1// [DEAR IMGUI]
2// This is a slightly modified version of stb_textedit.h 1.13.
3// Those changes would need to be pushed into nothings/stb:
4// - Fix in stb_textedit_discard_redo (see https://github.com/nothings/stb/issues/321)
5// Grep for [DEAR IMGUI] to find the changes.
6
7// stb_textedit.h - v1.13 - public domain - Sean Barrett
8// Development of this library was sponsored by RAD Game Tools
9//
10// This C header file implements the guts of a multi-line text-editing
11// widget; you implement display, word-wrapping, and low-level string
12// insertion/deletion, and stb_textedit will map user inputs into
13// insertions & deletions, plus updates to the cursor position,
14// selection state, and undo state.
15//
16// It is intended for use in games and other systems that need to build
17// their own custom widgets and which do not have heavy text-editing
18// requirements (this library is not recommended for use for editing large
19// texts, as its performance does not scale and it has limited undo).
20//
21// Non-trivial behaviors are modelled after Windows text controls.
22//
23//
24// LICENSE
25//
26// See end of file for license information.
27//
28//
29// DEPENDENCIES
30//
31// Uses the C runtime function 'memmove', which you can override
32// by defining STB_TEXTEDIT_memmove before the implementation.
33// Uses no other functions. Performs no runtime allocations.
34//
35//
36// VERSION HISTORY
37//
38// 1.13 (2019-02-07) fix bug in undo size management
39// 1.12 (2018-01-29) user can change STB_TEXTEDIT_KEYTYPE, fix redo to avoid crash
40// 1.11 (2017-03-03) fix HOME on last line, dragging off single-line textfield
41// 1.10 (2016-10-25) supress warnings about casting away const with -Wcast-qual
42// 1.9 (2016-08-27) customizable move-by-word
43// 1.8 (2016-04-02) better keyboard handling when mouse button is down
44// 1.7 (2015-09-13) change y range handling in case baseline is non-0
45// 1.6 (2015-04-15) allow STB_TEXTEDIT_memmove
46// 1.5 (2014-09-10) add support for secondary keys for OS X
47// 1.4 (2014-08-17) fix signed/unsigned warnings
48// 1.3 (2014-06-19) fix mouse clicking to round to nearest char boundary
49// 1.2 (2014-05-27) fix some RAD types that had crept into the new code
50// 1.1 (2013-12-15) move-by-word (requires STB_TEXTEDIT_IS_SPACE )
51// 1.0 (2012-07-26) improve documentation, initial public release
52// 0.3 (2012-02-24) bugfixes, single-line mode; insert mode
53// 0.2 (2011-11-28) fixes to undo/redo
54// 0.1 (2010-07-08) initial version
55//
56// ADDITIONAL CONTRIBUTORS
57//
58// Ulf Winklemann: move-by-word in 1.1
59// Fabian Giesen: secondary key inputs in 1.5
60// Martins Mozeiko: STB_TEXTEDIT_memmove in 1.6
61//
62// Bugfixes:
63// Scott Graham
64// Daniel Keller
65// Omar Cornut
66// Dan Thompson
67//
68// USAGE
69//
70// This file behaves differently depending on what symbols you define
71// before including it.
72//
73//
74// Header-file mode:
75//
76// If you do not define STB_TEXTEDIT_IMPLEMENTATION before including this,
77// it will operate in "header file" mode. In this mode, it declares a
78// single public symbol, STB_TexteditState, which encapsulates the current
79// state of a text widget (except for the string, which you will store
80// separately).
81//
82// To compile in this mode, you must define STB_TEXTEDIT_CHARTYPE to a
83// primitive type that defines a single character (e.g. char, wchar_t, etc).
