. 
        
        =================== ====================================================
        **Arguments**
        pos                 (length-2 sequence) The position of the handle 
                            relative to the shape of the ROI. A value of (0,0)
                            indicates the origin, whereas (1, 1) indicates the
                            upper-right corner, regardless of the ROI's size.
        item                The Handle instance to add. If None, a new handle
                            will be created.
        name                The name of this handle (optional). Handles are 
                            identified by name when calling 
                            getLocalHandlePositions and getSceneHandlePositions.
        =================== ====================================================
        """
        if pos is not None:
            pos = Point(pos)
        return self.addHandle({'name': name, 'type': 'f', 'pos': pos, 'item': item}, index=index)
    
    def addScaleHandle(self, pos, center, axes=None, item=None, name=None, lockAspect=False, index=None):
        """
        Add a new scale handle to the ROI. Dragging a scale handle allows the
        user to change the height and/or width of the ROI.
        
        =================== ====================================================
        **Arguments**
        pos                 (length-2 sequence) The position of the handle 
                            relative to the shape of the ROI. A value of (0,0)
                            indicates the origin, whereas (1, 1) indicates the
                            upper-right corner, regardless of the ROI's size.
        center              (length-2 sequence) The center point around which 
                            scaling takes place. If the center point has the
                            same x or y value as the handle position, then 
                            scaling will be disabled for that axis.
        item                The Handle instance to add. If None, a new handle
                            will be created.
        name                The name of this handle (optional). Handles are 
                            identified by name when calling 
                            getLocalHandlePositions and getSceneHandlePositions.
        =================== ====================================================
        """
        pos = Point(pos)
        center = Point(center)
        info = {'name': name, 'type': 's', 'center': center, 'pos': pos, 'item': item, 'lockAspect': lockAspect}
        if pos.x() == center.x():
            info['xoff'] = True
        if pos.y() == center.y():
            info['yoff'] = True
        return self.addHandle(info, index=index)
    
    def addRotateHandle(self, pos, center, item=None, name=None, index=None):
        """
        Add a new rotation handle to the ROI. Dragging a rotation handle allows 
        the user to change the angle of the ROI.
        
        =================== ====================================================
        **Arguments**
        pos                 (length-2 sequence) The position of the handle 
                            relative to the shape of the ROI. A value of (0,0)
                            indicates the origin, whereas (1, 1) indicates the
                            upper-right corner, regardless of the ROI's size.
        center              (length-2 sequence) The center point around which 
                            rotation takes place.
        item                The Handle instance to add. If None, a new handle
                            will be created.
        name                The name of this handle (optional). Handles are 
                            identified by name when calling 
                            getLocalHandlePositions and getSceneHandlePositions.
        =================== ====================================================
        """
        pos = Point(pos)
        center = Point(center)
        return self.addHandle({'name': name, 'type': 'r', 'center': center, 'pos': pos, 'item': item}, index=index)
    
    def addScaleRotateHandle(self, pos, center, item=None, name=None, index=None):
        """
        Add a new scale+rotation handle to the ROI. When dragging a handle of 
        this type, the user can simultaneously rotate the ROI around an 
        arbitrary center point as well as scale the ROI by dragging the handle
        toward or away from the center point.
        
        =================== ====================================================
        **Arguments**
        pos                 (length-2 sequence) The position of the handle 
                            relative to the shape of the ROI. A value of (0,0)
                            indicates the origin, whereas (1, 1) indicates the
                            upper-right corner, regardless of the ROI's size.
        center              (length-2 sequence) The center point around which 
                            scaling and rotation take place.
        item                The Handle instance to add. If None, a new handle
                            will be created.
        name                The name of this handle (optional). Handles are 
                            identified by name when calling 
                            getLocalHandlePositions and getSceneHandlePositions.
        =================== ====================================================
        """
        pos = Point(pos)
        center = Point(center)
        if pos[0] != center[0] and pos[1] != center[1]:
            raise Exception("Scale/rotate handles must have either the same x or y coordinate as their center point.")
        return self.addHandle({'name': name, 'type': 'sr', 'center': center, 'pos': pos, 'item': item}, index=index)
    
    def addRotateFreeHandle(self, pos, center, axes=None, item=None, name=None, index=None):
        """
        Add a new rotation+free handle to the ROI. When dragging a handle of 
        this type, the user can rotate the ROI around an 
        arbitrary center point, while moving toward or away from the center 
        point has no effect on the shape of the ROI.
        
        =================== ====================================================
        **Arguments**
        pos                 (length-2 sequence) The position of the handle 
                            relative to the shape of the ROI. A value of (0,0)
                            indicates the origin, whereas (1, 1) indicates the
                            upper-right corner, regardless of the ROI's size.
        center              (length-2 sequence) The center point around which 
                            rotation takes place.
        item                The Handle instance to add. If None, a new handle
                            will be created.
        name                The name of this handle (optional). Handles are 
                            identified by name when calling 
                            getLocalHandlePositions and getSceneHandlePositions.
        =================== ====================================================
        """
        pos = Point(pos)
        center = Point(center)
        return self.addHandle({'name': name, 'type': 'rf', 'center': center, 'pos': pos, 'item': item}, index=index)
    
    def addHandle(self, info, index=None):
        ## If a Handle was not supplied, create it now
        if 'item' not in info or info['item'] is None:
            h = Handle(self.handleSize, typ=info['type'], pen=self.handlePen, parent=self)
            h.setPos(info['pos'] * self.state['size'])
            info['item'] = h
        else:
            h = info['item']
            if info['pos'] is None:
                info['pos'] = h.pos()
            
        ## connect the handle to this ROI
        #iid = len(self.handles)
        h.connectROI(self)
        if index is None:
            self.handles.append(info)
        else:
            self.handles.insert(index, info)
        
        h.setZValue(self.zValue()+1)
        self.stateChanged()
        return h
    
    def indexOfHandle(self, handle):
        """
        Return the index of *handle* in the list of this ROI's handles.
        """
        if isinstance(handle, Handle):
            index = [i for i, info in enumerate(self.handles) if info['item'] is handle]    
            if len(index) == 0:
                raise Exception("Cannot remove handle; it is not attached to this ROI")
            return index[0]
        else:
            return handle
        
    def removeHandle(self, handle):
        """Remove a handle from this ROI. Argument may be either a Handle 
        instance or the integer index of the handle."""
        index = self.indexOfHandle(handle)
            
        handle = self.handles[index]['item']
        self.handles.pop(index)
        handle.disconnectROI(self)
        if len(handle.rois) == 0:
            self.scene().removeItem(handle)
        self.stateChanged()
    
    def replaceHandle(self, oldHandle, newHandle):
        """Replace one handle in the ROI for another. This is useful when 
        connecting multiple ROIs together.
        
        *oldHandle* may be a Handle instance or the index of a handle to be
        replaced."""
        index = self.indexOfHandle(oldHandle)
        info = self.handles[index]
        self.removeHandle(index)
        info['item'] = newHandle
        info['pos'] = newHandle.pos()
        self.addHandle(info, index=index)
        
    def checkRemoveHandle(self, handle):
        ## This is used when displaying a Handle's context menu to determine
        ## whether removing is allowed. 
        ## Subclasses may wish to override this to disable the menu entry.
        ## Note: by default, handles are not user-removable even if this method returns True.
        return True
        
        
    def getLocalHandlePositions(self, index=None):
        """Returns the position of handles in the ROI's coordinate system.
        
        The format returned is a list of (name, pos) tuples.
        """
        if index == None:
            positions = []
            for h in self.handles:
                positions.append((h['name'], h['pos']))
            return positions
        else:
            return (self.handles[index]['name'], self.handles[index]['pos'])
            
    def getSceneHandlePositions(self, index=None):
        """Returns the position of handles in the scene coordinate system.
        
