This file is indexed.

/usr/lib/python3/dist-packages/Onboard/LayoutView.py is in onboard 1.2.0-0ubuntu5.

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
# -*- coding: utf-8 -*-

# Copyright © 2012-2015 marmuta <marmvta@gmail.com>
#
# This file is part of Onboard.
#
# Onboard is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# Onboard is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

""" Keyboard layout view """

from __future__ import division, print_function, unicode_literals

import time
from math import pi

import cairo
from Onboard.Version import require_gi_versions
require_gi_versions()
from gi.repository         import Gtk, Gdk, GdkPixbuf

from Onboard.utils         import Rect, \
                                  roundrect_arc, roundrect_curve, \
                                  gradient_line, brighten, \
                                  unicode_str
from Onboard.WindowUtils   import get_monitor_dimensions
from Onboard.KeyGtk        import Key
from Onboard.KeyCommon     import LOD
from Onboard.definitions   import UIMask


### Logging ###
import logging
_logger = logging.getLogger("LayoutView")
###############

### Config Singleton ###
from Onboard.Config import Config
config = Config()
########################

class LayoutView:
    """
    Viewer for a tree of layout items.
    """

    def __init__(self, keyboard):
        self.keyboard = keyboard
        self.supports_alpha = False

        self._lod = LOD.FULL
        self._font_sizes_valid = False
        self._shadow_quality_valid = False
        self._last_canvas_shadow_rect = Rect()

        self._starting_up = True
        self._keys_pre_rendered = False

        self.keyboard.register_view(self)

    def cleanup(self):
        self.keyboard.deregister_view(self)

        # free xserver memory
        self.invalidate_keys()
        self.invalidate_shadows()

    def handle_realize_event(self):
        self.update_touch_input_mode()
        self.update_input_event_source()

    def on_layout_loaded(self):
        """ Layout has been loaded. """
        self.invalidate_shadow_quality()

    def get_layout(self):
        return self.keyboard.layout

    def get_color_scheme(self):
        return self.keyboard.color_scheme

    def invalidate_for_resize(self, lod=LOD.FULL):
        self.invalidate_keys()
        if self._lod == LOD.FULL:
            self.invalidate_shadows()
        self.invalidate_font_sizes()
        # self.invalidate_label_extents()
        self.keyboard.invalidate_for_resize()

    def invalidate_font_sizes(self):
        """
        Update font_sizes at the next possible chance.
        """
        self._font_sizes_valid = False

    def invalidate_keys(self):
        """
        Clear cached key surfaces, e.g. after resizing,
        change of theme settings.
        """
        layout = self.get_layout()
        if layout:
            for item in layout.iter_keys():
                item.invalidate_key()

    def invalidate_images(self):
        """
        Clear cached images, e.g. after changing window_scaling_factor.
        """
        layout = self.get_layout()
        if layout:
            for item in layout.iter_keys():
                item.invalidate_image()

    def invalidate_shadows(self):
        """
        Clear cached shadow surfaces, e.g. after resizing,
        change of theme settings.
        """
        layout = self.get_layout()
        if layout:
            for item in layout.iter_keys():
                item.invalidate_shadow()

    def invalidate_shadow_quality(self):
        self._shadow_quality_valid = False

    def invalidate_label_extents(self):
        """
        Clear cached resolution independent label extents, e.g.
        after changes to the systems font dpi setting (gtk-xft-dpi).
        """
        layout = self.get_layout()
        if layout:
            for item in layout.iter_keys():
                item.invalidate_label_extents()

    def reset_lod(self):
        """ Reset to full level of detail """
        if self._lod != LOD.FULL:
            self._lod = LOD.FULL
            self.invalidate_for_resize()
            self.keyboard.invalidate_context_ui()
            self.keyboard.invalidate_canvas()
            self.keyboard.commit_ui_updates()

    def is_visible(self):
        return None

    def set_visible(self, visible):
        pass

    def toggle_visible(self):
        pass

    def raise_to_top(self):
        pass

    def redraw(self, items=None, invalidate=True):
        """
        Queue redrawing for individual keys or the whole keyboard.
        """
        if items is None:
            self.queue_draw()

        elif len(items) == 0:
            pass

        else:
            area = None
            for item in items:
                rect = item.get_canvas_border_rect()
                area = area.union(rect) if area else rect