84//
85// To save space or increase undo-ability, you can optionally define the
86// following things that are used by the undo system:
87//
88// STB_TEXTEDIT_POSITIONTYPE small int type encoding a valid cursor position
89// STB_TEXTEDIT_UNDOSTATECOUNT the number of undo states to allow
90// STB_TEXTEDIT_UNDOCHARCOUNT the number of characters to store in the undo buffer
91//
92// If you don't define these, they are set to permissive types and
93// moderate sizes. The undo system does no memory allocations, so
94// it grows STB_TexteditState by the worst-case storage which is (in bytes):
95//
96// [4 + 3 * sizeof(STB_TEXTEDIT_POSITIONTYPE)] * STB_TEXTEDIT_UNDOSTATE_COUNT
97// + sizeof(STB_TEXTEDIT_CHARTYPE) * STB_TEXTEDIT_UNDOCHAR_COUNT
98//
99//
100// Implementation mode:
101//
102// If you define STB_TEXTEDIT_IMPLEMENTATION before including this, it
103// will compile the implementation of the text edit widget, depending
104// on a large number of symbols which must be defined before the include.
105//
106// The implementation is defined only as static functions. You will then
107// need to provide your own APIs in the same file which will access the
108// static functions.
109//
110// The basic concept is that you provide a "string" object which
111// behaves like an array of characters. stb_textedit uses indices to
112// refer to positions in the string, implicitly representing positions
113// in the displayed textedit. This is true for both plain text and
114// rich text; even with rich text stb_truetype interacts with your
115// code as if there was an array of all the displayed characters.
116//
117// Symbols that must be the same in header-file and implementation mode:
118//
119// STB_TEXTEDIT_CHARTYPE the character type
120// STB_TEXTEDIT_POSITIONTYPE small type that is a valid cursor position
121// STB_TEXTEDIT_UNDOSTATECOUNT the number of undo states to allow
122// STB_TEXTEDIT_UNDOCHARCOUNT the number of characters to store in the undo buffer
123//
124// Symbols you must define for implementation mode:
125//
126// STB_TEXTEDIT_STRING the type of object representing a string being edited,
127// typically this is a wrapper object with other data you need
128//
129// STB_TEXTEDIT_STRINGLEN(obj) the length of the string (ideally O(1))
130// STB_TEXTEDIT_LAYOUTROW(&r,obj,n) returns the results of laying out a line of characters
131// starting from character #n (see discussion below)
132// STB_TEXTEDIT_GETWIDTH(obj,n,i) returns the pixel delta from the xpos of the i'th character
133// to the xpos of the i+1'th char for a line of characters
134// starting at character #n (i.e. accounts for kerning
135// with previous char)
136// STB_TEXTEDIT_KEYTOTEXT(k) maps a keyboard input to an insertable character
137// (return type is int, -1 means not valid to insert)
138// STB_TEXTEDIT_GETCHAR(obj,i) returns the i'th character of obj, 0-based
139// STB_TEXTEDIT_NEWLINE the character returned by _GETCHAR() we recognize
140// as manually wordwrapping for end-of-line positioning
141//
142// STB_TEXTEDIT_DELETECHARS(obj,i,n) delete n characters starting at i
143// STB_TEXTEDIT_INSERTCHARS(obj,i,c*,n) insert n characters at i (pointed to by STB_TEXTEDIT_CHARTYPE*)
144//
145// STB_TEXTEDIT_K_SHIFT a power of two that is or'd in to a keyboard input to represent the shift key
146//
147// STB_TEXTEDIT_K_LEFT keyboard input to move cursor left
148// STB_TEXTEDIT_K_RIGHT keyboard input to move cursor right
149// STB_TEXTEDIT_K_UP keyboard input to move cursor up
150// STB_TEXTEDIT_K_DOWN keyboard input to move cursor down
151// STB_TEXTEDIT_K_PGUP keyboard input to move cursor up a page
152// STB_TEXTEDIT_K_PGDOWN keyboard input to move cursor down a page
153// STB_TEXTEDIT_K_LINESTART keyboard input to move cursor to start of line // e.g. HOME
154// STB_TEXTEDIT_K_LINEEND keyboard input to move cursor to end of line // e.g. END
155// STB_TEXTEDIT_K_TEXTSTART keyboard input to move cursor to start of text // e.g. ctrl-HOME
156// STB_TEXTEDIT_K_TEXTEND keyboard input to move cursor to end of text // e.g. ctrl-END
157// STB_TEXTEDIT_K_DELETE keyboard input to delete selection or character under cursor
158// STB_TEXTEDIT_K_BACKSPACE keyboard input to delete selection or character left of cursor