        The format returned is a list of (name, pos) tuples.
        """
        if index == None:
            positions = []
            for h in self.handles:
                positions.append((h['name'], h['item'].scenePos()))
            return positions
        else:
            return (self.handles[index]['name'], self.handles[index]['item'].scenePos())
        
    def getHandles(self):
        """
        Return a list of this ROI's Handles.
        """
        return [h['item'] for h in self.handles]
    
    def mapSceneToParent(self, pt):
        return self.mapToParent(self.mapFromScene(pt))

    def setSelected(self, s):
        QtGui.QGraphicsItem.setSelected(self, s)
        #print "select", self, s
        if s:
            for h in self.handles:
                h['item'].show()
        else:
            for h in self.handles:
                h['item'].hide()


    def hoverEvent(self, ev):
        hover = False
        if not ev.isExit():
            if self.translatable and ev.acceptDrags(QtCore.Qt.LeftButton):
                hover=True
                
            for btn in [QtCore.Qt.LeftButton, QtCore.Qt.RightButton, QtCore.Qt.MidButton]:
                if int(self.acceptedMouseButtons() & btn) > 0 and ev.acceptClicks(btn):
                    hover=True
            if self.contextMenuEnabled():
                ev.acceptClicks(QtCore.Qt.RightButton)
                
        if hover:
            self.setMouseHover(True)
            self.sigHoverEvent.emit(self)
            ev.acceptClicks(QtCore.Qt.LeftButton)  ## If the ROI is hilighted, we should accept all clicks to avoid confusion.
            ev.acceptClicks(QtCore.Qt.RightButton)
            ev.acceptClicks(QtCore.Qt.MidButton)
        else:
            self.setMouseHover(False)

    def setMouseHover(self, hover):
        ## Inform the ROI that the mouse is(not) hovering over it
        if self.mouseHovering == hover:
            return
        self.mouseHovering = hover
        if hover:
            self.currentPen = fn.mkPen(255, 255, 0)
        else:
            self.currentPen = self.pen
        self.update()

    def contextMenuEnabled(self):
        return self.removable
    
    def raiseContextMenu(self, ev):
        if not self.contextMenuEnabled():
            return
        menu = self.getMenu()
        menu = self.scene().addParentContextMenus(self, menu, ev)
        pos = ev.screenPos()
        menu.popup(QtCore.QPoint(pos.x(), pos.y()))

    def getMenu(self):
        if self.menu is None:
            self.menu = QtGui.QMenu()
            self.menu.setTitle("ROI")
            remAct = QtGui.QAction("Remove ROI", self.menu)
            remAct.triggered.connect(self.removeClicked)
            self.menu.addAction(remAct)
            self.menu.remAct = remAct
        return self.menu

    def removeClicked(self):
        ## Send remove event only after we have exited the menu event handler
        QtCore.QTimer.singleShot(0, lambda: self.sigRemoveRequested.emit(self))
        
    def mouseDragEvent(self, ev):
        if ev.isStart():
            #p = ev.pos()
            #if not self.isMoving and not self.shape().contains(p):
                #ev.ignore()
                #return        
            if ev.button() == QtCore.Qt.LeftButton:
                self.setSelected(True)
                if self.translatable:
                    self.isMoving = True
                    self.preMoveState = self.getState()
                    self.cursorOffset = self.pos() - self.mapToParent(ev.buttonDownPos())
                    self.sigRegionChangeStarted.emit(self)
                    ev.accept()
                else:
                    ev.ignore()

        elif ev.isFinish():
            if self.translatable:
                if self.isMoving:
                    self.stateChangeFinished()
                self.isMoving = False
            return

        if self.translatable and self.isMoving and ev.buttons() == QtCore.Qt.LeftButton:
            snap = True if (ev.modifiers() & QtCore.Qt.ControlModifier) else None
            newPos = self.mapToParent(ev.pos()) + self.cursorOffset
            self.translate(newPos - self.pos(), snap=snap, finish=False)
        
    def mouseClickEvent(self, ev):
        if ev.button() == QtCore.Qt.RightButton and self.isMoving:
            ev.accept()
            self.cancelMove()
        if ev.button() == QtCore.Qt.RightButton and self.contextMenuEnabled():
            self.raiseContextMenu(ev)
            ev.accept()
        elif int(ev.button() & self.acceptedMouseButtons()) > 0:
            ev.accept()
            self.sigClicked.emit(self, ev)
        else:
            ev.ignore()

    def cancelMove(self):
        self.isMoving = False
        self.setState(self.preMoveState)

    def checkPointMove(self, handle, pos, modifiers):
        """When handles move, they must ask the ROI if the move is acceptable.
        By default, this always returns True. Subclasses may wish override.
        """
        return True

    def movePoint(self, handle, pos, modifiers=QtCore.Qt.KeyboardModifier(), finish=True, coords='parent'):
        ## called by Handles when they are moved. 
        ## pos is the new position of the handle in scene coords, as requested by the handle.
        
        newState = self.stateCopy()
        index = self.indexOfHandle(handle)
        h = self.handles[index]
        p0 = self.mapToParent(h['pos'] * self.state['size'])
        p1 = Point(pos)
        
        if coords == 'parent':
            pass
        elif coords == 'scene':
            p1 = self.mapSceneToParent(p1)
        else:
            raise Exception("New point location must be given in either 'parent' or 'scene' coordinates.")

        
        ## transform p0 and p1 into parent's coordinates (same as scene coords if there is no parent). I forget why.
        #p0 = self.mapSceneToParent(p0)
        #p1 = self.mapSceneToParent(p1)

        ## Handles with a 'center' need to know their local position relative to the center point (lp0, lp1)
        if 'center' in h:
            c = h['center']
            cs = c * self.state['size']
            lp0 = self.mapFromParent(p0) - cs
            lp1 = self.mapFromParent(p1) - cs
        
        if h['type'] == 't':
            snap = True if (modifiers & QtCore.Qt.ControlModifier) else None
            #if self.translateSnap or ():
                #snap = Point(self.snapSize, self.snapSize)
            self.translate(p1-p0, snap=snap, update=False)
        
        elif h['type'] == 'f':
            newPos = self.mapFromParent(p1)
            h['item'].setPos(newPos)
            h['pos'] = newPos
            self.freeHandleMoved = True
            #self.sigRegionChanged.emit(self)  ## should be taken care of by call to stateChanged()
            
        elif h['type'] == 's':
            ## If a handle and its center have the same x or y value, we can't scale across that axis.
            if h['center'][0] == h['pos'][0]:
                lp1[0] = 0
            if h['center'][1] == h['pos'][1]:
                lp1[1] = 0
            
            ## snap 
            if self.scaleSnap or (modifiers & QtCore.Qt.ControlModifier):
                lp1[0] = round(lp1[0] / self.snapSize) * self.snapSize
                lp1[1] = round(lp1[1] / self.snapSize) * self.snapSize
                
            ## preserve aspect ratio (this can override snapping)
            if h['lockAspect'] or (modifiers & QtCore.Qt.AltModifier):
                #arv = Point(self.preMoveState['size']) - 
                lp1 = lp1.proj(lp0)
            
            ## determine scale factors and new size of ROI
            hs = h['pos'] - c
            if hs[0] == 0:
                hs[0] = 1
            if hs[1] == 0:
                hs[1] = 1
            newSize = lp1 / hs
            
            ## Perform some corrections and limit checks
            if newSize[0] == 0:
                newSize[0] = newState['size'][0]
            if newSize[1] == 0:
                newSize[1] = newState['size'][1]
            if not self.invertible:
                if newSize[0] < 0:
                    newSize[0] = newState['size'][0]
                if newSize[1] < 0:
                    newSize[1] = newState['size'][1]
            if self.aspectLocked:
                newSize[0] = newSize[1]
            
            ## Move ROI so the center point occupies the same scene location after the scale
            s0 = c * self.state['size']
            s1 = c * newSize
            cc = self.mapToParent(s0 - s1) - self.mapToParent(Point(0, 0))
            
            ## update state, do more boundary checks
            newState['size'] = newSize
            newState['pos'] = newState['pos'] + cc
            if self.maxBounds is not None:
                r = self.stateRect(newState)
                if not self.maxBounds.contains(r):
                    return
            
            self.setPos(newState['pos'], update=False)
            self.setSize(newState['size'], update=False)
        
        elif h['type'] in ['r', 'rf']:
            if h['type'] == 'rf':
                self.freeHandleMoved = True
            
            if not self.rotateAllowed:
                return
            ## If the handle is directly over its center point, we can't compute an angle.
            try:
                if lp1.length() == 0 or lp0.length() == 0:
                    return
            except OverflowError:
                return
            
            ## determine new rotation angle, constrained if necessary
            ang = newState['angle'] - lp0.angle(lp1)
            if ang is None:  ## this should never happen..
                return
            if self.rotateSnap or (modifiers & QtCore.Qt.ControlModifier):
                ang = round(ang / 15.) * 15.  ## 180/12 = 15
            
            ## create rotation transform
            tr = QtGui.QTransform()
            tr.rotate(ang)
            
            ## move ROI so that center point remains stationary after rotate
            cc = self.mapToParent(cs) - (tr.map(cs) + self.state['pos'])
            newState['angle'] = ang
            newState['pos'] = newState['pos'] + cc
            
