forked from ocornut/imgui
-
Notifications
You must be signed in to change notification settings - Fork 0
/
imgui_widgets.cpp
8587 lines (7582 loc) · 413 KB
/
imgui_widgets.cpp
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
// dear imgui, v1.89.5 WIP
// (widgets code)
/*
Index of this file:
// [SECTION] Forward Declarations
// [SECTION] Widgets: Text, etc.
// [SECTION] Widgets: Main (Button, Image, Checkbox, RadioButton, ProgressBar, Bullet, etc.)
// [SECTION] Widgets: Low-level Layout helpers (Spacing, Dummy, NewLine, Separator, etc.)
// [SECTION] Widgets: ComboBox
// [SECTION] Data Type and Data Formatting Helpers
// [SECTION] Widgets: DragScalar, DragFloat, DragInt, etc.
// [SECTION] Widgets: SliderScalar, SliderFloat, SliderInt, etc.
// [SECTION] Widgets: InputScalar, InputFloat, InputInt, etc.
// [SECTION] Widgets: InputText, InputTextMultiline
// [SECTION] Widgets: ColorEdit, ColorPicker, ColorButton, etc.
// [SECTION] Widgets: TreeNode, CollapsingHeader, etc.
// [SECTION] Widgets: Selectable
// [SECTION] Widgets: ListBox
// [SECTION] Widgets: PlotLines, PlotHistogram
// [SECTION] Widgets: Value helpers
// [SECTION] Widgets: MenuItem, BeginMenu, EndMenu, etc.
// [SECTION] Widgets: BeginTabBar, EndTabBar, etc.
// [SECTION] Widgets: BeginTabItem, EndTabItem, etc.
// [SECTION] Widgets: Columns, BeginColumns, EndColumns, etc.
*/
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif
#ifndef IMGUI_DEFINE_MATH_OPERATORS
#define IMGUI_DEFINE_MATH_OPERATORS
#endif
#include "imgui.h"
#ifndef IMGUI_DISABLE
#include "imgui_internal.h"
// System includes
#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
#include <stddef.h> // intptr_t
#else
#include <stdint.h> // intptr_t
#endif
//-------------------------------------------------------------------------
// Warnings
//-------------------------------------------------------------------------
// Visual Studio warnings
#ifdef _MSC_VER
#pragma warning (disable: 4127) // condition expression is constant
#pragma warning (disable: 4996) // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen
#if defined(_MSC_VER) && _MSC_VER >= 1922 // MSVC 2019 16.2 or later
#pragma warning (disable: 5054) // operator '|': deprecated between enumerations of different types
#endif
#pragma warning (disable: 26451) // [Static Analyzer] Arithmetic overflow : Using operator 'xxx' on a 4 byte value and then casting the result to a 8 byte value. Cast the value to the wider type before calling operator 'xxx' to avoid overflow(io.2).
#pragma warning (disable: 26812) // [Static Analyzer] The enum type 'xxx' is unscoped. Prefer 'enum class' over 'enum' (Enum.3).
#endif
// Clang/GCC warnings with -Weverything
#if defined(__clang__)
#if __has_warning("-Wunknown-warning-option")
#pragma clang diagnostic ignored "-Wunknown-warning-option" // warning: unknown warning group 'xxx' // not all warnings are known by all Clang versions and they tend to be rename-happy.. so ignoring warnings triggers new warnings on some configuration. Great!
#endif
#pragma clang diagnostic ignored "-Wunknown-pragmas" // warning: unknown warning group 'xxx'
#pragma clang diagnostic ignored "-Wold-style-cast" // warning: use of old-style cast // yes, they are more terse.
#pragma clang diagnostic ignored "-Wfloat-equal" // warning: comparing floating point with == or != is unsafe // storing and comparing against same constants (typically 0.0f) is ok.
#pragma clang diagnostic ignored "-Wformat-nonliteral" // warning: format string is not a string literal // passing non-literal to vsnformat(). yes, user passing incorrect format strings can crash the code.
#pragma clang diagnostic ignored "-Wsign-conversion" // warning: implicit conversion changes signedness
#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant" // warning: zero as null pointer constant // some standard header variations use #define NULL 0
#pragma clang diagnostic ignored "-Wdouble-promotion" // warning: implicit conversion from 'float' to 'double' when passing argument to function // using printf() is a misery with this as C++ va_arg ellipsis changes float to double.
#pragma clang diagnostic ignored "-Wenum-enum-conversion" // warning: bitwise operation between different enumeration types ('XXXFlags_' and 'XXXFlagsPrivate_')
#pragma clang diagnostic ignored "-Wdeprecated-enum-enum-conversion"// warning: bitwise operation between different enumeration types ('XXXFlags_' and 'XXXFlagsPrivate_') is deprecated
#pragma clang diagnostic ignored "-Wimplicit-int-float-conversion" // warning: implicit conversion from 'xxx' to 'float' may lose precision
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wpragmas" // warning: unknown option after '#pragma GCC diagnostic' kind
#pragma GCC diagnostic ignored "-Wformat-nonliteral" // warning: format not a string literal, format string not checked
#pragma GCC diagnostic ignored "-Wclass-memaccess" // [__GNUC__ >= 8] warning: 'memset/memcpy' clearing/writing an object of type 'xxxx' with no trivial copy-assignment; use assignment or value-initialization instead
#pragma GCC diagnostic ignored "-Wdeprecated-enum-enum-conversion" // warning: bitwise operation between different enumeration types ('XXXFlags_' and 'XXXFlagsPrivate_') is deprecated
#endif
//-------------------------------------------------------------------------
// Data
//-------------------------------------------------------------------------
// Widgets
static const float DRAGDROP_HOLD_TO_OPEN_TIMER = 0.70f; // Time for drag-hold to activate items accepting the ImGuiButtonFlags_PressedOnDragDropHold button behavior.
static const float DRAG_MOUSE_THRESHOLD_FACTOR = 0.50f; // Multiplier for the default value of io.MouseDragThreshold to make DragFloat/DragInt react faster to mouse drags.
