/usr/share/doc/gstreamer0.10-doc/gstreamer-0.10/gstreamer-GstIterator.html is in gstreamer0.10-doc 0.10.36-1.5.
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 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>GStreamer 0.10 Core Reference Manual: GstIterator</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
<link rel="home" href="index.html" title="GStreamer 0.10 Core Reference Manual">
<link rel="up" href="libgstreamer.html" title="GStreamer Core Library">
<link rel="prev" href="GstIndexFactory.html" title="GstIndexFactory">
<link rel="next" href="gstreamer-GstMessage.html" title="GstMessage">
<meta name="generator" content="GTK-Doc V1.21 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle">
<td width="100%" align="left" class="shortcuts">
<a href="#" class="shortcut">Top</a><span id="nav_description"> <span class="dim">|</span>
<a href="#gstreamer-GstIterator.description" class="shortcut">Description</a></span>
</td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td>
<td><a accesskey="u" href="libgstreamer.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="GstIndexFactory.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="gstreamer-GstMessage.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="refentry">
<a name="gstreamer-GstIterator"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="gstreamer-GstIterator.top_of_page"></a>GstIterator</span></h2>
<p>GstIterator — Object to retrieve multiple elements in a threadsafe
way.</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="gstreamer-GstIterator.functions"></a><h2>Functions</h2>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gstreamer-GstIterator.html#GstIteratorDisposeFunction" title="GstIteratorDisposeFunction ()">*GstIteratorDisposeFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gstreamer-GstIterator.html#GstIteratorNextFunction" title="GstIteratorNextFunction ()">*GstIteratorNextFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIteratorItem" title="enum GstIteratorItem"><span class="returnvalue">GstIteratorItem</span></a>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gstreamer-GstIterator.html#GstIteratorItemFunction" title="GstIteratorItemFunction ()">*GstIteratorItemFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gstreamer-GstIterator.html#GstIteratorResyncFunction" title="GstIteratorResyncFunction ()">*GstIteratorResyncFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gstreamer-GstIterator.html#GstIteratorFreeFunction" title="GstIteratorFreeFunction ()">*GstIteratorFreeFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gstreamer-GstIterator.html#GstIteratorFoldFunction" title="GstIteratorFoldFunction ()">*GstIteratorFoldFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="returnvalue">gpointer</span></a>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gstreamer-GstIterator.html#GstCopyFunction" title="GstCopyFunction ()">*GstCopyFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR:CAPS" title="GST_ITERATOR()">GST_ITERATOR</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-LOCK:CAPS" title="GST_ITERATOR_LOCK()">GST_ITERATOR_LOCK</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-COOKIE:CAPS" title="GST_ITERATOR_COOKIE()">GST_ITERATOR_COOKIE</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-ORIG-COOKIE:CAPS" title="GST_ITERATOR_ORIG_COOKIE()">GST_ITERATOR_ORIG_COOKIE</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-new" title="gst_iterator_new ()">gst_iterator_new</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-new-list" title="gst_iterator_new_list ()">gst_iterator_new_list</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-new-single" title="gst_iterator_new_single ()">gst_iterator_new_single</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-next" title="gst_iterator_next ()">gst_iterator_next</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-resync" title="gst_iterator_resync ()">gst_iterator_resync</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-free" title="gst_iterator_free ()">gst_iterator_free</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-push" title="gst_iterator_push ()">gst_iterator_push</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-filter" title="gst_iterator_filter ()">gst_iterator_filter</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-fold" title="gst_iterator_fold ()">gst_iterator_fold</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-foreach" title="gst_iterator_foreach ()">gst_iterator_foreach</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="returnvalue">gpointer</span></a>
</td>
<td class="function_name">
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-find-custom" title="gst_iterator_find_custom ()">gst_iterator_find_custom</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gstreamer-GstIterator.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator">GstIterator</a></td>
</tr>
<tr>
<td class="datatype_keyword">enum</td>
<td class="function_name"><a class="link" href="gstreamer-GstIterator.html#GstIteratorItem" title="enum GstIteratorItem">GstIteratorItem</a></td>