            ## check boundaries, update
            if self.maxBounds is not None:
                r = self.stateRect(newState)
                if not self.maxBounds.contains(r):
                    return
            #self.setTransform(tr)
            self.setPos(newState['pos'], update=False)
            self.setAngle(ang, update=False)
            #self.state = newState
            
            ## If this is a free-rotate handle, its distance from the center may change.
            
            if h['type'] == 'rf':
                h['item'].setPos(self.mapFromScene(p1))  ## changes ROI coordinates of handle
                
        elif h['type'] == 'sr':
            if h['center'][0] == h['pos'][0]:
                scaleAxis = 1
                nonScaleAxis=0
            else:
                scaleAxis = 0
                nonScaleAxis=1
            
            try:
                if lp1.length() == 0 or lp0.length() == 0:
                    return
            except OverflowError:
                return
            
            ang = newState['angle'] - lp0.angle(lp1)
            if ang is None:
                return
            if self.rotateSnap or (modifiers & QtCore.Qt.ControlModifier):
                #ang = round(ang / (np.pi/12.)) * (np.pi/12.)
                ang = round(ang / 15.) * 15.
            
            hs = abs(h['pos'][scaleAxis] - c[scaleAxis])
            newState['size'][scaleAxis] = lp1.length() / hs
            #if self.scaleSnap or (modifiers & QtCore.Qt.ControlModifier):
            if self.scaleSnap:  ## use CTRL only for angular snap here.
                newState['size'][scaleAxis] = round(newState['size'][scaleAxis] / self.snapSize) * self.snapSize
            if newState['size'][scaleAxis] == 0:
                newState['size'][scaleAxis] = 1
            if self.aspectLocked:
                newState['size'][nonScaleAxis] = newState['size'][scaleAxis]
                
            c1 = c * newState['size']
            tr = QtGui.QTransform()
            tr.rotate(ang)
            
            cc = self.mapToParent(cs) - (tr.map(c1) + self.state['pos'])
            newState['angle'] = ang
            newState['pos'] = newState['pos'] + cc
            if self.maxBounds is not None:
                r = self.stateRect(newState)
                if not self.maxBounds.contains(r):
                    return
            #self.setTransform(tr)
            #self.setPos(newState['pos'], update=False)
            #self.prepareGeometryChange()
            #self.state = newState
            self.setState(newState, update=False)
        
        self.stateChanged(finish=finish)
    
    def stateChanged(self, finish=True):
        """Process changes to the state of the ROI.
        If there are any changes, then the positions of handles are updated accordingly
        and sigRegionChanged is emitted. If finish is True, then 
        sigRegionChangeFinished will also be emitted."""
        
        changed = False
        if self.lastState is None:
            changed = True
        else:
            for k in list(self.state.keys()):
                if self.state[k] != self.lastState[k]:
                    changed = True
        
        self.prepareGeometryChange()
        if changed:
            ## Move all handles to match the current configuration of the ROI
            for h in self.handles:
                if h['item'] in self.childItems():
                    p = h['pos']
                    h['item'].setPos(h['pos'] * self.state['size'])
                #else:
                #    trans = self.state['pos']-self.lastState['pos']
                #    h['item'].setPos(h['pos'] + h['item'].parentItem().mapFromParent(trans))
                    
            self.update()
            self.sigRegionChanged.emit(self)
        elif self.freeHandleMoved:
            self.sigRegionChanged.emit(self)
            
        self.freeHandleMoved = False
        self.lastState = self.stateCopy()
            
        if finish:
            self.stateChangeFinished()
    
    def stateChangeFinished(self):
        self.sigRegionChangeFinished.emit(self)
    
    def stateRect(self, state):
        r = QtCore.QRectF(0, 0, state['size'][0], state['size'][1])
        tr = QtGui.QTransform()
        #tr.rotate(-state['angle'] * 180 / np.pi)
        tr.rotate(-state['angle'])
        r = tr.mapRect(r)
        return r.adjusted(state['pos'][0], state['pos'][1], state['pos'][0], state['pos'][1])
    
    
    def getSnapPosition(self, pos, snap=None):
        ## Given that pos has been requested, return the nearest snap-to position
        ## optionally, snap may be passed in to specify a rectangular snap grid.
        ## override this function for more interesting snap functionality..
        
        if snap is None or snap is True:
            if self.snapSize is None:
                return pos
            snap = Point(self.snapSize, self.snapSize)
        
        return Point(
            round(pos[0] / snap[0]) * snap[0],
            round(pos[1] / snap[1]) * snap[1]
        )
    
    def boundingRect(self):
        return QtCore.QRectF(0, 0, self.state['size'][0], self.state['size'][1]).normalized()

    def paint(self, p, opt, widget):
        # p.save()
        # Note: don't use self.boundingRect here, because subclasses may need to redefine it.
        r = QtCore.QRectF(0, 0, self.state['size'][0], self.state['size'][1]).normalized()
        
        p.setRenderHint(QtGui.QPainter.Antialiasing)
        p.setPen(self.currentPen)
        p.translate(r.left(), r.top())
        p.scale(r.width(), r.height())
        p.drawRect(0, 0, 1, 1)
        # p.restore()

    def getArraySlice(self, data, img, axes=(0,1), returnSlice=True):
        """Return a tuple of slice objects that can be used to slice the region from data covered by this ROI.
        Also returns the transform which maps the ROI into data coordinates.
        
        If returnSlice is set to False, the function returns a pair of tuples with the values that would have 
        been used to generate the slice objects. ((ax0Start, ax0Stop), (ax1Start, ax1Stop))
        
        If the slice can not be computed (usually because the scene/transforms are not properly
        constructed yet), then the method returns None.
        """
        #print "getArraySlice"
        
        ## Determine shape of array along ROI axes
        dShape = (data.shape[axes[0]], data.shape[axes[1]])
        #print "  dshape", dShape
        
        ## Determine transform that maps ROI bounding box to image coordinates
        try:
            tr = self.sceneTransform() * fn.invertQTransform(img.sceneTransform())
        except np.linalg.linalg.LinAlgError:
            return None
            
        ## Modify transform to scale from image coords to data coords
        #m = QtGui.QTransform()
        tr.scale(float(dShape[0]) / img.width(), float(dShape[1]) / img.height())
        #tr = tr * m
        
        ## Transform ROI bounds into data bounds
        dataBounds = tr.mapRect(self.boundingRect())
        #print "  boundingRect:", self.boundingRect()
        #print "  dataBounds:", dataBounds
        
        ## Intersect transformed ROI bounds with data bounds
        intBounds = dataBounds.intersect(QtCore.QRectF(0, 0, dShape[0], dShape[1]))
        #print "  intBounds:", intBounds
        
        ## Determine index values to use when referencing the array. 
        bounds = (
            (int(min(intBounds.left(), intBounds.right())), int(1+max(intBounds.left(), intBounds.right()))),
            (int(min(intBounds.bottom(), intBounds.top())), int(1+max(intBounds.bottom(), intBounds.top())))
        )
        #print "  bounds:", bounds
        
        if returnSlice:
            ## Create slice objects
            sl = [slice(None)] * data.ndim
            sl[axes[0]] = slice(*bounds[0])
            sl[axes[1]] = slice(*bounds[1])
            return tuple(sl), tr
        else:
            return bounds, tr

    def getArrayRegion(self, data, img, axes=(0,1), returnMappedCoords=False, **kwds):
        """Use the position and orientation of this ROI relative to an imageItem 
        to pull a slice from an array.
        
        =================== ====================================================
        **Arguments**
        data                The array to slice from. Note that this array does
                            *not* have to be the same data that is represented
                            in *img*.
        img                 (ImageItem or other suitable QGraphicsItem)
                            Used to determine the relationship between the 
                            ROI and the boundaries of *data*.
        axes                (length-2 tuple) Specifies the axes in *data* that
                            correspond to the x and y axes of *img*.
        returnMappedCoords  (bool) If True, the array slice is returned along
                            with a corresponding array of coordinates that were
                            used to extract data from the original array.
        \**kwds             All keyword arguments are passed to 
                            :func:`affineSlice <pyqtgraph.affineSlice>`.
        =================== ====================================================
        
        This method uses :func:`affineSlice <pyqtgraph.affineSlice>` to generate
        the slice from *data* and uses :func:`getAffineSliceParams <pyqtgraph.ROI.getAffineSliceParams>` to determine the parameters to 
        pass to :func:`affineSlice <pyqtgraph.affineSlice>`.
        