// Those MIN/MAX values are not define because we need to point to them
static const signed char IM_S8_MIN = -128;
static const signed char IM_S8_MAX = 127;
static const unsigned char IM_U8_MIN = 0;
static const unsigned char IM_U8_MAX = 0xFF;
static const signed short IM_S16_MIN = -32768;
static const signed short IM_S16_MAX = 32767;
static const unsigned short IM_U16_MIN = 0;
static const unsigned short IM_U16_MAX = 0xFFFF;
static const ImS32 IM_S32_MIN = INT_MIN; // (-2147483647 - 1), (0x80000000);
static const ImS32 IM_S32_MAX = INT_MAX; // (2147483647), (0x7FFFFFFF)
static const ImU32 IM_U32_MIN = 0;
static const ImU32 IM_U32_MAX = UINT_MAX; // (0xFFFFFFFF)
#ifdef LLONG_MIN
static const ImS64 IM_S64_MIN = LLONG_MIN; // (-9223372036854775807ll - 1ll);
static const ImS64 IM_S64_MAX = LLONG_MAX; // (9223372036854775807ll);
#else
static const ImS64 IM_S64_MIN = -9223372036854775807LL - 1;
static const ImS64 IM_S64_MAX = 9223372036854775807LL;
#endif
static const ImU64 IM_U64_MIN = 0;
#ifdef ULLONG_MAX
static const ImU64 IM_U64_MAX = ULLONG_MAX; // (0xFFFFFFFFFFFFFFFFull);
#else
static const ImU64 IM_U64_MAX = (2ULL * 9223372036854775807LL + 1);
#endif
//-------------------------------------------------------------------------
// [SECTION] Forward Declarations
//-------------------------------------------------------------------------
// For InputTextEx()
static bool InputTextFilterCharacter(unsigned int* p_char, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data, ImGuiInputSource input_source);
static int InputTextCalcTextLenAndLineCount(const char* text_begin, const char** out_text_end);
static ImVec2 InputTextCalcTextSizeW(ImGuiContext* ctx, const ImWchar* text_begin, const ImWchar* text_end, const ImWchar** remaining = NULL, ImVec2* out_offset = NULL, bool stop_on_new_line = false);
//-------------------------------------------------------------------------
// [SECTION] Widgets: Text, etc.
//-------------------------------------------------------------------------
// - TextEx() [Internal]
// - TextUnformatted()
// - Text()
// - TextV()
// - TextColored()
// - TextColoredV()
// - TextDisabled()
// - TextDisabledV()
// - TextWrapped()
// - TextWrappedV()
// - LabelText()
// - LabelTextV()
// - BulletText()
// - BulletTextV()
//-------------------------------------------------------------------------
void ImGui::TextEx(const char* text, const char* text_end, ImGuiTextFlags flags)
{
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return;
ImGuiContext& g = *GImGui;
// Accept null ranges
if (text == text_end)
text = text_end = "";
// Calculate length
const char* text_begin = text;
if (text_end == NULL)
text_end = text + strlen(text); // FIXME-OPT
const ImVec2 text_pos(window->DC.CursorPos.x, window->DC.CursorPos.y + window->DC.CurrLineTextBaseOffset);
const float wrap_pos_x = window->DC.TextWrapPos;
const bool wrap_enabled = (wrap_pos_x >= 0.0f);
if (text_end - text <= 2000 || wrap_enabled)
{
// Common case
const float wrap_width = wrap_enabled ? CalcWrapWidthForPos(window->DC.CursorPos, wrap_pos_x) : 0.0f;
const ImVec2 text_size = CalcTextSize(text_begin, text_end, false, wrap_width);
ImRect bb(text_pos, text_pos + text_size);
ItemSize(text_size, 0.0f);
if (!ItemAdd(bb, 0))
return;
// Render (we don't hide text after ## in this end-user function)
RenderTextWrapped(bb.Min, text_begin, text_end, wrap_width);
}
else
{
// Long text!
// Perform manual coarse clipping to optimize for long multi-line text
// - From this point we will only compute the width of lines that are visible. Optimization only available when word-wrapping is disabled.
// - We also don't vertically center the text within the line full height, which is unlikely to matter because we are likely the biggest and only item on the line.
// - We use memchr(), pay attention that well optimized versions of those str/mem functions are much faster than a casually written loop.