159// STB_TEXTEDIT_K_UNDO keyboard input to perform undo
160// STB_TEXTEDIT_K_REDO keyboard input to perform redo
161//
162// Optional:
163// STB_TEXTEDIT_K_INSERT keyboard input to toggle insert mode
164// STB_TEXTEDIT_IS_SPACE(ch) true if character is whitespace (e.g. 'isspace'),
165// required for default WORDLEFT/WORDRIGHT handlers
166// STB_TEXTEDIT_MOVEWORDLEFT(obj,i) custom handler for WORDLEFT, returns index to move cursor to
167// STB_TEXTEDIT_MOVEWORDRIGHT(obj,i) custom handler for WORDRIGHT, returns index to move cursor to
168// STB_TEXTEDIT_K_WORDLEFT keyboard input to move cursor left one word // e.g. ctrl-LEFT
169// STB_TEXTEDIT_K_WORDRIGHT keyboard input to move cursor right one word // e.g. ctrl-RIGHT
170// STB_TEXTEDIT_K_LINESTART2 secondary keyboard input to move cursor to start of line
171// STB_TEXTEDIT_K_LINEEND2 secondary keyboard input to move cursor to end of line
172// STB_TEXTEDIT_K_TEXTSTART2 secondary keyboard input to move cursor to start of text
173// STB_TEXTEDIT_K_TEXTEND2 secondary keyboard input to move cursor to end of text
174//
175// Keyboard input must be encoded as a single integer value; e.g. a character code
176// and some bitflags that represent shift states. to simplify the interface, SHIFT must
177// be a bitflag, so we can test the shifted state of cursor movements to allow selection,
178// i.e. (STB_TEXTEDIT_K_RIGHT|STB_TEXTEDIT_K_SHIFT) should be shifted right-arrow.
179//
180// You can encode other things, such as CONTROL or ALT, in additional bits, and
181// then test for their presence in e.g. STB_TEXTEDIT_K_WORDLEFT. For example,
182// my Windows implementations add an additional CONTROL bit, and an additional KEYDOWN
183// bit. Then all of the STB_TEXTEDIT_K_ values bitwise-or in the KEYDOWN bit,
184// and I pass both WM_KEYDOWN and WM_CHAR events to the "key" function in the
185// API below. The control keys will only match WM_KEYDOWN events because of the
186// keydown bit I add, and STB_TEXTEDIT_KEYTOTEXT only tests for the KEYDOWN
187// bit so it only decodes WM_CHAR events.
188//
189// STB_TEXTEDIT_LAYOUTROW returns information about the shape of one displayed
190// row of characters assuming they start on the i'th character--the width and
191// the height and the number of characters consumed. This allows this library
192// to traverse the entire layout incrementally. You need to compute word-wrapping
193// here.
194//
195// Each textfield keeps its own insert mode state, which is not how normal
196// applications work. To keep an app-wide insert mode, update/copy the
197// "insert_mode" field of STB_TexteditState before/after calling API functions.
198//
199// API
200//
201// void stb_textedit_initialize_state(STB_TexteditState *state, int is_single_line)
202//
203// void stb_textedit_click(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
204// void stb_textedit_drag(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
205// int stb_textedit_cut(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
206// int stb_textedit_paste(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_CHARTYPE *text, int len)
207// void stb_textedit_key(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXEDIT_KEYTYPE key)
208//
209// Each of these functions potentially updates the string and updates the
210// state.
211//
212// initialize_state:
213// set the textedit state to a known good default state when initially
214// constructing the textedit.
215//
216// click:
217// call this with the mouse x,y on a mouse down; it will update the cursor
218// and reset the selection start/end to the cursor point. the x,y must
219// be relative to the text widget, with (0,0) being the top left.
220//
221// drag:
222// call this with the mouse x,y on a mouse drag/up; it will update the
223// cursor and the selection end point
224//
225// cut:
226// call this to delete the current selection; returns true if there was
227// one. you should FIRST copy the current selection to the system paste buffer.
228// (To copy, just copy the current selection out of the string yourself.)
229//
230// paste:
231// call this to paste text at the current cursor point or over the current
232// selection if there is one.