        If *returnMappedCoords* is True, then the method returns a tuple (result, coords) 
        such that coords is the set of coordinates used to interpolate values from the original
        data, mapped into the parent coordinate system of the image. This is useful, when slicing
        data from images that have been transformed, for determining the location of each value
        in the sliced data.
        
        All extra keyword arguments are passed to :func:`affineSlice <pyqtgraph.affineSlice>`.
        """
        
        shape, vectors, origin = self.getAffineSliceParams(data, img, axes)
        if not returnMappedCoords:
            return fn.affineSlice(data, shape=shape, vectors=vectors, origin=origin, axes=axes, **kwds)
        else:
            kwds['returnCoords'] = True
            result, coords = fn.affineSlice(data, shape=shape, vectors=vectors, origin=origin, axes=axes, **kwds)
            #tr = fn.transformToArray(img.transform())[:2]  ## remove perspective transform values
            
            ### separate translation from scale/rotate
            #translate = tr[:,2]
            #tr = tr[:,:2]
            #tr = tr.reshape((2,2) + (1,)*(coords.ndim-1))
            #coords = coords[np.newaxis, ...]
            
            ### map coordinates and return
            #mapped = (tr*coords).sum(axis=0)  ## apply scale/rotate
            #mapped += translate.reshape((2,1,1))
            mapped = fn.transformCoordinates(img.transform(), coords)
            return result, mapped

    def getAffineSliceParams(self, data, img, axes=(0,1)):
        """
        Returns the parameters needed to use :func:`affineSlice <pyqtgraph.affineSlice>` to 
        extract a subset of *data* using this ROI and *img* to specify the subset.
        
        See :func:`getArrayRegion <pyqtgraph.ROI.getArrayRegion>` for more information.
        """
        if self.scene() is not img.scene():
            raise Exception("ROI and target item must be members of the same scene.")
        
        shape = self.state['size']
        
        origin = self.mapToItem(img, QtCore.QPointF(0, 0))
        
        ## vx and vy point in the directions of the slice axes, but must be scaled properly
        vx = self.mapToItem(img, QtCore.QPointF(1, 0)) - origin
        vy = self.mapToItem(img, QtCore.QPointF(0, 1)) - origin
        
        lvx = np.sqrt(vx.x()**2 + vx.y()**2)
        lvy = np.sqrt(vy.x()**2 + vy.y()**2)
        pxLen = img.width() / float(data.shape[axes[0]])
        #img.width is number of pixels or width of item?
        #need pxWidth and pxHeight instead of pxLen ?
        sx =  pxLen / lvx
        sy =  pxLen / lvy
        
        vectors = ((vx.x()*sx, vx.y()*sx), (vy.x()*sy, vy.y()*sy))
        shape = self.state['size']
        shape = [abs(shape[0]/sx), abs(shape[1]/sy)]
        
        origin = (origin.x(), origin.y())
        return shape, vectors, origin
        
    def getGlobalTransform(self, relativeTo=None):
        """Return global transformation (rotation angle+translation) required to move 
        from relative state to current state. If relative state isn't specified,
        then we use the state of the ROI when mouse is pressed."""
        if relativeTo == None:
            relativeTo = self.preMoveState
        st = self.getState()
        
        ## this is only allowed because we will be comparing the two 
        relativeTo['scale'] = relativeTo['size']
        st['scale'] = st['size']
        
        
        
        t1 = SRTTransform(relativeTo)
        t2 = SRTTransform(st)
        return t2/t1
        
        
        #st = self.getState()
        
        ### rotation
        #ang = (st['angle']-relativeTo['angle']) * 180. / 3.14159265358
        #rot = QtGui.QTransform()
        #rot.rotate(-ang)

        ### We need to come up with a universal transformation--one that can be applied to other objects 
        ### such that all maintain alignment. 
        ### More specifically, we need to turn the ROI's position and angle into
        ### a rotation _around the origin_ and a translation.
        
        #p0 = Point(relativeTo['pos'])

        ### base position, rotated
        #p1 = rot.map(p0)
        
        #trans = Point(st['pos']) - p1
        #return trans, ang

    def applyGlobalTransform(self, tr):
        st = self.getState()
        
        st['scale'] = st['size']
        st = SRTTransform(st)
        st = (st * tr).saveState()
        st['size'] = st['scale']
        self.setState(st)


class Handle(UIGraphicsItem):
    """
    Handle represents a single user-interactable point attached to an ROI. They
    are usually created by a call to one of the ROI.add___Handle() methods.
    
    Handles are represented as a square, diamond, or circle, and are drawn with 
    fixed pixel size regardless of the scaling of the view they are displayed in.
    
    Handles may be dragged to change the position, size, orientation, or other
    properties of the ROI they are attached to.
    
    
    """
    types = {   ## defines number of sides, start angle for each handle type
        't': (4, np.pi/4),
        'f': (4, np.pi/4), 
        's': (4, 0),
        'r': (12, 0),
        'sr': (12, 0),
        'rf': (12, 0),
    }

    sigClicked = QtCore.Signal(object, object)   # self, event
    sigRemoveRequested = QtCore.Signal(object)   # self
    
    def __init__(self, radius, typ=None, pen=(200, 200, 220), parent=None, deletable=False):
        #print "   create item with parent", parent
        #self.bounds = QtCore.QRectF(-1e-10, -1e-10, 2e-10, 2e-10)
        #self.setFlags(self.ItemIgnoresTransformations | self.ItemSendsScenePositionChanges)
        self.rois = []
        self.radius = radius
        self.typ = typ
        self.pen = fn.mkPen(pen)
        self.currentPen = self.pen
        self.pen.setWidth(0)
        self.pen.setCosmetic(True)
        self.isMoving = False
        self.sides, self.startAng = self.types[typ]
        self.buildPath()
        self._shape = None
        self.menu = self.buildMenu()
        
        UIGraphicsItem.__init__(self, parent=parent)
        self.setAcceptedMouseButtons(QtCore.Qt.NoButton)
        self.deletable = deletable
        if deletable:
            self.setAcceptedMouseButtons(QtCore.Qt.RightButton)        
        #self.updateShape()
        self.setZValue(11)
            
    def connectROI(self, roi):
        ### roi is the "parent" roi, i is the index of the handle in roi.handles
        self.rois.append(roi)
        
    def disconnectROI(self, roi):
        self.rois.remove(roi)
        #for i, r in enumerate(self.roi):
            #if r[0] == roi:
                #self.roi.pop(i)
                
    #def close(self):
        #for r in self.roi:
            #r.removeHandle(self)
            
    def setDeletable(self, b):
        self.deletable = b
        if b:
            self.setAcceptedMouseButtons(self.acceptedMouseButtons() | QtCore.Qt.RightButton)
        else:
            self.setAcceptedMouseButtons(self.acceptedMouseButtons() & ~QtCore.Qt.RightButton)
            
    def removeClicked(self):
        self.sigRemoveRequested.emit(self)

    def hoverEvent(self, ev):
        hover = False
        if not ev.isExit():
            if ev.acceptDrags(QtCore.Qt.LeftButton):
                hover=True
            for btn in [QtCore.Qt.LeftButton, QtCore.Qt.RightButton, QtCore.Qt.MidButton]:
                if int(self.acceptedMouseButtons() & btn) > 0 and ev.acceptClicks(btn):
                    hover=True
                    
        if hover:
            self.currentPen = fn.mkPen(255, 255,0)
        else:
            self.currentPen = self.pen
        self.update()
        #if (not ev.isExit()) and ev.acceptDrags(QtCore.Qt.LeftButton):
            #self.currentPen = fn.mkPen(255, 255,0)
        #else:
            #self.currentPen = self.pen
        #self.update()
            


    def mouseClickEvent(self, ev):
        ## right-click cancels drag
        if ev.button() == QtCore.Qt.RightButton and self.isMoving:
            self.isMoving = False  ## prevents any further motion
            self.movePoint(self.startPos, finish=True)
            #for r in self.roi:
                #r[0].cancelMove()
            ev.accept()
        elif int(ev.button() & self.acceptedMouseButtons()) > 0:
            ev.accept()
            if ev.button() == QtCore.Qt.RightButton and self.deletable:
                self.raiseContextMenu(ev)
            self.sigClicked.emit(self, ev)
        else:
            ev.ignore()        
            