const char* line = text;
const float line_height = GetTextLineHeight();
ImVec2 text_size(0, 0);
// Lines to skip (can't skip when logging text)
ImVec2 pos = text_pos;
if (!g.LogEnabled)
{
int lines_skippable = (int)((window->ClipRect.Min.y - text_pos.y) / line_height);
if (lines_skippable > 0)
{
int lines_skipped = 0;
while (line < text_end && lines_skipped < lines_skippable)
{
const char* line_end = (const char*)memchr(line, '\n', text_end - line);
if (!line_end)
line_end = text_end;
if ((flags & ImGuiTextFlags_NoWidthForLargeClippedText) == 0)
text_size.x = ImMax(text_size.x, CalcTextSize(line, line_end).x);
line = line_end + 1;
lines_skipped++;
}
pos.y += lines_skipped * line_height;
}
}
// Lines to render
if (line < text_end)
{
ImRect line_rect(pos, pos + ImVec2(FLT_MAX, line_height));
while (line < text_end)
{
if (IsClippedEx(line_rect, 0))
break;
const char* line_end = (const char*)memchr(line, '\n', text_end - line);
if (!line_end)
line_end = text_end;
text_size.x = ImMax(text_size.x, CalcTextSize(line, line_end).x);
RenderText(pos, line, line_end, false);
line = line_end + 1;
line_rect.Min.y += line_height;
line_rect.Max.y += line_height;
pos.y += line_height;
}
// Count remaining lines
int lines_skipped = 0;
while (line < text_end)
{
const char* line_end = (const char*)memchr(line, '\n', text_end - line);
if (!line_end)
line_end = text_end;
if ((flags & ImGuiTextFlags_NoWidthForLargeClippedText) == 0)
text_size.x = ImMax(text_size.x, CalcTextSize(line, line_end).x);
line = line_end + 1;
lines_skipped++;
}
pos.y += lines_skipped * line_height;
}
text_size.y = (pos - text_pos).y;
ImRect bb(text_pos, text_pos + text_size);
ItemSize(text_size, 0.0f);
ItemAdd(bb, 0);
IMGUI_HOVERED_DEBUG_BREAK(0, bb.Min, bb.Max);
}
}
void ImGui::TextUnformatted(const char* text, const char* text_end)
{
TextEx(text, text_end, ImGuiTextFlags_NoWidthForLargeClippedText);
}
void ImGui::Text(const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
TextV(fmt, args);
va_end(args);
}
void ImGui::TextV(const char* fmt, va_list args)
{
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return;
const char* text, *text_end;
ImFormatStringToTempBufferV(&text, &text_end, fmt, args);
TextEx(text, text_end, ImGuiTextFlags_NoWidthForLargeClippedText);
}
void ImGui::TextColored(const ImVec4& col, const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
TextColoredV(col, fmt, args);
va_end(args);
}
void ImGui::TextColoredV(const ImVec4& col, const char* fmt, va_list args)
{
PushStyleColor(ImGuiCol_Text, col);
TextV(fmt, args);
PopStyleColor();
}
void ImGui::TextDisabled(const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
TextDisabledV(fmt, args);
va_end(args);
}
void ImGui::TextDisabledV(const char* fmt, va_list args)
{
ImGuiContext& g = *GImGui;
PushStyleColor(ImGuiCol_Text, g.Style.Colors[ImGuiCol_TextDisabled]);
TextV(fmt, args);
PopStyleColor();
}
void ImGui::TextWrapped(const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
TextWrappedV(fmt, args);
va_end(args);
}
void ImGui::TextWrappedV(const char* fmt, va_list args)
{
ImGuiContext& g = *GImGui;
const bool need_backup = (g.CurrentWindow->DC.TextWrapPos < 0.0f); // Keep existing wrap position if one is already set
if (need_backup)
PushTextWrapPos(0.0f);
TextV(fmt, args);
if (need_backup)
PopTextWrapPos();
}
void ImGui::LabelText(const char* label, const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
LabelTextV(label, fmt, args);
va_end(args);
}
// Add a label+text combo aligned to other label+value widgets
void ImGui::LabelTextV(const char* label, const char* fmt, va_list args)
{
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return;
ImGuiContext& g = *GImGui;
const ImGuiStyle& style = g.Style;
const float w = CalcItemWidth();
const char* value_text_begin, *value_text_end;
ImFormatStringToTempBufferV(&value_text_begin, &value_text_end, fmt, args);
const ImVec2 value_size = CalcTextSize(value_text_begin, value_text_end, false);
const ImVec2 label_size = CalcTextSize(label, NULL, true);
const ImVec2 pos = window->DC.CursorPos;
const ImRect value_bb(pos, pos + ImVec2(w, value_size.y + style.FramePadding.y * 2));
const ImRect total_bb(pos, pos + ImVec2(w + (label_size.x > 0.0f ? style.ItemInnerSpacing.x + label_size.x : 0.0f), ImMax(value_size.y, label_size.y) + style.FramePadding.y * 2));
ItemSize(total_bb, style.FramePadding.y);
if (!ItemAdd(total_bb, 0))
return;
// Render
RenderTextClipped(value_bb.Min + style.FramePadding, value_bb.Max, value_text_begin, value_text_end, &value_size, ImVec2(0.0f, 0.0f));
if (label_size.x > 0.0f)
RenderText(ImVec2(value_bb.Max.x + style.ItemInnerSpacing.x, value_bb.Min.y + style.FramePadding.y), label);
}
void ImGui::BulletText(const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
BulletTextV(fmt, args);
va_end(args);
}
// Text with a little bullet aligned to the typical tree node.
void ImGui::BulletTextV(const char* fmt, va_list args)
{
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return;
ImGuiContext& g = *GImGui;
const ImGuiStyle& style = g.Style;
const char* text_begin, *text_end;
ImFormatStringToTempBufferV(&text_begin, &text_end, fmt, args);
const ImVec2 label_size = CalcTextSize(text_begin, text_end, false);
const ImVec2 total_size = ImVec2(g.FontSize + (label_size.x > 0.0f ? (label_size.x + style.FramePadding.x * 2) : 0.0f), label_size.y); // Empty text doesn't add padding
ImVec2 pos = window->DC.CursorPos;
pos.y += window->DC.CurrLineTextBaseOffset;
ItemSize(total_size, 0.0f);
const ImRect bb(pos, pos + total_size);
if (!ItemAdd(bb, 0))
return;
// Render
ImU32 text_col = GetColorU32(ImGuiCol_Text);
RenderBullet(window->DrawList, bb.Min + ImVec2(style.FramePadding.x + g.FontSize * 0.5f, g.FontSize * 0.5f), text_col);
RenderText(bb.Min + ImVec2(g.FontSize + style.FramePadding.x * 2, 0.0f), text_begin, text_end, false);
}
//-------------------------------------------------------------------------
// [SECTION] Widgets: Main
//-------------------------------------------------------------------------
// - ButtonBehavior() [Internal]
// - Button()
// - SmallButton()
// - InvisibleButton()
// - ArrowButton()
// - CloseButton() [Internal]
// - CollapseButton() [Internal]
// - GetWindowScrollbarID() [Internal]
// - GetWindowScrollbarRect() [Internal]
// - Scrollbar() [Internal]
// - ScrollbarEx() [Internal]
// - Image()
// - ImageButton()
// - Checkbox()
// - CheckboxFlagsT() [Internal]
// - CheckboxFlags()
// - RadioButton()
// - ProgressBar()
// - Bullet()
//-------------------------------------------------------------------------
// The ButtonBehavior() function is key to many interactions and used by many/most widgets.