</tr>
<tr>
<td class="datatype_keyword">enum</td>
<td class="function_name"><a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult">GstIteratorResult</a></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gstreamer-GstIterator.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include <gst/gst.h>
</pre>
</div>
<div class="refsect1">
<a name="gstreamer-GstIterator.description"></a><h2>Description</h2>
<p>A GstIterator is used to retrieve multiple objects from another object in
a threadsafe way.</p>
<p>Various GStreamer objects provide access to their internal structures using
an iterator.</p>
<p>In general, whenever calling a GstIterator function results in your code
receiving a refcounted object, the refcount for that object will have been
increased. Your code is responsible for unrefing that object after use.</p>
<p>The basic use pattern of an iterator is as follows:</p>
<div class="example">
<a name="id-1.3.24.6.6"></a><p class="title"><b>Example 13. Using an iterator</b></p>
<div class="example-contents">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22</pre></td>
<td class="listing_code"><pre class="programlisting">it <span class="gtkdoc opt">=</span> <span class="function">_get_iterator</span><span class="gtkdoc opt">(</span>object<span class="gtkdoc opt">);</span>
done <span class="gtkdoc opt">=</span> FALSE<span class="gtkdoc opt">;</span>
<span class="keyword">while</span> <span class="gtkdoc opt">(!</span>done<span class="gtkdoc opt">) {</span>
<span class="keyword">switch</span> <span class="gtkdoc opt">(</span><span class="function"><a href="../gstreamer-0.10/gstreamer-GstIterator.html#gst-iterator-next">gst_iterator_next</a></span> <span class="gtkdoc opt">(</span>it<span class="gtkdoc opt">, &</span>item<span class="gtkdoc opt">)) {</span>
<span class="keyword">case</span> GST_ITERATOR_OK<span class="gtkdoc opt">:</span>
<span class="gtkdoc opt">...</span> use<span class="gtkdoc opt">/</span>change item here<span class="gtkdoc opt">...</span>
<span class="function"><a href="../gstreamer-0.10/GstObject.html#gst-object-unref">gst_object_unref</a></span> <span class="gtkdoc opt">(</span>item<span class="gtkdoc opt">);</span>
<span class="keyword">break</span><span class="gtkdoc opt">;</span>
<span class="keyword">case</span> GST_ITERATOR_RESYNC<span class="gtkdoc opt">:</span>
<span class="gtkdoc opt">...</span>rollback changes to items<span class="gtkdoc opt">...</span>
<span class="function"><a href="../gstreamer-0.10/gstreamer-GstIterator.html#gst-iterator-resync">gst_iterator_resync</a></span> <span class="gtkdoc opt">(</span>it<span class="gtkdoc opt">);</span>
<span class="keyword">break</span><span class="gtkdoc opt">;</span>
<span class="keyword">case</span> GST_ITERATOR_ERROR<span class="gtkdoc opt">:</span>
<span class="gtkdoc opt">...</span>wrong parameters were given<span class="gtkdoc opt">...</span>
done <span class="gtkdoc opt">=</span> TRUE<span class="gtkdoc opt">;</span>
<span class="keyword">break</span><span class="gtkdoc opt">;</span>
<span class="keyword">case</span> GST_ITERATOR_DONE<span class="gtkdoc opt">:</span>
done <span class="gtkdoc opt">=</span> TRUE<span class="gtkdoc opt">;</span>
<span class="keyword">break</span><span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc opt">}</span>
<span class="function"><a href="../gstreamer-0.10/gstreamer-GstIterator.html#gst-iterator-free">gst_iterator_free</a></span> <span class="gtkdoc opt">(</span>it<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="example-break"><p>Last reviewed on 2009-06-16 (0.10.24)</p>
</div>
<div class="refsect1">
<a name="gstreamer-GstIterator.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="GstIteratorDisposeFunction"></a><h3>GstIteratorDisposeFunction ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GstIteratorDisposeFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> owner</code></em>);</pre>
<p>The function that will be called when a <a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GList"><span class="type">GList</span></a> iterator is freed. The
owner of the <a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GList"><span class="type">GList</span></a> iterator can then clean up its resources.</p>
<div class="refsect3">
<a name="id-1.3.24.7.2.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>owner</p></td>
<td class="parameter_description"><p>the owner of the iterator</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstIteratorNextFunction"></a><h3>GstIteratorNextFunction ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
<span class="c_punctuation">(</span>*GstIteratorNextFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> *result</code></em>);</pre>
<p>The function that will be called when the next element of the iterator
should be retrieved. </p>
<p>Implementors of a <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> should implement this
function and pass it to the constructor of the custom iterator.