            #elif self.deletable:
                #ev.accept()
                #self.raiseContextMenu(ev)
            #else:
                #ev.ignore()
                
    def buildMenu(self):
        menu = QtGui.QMenu()
        menu.setTitle("Handle")
        self.removeAction = menu.addAction("Remove handle", self.removeClicked) 
        return menu
        
    def getMenu(self):
        return self.menu

    def raiseContextMenu(self, ev):
        menu = self.scene().addParentContextMenus(self, self.getMenu(), ev)
        
        ## Make sure it is still ok to remove this handle
        removeAllowed = all([r.checkRemoveHandle(self) for r in self.rois])
        self.removeAction.setEnabled(removeAllowed)
        pos = ev.screenPos()
        menu.popup(QtCore.QPoint(pos.x(), pos.y()))    

    def mouseDragEvent(self, ev):
        if ev.button() != QtCore.Qt.LeftButton:
            return
        ev.accept()
        
        ## Inform ROIs that a drag is happening 
        ##  note: the ROI is informed that the handle has moved using ROI.movePoint
        ##  this is for other (more nefarious) purposes.
        #for r in self.roi:
            #r[0].pointDragEvent(r[1], ev)
            
        if ev.isFinish():
            if self.isMoving:
                for r in self.rois:
                    r.stateChangeFinished()
            self.isMoving = False
        elif ev.isStart():
            for r in self.rois:
                r.handleMoveStarted()
            self.isMoving = True
            self.startPos = self.scenePos()
            self.cursorOffset = self.scenePos() - ev.buttonDownScenePos()
            
        if self.isMoving:  ## note: isMoving may become False in mid-drag due to right-click.
            pos = ev.scenePos() + self.cursorOffset
            self.movePoint(pos, ev.modifiers(), finish=False)

    def movePoint(self, pos, modifiers=QtCore.Qt.KeyboardModifier(), finish=True):
        for r in self.rois:
            if not r.checkPointMove(self, pos, modifiers):
                return
        #print "point moved; inform %d ROIs" % len(self.roi)
        # A handle can be used by multiple ROIs; tell each to update its handle position
        for r in self.rois:
            r.movePoint(self, pos, modifiers, finish=finish, coords='scene')
        
    def buildPath(self):
        size = self.radius
        self.path = QtGui.QPainterPath()
        ang = self.startAng
        dt = 2*np.pi / self.sides
        for i in range(0, self.sides+1):
            x = size * cos(ang)
            y = size * sin(ang)
            ang += dt
            if i == 0:
                self.path.moveTo(x, y)
            else:
                self.path.lineTo(x, y)            
            
    def paint(self, p, opt, widget):
        ### determine rotation of transform
        #m = self.sceneTransform()
        ##mi = m.inverted()[0]
        #v = m.map(QtCore.QPointF(1, 0)) - m.map(QtCore.QPointF(0, 0))
        #va = np.arctan2(v.y(), v.x())
        
        ### Determine length of unit vector in painter's coords
        ##size = mi.map(Point(self.radius, self.radius)) - mi.map(Point(0, 0))
        ##size = (size.x()*size.x() + size.y() * size.y()) ** 0.5
        #size = self.radius
        
        #bounds = QtCore.QRectF(-size, -size, size*2, size*2)
        #if bounds != self.bounds:
            #self.bounds = bounds
            #self.prepareGeometryChange()
        p.setRenderHints(p.Antialiasing, True)
        p.setPen(self.currentPen)
        
        #p.rotate(va * 180. / 3.1415926)
        #p.drawPath(self.path)        
        p.drawPath(self.shape())
        #ang = self.startAng + va
        #dt = 2*np.pi / self.sides
        #for i in range(0, self.sides):
            #x1 = size * cos(ang)
            #y1 = size * sin(ang)
            #x2 = size * cos(ang+dt)
            #y2 = size * sin(ang+dt)
            #ang += dt
            #p.drawLine(Point(x1, y1), Point(x2, y2))
            
    def shape(self):
        if self._shape is None:
            s = self.generateShape()
            if s is None:
                return self.path
            self._shape = s
            self.prepareGeometryChange()  ## beware--this can cause the view to adjust, which would immediately invalidate the shape.
        return self._shape
    
    def boundingRect(self):
        #print 'roi:', self.roi
        s1 = self.shape()
        #print "   s1:", s1
        #s2 = self.shape()
        #print "   s2:", s2
        
        return self.shape().boundingRect()
            
    def generateShape(self):
        ## determine rotation of transform
        #m = self.sceneTransform()  ## Qt bug: do not access sceneTransform() until we know this object has a scene.
        #mi = m.inverted()[0]
        dt = self.deviceTransform()
        
        if dt is None:
            self._shape = self.path
            return None
        
        v = dt.map(QtCore.QPointF(1, 0)) - dt.map(QtCore.QPointF(0, 0))
        va = np.arctan2(v.y(), v.x())
        
        dti = fn.invertQTransform(dt)
        devPos = dt.map(QtCore.QPointF(0,0))
        tr = QtGui.QTransform()
        tr.translate(devPos.x(), devPos.y())
        tr.rotate(va * 180. / 3.1415926)
        
        return dti.map(tr.map(self.path))
        
        
    def viewTransformChanged(self):
        GraphicsObject.viewTransformChanged(self)
        self._shape = None  ## invalidate shape, recompute later if requested.
        self.update()
        
    #def itemChange(self, change, value):
        #if change == self.ItemScenePositionHasChanged:
            #self.updateShape()


class TestROI(ROI):
    def __init__(self, pos, size, **args):
        #QtGui.QGraphicsRectItem.__init__(self, pos[0], pos[1], size[0], size[1])
        ROI.__init__(self, pos, size, **args)
        #self.addTranslateHandle([0, 0])
        self.addTranslateHandle([0.5, 0.5])
        self.addScaleHandle([1, 1], [0, 0])
        self.addScaleHandle([0, 0], [1, 1])
        self.addScaleRotateHandle([1, 0.5], [0.5, 0.5])
        self.addScaleHandle([0.5, 1], [0.5, 0.5])
        self.addRotateHandle([1, 0], [0, 0])
        self.addRotateHandle([0, 1], [1, 1])



class RectROI(ROI):
    """
    Rectangular ROI subclass with a single scale handle at the top-right corner.
    
    ============== =============================================================
    **Arguments**
    pos            (length-2 sequence) The position of the ROI origin.
                   See ROI().
    size           (length-2 sequence) The size of the ROI. See ROI().
    centered       (bool) If True, scale handles affect the ROI relative to its
                   center, rather than its origin.
    sideScalers    (bool) If True, extra scale handles are added at the top and 
                   right edges.
    \**args        All extra keyword arguments are passed to ROI()
    ============== =============================================================
    
    """
    def __init__(self, pos, size, centered=False, sideScalers=False, **args):
        #QtGui.QGraphicsRectItem.__init__(self, 0, 0, size[0], size[1])
        ROI.__init__(self, pos, size, **args)
        if centered:
            center = [0.5, 0.5]
        else:
            center = [0, 0]
            
        #self.addTranslateHandle(center)
        self.addScaleHandle([1, 1], center)
        if sideScalers:
            self.addScaleHandle([1, 0.5], [center[0], 0.5])
            self.addScaleHandle([0.5, 1], [0.5, center[1]])

class LineROI(ROI):
    """
    Rectangular ROI subclass with scale-rotate handles on either side. This
    allows the ROI to be positioned as if moving the ends of a line segment.
    A third handle controls the width of the ROI orthogonal to its "line" axis.
    
    ============== =============================================================
    **Arguments**
    pos1           (length-2 sequence) The position of the center of the ROI's
                   left edge.
    pos2           (length-2 sequence) The position of the center of the ROI's
                   right edge.
    width          (float) The width of the ROI.
    \**args        All extra keyword arguments are passed to ROI()
    ============== =============================================================
    
    """
    def __init__(self, pos1, pos2, width, **args):
        pos1 = Point(pos1)
        pos2 = Point(pos2)
        d = pos2-pos1
        l = d.length()
        ang = Point(1, 0).angle(d)
        ra = ang * np.pi / 180.
        c = Point(-width/2. * sin(ra), -width/2. * cos(ra))
        pos1 = pos1 + c
        
        ROI.__init__(self, pos1, size=Point(l, width), angle=ang, **args)
        self.addScaleRotateHandle([0, 0.5], [1, 0.5])
        self.addScaleRotateHandle([1, 0.5], [0, 0.5])
        self.addScaleHandle([0.5, 1], [0.5, 0.5])
        

        
class MultiRectROI(QtGui.QGraphicsObject):
    """
    Chain of rectangular ROIs connected by handles. 
    