// Because we handle so many cases (keyboard/gamepad navigation, drag and drop) and many specific behavior (via ImGuiButtonFlags_),
// this code is a little complex.
// By far the most common path is interacting with the Mouse using the default ImGuiButtonFlags_PressedOnClickRelease button behavior.
// See the series of events below and the corresponding state reported by dear imgui:
//------------------------------------------------------------------------------------------------------------------------------------------------
// with PressedOnClickRelease: return-value IsItemHovered() IsItemActive() IsItemActivated() IsItemDeactivated() IsItemClicked()
// Frame N+0 (mouse is outside bb) - - - - - -
// Frame N+1 (mouse moves inside bb) - true - - - -
// Frame N+2 (mouse button is down) - true true true - true
// Frame N+3 (mouse button is down) - true true - - -
// Frame N+4 (mouse moves outside bb) - - true - - -
// Frame N+5 (mouse moves inside bb) - true true - - -
// Frame N+6 (mouse button is released) true true - - true -
// Frame N+7 (mouse button is released) - true - - - -
// Frame N+8 (mouse moves outside bb) - - - - - -
//------------------------------------------------------------------------------------------------------------------------------------------------
// with PressedOnClick: return-value IsItemHovered() IsItemActive() IsItemActivated() IsItemDeactivated() IsItemClicked()
// Frame N+2 (mouse button is down) true true true true - true
// Frame N+3 (mouse button is down) - true true - - -
// Frame N+6 (mouse button is released) - true - - true -
// Frame N+7 (mouse button is released) - true - - - -
//------------------------------------------------------------------------------------------------------------------------------------------------
// with PressedOnRelease: return-value IsItemHovered() IsItemActive() IsItemActivated() IsItemDeactivated() IsItemClicked()
// Frame N+2 (mouse button is down) - true - - - true
// Frame N+3 (mouse button is down) - true - - - -
// Frame N+6 (mouse button is released) true true - - - -
// Frame N+7 (mouse button is released) - true - - - -
//------------------------------------------------------------------------------------------------------------------------------------------------
// with PressedOnDoubleClick: return-value IsItemHovered() IsItemActive() IsItemActivated() IsItemDeactivated() IsItemClicked()
// Frame N+0 (mouse button is down) - true - - - true
// Frame N+1 (mouse button is down) - true - - - -
// Frame N+2 (mouse button is released) - true - - - -
// Frame N+3 (mouse button is released) - true - - - -
// Frame N+4 (mouse button is down) true true true true - true
// Frame N+5 (mouse button is down) - true true - - -
// Frame N+6 (mouse button is released) - true - - true -
// Frame N+7 (mouse button is released) - true - - - -
//------------------------------------------------------------------------------------------------------------------------------------------------
// Note that some combinations are supported,
// - PressedOnDragDropHold can generally be associated with any flag.
// - PressedOnDoubleClick can be associated by PressedOnClickRelease/PressedOnRelease, in which case the second release event won't be reported.
//------------------------------------------------------------------------------------------------------------------------------------------------
// The behavior of the return-value changes when ImGuiButtonFlags_Repeat is set:
// Repeat+ Repeat+ Repeat+ Repeat+
// PressedOnClickRelease PressedOnClick PressedOnRelease PressedOnDoubleClick
//-------------------------------------------------------------------------------------------------------------------------------------------------
// Frame N+0 (mouse button is down) - true - true
// ... - - - -
// Frame N + RepeatDelay true true - true
// ... - - - -
// Frame N + RepeatDelay + RepeatRate*N true true - true
//-------------------------------------------------------------------------------------------------------------------------------------------------
bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool* out_held, ImGuiButtonFlags flags)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = GetCurrentWindow();
// Default only reacts to left mouse button
if ((flags & ImGuiButtonFlags_MouseButtonMask_) == 0)
flags |= ImGuiButtonFlags_MouseButtonDefault_;
// Default behavior requires click + release inside bounding box
if ((flags & ImGuiButtonFlags_PressedOnMask_) == 0)
flags |= ImGuiButtonFlags_PressedOnDefault_;
ImGuiWindow* backup_hovered_window = g.HoveredWindow;
const bool flatten_hovered_children = (flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredWindow && g.HoveredWindow->RootWindow == window;
if (flatten_hovered_children)
g.HoveredWindow = window;
#ifdef IMGUI_ENABLE_TEST_ENGINE
// Alternate registration spot, for when caller didn't use ItemAdd()
if (id != 0 && g.LastItemData.ID != id)
IMGUI_TEST_ENGINE_ITEM_ADD(id, bb, NULL);
#endif
bool pressed = false;
bool hovered = ItemHoverable(bb, id);
// Drag source doesn't report as hovered
if (hovered && g.DragDropActive && g.DragDropPayload.SourceId == id && !(g.DragDropSourceFlags & ImGuiDragDropFlags_SourceNoDisableHover))
hovered = false;
// Special mode for Drag and Drop where holding button pressed for a long time while dragging another item triggers the button
if (g.DragDropActive && (flags & ImGuiButtonFlags_PressedOnDragDropHold) && !(g.DragDropSourceFlags & ImGuiDragDropFlags_SourceNoHoldToOpenOthers))
if (IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem))
{
hovered = true;
SetHoveredID(id);
if (g.HoveredIdTimer - g.IO.DeltaTime <= DRAGDROP_HOLD_TO_OPEN_TIMER && g.HoveredIdTimer >= DRAGDROP_HOLD_TO_OPEN_TIMER)
{
pressed = true;
g.DragDropHoldJustPressedId = id;
FocusWindow(window);
}
}
if (flatten_hovered_children)
g.HoveredWindow = backup_hovered_window;
// AllowOverlap mode (rarely used) requires previous frame HoveredId to be null or to match. This allows using patterns where a later submitted widget overlaps a previous one.