The function will be called with the iterator lock held.</p>
<div class="refsect3">
<a name="id-1.3.24.7.3.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the iterator</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>result</p></td>
<td class="parameter_description"><p>a pointer to hold the next item</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.3.7"></a><h4>Returns</h4>
<p> the result of the operation.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstIteratorItemFunction"></a><h3>GstIteratorItemFunction ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIteratorItem" title="enum GstIteratorItem"><span class="returnvalue">GstIteratorItem</span></a>
<span class="c_punctuation">(</span>*GstIteratorItemFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> item</code></em>);</pre>
<p>The function that will be called after the next item of the iterator
has been retrieved. This function will typically increase the refcount
of the item or make a copy.</p>
<p>Implementors of a <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> should implement this
function and pass it to the constructor of the custom iterator.
The function will be called with the iterator lock held.</p>
<div class="refsect3">
<a name="id-1.3.24.7.4.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the iterator</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>item</p></td>
<td class="parameter_description"><p>the item being retrieved.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.4.7"></a><h4>Returns</h4>
<p> the result of the operation.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstIteratorResyncFunction"></a><h3>GstIteratorResyncFunction ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GstIteratorResyncFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>);</pre>
<p>This function will be called whenever a concurrent update happened
to the iterated datastructure. The implementor of the iterator should
restart the iterator from the beginning and clean up any state it might
have.</p>
<p>Implementors of a <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> should implement this
function and pass it to the constructor of the custom iterator.
The function will be called with the iterator lock held.</p>
<div class="refsect3">
<a name="id-1.3.24.7.5.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the iterator</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstIteratorFreeFunction"></a><h3>GstIteratorFreeFunction ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GstIteratorFreeFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>);</pre>
<p>This function will be called when the iterator is freed.</p>
<p>Implementors of a <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> should implement this
function and pass it to the constructor of the custom iterator.
The function will be called with the iterator lock held.</p>
<div class="refsect3">
<a name="id-1.3.24.7.6.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the iterator</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstIteratorFoldFunction"></a><h3>GstIteratorFoldFunction ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
<span class="c_punctuation">(</span>*GstIteratorFoldFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> item</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> *ret</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre>
<p>A function to be passed to <a class="link" href="gstreamer-GstIterator.html#gst-iterator-fold" title="gst_iterator_fold ()"><code class="function">gst_iterator_fold()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.24.7.7.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>item</p></td>
<td class="parameter_description"><p>the item to fold</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>ret</p></td>
<td class="parameter_description"><p>a <a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> collecting the result</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p>data passed to <a class="link" href="gstreamer-GstIterator.html#gst-iterator-fold" title="gst_iterator_fold ()"><code class="function">gst_iterator_fold()</code></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.7.6"></a><h4>Returns</h4>
<p> TRUE if the fold should continue, FALSE if it should stop.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstCopyFunction"></a><h3>GstCopyFunction ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="returnvalue">gpointer</span></a>
<span class="c_punctuation">(</span>*GstCopyFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> object</code></em>);</pre>
<p>A function to create a copy of some object or
increase its reference count.</p>
<div class="refsect3">
<a name="id-1.3.24.7.8.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>object</p></td>
<td class="parameter_description"><p>The object to copy</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.8.6"></a><h4>Returns</h4>
<p> a copy of the object or the same object with increased reference count</p>
<p></p>
</div>
<p class="since">Since 0.10.25</p>
</div>
<hr>
<div class="refsect2">
<a name="GST-ITERATOR:CAPS"></a><h3>GST_ITERATOR()</h3>
<pre class="programlisting">#define GST_ITERATOR(it) ((GstIterator*)(it))
</pre>
<p>Macro to cast to a <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a></p>
<div class="refsect3">
<a name="id-1.3.24.7.9.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> value</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GST-ITERATOR-LOCK:CAPS"></a><h3>GST_ITERATOR_LOCK()</h3>
<pre class="programlisting">#define GST_ITERATOR_LOCK(it) (GST_ITERATOR(it)->lock)
</pre>
<p>Macro to get the lock protecting the datastructure being iterated.</p>
<div class="refsect3">
<a name="id-1.3.24.7.10.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to get the lock of</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GST-ITERATOR-COOKIE:CAPS"></a><h3>GST_ITERATOR_COOKIE()</h3>
<pre class="programlisting">#define GST_ITERATOR_COOKIE(it) (GST_ITERATOR(it)->cookie)
</pre>
<p>Macro to get the cookie of a <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a>. The cookie of the
iterator is the value of the master cookie when the iterator
was created.