    This is generally used to mark a curved path through 
    an image similarly to PolyLineROI. It differs in that each segment
    of the chain is rectangular instead of linear and thus has width.
    
    ============== =============================================================
    **Arguments**
    points         (list of length-2 sequences) The list of points in the path.
    width          (float) The width of the ROIs orthogonal to the path.
    \**args        All extra keyword arguments are passed to ROI()
    ============== =============================================================
    """
    sigRegionChangeFinished = QtCore.Signal(object)
    sigRegionChangeStarted = QtCore.Signal(object)
    sigRegionChanged = QtCore.Signal(object)
    
    def __init__(self, points, width, pen=None, **args):
        QtGui.QGraphicsObject.__init__(self)
        self.pen = pen
        self.roiArgs = args
        self.lines = []
        if len(points) < 2:
            raise Exception("Must start with at least 2 points")
        
        ## create first segment
        self.addSegment(points[1], connectTo=points[0], scaleHandle=True)
        
        ## create remaining segments
        for p in points[2:]:
            self.addSegment(p)
        
        
    def paint(self, *args):
        pass
    
    def boundingRect(self):
        return QtCore.QRectF()
        
    def roiChangedEvent(self):
        w = self.lines[0].state['size'][1]
        for l in self.lines[1:]:
            w0 = l.state['size'][1]
            if w == w0:
                continue
            l.scale([1.0, w/w0], center=[0.5,0.5])
        self.sigRegionChanged.emit(self)
            
    def roiChangeStartedEvent(self):
        self.sigRegionChangeStarted.emit(self)
        
    def roiChangeFinishedEvent(self):
        self.sigRegionChangeFinished.emit(self)
        
    def getHandlePositions(self):
        """Return the positions of all handles in local coordinates."""
        pos = [self.mapFromScene(self.lines[0].getHandles()[0].scenePos())]
        for l in self.lines:
            pos.append(self.mapFromScene(l.getHandles()[1].scenePos()))
        return pos
        
    def getArrayRegion(self, arr, img=None, axes=(0,1)):
        rgns = []
        for l in self.lines:
            rgn = l.getArrayRegion(arr, img, axes=axes)
            if rgn is None:
                continue
                #return None
            rgns.append(rgn)
            #print l.state['size']
            
        ## make sure orthogonal axis is the same size
        ## (sometimes fp errors cause differences)
        ms = min([r.shape[axes[1]] for r in rgns])
        sl = [slice(None)] * rgns[0].ndim
        sl[axes[1]] = slice(0,ms)
        rgns = [r[sl] for r in rgns]
        #print [r.shape for r in rgns], axes
        
        return np.concatenate(rgns, axis=axes[0])
        
    def addSegment(self, pos=(0,0), scaleHandle=False, connectTo=None):
        """
        Add a new segment to the ROI connecting from the previous endpoint to *pos*.
        (pos is specified in the parent coordinate system of the MultiRectROI)
        """
        
        ## by default, connect to the previous endpoint
        if connectTo is None:
            connectTo = self.lines[-1].getHandles()[1]
            
        ## create new ROI
        newRoi = ROI((0,0), [1, 5], parent=self, pen=self.pen, **self.roiArgs)
        self.lines.append(newRoi)
        
        ## Add first SR handle
        if isinstance(connectTo, Handle):
            self.lines[-1].addScaleRotateHandle([0, 0.5], [1, 0.5], item=connectTo)
            newRoi.movePoint(connectTo, connectTo.scenePos(), coords='scene')
        else:
            h = self.lines[-1].addScaleRotateHandle([0, 0.5], [1, 0.5])
            newRoi.movePoint(h, connectTo, coords='scene')
            
        ## add second SR handle
        h = self.lines[-1].addScaleRotateHandle([1, 0.5], [0, 0.5]) 
        newRoi.movePoint(h, pos)
        
        ## optionally add scale handle (this MUST come after the two SR handles)
        if scaleHandle:
            newRoi.addScaleHandle([0.5, 1], [0.5, 0.5])
            
        newRoi.translatable = False 
        newRoi.sigRegionChanged.connect(self.roiChangedEvent) 
        newRoi.sigRegionChangeStarted.connect(self.roiChangeStartedEvent) 
        newRoi.sigRegionChangeFinished.connect(self.roiChangeFinishedEvent)
        self.sigRegionChanged.emit(self) 
    

    def removeSegment(self, index=-1): 
        """Remove a segment from the ROI."""
        roi = self.lines[index]
        self.lines.pop(index)
        self.scene().removeItem(roi)
        roi.sigRegionChanged.disconnect(self.roiChangedEvent) 
        roi.sigRegionChangeStarted.disconnect(self.roiChangeStartedEvent) 
        roi.sigRegionChangeFinished.disconnect(self.roiChangeFinishedEvent)
        
        self.sigRegionChanged.emit(self)
        
        
class MultiLineROI(MultiRectROI):
    def __init__(self, *args, **kwds):
        MultiRectROI.__init__(self, *args, **kwds)
        print("Warning: MultiLineROI has been renamed to MultiRectROI. (and MultiLineROI may be redefined in the future)")
        
class EllipseROI(ROI):
    """
    Elliptical ROI subclass with one scale handle and one rotation handle.
    
    
    ============== =============================================================
    **Arguments**
    pos            (length-2 sequence) The position of the ROI's origin.
    size           (length-2 sequence) The size of the ROI's bounding rectangle.
    \**args        All extra keyword arguments are passed to ROI()
    ============== =============================================================
    
    """
    def __init__(self, pos, size, **args):
        #QtGui.QGraphicsRectItem.__init__(self, 0, 0, size[0], size[1])
        ROI.__init__(self, pos, size, **args)
        self.addRotateHandle([1.0, 0.5], [0.5, 0.5])
        self.addScaleHandle([0.5*2.**-0.5 + 0.5, 0.5*2.**-0.5 + 0.5], [0.5, 0.5])
            
    def paint(self, p, opt, widget):
        r = self.boundingRect()
        p.setRenderHint(QtGui.QPainter.Antialiasing)
        p.setPen(self.currentPen)
        
        p.scale(r.width(), r.height())## workaround for GL bug
        r = QtCore.QRectF(r.x()/r.width(), r.y()/r.height(), 1,1)
        
        p.drawEllipse(r)
        
    def getArrayRegion(self, arr, img=None):
        """
        Return the result of ROI.getArrayRegion() masked by the elliptical shape
        of the ROI. Regions outside the ellipse are set to 0.
        """
        arr = ROI.getArrayRegion(self, arr, img)
        if arr is None or arr.shape[0] == 0 or arr.shape[1] == 0:
            return None
        w = arr.shape[0]
        h = arr.shape[1]
        ## generate an ellipsoidal mask
        mask = np.fromfunction(lambda x,y: (((x+0.5)/(w/2.)-1)**2+ ((y+0.5)/(h/2.)-1)**2)**0.5 < 1, (w, h))
    
        return arr * mask
    
    def shape(self):
        self.path = QtGui.QPainterPath()
        self.path.addEllipse(self.boundingRect())
        return self.path
        
        
class CircleROI(EllipseROI):
    """
    Circular ROI subclass. Behaves exactly as EllipseROI, but may only be scaled
    proportionally to maintain its aspect ratio.
    
    ============== =============================================================
    **Arguments**
    pos            (length-2 sequence) The position of the ROI's origin.
    size           (length-2 sequence) The size of the ROI's bounding rectangle.
    \**args        All extra keyword arguments are passed to ROI()
    ============== =============================================================
    
    """
    def __init__(self, pos, size, **args):
        ROI.__init__(self, pos, size, **args)
        self.aspectLocked = True
        #self.addTranslateHandle([0.5, 0.5])
        self.addScaleHandle([0.5*2.**-0.5 + 0.5, 0.5*2.**-0.5 + 0.5], [0.5, 0.5])


class PolygonROI(ROI):
    ## deprecated. Use PloyLineROI instead.
    
    def __init__(self, positions, pos=None, **args):
        if pos is None:
            pos = [0,0]
        ROI.__init__(self, pos, [1,1], **args)
        #ROI.__init__(self, positions[0])
        for p in positions:
            self.addFreeHandle(p)
        self.setZValue(1000)
        print("Warning: PolygonROI is deprecated. Use PolyLineROI instead.")
        
            
    def listPoints(self):
        return [p['item'].pos() for p in self.handles]
            
    #def movePoint(self, *args, **kargs):
        #ROI.movePoint(self, *args, **kargs)
        #self.prepareGeometryChange()
        #for h in self.handles:
            #h['pos'] = h['item'].pos()
            
    def paint(self, p, *args):
        p.setRenderHint(QtGui.QPainter.Antialiasing)
        p.setPen(self.currentPen)
        for i in range(len(self.handles)):
            h1 = self.handles[i]['item'].pos()
            h2 = self.handles[i-1]['item'].pos()
            p.drawLine(h1, h2)
        
    def boundingRect(self):
        r = QtCore.QRectF()
        for h in self.handles:
            r |= self.mapFromItem(h['item'], h['item'].boundingRect()).boundingRect()   ## |= gives the union of the two QRectFs
        return r
    
    def shape(self):
        p = QtGui.QPainterPath()
        p.moveTo(self.handles[0]['item'].pos())
        for i in range(len(self.handles)):
            p.lineTo(self.handles[i]['item'].pos())
        return p
    
    def stateCopy(self):
        sc = {}
        sc['pos'] = Point(self.state['pos'])
        sc['size'] = Point(self.state['size'])
        sc['angle'] = self.state['angle']
        #sc['handles'] = self.handles
        return sc

class PolyLineROI(ROI):
    """
    Container class for multiple connected LineSegmentROIs.
    