if (hovered && (flags & ImGuiButtonFlags_AllowItemOverlap) && (g.HoveredIdPreviousFrame != id && g.HoveredIdPreviousFrame != 0))
hovered = false;
// Mouse handling
const ImGuiID test_owner_id = (flags & ImGuiButtonFlags_NoTestKeyOwner) ? ImGuiKeyOwner_Any : id;
if (hovered)
{
// Poll mouse buttons
// - 'mouse_button_clicked' is generally carried into ActiveIdMouseButton when setting ActiveId.
// - Technically we only need some values in one code path, but since this is gated by hovered test this is fine.
int mouse_button_clicked = -1;
int mouse_button_released = -1;
for (int button = 0; button < 3; button++)
if (flags & (ImGuiButtonFlags_MouseButtonLeft << button)) // Handle ImGuiButtonFlags_MouseButtonRight and ImGuiButtonFlags_MouseButtonMiddle here.
{
if (IsMouseClicked(button, test_owner_id) && mouse_button_clicked == -1) { mouse_button_clicked = button; }
if (IsMouseReleased(button, test_owner_id) && mouse_button_released == -1) { mouse_button_released = button; }
}
// Process initial action
if (!(flags & ImGuiButtonFlags_NoKeyModifiers) || (!g.IO.KeyCtrl && !g.IO.KeyShift && !g.IO.KeyAlt))
{
if (mouse_button_clicked != -1 && g.ActiveId != id)
{
if (!(flags & ImGuiButtonFlags_NoSetKeyOwner))
SetKeyOwner(MouseButtonToKey(mouse_button_clicked), id);
if (flags & (ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnClickReleaseAnywhere))
{
SetActiveID(id, window);
g.ActiveIdMouseButton = mouse_button_clicked;
if (!(flags & ImGuiButtonFlags_NoNavFocus))
SetFocusID(id, window);
FocusWindow(window);
}
if ((flags & ImGuiButtonFlags_PressedOnClick) || ((flags & ImGuiButtonFlags_PressedOnDoubleClick) && g.IO.MouseClickedCount[mouse_button_clicked] == 2))
{
pressed = true;
if (flags & ImGuiButtonFlags_NoHoldingActiveId)
ClearActiveID();
else
SetActiveID(id, window); // Hold on ID
if (!(flags & ImGuiButtonFlags_NoNavFocus))
SetFocusID(id, window);
g.ActiveIdMouseButton = mouse_button_clicked;
FocusWindow(window);
}
}
if (flags & ImGuiButtonFlags_PressedOnRelease)
{
if (mouse_button_released != -1)
{
const bool has_repeated_at_least_once = (flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[mouse_button_released] >= g.IO.KeyRepeatDelay; // Repeat mode trumps on release behavior
if (!has_repeated_at_least_once)
pressed = true;
if (!(flags & ImGuiButtonFlags_NoNavFocus))
SetFocusID(id, window);
ClearActiveID();
}
}
// 'Repeat' mode acts when held regardless of _PressedOn flags (see table above).
// Relies on repeat logic of IsMouseClicked() but we may as well do it ourselves if we end up exposing finer RepeatDelay/RepeatRate settings.
if (g.ActiveId == id && (flags & ImGuiButtonFlags_Repeat))
if (g.IO.MouseDownDuration[g.ActiveIdMouseButton] > 0.0f && IsMouseClicked(g.ActiveIdMouseButton, test_owner_id, ImGuiInputFlags_Repeat))
pressed = true;
}
if (pressed)
g.NavDisableHighlight = true;
}
// Gamepad/Keyboard navigation
// We report navigated item as hovered but we don't set g.HoveredId to not interfere with mouse.
if (g.NavId == id && !g.NavDisableHighlight && g.NavDisableMouseHover && (g.ActiveId == 0 || g.ActiveId == id || g.ActiveId == window->MoveId))
if (!(flags & ImGuiButtonFlags_NoHoveredOnFocus))
hovered = true;
if (g.NavActivateDownId == id)
{
bool nav_activated_by_code = (g.NavActivateId == id);
bool nav_activated_by_inputs = (g.NavActivatePressedId == id);
if (!nav_activated_by_inputs && (flags & ImGuiButtonFlags_Repeat))
{
// Avoid pressing multiple keys from triggering excessive amount of repeat events
const ImGuiKeyData* key1 = GetKeyData(ImGuiKey_Space);
const ImGuiKeyData* key2 = GetKeyData(ImGuiKey_Enter);
const ImGuiKeyData* key3 = GetKeyData(ImGuiKey_NavGamepadActivate);
const float t1 = ImMax(ImMax(key1->DownDuration, key2->DownDuration), key3->DownDuration);
nav_activated_by_inputs = CalcTypematicRepeatAmount(t1 - g.IO.DeltaTime, t1, g.IO.KeyRepeatDelay, g.IO.KeyRepeatRate) > 0;
}
if (nav_activated_by_code || nav_activated_by_inputs)
{
// Set active id so it can be queried by user via IsItemActive(), equivalent of holding the mouse button.