                # assume keys need to be refreshed when actively redrawn
                # e.g. for pressed state changes, dwell progress updates...
                if invalidate and \
                   item.is_key():
                    item.invalidate_key()

            # account for stroke width, anti-aliasing
            if self.get_layout():
                extra_size = items[0].get_extra_render_size()
                area = area.inflate(*extra_size)

            self.queue_draw_area(*area)

    def redraw_labels(self, invalidate=True):
        self.redraw(self.update_labels(), invalidate)

    def update_transparency(self):
        pass

    def update_input_event_source(self):
        self.register_input_events(True, config.is_event_source_gtk())

    def update_touch_input_mode(self):
        self.set_touch_input_mode(config.keyboard.touch_input)

    def can_delay_sequence_begin(self, sequence):
        """
        Veto gesture delay for move buttons. Have the keyboard start
        moving right away and not lag behind the pointer.
        """
        layout = self.get_layout()
        if layout:
            for item in layout.find_ids(["move"]):
                if item.is_path_visible() and \
                   item.is_point_within(sequence.point):
                    return False
        return True

    def show_touch_handles(self, show, auto_hide):
        pass

    def apply_ui_updates(self, mask):
        if mask & UIMask.SIZE:
            self.invalidate_for_resize()

    def update_layout(self):
        pass

    def process_updates(self):
        """ Draw now, synchronously. """
        window = self.get_window()
        if window:
            window.process_updates(True)

    def render(self, context):
        """ Pre-render key surfaces for instant initial drawing. """

        # lazily update font sizes and labels
        if not self._font_sizes_valid:
            self.update_labels()

        layout = self.get_layout()
        if not layout:
            return

        self._auto_select_shadow_quality(context)

        # run through all visible layout items
        for item in layout.iter_visible_items():
            if item.is_key():
                item.draw_shadow_cached(context)
                item.draw_cached(context)

        self._keys_pre_rendered = True

    def _can_draw_cached(self, lod):
        """
        Draw cached key surfaces?

        On first startup draw cached only if keys were pre-rendered, i.e. the
        time to render keys was hidden before the window was shown.

        We can't easily pre-render keys in xembed mode because the window size
        is unknown in advance. Draw there once uncached instead (faster).
        """
        return (lod == LOD.FULL) and \
               (not self._starting_up or self._keys_pre_rendered)

    def draw(self, widget, context):
        if not Gtk.cairo_should_draw_window(context, widget.get_window()):
            return

        lod = self._lod
        draw_cached = self._can_draw_cached(lod)

        # lazily update font sizes and labels
        if not self._font_sizes_valid:
            self.update_labels(lod)

        draw_rect = self.get_damage_rect(context)

        # draw background
        decorated = self._draw_background(context, lod)

        layout = self.get_layout()
        if not layout:
            return

        # draw layer 0 and None-layer background
        layer_ids = layout.get_layer_ids()
        if config.window.transparent_background:
            alpha = 0.0
        elif decorated:
            alpha = self.get_background_rgba()[3]
        else:
            alpha = 1.0
        self._draw_layer_key_background(context, alpha,
                                        None, None, lod)
        if layer_ids:
            self._draw_layer_key_background(context, alpha,
                                            None, layer_ids[0], lod)

        # run through all visible layout items
        for item in layout.iter_visible_items():
            if item.layer_id:
                self._draw_layer_background(context, item, layer_ids, decorated)

            # draw key
            if item.is_key() and \
               draw_rect.intersects(item.get_canvas_border_rect()):
                if draw_cached:
                    item.draw_cached(context)
                else:
                    item.draw(context, lod)

        self._starting_up = False

        return decorated

    def _draw_background(self, context, lod):
        """ Draw keyboard background """
        transparent_bg = False
        plain_bg = False

        if config.xid_mode and \
           config.is_keep_aspect_ratio_enabled():
            if self.supports_alpha:
                self._clear_xembed_background(context)
                transparent_bg = True
            else:
                plain_bg = True

        elif config.xid_mode:
            # xembed mode
            # Disable transparency in lightdm and g-s-s for now.
            # There are too many issues and there is no real
            # visual improvement.
            plain_bg = True