    This class allows the user to draw paths of multiple line segments.
    
    ============== =============================================================
    **Arguments**
    positions      (list of length-2 sequences) The list of points in the path.
                   Note that, unlike the handle positions specified in other
                   ROIs, these positions must be expressed in the normal
                   coordinate system of the ROI, rather than (0 to 1) relative
                   to the size of the ROI.
    closed         (bool) if True, an extra LineSegmentROI is added connecting 
                   the beginning and end points.
    \**args        All extra keyword arguments are passed to ROI()
    ============== =============================================================
    
    """
    def __init__(self, positions, closed=False, pos=None, **args):
        
        if pos is None:
            pos = [0,0]
            
        self.closed = closed
        self.segments = []
        ROI.__init__(self, pos, size=[1,1], **args)
        
        self.setPoints(positions)
        #for p in positions:
            #self.addFreeHandle(p)
         
        #start = -1 if self.closed else 0
        #for i in range(start, len(self.handles)-1):
            #self.addSegment(self.handles[i]['item'], self.handles[i+1]['item'])

    def setPoints(self, points, closed=None):
        """
        Set the complete sequence of points displayed by this ROI.
        
        ============= =========================================================
        **Arguments**
        points        List of (x,y) tuples specifying handle locations to set.
        closed        If bool, then this will set whether the ROI is closed 
                      (the last point is connected to the first point). If
                      None, then the closed mode is left unchanged.
        ============= =========================================================
        
        """
        if closed is not None:
            self.closed = closed
        
        for p in points:
            self.addFreeHandle(p)
        
        start = -1 if self.closed else 0
        for i in range(start, len(self.handles)-1):
            self.addSegment(self.handles[i]['item'], self.handles[i+1]['item'])
        
        
    def clearPoints(self):
        """
        Remove all handles and segments.
        """
        while len(self.handles) > 0:
            self.removeHandle(self.handles[0]['item'])

    def saveState(self):
        state = ROI.saveState(self)
        state['closed'] = self.closed
        state['points'] = [tuple(h.pos()) for h in self.getHandles()]
        return state

    def setState(self, state):
        ROI.setState(self, state)
        self.clearPoints()
        self.setPoints(state['points'], closed=state['closed'])
        
    def addSegment(self, h1, h2, index=None):
        seg = LineSegmentROI(handles=(h1, h2), pen=self.pen, parent=self, movable=False)
        if index is None:
            self.segments.append(seg)
        else:
            self.segments.insert(index, seg)
        seg.sigClicked.connect(self.segmentClicked)
        seg.setAcceptedMouseButtons(QtCore.Qt.LeftButton)
        seg.setZValue(self.zValue()+1)
        for h in seg.handles:
            h['item'].setDeletable(True)
            h['item'].setAcceptedMouseButtons(h['item'].acceptedMouseButtons() | QtCore.Qt.LeftButton) ## have these handles take left clicks too, so that handles cannot be added on top of other handles
        
    def setMouseHover(self, hover):
        ## Inform all the ROI's segments that the mouse is(not) hovering over it
        ROI.setMouseHover(self, hover)
        for s in self.segments:
            s.setMouseHover(hover)
          
    def addHandle(self, info, index=None):
        h = ROI.addHandle(self, info, index=index)
        h.sigRemoveRequested.connect(self.removeHandle)
        return h
        
    def segmentClicked(self, segment, ev=None, pos=None): ## pos should be in this item's coordinate system
        if ev != None:
            pos = segment.mapToParent(ev.pos())
        elif pos != None:
            pos = pos
        else:
            raise Exception("Either an event or a position must be given.")
        h1 = segment.handles[0]['item']
        h2 = segment.handles[1]['item']
        
        i = self.segments.index(segment)
        h3 = self.addFreeHandle(pos, index=self.indexOfHandle(h2))
        self.addSegment(h3, h2, index=i+1)
        segment.replaceHandle(h2, h3)
        
    def removeHandle(self, handle, updateSegments=True):
        ROI.removeHandle(self, handle)
        handle.sigRemoveRequested.disconnect(self.removeHandle)
        
        if not updateSegments:
            return
        segments = handle.rois[:]
        
        if len(segments) == 1:
            self.removeSegment(segments[0])
        else:
            handles = [h['item'] for h in segments[1].handles]
            handles.remove(handle)
            segments[0].replaceHandle(handle, handles[0])
            self.removeSegment(segments[1])
        
    def removeSegment(self, seg):
        for handle in seg.handles[:]:
            seg.removeHandle(handle['item'])
        self.segments.remove(seg)
        seg.sigClicked.disconnect(self.segmentClicked)
        self.scene().removeItem(seg)
        
    def checkRemoveHandle(self, h):
        ## called when a handle is about to display its context menu
        if self.closed:
            return len(self.handles) > 3
        else:
            return len(self.handles) > 2
        
    def paint(self, p, *args):
        #for s in self.segments:
            #s.update()
        #p.setPen(self.currentPen)
        #p.setPen(fn.mkPen('w'))
        #p.drawRect(self.boundingRect())
        #p.drawPath(self.shape())
        pass
    
    def boundingRect(self):
        return self.shape().boundingRect()
        #r = QtCore.QRectF()
        #for h in self.handles:
            #r |= self.mapFromItem(h['item'], h['item'].boundingRect()).boundingRect()   ## |= gives the union of the two QRectFs
        #return r 

    def shape(self):
        p = QtGui.QPainterPath()
        if len(self.handles) == 0:
            return p
        p.moveTo(self.handles[0]['item'].pos())
        for i in range(len(self.handles)):
            p.lineTo(self.handles[i]['item'].pos())
        p.lineTo(self.handles[0]['item'].pos())
        return p        

    def getArrayRegion(self, data, img, axes=(0,1), returnMappedCoords=False, **kwds):
        """
        Return the result of ROI.getArrayRegion(), masked by the shape of the 
        ROI. Values outside the ROI shape are set to 0.
        """
        sl = self.getArraySlice(data, img, axes=(0,1))
        if sl is None:
            return None
        sliced = data[sl[0]]
        im = QtGui.QImage(sliced.shape[axes[0]], sliced.shape[axes[1]], QtGui.QImage.Format_ARGB32)
        im.fill(0x0)
        p = QtGui.QPainter(im)
        p.setPen(fn.mkPen(None))
        p.setBrush(fn.mkBrush('w'))
        p.setTransform(self.itemTransform(img)[0])
        bounds = self.mapRectToItem(img, self.boundingRect())
        p.translate(-bounds.left(), -bounds.top()) 
        p.drawPath(self.shape())
        p.end()
        mask = fn.imageToArray(im)[:,:,0].astype(float) / 255.
        shape = [1] * data.ndim
        shape[axes[0]] = sliced.shape[axes[0]]
        shape[axes[1]] = sliced.shape[axes[1]]
        return sliced * mask.reshape(shape)

    def setPen(self, *args, **kwds):
        ROI.setPen(self, *args, **kwds)
        for seg in self.segments:
            seg.setPen(*args, **kwds)



class LineSegmentROI(ROI):
    """
    ROI subclass with two freely-moving handles defining a line.
    