pressed = true;
SetActiveID(id, window);
g.ActiveIdSource = ImGuiInputSource_Nav;
if (!(flags & ImGuiButtonFlags_NoNavFocus))
SetFocusID(id, window);
}
}
// Process while held
bool held = false;
if (g.ActiveId == id)
{
if (g.ActiveIdSource == ImGuiInputSource_Mouse)
{
if (g.ActiveIdIsJustActivated)
g.ActiveIdClickOffset = g.IO.MousePos - bb.Min;
const int mouse_button = g.ActiveIdMouseButton;
if (IsMouseDown(mouse_button, test_owner_id))
{
held = true;
}
else
{
bool release_in = hovered && (flags & ImGuiButtonFlags_PressedOnClickRelease) != 0;
bool release_anywhere = (flags & ImGuiButtonFlags_PressedOnClickReleaseAnywhere) != 0;
if ((release_in || release_anywhere) && !g.DragDropActive)
{
// Report as pressed when releasing the mouse (this is the most common path)
bool is_double_click_release = (flags & ImGuiButtonFlags_PressedOnDoubleClick) && g.IO.MouseReleased[mouse_button] && g.IO.MouseClickedLastCount[mouse_button] == 2;
bool is_repeating_already = (flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[mouse_button] >= g.IO.KeyRepeatDelay; // Repeat mode trumps <on release>
bool is_button_avail_or_owned = TestKeyOwner(MouseButtonToKey(mouse_button), test_owner_id);
if (!is_double_click_release && !is_repeating_already && is_button_avail_or_owned)
pressed = true;
}
ClearActiveID();
}
if (!(flags & ImGuiButtonFlags_NoNavFocus))
g.NavDisableHighlight = true;
}
else if (g.ActiveIdSource == ImGuiInputSource_Nav)
{
// When activated using Nav, we hold on the ActiveID until activation button is released
if (g.NavActivateDownId != id)
ClearActiveID();
}
if (pressed)
g.ActiveIdHasBeenPressedBefore = true;
}
if (out_hovered) *out_hovered = hovered;
if (out_held) *out_held = held;
return pressed;
}
bool ImGui::ButtonEx(const char* label, const ImVec2& size_arg, ImGuiButtonFlags flags)
{
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return false;
ImGuiContext& g = *GImGui;
const ImGuiStyle& style = g.Style;
const ImGuiID id = window->GetID(label);
const ImVec2 label_size = CalcTextSize(label, NULL, true);
ImVec2 pos = window->DC.CursorPos;
if ((flags & ImGuiButtonFlags_AlignTextBaseLine) && style.FramePadding.y < window->DC.CurrLineTextBaseOffset) // Try to vertically align buttons that are smaller/have no padding so that text baseline matches (bit hacky, since it shouldn't be a flag)
pos.y += window->DC.CurrLineTextBaseOffset - style.FramePadding.y;
ImVec2 size = CalcItemSize(size_arg, label_size.x + style.FramePadding.x * 2.0f, label_size.y + style.FramePadding.y * 2.0f);
const ImRect bb(pos, pos + size);
ItemSize(size, style.FramePadding.y);
if (!ItemAdd(bb, id))
return false;
if (g.LastItemData.InFlags & ImGuiItemFlags_ButtonRepeat)
flags |= ImGuiButtonFlags_Repeat;
bool hovered, held;
bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);
// Render
const ImU32 col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
RenderNavHighlight(bb, id);
RenderFrame(bb.Min, bb.Max, col, true, style.FrameRounding);
if (g.LogEnabled)
LogSetNextTextDecoration("[", "]");
RenderTextClipped(bb.Min + style.FramePadding, bb.Max - style.FramePadding, label, NULL, &label_size, style.ButtonTextAlign, &bb);
// Automatically close popups
//if (pressed && !(flags & ImGuiButtonFlags_DontClosePopups) && (window->Flags & ImGuiWindowFlags_Popup))
// CloseCurrentPopup();
IMGUI_HOVERED_DEBUG_BREAK(label, bb.Min, bb.Max);
IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags);
return pressed;
}
bool ImGui::Button(const char* label, const ImVec2& size_arg)
{
return ButtonEx(label, size_arg, ImGuiButtonFlags_None);
}
// Small buttons fits within text without additional vertical spacing.
bool ImGui::SmallButton(const char* label)
{
ImGuiContext& g = *GImGui;
float backup_padding_y = g.Style.FramePadding.y;
g.Style.FramePadding.y = 0.0f;
bool pressed = ButtonEx(label, ImVec2(0, 0), ImGuiButtonFlags_AlignTextBaseLine);
g.Style.FramePadding.y = backup_padding_y;
return pressed;
}
// Tip: use ImGui::PushID()/PopID() to push indices or pointers in the ID stack.
// Then you can keep 'str_id' empty or the same for all your buttons (instead of creating a string based on a non-string id)
bool ImGui::InvisibleButton(const char* str_id, const ImVec2& size_arg, ImGuiButtonFlags flags)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return false;
// Cannot use zero-size for InvisibleButton(). Unlike Button() there is not way to fallback using the label size.