233//
234// key:
235// call this for keyboard inputs sent to the textfield. you can use it
236// for "key down" events or for "translated" key events. if you need to
237// do both (as in Win32), or distinguish Unicode characters from control
238// inputs, set a high bit to distinguish the two; then you can define the
239// various definitions like STB_TEXTEDIT_K_LEFT have the is-key-event bit
240// set, and make STB_TEXTEDIT_KEYTOCHAR check that the is-key-event bit is
241// clear. STB_TEXTEDIT_KEYTYPE defaults to int, but you can #define it to
242// anything other type you wante before including.
243//
244//
245// When rendering, you can read the cursor position and selection state from
246// the STB_TexteditState.
247//
248//
249// Notes:
250//
251// This is designed to be usable in IMGUI, so it allows for the possibility of
252// running in an IMGUI that has NOT cached the multi-line layout. For this
253// reason, it provides an interface that is compatible with computing the
254// layout incrementally--we try to make sure we make as few passes through
255// as possible. (For example, to locate the mouse pointer in the text, we
256// could define functions that return the X and Y positions of characters
257// and binary search Y and then X, but if we're doing dynamic layout this
258// will run the layout algorithm many times, so instead we manually search
259// forward in one pass. Similar logic applies to e.g. up-arrow and
260// down-arrow movement.)
261//
262// If it's run in a widget that *has* cached the layout, then this is less
263// efficient, but it's not horrible on modern computers. But you wouldn't
264// want to edit million-line files with it.
265
266
267////////////////////////////////////////////////////////////////////////////
268////////////////////////////////////////////////////////////////////////////
269////
270//// Header-file mode
271////
272////
273
274#ifndef INCLUDE_STB_TEXTEDIT_H
275#define INCLUDE_STB_TEXTEDIT_H
276
277////////////////////////////////////////////////////////////////////////
278//
279// STB_TexteditState
280//
281// Definition of STB_TexteditState which you should store
282// per-textfield; it includes cursor position, selection state,
283// and undo state.
284//
285
286#ifndef STB_TEXTEDIT_UNDOSTATECOUNT
287#define STB_TEXTEDIT_UNDOSTATECOUNT 99
288#endif
289#ifndef STB_TEXTEDIT_UNDOCHARCOUNT
290#define STB_TEXTEDIT_UNDOCHARCOUNT 999
291#endif
292#ifndef STB_TEXTEDIT_CHARTYPE
293#define STB_TEXTEDIT_CHARTYPE int
294#endif
295#ifndef STB_TEXTEDIT_POSITIONTYPE
296#define STB_TEXTEDIT_POSITIONTYPE int
297#endif
298
299typedef struct
300{
301 // private data
302 STB_TEXTEDIT_POSITIONTYPE where;
303 STB_TEXTEDIT_POSITIONTYPE insert_length;
304 STB_TEXTEDIT_POSITIONTYPE delete_length;
305 int char_storage;
306} StbUndoRecord;
307
308typedef struct
309{
310 // private data
311 StbUndoRecord undo_rec [STB_TEXTEDIT_UNDOSTATECOUNT];
312 STB_TEXTEDIT_CHARTYPE undo_char[STB_TEXTEDIT_UNDOCHARCOUNT];
313 short undo_point, redo_point;
314 int undo_char_point, redo_char_point;
315} StbUndoState;
316
317typedef struct
318{
319 /////////////////////
320 //
321 // public data
322 //
323
324 int cursor;
325 // position of the text cursor within the string
326
327 int select_start; // selection start point
328 int select_end;
329 // selection start and end point in characters; if equal, no selection.
330 // note that start may be less than or greater than end (e.g. when
331 // dragging the mouse, start is where the initial click was, and you
332 // can drag in either direction)
333
334 unsigned char insert_mode;
335 // each textfield keeps its own insert mode state. to keep an app-wide
336 // insert mode, copy this value in/out of the app state
337
338 int row_count_per_page;
339 // page size in number of row.
340 // this value MUST be set to >0 for pageup or pagedown in multilines documents.