Whenever the iterator is iterated, the value is compared to the
value of the master cookie. If they are different, a concurrent
modification happened to the iterator and a resync is needed.</p>
<div class="refsect3">
<a name="id-1.3.24.7.11.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to get the cookie of</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GST-ITERATOR-ORIG-COOKIE:CAPS"></a><h3>GST_ITERATOR_ORIG_COOKIE()</h3>
<pre class="programlisting">#define GST_ITERATOR_ORIG_COOKIE(it) (GST_ITERATOR(it)->master_cookie)
</pre>
<p>Macro to get a pointer to where the master cookie is stored. The
master cookie protects the structure being iterated and gets updated
whenever the datastructure changes.</p>
<div class="refsect3">
<a name="id-1.3.24.7.12.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>the <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to get the master cookie of</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-new"></a><h3>gst_iterator_new ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
gst_iterator_new (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> size</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#GType"><span class="type">GType</span></a> type</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Threads.html#GMutex"><span class="type">GMutex</span></a> *lock</code></em>,
<em class="parameter"><code><span class="type">guint32</span> *master_cookie</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIteratorNextFunction" title="GstIteratorNextFunction ()"><span class="type">GstIteratorNextFunction</span></a> next</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIteratorItemFunction" title="GstIteratorItemFunction ()"><span class="type">GstIteratorItemFunction</span></a> item</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIteratorResyncFunction" title="GstIteratorResyncFunction ()"><span class="type">GstIteratorResyncFunction</span></a> resync</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIteratorFreeFunction" title="GstIteratorFreeFunction ()"><span class="type">GstIteratorFreeFunction</span></a> free</code></em>);</pre>
<p>Create a new iterator. This function is mainly used for objects
implementing the next/resync/free function to iterate a data structure.</p>
<p>For each item retrieved, the <em class="parameter"><code>item</code></em>
function is called with the lock
held. The <em class="parameter"><code>free</code></em>
function is called when the iterator is freed.</p>
<div class="refsect3">
<a name="id-1.3.24.7.13.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>size</p></td>
<td class="parameter_description"><p>the size of the iterator structure</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>type</p></td>
<td class="parameter_description"><p><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#GType"><span class="type">GType</span></a> of children</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>lock</p></td>
<td class="parameter_description"><p>pointer to a <a href="/usr/share/gtk-doc/html/glib/glib-Threads.html#GMutex"><span class="type">GMutex</span></a>.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>master_cookie</p></td>
<td class="parameter_description"><p>pointer to a guint32 that is changed when the items in the
iterator changed.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>next</p></td>
<td class="parameter_description"><p>function to get next item</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>item</p></td>
<td class="parameter_description"><p>function to call on each item retrieved</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>resync</p></td>
<td class="parameter_description"><p>function to resync the iterator</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>free</p></td>
<td class="parameter_description"><p>function to free the iterator</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.13.7"></a><h4>Returns</h4>
<p> the new <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a>.</p>
<p>MT safe.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-new-list"></a><h3>gst_iterator_new_list ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
gst_iterator_new_list (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#GType"><span class="type">GType</span></a> type</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Threads.html#GMutex"><span class="type">GMutex</span></a> *lock</code></em>,
<em class="parameter"><code><span class="type">guint32</span> *master_cookie</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GList"><span class="type">GList</span></a> **list</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> owner</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIteratorItemFunction" title="GstIteratorItemFunction ()"><span class="type">GstIteratorItemFunction</span></a> item</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIteratorDisposeFunction" title="GstIteratorDisposeFunction ()"><span class="type">GstIteratorDisposeFunction</span></a> free</code></em>);</pre>
<p>Create a new iterator designed for iterating <em class="parameter"><code>list</code></em>
.</p>
<p>The list you iterate is usually part of a data structure <em class="parameter"><code>owner</code></em>