    ============== =============================================================
    **Arguments**
    positions      (list of two length-2 sequences) The endpoints of the line 
                   segment. Note that, unlike the handle positions specified in 
                   other ROIs, these positions must be expressed in the normal
                   coordinate system of the ROI, rather than (0 to 1) relative
                   to the size of the ROI.
    \**args        All extra keyword arguments are passed to ROI()
    ============== =============================================================
    """
    
    def __init__(self, positions=(None, None), pos=None, handles=(None,None), **args):
        if pos is None:
            pos = [0,0]
            
        ROI.__init__(self, pos, [1,1], **args)
        #ROI.__init__(self, positions[0])
        if len(positions) > 2:
            raise Exception("LineSegmentROI must be defined by exactly 2 positions. For more points, use PolyLineROI.")
        
        for i, p in enumerate(positions):
            self.addFreeHandle(p, item=handles[i])
                
        
    def listPoints(self):
        return [p['item'].pos() for p in self.handles]
            
    def paint(self, p, *args):
        p.setRenderHint(QtGui.QPainter.Antialiasing)
        p.setPen(self.currentPen)
        h1 = self.handles[0]['item'].pos()
        h2 = self.handles[1]['item'].pos()
        p.drawLine(h1, h2)
        
    def boundingRect(self):
        return self.shape().boundingRect()
    
    def shape(self):
        p = QtGui.QPainterPath()
    
        h1 = self.handles[0]['item'].pos()
        h2 = self.handles[1]['item'].pos()
        dh = h2-h1
        if dh.length() == 0:
            return p
        pxv = self.pixelVectors(dh)[1]
        if pxv is None:
            return p
            
        pxv *= 4
        
        p.moveTo(h1+pxv)
        p.lineTo(h2+pxv)
        p.lineTo(h2-pxv)
        p.lineTo(h1-pxv)
        p.lineTo(h1+pxv)
      
        return p
    
    def getArrayRegion(self, data, img, axes=(0,1)):
        """
        Use the position of this ROI relative to an imageItem to pull a slice 
        from an array.
        
        Since this pulls 1D data from a 2D coordinate system, the return value 
        will have ndim = data.ndim-1
        
        See ROI.getArrayRegion() for a description of the arguments.
        """
        
        imgPts = [self.mapToItem(img, h['item'].pos()) for h in self.handles]
        rgns = []
        for i in range(len(imgPts)-1):
            d = Point(imgPts[i+1] - imgPts[i])
            o = Point(imgPts[i])
            r = fn.affineSlice(data, shape=(int(d.length()),), vectors=[Point(d.norm())], origin=o, axes=axes, order=1)
            rgns.append(r)
            
        return np.concatenate(rgns, axis=axes[0])
        

class SpiralROI(ROI):
    def __init__(self, pos=None, size=None, **args):
        if size == None:
            size = [100e-6,100e-6]
        if pos == None:
            pos = [0,0]
        ROI.__init__(self, pos, size, **args)
        self.translateSnap = False
        self.addFreeHandle([0.25,0], name='a')
        self.addRotateFreeHandle([1,0], [0,0], name='r')
        #self.getRadius()
        #QtCore.connect(self, QtCore.SIGNAL('regionChanged'), self.
        
        
    def getRadius(self):
        radius = Point(self.handles[1]['item'].pos()).length()
        #r2 = radius[1]
        #r3 = r2[0]
        return radius
    
    def boundingRect(self):
        r = self.getRadius()
        return QtCore.QRectF(-r*1.1, -r*1.1, 2.2*r, 2.2*r)
        #return self.bounds
    
    #def movePoint(self, *args, **kargs):
        #ROI.movePoint(self, *args, **kargs)
        #self.prepareGeometryChange()
        #for h in self.handles:
            #h['pos'] = h['item'].pos()/self.state['size'][0]
            
    def stateChanged(self, finish=True):
        ROI.stateChanged(self, finish=finish)
        if len(self.handles) > 1:
            self.path = QtGui.QPainterPath()
            h0 = Point(self.handles[0]['item'].pos()).length()
            a = h0/(2.0*np.pi)
            theta = 30.0*(2.0*np.pi)/360.0
            self.path.moveTo(QtCore.QPointF(a*theta*cos(theta), a*theta*sin(theta)))
            x0 = a*theta*cos(theta)
            y0 = a*theta*sin(theta)
            radius = self.getRadius()
            theta += 20.0*(2.0*np.pi)/360.0
            i = 0
            while Point(x0, y0).length() < radius and i < 1000:
                x1 = a*theta*cos(theta)
                y1 = a*theta*sin(theta)
                self.path.lineTo(QtCore.QPointF(x1,y1))
                theta += 20.0*(2.0*np.pi)/360.0
                x0 = x1
                y0 = y1
                i += 1
           
                
            return self.path
    
        
    def shape(self):
        p = QtGui.QPainterPath()
        p.addEllipse(self.boundingRect())
        return p
    
    def paint(self, p, *args):
        p.setRenderHint(QtGui.QPainter.Antialiasing)
        #path = self.shape()
        p.setPen(self.currentPen)
        p.drawPath(self.path)
        p.setPen(QtGui.QPen(QtGui.QColor(255,0,0)))
        p.drawPath(self.shape())
        p.setPen(QtGui.QPen(QtGui.QColor(0,0,255)))
        p.drawRect(self.boundingRect())
        
    
class CrosshairROI(ROI):
    """A crosshair ROI whose position is at the center of the crosshairs. By default, it is scalable, rotatable and translatable."""
    
    def __init__(self, pos=None, size=None, **kargs):
        if size == None:
            #size = [100e-6,100e-6]
            size=[1,1]
        if pos == None:
            pos = [0,0]
        self._shape = None
        ROI.__init__(self, pos, size, **kargs)
        
        self.sigRegionChanged.connect(self.invalidate)
        self.addScaleRotateHandle(Point(1, 0), Point(0, 0))
        self.aspectLocked = True

    def invalidate(self):
        self._shape = None
        self.prepareGeometryChange()
        
    def boundingRect(self):
        #size = self.size()
        #return QtCore.QRectF(-size[0]/2., -size[1]/2., size[0], size[1]).normalized()
        return self.shape().boundingRect()
    
    #def getRect(self):
        ### same as boundingRect -- for internal use so that boundingRect can be re-implemented in subclasses
        #size = self.size()
        #return QtCore.QRectF(-size[0]/2., -size[1]/2., size[0], size[1]).normalized()
        
    
    def shape(self):
        if self._shape is None:
            radius = self.getState()['size'][1]
            p = QtGui.QPainterPath()
            p.moveTo(Point(0, -radius))
            p.lineTo(Point(0, radius))
            p.moveTo(Point(-radius, 0))
            p.lineTo(Point(radius, 0))
            p = self.mapToDevice(p)
            stroker = QtGui.QPainterPathStroker()
            stroker.setWidth(10)
            outline = stroker.createStroke(p)
            self._shape = self.mapFromDevice(outline)
            
        
            ##h1 = self.handles[0]['item'].pos()
            ##h2 = self.handles[1]['item'].pos()
            #w1 = Point(-0.5, 0)*self.size()
            #w2 = Point(0.5, 0)*self.size()
            #h1 = Point(0, -0.5)*self.size()
            #h2 = Point(0, 0.5)*self.size()
            
            #dh = h2-h1
            #dw = w2-w1
            #if dh.length() == 0 or dw.length() == 0:
                #return p
            #pxv = self.pixelVectors(dh)[1]
            #if pxv is None:
                #return p
                
            #pxv *= 4
            
            #p.moveTo(h1+pxv)
            #p.lineTo(h2+pxv)
            #p.lineTo(h2-pxv)
            #p.lineTo(h1-pxv)
            #p.lineTo(h1+pxv)
            
            #pxv = self.pixelVectors(dw)[1]
            #if pxv is None:
                #return p
                
            #pxv *= 4
            
            #p.moveTo(w1+pxv)
            #p.lineTo(w2+pxv)
            #p.lineTo(w2-pxv)
            #p.lineTo(w1-pxv)
            #p.lineTo(w1+pxv)
        
        return self._shape
    
    def paint(self, p, *args):
        #p.save()
        #r = self.getRect()
        radius = self.getState()['size'][1]
        p.setRenderHint(QtGui.QPainter.Antialiasing)
        p.setPen(self.currentPen)
        #p.translate(r.left(), r.top())
        #p.scale(r.width()/10., r.height()/10.) ## need to scale up a little because drawLine has trouble dealing with 0.5
        #p.drawLine(0,5, 10,5)
        #p.drawLine(5,0, 5,10)
        #p.restore()
        
        p.drawLine(Point(0, -radius), Point(0, radius))
        p.drawLine(Point(-radius, 0), Point(radius, 0))