341
342 /////////////////////
343 //
344 // private data
345 //
346 unsigned char cursor_at_end_of_line; // not implemented yet
347 unsigned char initialized;
348 unsigned char has_preferred_x;
349 unsigned char single_line;
350 unsigned char padding1, padding2, padding3;
351 float preferred_x; // this determines where the cursor up/down tries to seek to along x
352 StbUndoState undostate;
353} STB_TexteditState;
354
355
356////////////////////////////////////////////////////////////////////////
357//
358// StbTexteditRow
359//
360// Result of layout query, used by stb_textedit to determine where
361// the text in each row is.
362
363// result of layout query
364typedef struct
365{
366 float x0,x1; // starting x location, end x location (allows for align=right, etc)
367 float baseline_y_delta; // position of baseline relative to previous row's baseline
368 float ymin,ymax; // height of row above and below baseline
369 int num_chars;
370} StbTexteditRow;
371#endif //INCLUDE_STB_TEXTEDIT_H
372
373
374////////////////////////////////////////////////////////////////////////////
375////////////////////////////////////////////////////////////////////////////
376////
377//// Implementation mode
378////
379////
380
381
382// implementation isn't include-guarded, since it might have indirectly
383// included just the "header" portion
384#ifdef STB_TEXTEDIT_IMPLEMENTATION
385
386#ifndef STB_TEXTEDIT_memmove
387#include <string.h>
388#define STB_TEXTEDIT_memmove memmove
389#endif
390
391
392/////////////////////////////////////////////////////////////////////////////
393//
394// Mouse input handling
395//
396
397// traverse the layout to locate the nearest character to a display position
398static int stb_text_locate_coord(STB_TEXTEDIT_STRING *str, float x, float y)
399{
400 StbTexteditRow r;
401 int n = STB_TEXTEDIT_STRINGLEN(str);
402 float base_y = 0, prev_x;
403 int i=0, k;
404
405 r.x0 = r.x1 = 0;
406 r.ymin = r.ymax = 0;
407 r.num_chars = 0;
408
409 // search rows to find one that straddles 'y'
410 while (i < n) {
411 STB_TEXTEDIT_LAYOUTROW(&r, str, i);
412 if (r.num_chars <= 0)
413 return n;
414
415 if (i==0 && y < base_y + r.ymin)
416 return 0;
417
418 if (y < base_y + r.ymax)
419 break;
420
421 i += r.num_chars;
422 base_y += r.baseline_y_delta;
423 }
424
425 // below all text, return 'after' last character
426 if (i >= n)
427 return n;
428
429 // check if it's before the beginning of the line
430 if (x < r.x0)
431 return i;
432
433 // check if it's before the end of the line
434 if (x < r.x1) {
435 // search characters in row for one that straddles 'x'
436 prev_x = r.x0;
437 for (k=0; k < r.num_chars; ++k) {
438 float w = STB_TEXTEDIT_GETWIDTH(str, i, k);
439 if (x < prev_x+w) {
440 if (x < prev_x+w/2)
441 return k+i;
442 else
443 return k+i+1;
444 }
445 prev_x += w;
446 }
447 // shouldn't happen, but if it does, fall through to end-of-line case
448 }
449
450 // if the last character is a newline, return that. otherwise return 'after' the last character
451 if (STB_TEXTEDIT_GETCHAR(str, i+r.num_chars-1) == STB_TEXTEDIT_NEWLINE)
452 return i+r.num_chars-1;
453 else
454 return i+r.num_chars;
455}
456
457// API click: on mouse down, move the cursor to the clicked location, and reset the selection
458static void stb_textedit_click(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
459{
460 // In single-line mode, just always make y = 0. This lets the drag keep working if the mouse
461 // goes off the top or bottom of the text
462 if( state->single_line )
463 {
464 StbTexteditRow r;
465 STB_TEXTEDIT_LAYOUTROW(&r, str, 0);
466 y = r.ymin;
467 }
468
469 state->cursor = stb_text_locate_coord(str, x, y);
470 state->select_start = state->cursor;
471 state->select_end = state->cursor;
472 state->has_preferred_x = 0;
473}
474
475// API drag: on mouse drag, move the cursor and selection endpoint to the clicked location
476static void stb_textedit_drag(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
477{
478 int p = 0;
479