and is
protected with <em class="parameter"><code>lock</code></em>
. </p>
<p>The iterator will use <em class="parameter"><code>lock</code></em>
to retrieve the next item of the list and it
will then call the <em class="parameter"><code>item</code></em>
function before releasing <em class="parameter"><code>lock</code></em>
again.</p>
<p>The <em class="parameter"><code>item</code></em>
function usualy makes sure that the item remains alive while
<em class="parameter"><code>lock</code></em>
is released and the application is using the item. The application is
responsible for freeing/unreffing the item after usage as explained in
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-next" title="gst_iterator_next ()"><code class="function">gst_iterator_next()</code></a>.</p>
<p>When a concurrent update to the list is performed, usually by <em class="parameter"><code>owner</code></em>
while
holding <em class="parameter"><code>lock</code></em>
, <em class="parameter"><code>master_cookie</code></em>
will be updated. The iterator implementation
will notice the update of the cookie and will return <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-RESYNC:CAPS"><code class="literal">GST_ITERATOR_RESYNC</code></a> to
the user of the iterator in the next call to <a class="link" href="gstreamer-GstIterator.html#gst-iterator-next" title="gst_iterator_next ()"><code class="function">gst_iterator_next()</code></a>.</p>
<p><em class="parameter"><code>owner</code></em>
will be passed to the <em class="parameter"><code>free</code></em>
function when the iterator is freed.</p>
<div class="refsect3">
<a name="id-1.3.24.7.14.10"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>type</p></td>
<td class="parameter_description"><p><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#GType"><span class="type">GType</span></a> of elements</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>lock</p></td>
<td class="parameter_description"><p>pointer to a <a href="/usr/share/gtk-doc/html/glib/glib-Threads.html#GMutex"><span class="type">GMutex</span></a> protecting the list.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>master_cookie</p></td>
<td class="parameter_description"><p>pointer to a guint32 that is incremented when the list
is changed.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>list</p></td>
<td class="parameter_description"><p>pointer to the list</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>owner</p></td>
<td class="parameter_description"><p>object owning the list</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>item</p></td>
<td class="parameter_description"><p>function to call for each item</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>free</p></td>
<td class="parameter_description"><p>function to call when the iterator is freed</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.14.11"></a><h4>Returns</h4>
<p> the new <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> for <em class="parameter"><code>list</code></em>
.</p>
<p>MT safe.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-new-single"></a><h3>gst_iterator_new_single ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
gst_iterator_new_single (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#GType"><span class="type">GType</span></a> type</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> object</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstCopyFunction" title="GstCopyFunction ()"><span class="type">GstCopyFunction</span></a> copy</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Miscellaneous-Utility-Functions.html#GFreeFunc"><span class="type">GFreeFunc</span></a> free</code></em>);</pre>
<p>This <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> is a convenient iterator for the common
case where a <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> needs to be returned but only
a single object has to be considered. This happens often
for the <a class="link" href="GstPad.html#GstPadIterIntLinkFunction" title="GstPadIterIntLinkFunction ()"><span class="type">GstPadIterIntLinkFunction</span></a>.</p>
<div class="refsect3">
<a name="id-1.3.24.7.15.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>type</p></td>
<td class="parameter_description"><p><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#GType"><span class="type">GType</span></a> of the passed object</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>object</p></td>
<td class="parameter_description"><p>object that this iterator should return</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>copy</p></td>
<td class="parameter_description"><p>Function that returns a copy of <em class="parameter"><code>object</code></em>
or increases its refcount</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>free</p></td>
<td class="parameter_description"><p>Function to be called for freeing <em class="parameter"><code>object</code></em>
</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.15.6"></a><h4>Returns</h4>
<p> the new <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> for <em class="parameter"><code>object</code></em>
.</p>
<p></p>
</div>