IM_ASSERT(size_arg.x != 0.0f && size_arg.y != 0.0f);
const ImGuiID id = window->GetID(str_id);
ImVec2 size = CalcItemSize(size_arg, 0.0f, 0.0f);
const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
ItemSize(size);
if (!ItemAdd(bb, id))
return false;
bool hovered, held;
bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);
IMGUI_HOVERED_DEBUG_BREAK(str_id, bb.Min, bb.Max);
IMGUI_TEST_ENGINE_ITEM_INFO(id, str_id, g.LastItemData.StatusFlags);
return pressed;
}
bool ImGui::ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size, ImGuiButtonFlags flags)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = GetCurrentWindow();
if (window->SkipItems)
return false;
const ImGuiID id = window->GetID(str_id);
const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
const float default_size = GetFrameHeight();
ItemSize(size, (size.y >= default_size) ? g.Style.FramePadding.y : -1.0f);
if (!ItemAdd(bb, id))
return false;
if (g.LastItemData.InFlags & ImGuiItemFlags_ButtonRepeat)
flags |= ImGuiButtonFlags_Repeat;
bool hovered, held;
bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);
// Render
const ImU32 bg_col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
const ImU32 text_col = GetColorU32(ImGuiCol_Text);
RenderNavHighlight(bb, id);
RenderFrame(bb.Min, bb.Max, bg_col, true, g.Style.FrameRounding);
RenderArrow(window->DrawList, bb.Min + ImVec2(ImMax(0.0f, (size.x - g.FontSize) * 0.5f), ImMax(0.0f, (size.y - g.FontSize) * 0.5f)), text_col, dir);
IMGUI_TEST_ENGINE_ITEM_INFO(id, str_id, g.LastItemData.StatusFlags);
return pressed;
}
bool ImGui::ArrowButton(const char* str_id, ImGuiDir dir)
{
float sz = GetFrameHeight();
return ArrowButtonEx(str_id, dir, ImVec2(sz, sz), ImGuiButtonFlags_None);
}
// Button to close a window
bool ImGui::CloseButton(ImGuiID id, const ImVec2& pos)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
// Tweak 1: Shrink hit-testing area if button covers an abnormally large proportion of the visible region. That's in order to facilitate moving the window away. (#3825)
// This may better be applied as a general hit-rect reduction mechanism for all widgets to ensure the area to move window is always accessible?
const ImRect bb(pos, pos + ImVec2(g.FontSize, g.FontSize) + g.Style.FramePadding * 2.0f);
ImRect bb_interact = bb;
const float area_to_visible_ratio = window->OuterRectClipped.GetArea() / bb.GetArea();
if (area_to_visible_ratio < 1.5f)
bb_interact.Expand(ImFloor(bb_interact.GetSize() * -0.25f));
// Tweak 2: We intentionally allow interaction when clipped so that a mechanical Alt,Right,Activate sequence can always close a window.
// (this isn't the regular behavior of buttons, but it doesn't affect the user much because navigation tends to keep items visible).
bool is_clipped = !ItemAdd(bb_interact, id);
bool hovered, held;
bool pressed = ButtonBehavior(bb_interact, id, &hovered, &held);
if (is_clipped)
return pressed;
// Render
// FIXME: Clarify this mess
ImU32 col = GetColorU32(held ? ImGuiCol_ButtonActive : ImGuiCol_ButtonHovered);
ImVec2 center = bb.GetCenter();
if (hovered)
window->DrawList->AddCircleFilled(center, ImMax(2.0f, g.FontSize * 0.5f + 1.0f), col, 12);
float cross_extent = g.FontSize * 0.5f * 0.7071f - 1.0f;
ImU32 cross_col = GetColorU32(ImGuiCol_Text);
center -= ImVec2(0.5f, 0.5f);
window->DrawList->AddLine(center + ImVec2(+cross_extent, +cross_extent), center + ImVec2(-cross_extent, -cross_extent), cross_col, 1.0f);
window->DrawList->AddLine(center + ImVec2(+cross_extent, -cross_extent), center + ImVec2(-cross_extent, +cross_extent), cross_col, 1.0f);
return pressed;
}
bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
ImRect bb(pos, pos + ImVec2(g.FontSize, g.FontSize) + g.Style.FramePadding * 2.0f);
ItemAdd(bb, id);
bool hovered, held;
bool pressed = ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_None);
// Render
ImU32 bg_col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
ImU32 text_col = GetColorU32(ImGuiCol_Text);
if (hovered || held)
window->DrawList->AddCircleFilled(bb.GetCenter()/*+ ImVec2(0.0f, -0.5f)*/, g.FontSize * 0.5f + 1.0f, bg_col, 12);
RenderArrow(window->DrawList, bb.Min + g.Style.FramePadding, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);
// Switch to moving the window after mouse is moved beyond the initial drag threshold
if (IsItemActive() && IsMouseDragging(0))
StartMouseMovingWindow(window);
return pressed;
}
ImGuiID ImGui::GetWindowScrollbarID(ImGuiWindow* window, ImGuiAxis axis)
{
return window->GetID(axis == ImGuiAxis_X ? "#SCROLLX" : "#SCROLLY");
}
// Return scrollbar rectangle, must only be called for corresponding axis if window->ScrollbarX/Y is set.