        elif config.has_window_decoration():
            # decorated window
            if self.supports_alpha and \
               config.window.transparent_background:
                self._clear_background(context)
            else:
                plain_bg = True

        else:
            # undecorated window
            if self.supports_alpha:
                self._clear_background(context)
                if not config.window.transparent_background:
                    transparent_bg = True
            else:
                plain_bg = True

        if plain_bg:
            self._draw_plain_background(context)
        if transparent_bg:
            self._draw_transparent_background(context, lod)

        return transparent_bg

    def _clear_background(self, context):
        """
        Clear the whole gtk background.
        Makes the whole strut transparent in xembed mode.
        """
        context.save()
        context.set_operator(cairo.OPERATOR_CLEAR)
        context.paint()
        context.restore()

    def _clear_xembed_background(self, context):
        """ fill with plain layer 0 color; no alpha support required """
        rect = Rect(0, 0, self.get_allocated_width(),
                          self.get_allocated_height())

        # draw background image
        if config.get_xembed_background_image_enabled():
            pixbuf = self._get_xembed_background_image()
            if pixbuf:
                src_size = (pixbuf.get_width(), pixbuf.get_height())
                x, y = 0, rect.bottom() - src_size[1]
                Gdk.cairo_set_source_pixbuf(context, pixbuf, x, y)
                context.paint()

        # draw solid colored bar on top (with transparency, usually)
        rgba = config.get_xembed_background_rgba()
        if rgba is None:
            rgba = self.get_background_rgba()
            rgba[3] = 0.5
        context.set_source_rgba(*rgba)
        context.rectangle(*rect)
        context.fill()

    def _get_xembed_background_image(self):
        """ load the desktop background image in Unity """
        try:
            pixbuf = self._xid_background_image
        except AttributeError:
            size, size_mm = get_monitor_dimensions(self)
            filename = config.get_desktop_background_filename()
            if not filename:
                pixbuf = None
            else:
                try:
                    # load image
                    pixbuf = GdkPixbuf.Pixbuf.new_from_file(filename)

                    # Scale image to mimic the behavior of gnome-screen-saver.
                    # Take the largest, aspect correct, centered rectangle
                    # that fits on the monitor.
                    rm = Rect(0, 0, size[0], size[1])
                    rp = Rect(0, 0, pixbuf.get_width(), pixbuf.get_height())
                    ra = rm.inscribe_with_aspect(rp)
                    pixbuf = pixbuf.new_subpixbuf(*ra)
                    pixbuf = pixbuf.scale_simple(size[0], size[1],
                                                GdkPixbuf.InterpType.BILINEAR)
                except Exception as ex: # private exception gi._glib.GError when
                                        # librsvg2-common wasn't installed
                    _logger.error("_get_xembed_background_image(): " + \
                                unicode_str(ex))
                    pixbuf = None

            self._xid_background_image = pixbuf

        return pixbuf

    def _draw_transparent_background(self, context, lod):
        """ fill with the transparent background color """
        corner_radius = config.CORNER_RADIUS
        rect = self.get_keyboard_frame_rect()
        fill = self.get_background_rgba()

        fill_gradient = config.theme_settings.background_gradient
        if lod == LOD.MINIMAL or \
           fill_gradient == 0:
            context.set_source_rgba(*fill)
        else:
            fill_gradient /= 100.0
            direction = config.theme_settings.key_gradient_direction
            alpha = -pi/2.0 + pi * direction / 180.0
            gline = gradient_line(rect, alpha)

            pat = cairo.LinearGradient (*gline)
            rgba = brighten(+fill_gradient*.5, *fill)
            pat.add_color_stop_rgba(0, *rgba)
            rgba = brighten(-fill_gradient*.5, *fill)
            pat.add_color_stop_rgba(1, *rgba)
            context.set_source (pat)

        if config.xid_mode:
            frame = False
        else:
            frame = self.can_draw_frame()

        if frame:
            roundrect_arc(context, rect, corner_radius)
        else:
            context.rectangle(*rect)
        context.fill()

        if frame:
            self.draw_window_frame(context, lod)
            self.draw_keyboard_frame(context, lod)

    def can_draw_frame(self):
        """ overloaded in popups """
        return True

    def draw_window_frame(self, context, lod):
        pass

    def draw_keyboard_frame(self, context, lod):
        """ draw frame around the (potentially aspect corrected) keyboard """
        corner_radius = config.CORNER_RADIUS
        rect = self.get_keyboard_frame_rect()
        fill = self.get_background_rgba()