<p class="since">Since 0.10.25</p>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-next"></a><h3>gst_iterator_next ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
gst_iterator_next (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> *elem</code></em>);</pre>
<p>Get the next item from the iterator in <em class="parameter"><code>elem</code></em>
. </p>
<p>Only when this function returns <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-OK:CAPS"><code class="literal">GST_ITERATOR_OK</code></a>, <em class="parameter"><code>elem</code></em>
will contain a valid
value. For iterators that return refcounted objects, the returned object
will have its refcount increased and should therefore be unreffed after
usage.</p>
<p>When this function returns <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-DONE:CAPS"><code class="literal">GST_ITERATOR_DONE</code></a>, no more elements can be
retrieved from <em class="parameter"><code>it</code></em>
.</p>
<p>A return value of <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-RESYNC:CAPS"><code class="literal">GST_ITERATOR_RESYNC</code></a> indicates that the element list was
concurrently updated. The user of <em class="parameter"><code>it</code></em>
should call <a class="link" href="gstreamer-GstIterator.html#gst-iterator-resync" title="gst_iterator_resync ()"><code class="function">gst_iterator_resync()</code></a> to
get the newly updated list. </p>
<p>A return value of <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-ERROR:CAPS"><code class="literal">GST_ITERATOR_ERROR</code></a> indicates an unrecoverable fatal error.</p>
<div class="refsect3">
<a name="id-1.3.24.7.16.9"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to iterate</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>elem</p></td>
<td class="parameter_description"><p>pointer to hold next element</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.16.10"></a><h4>Returns</h4>
<p> The result of the iteration. Unref <em class="parameter"><code>elem</code></em>
after usage if this
is a refcounted object.</p>
<p>MT safe.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-resync"></a><h3>gst_iterator_resync ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_iterator_resync (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>);</pre>
<p>Resync the iterator. this function is mostly called
after <a class="link" href="gstreamer-GstIterator.html#gst-iterator-next" title="gst_iterator_next ()"><code class="function">gst_iterator_next()</code></a> returned <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-RESYNC:CAPS"><code class="literal">GST_ITERATOR_RESYNC</code></a>.</p>
<p>When an iterator was pushed on <em class="parameter"><code>it</code></em>
, it will automatically be popped again
with this function.</p>
<p>MT safe.</p>
<div class="refsect3">
<a name="id-1.3.24.7.17.7"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to resync</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-free"></a><h3>gst_iterator_free ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_iterator_free (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>);</pre>
<p>Free the iterator.</p>
<p>MT safe.</p>
<div class="refsect3">
<a name="id-1.3.24.7.18.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to free</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-push"></a><h3>gst_iterator_push ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_iterator_push (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *other</code></em>);</pre>
<p>Pushes <em class="parameter"><code>other</code></em>
iterator onto <em class="parameter"><code>it</code></em>
. All calls performed on <em class="parameter"><code>it</code></em>
are
forwarded to <em class="parameter"><code>other</code></em>
. If <em class="parameter"><code>other</code></em>
returns <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-DONE:CAPS"><code class="literal">GST_ITERATOR_DONE</code></a>, it is
popped again and calls are handled by <em class="parameter"><code>it</code></em>
again.</p>
<p>This function is mainly used by objects implementing the iterator
next function to recurse into substructures.</p>
<p>When <a class="link" href="gstreamer-GstIterator.html#gst-iterator-resync" title="gst_iterator_resync ()"><code class="function">gst_iterator_resync()</code></a> is called on <em class="parameter"><code>it</code></em>
, <em class="parameter"><code>other</code></em>
will automatically be
popped.</p>
<p>MT safe.</p>
<div class="refsect3">
<a name="id-1.3.24.7.19.8"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to use</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>other</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to push</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-filter"></a><h3>gst_iterator_filter ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="returnvalue">GstIterator</span></a> *
gst_iterator_filter (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GCompareFunc"><span class="type">GCompareFunc</span></a> func</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre>
<p>Create a new iterator from an existing iterator. The new iterator
will only return those elements that match the given compare function <em class="parameter"><code>func</code></em>
.