480 // In single-line mode, just always make y = 0. This lets the drag keep working if the mouse
481 // goes off the top or bottom of the text
482 if( state->single_line )
483 {
484 StbTexteditRow r;
485 STB_TEXTEDIT_LAYOUTROW(&r, str, 0);
486 y = r.ymin;
487 }
488
489 if (state->select_start == state->select_end)
490 state->select_start = state->cursor;
491
492 p = stb_text_locate_coord(str, x, y);
493 state->cursor = state->select_end = p;
494}
495
496/////////////////////////////////////////////////////////////////////////////
497//
498// Keyboard input handling
499//
500
501// forward declarations
502static void stb_text_undo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state);
503static void stb_text_redo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state);
504static void stb_text_makeundo_delete(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int length);
505static void stb_text_makeundo_insert(STB_TexteditState *state, int where, int length);
506static void stb_text_makeundo_replace(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int old_length, int new_length);
507
508typedef struct
509{
510 float x,y; // position of n'th character
511 float height; // height of line
512 int first_char, length; // first char of row, and length
513 int prev_first; // first char of previous row
514} StbFindState;
515
516// find the x/y location of a character, and remember info about the previous row in
517// case we get a move-up event (for page up, we'll have to rescan)
518static void stb_textedit_find_charpos(StbFindState *find, STB_TEXTEDIT_STRING *str, int n, int single_line)
519{
520 StbTexteditRow r;
521 int prev_start = 0;
522 int z = STB_TEXTEDIT_STRINGLEN(str);
523 int i=0, first;
524
525 if (n == z) {
526 // if it's at the end, then find the last line -- simpler than trying to
527 // explicitly handle this case in the regular code
528 if (single_line) {
529 STB_TEXTEDIT_LAYOUTROW(&r, str, 0);
530 find->y = 0;
531 find->first_char = 0;
532 find->length = z;
533 find->height = r.ymax - r.ymin;
534 find->x = r.x1;
535 } else {
536 find->y = 0;
537 find->x = 0;
538 find->height = 1;
539 while (i < z) {
540 STB_TEXTEDIT_LAYOUTROW(&r, str, i);
541 prev_start = i;
542 i += r.num_chars;
543 }
544 find->first_char = i;
545 find->length = 0;
546 find->prev_first = prev_start;
547 }
548 return;
549 }
550
551 // search rows to find the one that straddles character n
552 find->y = 0;
553
554 for(;;) {
555 STB_TEXTEDIT_LAYOUTROW(&r, str, i);
556 if (n < i + r.num_chars)
557 break;
558 prev_start = i;
559 i += r.num_chars;
560 find->y += r.baseline_y_delta;
561 }
562
563 find->first_char = first = i;
564 find->length = r.num_chars;
565 find->height = r.ymax - r.ymin;
566 find->prev_first = prev_start;
567
568 // now scan to find xpos
569 find->x = r.x0;
570 for (i=0; first+i < n; ++i)
571 find->x += STB_TEXTEDIT_GETWIDTH(str, first, i);
572}
573
574#define STB_TEXT_HAS_SELECTION(s) ((s)->select_start != (s)->select_end)
575
576// make the selection/cursor state valid if client altered the string
577static void stb_textedit_clamp(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
578{
579 int n = STB_TEXTEDIT_STRINGLEN(str);
580 if (STB_TEXT_HAS_SELECTION(state)) {
581 if (state->select_start > n) state->select_start = n;
582 if (state->select_end > n) state->select_end = n;
583 // if clamping forced them to be equal, move the cursor to match
584 if (state->select_start == state->select_end)
585 state->cursor = state->select_start;
586 }
587 if (state->cursor > n) state->cursor = n;
588}
589
590// delete characters while updating undo
591static void stb_textedit_delete(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int len)
592{
593 stb_text_makeundo_delete(str, state, where, len);
594 STB_TEXTEDIT_DELETECHARS(str, where, len);
595 state->has_preferred_x = 0;
596}
597
598// delete the section
599static void stb_textedit_delete_selection(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
600{
601 stb_textedit_clamp(str, state);
602 if (STB_TEXT_HAS_SELECTION(state)) {