ImRect ImGui::GetWindowScrollbarRect(ImGuiWindow* window, ImGuiAxis axis)
{
const ImRect outer_rect = window->Rect();
const ImRect inner_rect = window->InnerRect;
const float border_size = window->WindowBorderSize;
const float scrollbar_size = window->ScrollbarSizes[axis ^ 1]; // (ScrollbarSizes.x = width of Y scrollbar; ScrollbarSizes.y = height of X scrollbar)
IM_ASSERT(scrollbar_size > 0.0f);
if (axis == ImGuiAxis_X)
return ImRect(inner_rect.Min.x, ImMax(outer_rect.Min.y, outer_rect.Max.y - border_size - scrollbar_size), inner_rect.Max.x, outer_rect.Max.y);
else
return ImRect(ImMax(outer_rect.Min.x, outer_rect.Max.x - border_size - scrollbar_size), inner_rect.Min.y, outer_rect.Max.x, inner_rect.Max.y);
}
void ImGui::Scrollbar(ImGuiAxis axis)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
const ImGuiID id = GetWindowScrollbarID(window, axis);
// Calculate scrollbar bounding box
ImRect bb = GetWindowScrollbarRect(window, axis);
ImDrawFlags rounding_corners = ImDrawFlags_RoundCornersNone;
if (axis == ImGuiAxis_X)
{
rounding_corners |= ImDrawFlags_RoundCornersBottomLeft;
if (!window->ScrollbarY)
rounding_corners |= ImDrawFlags_RoundCornersBottomRight;
}
else
{
if ((window->Flags & ImGuiWindowFlags_NoTitleBar) && !(window->Flags & ImGuiWindowFlags_MenuBar))
rounding_corners |= ImDrawFlags_RoundCornersTopRight;
if (!window->ScrollbarX)
rounding_corners |= ImDrawFlags_RoundCornersBottomRight;
}
float size_avail = window->InnerRect.Max[axis] - window->InnerRect.Min[axis];
float size_contents = window->ContentSize[axis] + window->WindowPadding[axis] * 2.0f;
ImS64 scroll = (ImS64)window->Scroll[axis];
ScrollbarEx(bb, id, axis, &scroll, (ImS64)size_avail, (ImS64)size_contents, rounding_corners);
window->Scroll[axis] = (float)scroll;
}
// Vertical/Horizontal scrollbar
// The entire piece of code below is rather confusing because:
// - We handle absolute seeking (when first clicking outside the grab) and relative manipulation (afterward or when clicking inside the grab)
// - We store values as normalized ratio and in a form that allows the window content to change while we are holding on a scrollbar
// - We handle both horizontal and vertical scrollbars, which makes the terminology not ideal.
// Still, the code should probably be made simpler..
bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, ImS64* p_scroll_v, ImS64 size_avail_v, ImS64 size_contents_v, ImDrawFlags flags)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
if (window->SkipItems)
return false;
const float bb_frame_width = bb_frame.GetWidth();
const float bb_frame_height = bb_frame.GetHeight();
if (bb_frame_width <= 0.0f || bb_frame_height <= 0.0f)
return false;
// When we are too small, start hiding and disabling the grab (this reduce visual noise on very small window and facilitate using the window resize grab)
float alpha = 1.0f;
if ((axis == ImGuiAxis_Y) && bb_frame_height < g.FontSize + g.Style.FramePadding.y * 2.0f)
alpha = ImSaturate((bb_frame_height - g.FontSize) / (g.Style.FramePadding.y * 2.0f));
if (alpha <= 0.0f)
return false;
const ImGuiStyle& style = g.Style;
const bool allow_interaction = (alpha >= 1.0f);
ImRect bb = bb_frame;
bb.Expand(ImVec2(-ImClamp(IM_FLOOR((bb_frame_width - 2.0f) * 0.5f), 0.0f, 3.0f), -ImClamp(IM_FLOOR((bb_frame_height - 2.0f) * 0.5f), 0.0f, 3.0f)));
// V denote the main, longer axis of the scrollbar (= height for a vertical scrollbar)
const float scrollbar_size_v = (axis == ImGuiAxis_X) ? bb.GetWidth() : bb.GetHeight();
// Calculate the height of our grabbable box. It generally represent the amount visible (vs the total scrollable amount)
// But we maintain a minimum size in pixel to allow for the user to still aim inside.
IM_ASSERT(ImMax(size_contents_v, size_avail_v) > 0.0f); // Adding this assert to check if the ImMax(XXX,1.0f) is still needed. PLEASE CONTACT ME if this triggers.
const ImS64 win_size_v = ImMax(ImMax(size_contents_v, size_avail_v), (ImS64)1);
const float grab_h_pixels = ImClamp(scrollbar_size_v * ((float)size_avail_v / (float)win_size_v), style.GrabMinSize, scrollbar_size_v);
const float grab_h_norm = grab_h_pixels / scrollbar_size_v;
// Handle input right away. None of the code of Begin() is relying on scrolling position before calling Scrollbar().
bool held = false;
bool hovered = false;
ItemAdd(bb_frame, id, NULL, ImGuiItemFlags_NoNav);
ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_NoNavFocus);
const ImS64 scroll_max = ImMax((ImS64)1, size_contents_v - size_avail_v);
float scroll_ratio = ImSaturate((float)*p_scroll_v / (float)scroll_max);
float grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v; // Grab position in normalized space
if (held && allow_interaction && grab_h_norm < 1.0f)
{
const float scrollbar_pos_v = bb.Min[axis];
const float mouse_pos_v = g.IO.MousePos[axis];
// Click position in scrollbar normalized space (0.0f->1.0f)
const float clicked_v_norm = ImSaturate((mouse_pos_v - scrollbar_pos_v) / scrollbar_size_v);
SetHoveredID(id);
bool seek_absolute = false;
if (g.ActiveIdIsJustActivated)
{
// On initial click calculate the distance between mouse and the center of the grab
seek_absolute = (clicked_v_norm < grab_v_norm || clicked_v_norm > grab_v_norm + grab_h_norm);
if (seek_absolute)
g.ScrollbarClickDeltaToGrabCenter = 0.0f;
else
g.ScrollbarClickDeltaToGrabCenter = clicked_v_norm - grab_v_norm - grab_h_norm * 0.5f;
}
// Apply scroll (p_scroll_v will generally point on one member of window->Scroll)
// It is ok to modify Scroll here because we are being called in Begin() after the calculation of ContentSize and before setting up our starting position
const float scroll_v_norm = ImSaturate((clicked_v_norm - g.ScrollbarClickDeltaToGrabCenter - grab_h_norm * 0.5f) / (1.0f - grab_h_norm));
*p_scroll_v = (ImS64)(scroll_v_norm * scroll_max);
// Update values for rendering
scroll_ratio = ImSaturate((float)*p_scroll_v / (float)scroll_max);
grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v;
// Update distance to grab now that we have seeked and saturated
if (seek_absolute)
g.ScrollbarClickDeltaToGrabCenter = clicked_v_norm - grab_v_norm - grab_h_norm * 0.5f;
}
// Render