<em class="parameter"><code>func</code></em>
should return 0 for elements that should be included
in the iterator.</p>
<p>When this iterator is freed, <em class="parameter"><code>it</code></em>
will also be freed.</p>
<div class="refsect3">
<a name="id-1.3.24.7.20.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to filter</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>func</p></td>
<td class="parameter_description"><p> the compare function to select elements. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="The callback is valid only during the call to the method."><span class="acronym">scope call</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p> user data passed to the compare function. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.20.7"></a><h4>Returns</h4>
<p> a new <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a>.</p>
<p>MT safe. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-fold"></a><h3>gst_iterator_fold ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
gst_iterator_fold (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIteratorFoldFunction" title="GstIteratorFoldFunction ()"><span class="type">GstIteratorFoldFunction</span></a> func</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/gobject/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> *ret</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre>
<p>Folds <em class="parameter"><code>func</code></em>
over the elements of <em class="parameter"><code>iter</code></em>
. That is to say, <em class="parameter"><code>func</code></em>
will be called
as <em class="parameter"><code>func</code></em>
(object, <em class="parameter"><code>ret</code></em>
, <em class="parameter"><code>user_data</code></em>
) for each object in <em class="parameter"><code>it</code></em>
. The normal use
of this procedure is to accumulate the results of operating on the objects in
<em class="parameter"><code>ret</code></em>
. If object is a refcounted object its refcount will be increased
before <em class="parameter"><code>func</code></em>
is called, and it should be unrefed after use in <em class="parameter"><code>func</code></em>
.</p>
<p>This procedure can be used (and is used internally) to implement the
<a class="link" href="gstreamer-GstIterator.html#gst-iterator-foreach" title="gst_iterator_foreach ()"><code class="function">gst_iterator_foreach()</code></a> and <a class="link" href="gstreamer-GstIterator.html#gst-iterator-find-custom" title="gst_iterator_find_custom ()"><code class="function">gst_iterator_find_custom()</code></a> operations.</p>
<p>The fold will proceed as long as <em class="parameter"><code>func</code></em>
returns TRUE. When the iterator has no
more arguments, <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-DONE:CAPS"><code class="literal">GST_ITERATOR_DONE</code></a> will be returned. If <em class="parameter"><code>func</code></em>
returns FALSE,
the fold will stop, and <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-OK:CAPS"><code class="literal">GST_ITERATOR_OK</code></a> will be returned. Errors or resyncs
will cause fold to return <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-ERROR:CAPS"><code class="literal">GST_ITERATOR_ERROR</code></a> or <a class="link" href="gstreamer-GstIterator.html#GST-ITERATOR-RESYNC:CAPS"><code class="literal">GST_ITERATOR_RESYNC</code></a> as
appropriate.</p>
<p>The iterator will not be freed.</p>
<div class="refsect3">
<a name="id-1.3.24.7.21.8"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to fold over</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>func</p></td>
<td class="parameter_description"><p> the fold function. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="The callback is valid only during the call to the method."><span class="acronym">scope call</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>ret</p></td>
<td class="parameter_description"><p>the seed value passed to the fold function</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p> user data passed to the fold function. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.21.9"></a><h4>Returns</h4>
<p> A <a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="type">GstIteratorResult</span></a>, as described above.</p>
<p>MT safe.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-foreach"></a><h3>gst_iterator_foreach ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstIterator.html#GstIteratorResult" title="enum GstIteratorResult"><span class="returnvalue">GstIteratorResult</span></a>
gst_iterator_foreach (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GFunc"><span class="type">GFunc</span></a> func</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre>
<p>Iterate over all element of <em class="parameter"><code>it</code></em>
and call the given function <em class="parameter"><code>func</code></em>
for
each element. As in <a class="link" href="gstreamer-GstIterator.html#gst-iterator-fold" title="gst_iterator_fold ()"><code class="function">gst_iterator_fold()</code></a>, the refcount of a refcounted
object will be increased before <em class="parameter"><code>func</code></em>
is called, and should be unrefed
after use.</p>
<div class="refsect3">
<a name="id-1.3.24.7.22.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to iterate</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>func</p></td>
<td class="parameter_description"><p> the function to call for each element. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="The callback is valid only during the call to the method."><span class="acronym">scope call</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p> user data passed to the function. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.22.6"></a><h4>Returns</h4>
<p> the result call to <a class="link" href="gstreamer-GstIterator.html#gst-iterator-fold" title="gst_iterator_fold ()"><code class="function">gst_iterator_fold()</code></a>. The iterator will not be
freed.</p>
<p>MT safe.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-iterator-find-custom"></a><h3>gst_iterator_find_custom ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="returnvalue">gpointer</span></a>
gst_iterator_find_custom (<em class="parameter"><code><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> *it</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GCompareFunc"><span class="type">GCompareFunc</span></a> func</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre>
<p>Find the first element in <em class="parameter"><code>it</code></em>
that matches the compare function <em class="parameter"><code>func</code></em>
.