        # inner decoration line
        line_rect = rect.deflate(1)
        roundrect_arc(context, line_rect, corner_radius)
        context.stroke()

    def _draw_plain_background(self, context, layer_index = 0):
        """ fill with plain layer 0 color; no alpha support required """
        rgba = self._get_layer_fill_rgba(layer_index)
        context.set_source_rgba(*rgba)
        context.paint()

    def _draw_layer_background(self, context, item, layer_ids, decorated):
        # layer background
        layer_index = layer_ids.index(item.layer_id)
        parent = item.parent
        if parent and \
           layer_index != 0:
            rect = parent.get_canvas_rect()
            context.rectangle(*rect.inflate(1))

            color_scheme = self.get_color_scheme()
            if color_scheme:
                rgba = color_scheme.get_layer_fill_rgba(layer_index)
            else:
                rgba = [0.5, 0.5, 0.5, 0.9]
            context.set_source_rgba(*rgba)
            context.fill()

            # per-layer key background
            self._draw_layer_key_background(context, 1.0, item, item.layer_id)

    def _draw_layer_key_background(self, context, alpha = 1.0, item = None,
                                   layer_id = None, lod = LOD.FULL):
        self._draw_dish_key_background(context, alpha, item, layer_id)
        self._draw_shadows(context, layer_id, lod)

    def _draw_dish_key_background(self, context, alpha = 1.0, item = None,
                                  layer_id = None):
        """
        Black background following the contours of key clusters
        to simulate the opening in the keyboard plane.
        """
        if config.theme_settings.key_style == "dish":
            layout = self.get_layout()
            context.push_group()

            context.set_source_rgba(0, 0, 0, 1)
            enlargement = layout.context.scale_log_to_canvas((0.8, 0.8))
            corner_radius = layout.context.scale_log_to_canvas_x(2.4)

            if item is None:
                item = layout

            for key in item.iter_layer_keys(layer_id):
                rect = key.get_canvas_fullsize_rect()
                rect = rect.inflate(*enlargement)
                roundrect_curve(context, rect, corner_radius)
                context.fill()

            context.pop_group_to_source()
            context.paint_with_alpha(alpha);

    def _draw_shadows(self, context, layer_id, lod):
        """
        Draw drop shadows for all keys.
        """
        if not config.theme_settings.key_shadow_strength:
            return

        self._auto_select_shadow_quality(context)

        # draw shadows
        context.save()
        self.set_shadow_scale(context, lod)

        draw_rect = self.get_damage_rect(context)
        layout = self.get_layout()
        for item in layout.iter_layer_keys(layer_id):
            if draw_rect.intersects(item.get_canvas_border_rect()):
                item.draw_shadow_cached(context)

        context.restore()

    def _auto_select_shadow_quality(self, context):
        """ auto-select shadow quality """
        if not self._shadow_quality_valid:
            quality = self._probe_shadow_performance(context)
            Key.set_shadow_quality(quality)
            self._shadow_quality_valid = True

    def _probe_shadow_performance(self, context):
        """
        Determine shadow quality based on the estimated render time of
        the first layer's shadows.
        """
        probe_begin = time.time()
        quality = None

        layout = self.get_layout()
        max_total_time = 0.03  # upper limit refreshing all key's shadows [s]
        max_probe_keys = 10
        keys = None
        for layer_id in layout.get_layer_ids():
            layer_keys = list(layout.iter_layer_keys(layer_id))
            num_first_layer_keys = len(layer_keys)
            keys = layer_keys[:max_probe_keys]
            break

        if keys:
            for quality, (steps, alpha) in enumerate(Key._shadow_presets):
                begin = time.time()
                for key in keys:
                    key.create_shadow_surface(context, steps, 0.1)
                elapsed = time.time() - begin
                estimate = elapsed / len(keys) * num_first_layer_keys
                _logger.debug("Probing shadow performance: "
                              "estimated full refresh time {:6.1f}ms "
                              "at quality {}, {} steps." \
                              .format(estimate * 1000,
                                      quality, steps))
                if estimate > max_total_time:
                    break