<em class="parameter"><code>func</code></em>
should return 0 when the element is found. As in <a class="link" href="gstreamer-GstIterator.html#gst-iterator-fold" title="gst_iterator_fold ()"><code class="function">gst_iterator_fold()</code></a>,
the refcount of a refcounted object will be increased before <em class="parameter"><code>func</code></em>
is
called, and should be unrefed after use in <em class="parameter"><code>func</code></em>
unless it is the matching
element.</p>
<p>The iterator will not be freed.</p>
<p>This function will return NULL if an error happened to the iterator.</p>
<div class="refsect3">
<a name="id-1.3.24.7.23.7"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>it</p></td>
<td class="parameter_description"><p>The <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> to iterate</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>func</p></td>
<td class="parameter_description"><p> the compare function to use. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="The callback is valid only during the call to the method."><span class="acronym">scope call</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p> user data passed to the compare function. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.24.7.23.8"></a><h4>Returns</h4>
<p> The element in the iterator that matches the compare
function or NULL when no element matched.</p>
<p>MT safe. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
</div>
<div class="refsect1">
<a name="gstreamer-GstIterator.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GstIterator"></a><h3>struct GstIterator</h3>
<pre class="programlisting">struct GstIterator {
};
</pre>
<p><a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a> base structure. The values of this structure are
protected for subclasses, use the methods to use the <a class="link" href="gstreamer-GstIterator.html#GstIterator" title="struct GstIterator"><span class="type">GstIterator</span></a>.</p>
<div class="refsect3">
<a name="id-1.3.24.8.2.5"></a><h4>Members</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="300px" class="struct_members_name">
<col class="struct_members_description">
<col width="200px" class="struct_members_annotations">
</colgroup>
<tbody></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstIteratorItem"></a><h3>enum GstIteratorItem</h3>
<p>The result of a <a class="link" href="gstreamer-GstIterator.html#GstIteratorItemFunction" title="GstIteratorItemFunction ()"><span class="type">GstIteratorItemFunction</span></a>.</p>
<div class="refsect3">
<a name="id-1.3.24.8.3.4"></a><h4>Members</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="300px" class="enum_members_name">
<col class="enum_members_description">
<col width="200px" class="enum_members_annotations">
</colgroup>
<tbody>
<tr>
<td class="enum_member_name"><p><a name="GST-ITERATOR-ITEM-SKIP:CAPS"></a>GST_ITERATOR_ITEM_SKIP</p></td>
<td class="enum_member_description">
<p>Skip this item</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="GST-ITERATOR-ITEM-PASS:CAPS"></a>GST_ITERATOR_ITEM_PASS</p></td>
<td class="enum_member_description">
<p>Return item</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="GST-ITERATOR-ITEM-END:CAPS"></a>GST_ITERATOR_ITEM_END</p></td>
<td class="enum_member_description">
<p>Stop after this item.</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GstIteratorResult"></a><h3>enum GstIteratorResult</h3>
<p>The result of <a class="link" href="gstreamer-GstIterator.html#gst-iterator-next" title="gst_iterator_next ()"><code class="function">gst_iterator_next()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.24.8.4.4"></a><h4>Members</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="300px" class="enum_members_name">
<col class="enum_members_description">
<col width="200px" class="enum_members_annotations">
</colgroup>
<tbody>
<tr>
<td class="enum_member_name"><p><a name="GST-ITERATOR-DONE:CAPS"></a>GST_ITERATOR_DONE</p></td>
<td class="enum_member_description">
<p>No more items in the iterator</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="GST-ITERATOR-OK:CAPS"></a>GST_ITERATOR_OK</p></td>
<td class="enum_member_description">
<p>An item was retrieved</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="GST-ITERATOR-RESYNC:CAPS"></a>GST_ITERATOR_RESYNC</p></td>
<td class="enum_member_description">
<p>Datastructure changed while iterating</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="GST-ITERATOR-ERROR:CAPS"></a>GST_ITERATOR_ERROR</p></td>
<td class="enum_member_description">
<p>An error happened</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="gstreamer-GstIterator.see-also"></a><h2>See Also</h2>
<p><a class="link" href="GstElement.html" title="GstElement"><span class="type">GstElement</span></a>, <a class="link" href="GstBin.html" title="GstBin"><span class="type">GstBin</span></a></p>
</div>
</div>
<div class="footer">
<hr>
Generated by GTK-Doc V1.21</div>
</body>
</html>
|