            _logger.info("Probing shadow performance took {:.1f}ms. "
                         "Selecting quality {}." \
                         .format((time.time() - probe_begin) * 1000,
                                 quality))
        return quality

    def set_shadow_scale(self, context, lod):
        """
        Shadows aren't normally refreshed while resizing.
        -> scale the cached ones to fit the new canvas size.
        Occasionally refresh them anyway if scaling becomes noticeable.
        """
        r  = self.get_keyboard_frame_rect()
        if lod < LOD.FULL:
            rl = self._last_canvas_shadow_rect
            scale_x = r.w / rl.w
            scale_y = r.h / rl.h

            # scale in a reasonable range? -> draw stretched shadows
            smin = 0.8
            smax = 1.2
            if smax > scale_x > smin and \
               smax > scale_y > smin:
                context.scale(scale_x, scale_y)
            else:
                # else scale is too far out -> refresh shadows
                self.invalidate_shadows()
                self._last_canvas_shadow_rect = r
        else:
            self._last_canvas_shadow_rect = r

    def _get_layer_fill_rgba(self, layer_index):
        color_scheme = self.get_color_scheme()
        if color_scheme:
            return color_scheme.get_layer_fill_rgba(layer_index)
        else:
            return [0.5, 0.5, 0.5, 1.0]

    def get_background_rgba(self):
        """ layer 0 color * background_transparency """
        layer0_rgba = self._get_layer_fill_rgba(0)
        background_alpha = config.window.get_background_opacity()
        background_alpha *= layer0_rgba[3]
        return layer0_rgba[:3] + [background_alpha]

    def get_popup_window_rgba(self, element = "border"):
        color_scheme = self.get_color_scheme()
        if color_scheme:
            rgba = color_scheme.get_window_rgba("key-popup", element)
        else:
            rgba = [0.8, 0.8, 0.8, 1.0]
        background_alpha = config.window.get_background_opacity()
        background_alpha *= rgba[3]
        return rgba[:3] + [background_alpha]

    def get_damage_rect(self, context):
        clip_rect = Rect.from_extents(*context.clip_extents())

        # Draw a little more than just the clip_rect.
        # Prevents glitches around pressed keys in at least classic theme.
        layout = self.get_layout()
        if layout:
            extra_size = layout.context.scale_log_to_canvas((2.0, 2.0))
        else:
            extra_size = 0, 0
        return clip_rect.inflate(*extra_size)

    def get_keyboard_frame_rect(self):
        """
        Rectangle of the potentially aspect-corrected
        frame around the layout.
        """
        layout = self.get_layout()
        if layout:
            rect = layout.get_canvas_border_rect()
            rect = rect.inflate(self.get_frame_width())
        else:
            rect = Rect(0, 0, self.get_allocated_width(),
                              self.get_allocated_height())
        return rect

    def is_docking_expanded(self):
        return self.window.docking_enabled and self.window.docking_expanded


    def update_labels(self, lod = LOD.FULL):
        """
        Iterate through all key groups and set each key's
        label font size to the maximum possible for that group.
        """
        changed_keys = set()
        layout = self.get_layout()

        mod_mask = self.keyboard.get_mod_mask()

        if layout:
            if lod == LOD.FULL:  # no label changes necessary while dragging

                for key in layout.iter_keys():
                    old_label = key.get_label()
                    key.configure_label(mod_mask)
                    if key.get_label() != old_label:
                        changed_keys.add(key)

            for keys in layout.get_key_groups().values():
                max_size = 0
                for key in keys:
                    best_size = key.get_best_font_size(mod_mask)
                    if best_size:
                        if key.ignore_group:
                            if key.font_size != best_size:
                                key.font_size = best_size
                                changed_keys.add(key)
                        else:
                            if not max_size or best_size < max_size:
                                max_size = best_size

                for key in keys:
                    if key.font_size != max_size and \
                       not key.ignore_group:
                        key.font_size = max_size
                        changed_keys.add(key)

        self._font_sizes_valid = True
        return tuple(changed_keys)

    def get_key_at_location(self, point):
        layout = self.get_layout()
        keyboard = self.keyboard
        if layout and keyboard:  # may be gone on exit
            return layout.get_key_at(point, keyboard.active_layer)
        return None