603 if (state->select_start < state->select_end) {
604 stb_textedit_delete(str, state, state->select_start, state->select_end - state->select_start);
605 state->select_end = state->cursor = state->select_start;
606 } else {
607 stb_textedit_delete(str, state, state->select_end, state->select_start - state->select_end);
608 state->select_start = state->cursor = state->select_end;
609 }
610 state->has_preferred_x = 0;
611 }
612}
613
614// canoncialize the selection so start <= end
615static void stb_textedit_sortselection(STB_TexteditState *state)
616{
617 if (state->select_end < state->select_start) {
618 int temp = state->select_end;
619 state->select_end = state->select_start;
620 state->select_start = temp;
621 }
622}
623
624// move cursor to first character of selection
625static void stb_textedit_move_to_first(STB_TexteditState *state)
626{
627 if (STB_TEXT_HAS_SELECTION(state)) {
628 stb_textedit_sortselection(state);
629 state->cursor = state->select_start;
630 state->select_end = state->select_start;
631 state->has_preferred_x = 0;
632 }
633}
634
635// move cursor to last character of selection
636static void stb_textedit_move_to_last(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
637{
638 if (STB_TEXT_HAS_SELECTION(state)) {
639 stb_textedit_sortselection(state);
640 stb_textedit_clamp(str, state);
641 state->cursor = state->select_end;
642 state->select_start = state->select_end;
643 state->has_preferred_x = 0;
644 }
645}
646
647#ifdef STB_TEXTEDIT_IS_SPACE
648static int is_word_boundary( STB_TEXTEDIT_STRING *str, int idx )
649{
650 return idx > 0 ? (STB_TEXTEDIT_IS_SPACE( STB_TEXTEDIT_GETCHAR(str,idx-1) ) && !STB_TEXTEDIT_IS_SPACE( STB_TEXTEDIT_GETCHAR(str, idx) ) ) : 1;
651}
652
653#ifndef STB_TEXTEDIT_MOVEWORDLEFT
654static int stb_textedit_move_to_word_previous( STB_TEXTEDIT_STRING *str, int c )
655{
656 --c; // always move at least one character
657 while( c >= 0 && !is_word_boundary( str, c ) )
658 --c;
659
660 if( c < 0 )
661 c = 0;
662
663 return c;
664}
665#define STB_TEXTEDIT_MOVEWORDLEFT stb_textedit_move_to_word_previous
666#endif
667
668#ifndef STB_TEXTEDIT_MOVEWORDRIGHT
669static int stb_textedit_move_to_word_next( STB_TEXTEDIT_STRING *str, int c )
670{
671 const int len = STB_TEXTEDIT_STRINGLEN(str);
672 ++c; // always move at least one character
673 while( c < len && !is_word_boundary( str, c ) )
674 ++c;
675
676 if( c > len )
677 c = len;
678
679 return c;
680}
681#define STB_TEXTEDIT_MOVEWORDRIGHT stb_textedit_move_to_word_next
682#endif
683
684#endif
685
686// update selection and cursor to match each other
687static void stb_textedit_prep_selection_at_cursor(STB_TexteditState *state)
688{
689 if (!STB_TEXT_HAS_SELECTION(state))
690 state->select_start = state->select_end = state->cursor;
691 else
692 state->cursor = state->select_end;
693}
694
695// API cut: delete selection
696static int stb_textedit_cut(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
697{
698 if (STB_TEXT_HAS_SELECTION(state)) {
699 stb_textedit_delete_selection(str,state); // implicitly clamps
700 state->has_preferred_x = 0;
701 return 1;
702 }
703 return 0;
704}
705
706// API paste: replace existing selection with passed-in text
707static int stb_textedit_paste_internal(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_CHARTYPE *text, int len)
708{
709 // if there's a selection, the paste should delete it
710 stb_textedit_clamp(str, state);
711 stb_textedit_delete_selection(str,state);
712 // try to insert the characters
713 if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, text, len)) {
714 stb_text_makeundo_insert(state, state->cursor, len);
715 state->cursor += len;
716 state->has_preferred_x = 0;
717 return 1;
718 }
719 // [DEAR IMGUI]
720 //// remove the undo since we didn't actually insert the characters
721 //if (state->undostate.undo_point)
722 // --state->undostate.undo_point;
723 // note: paste failure will leave deleted selection, may be restored with an undo (see https://github.com/nothings/stb/issues/734 for details)
724 return 0;
725}
726
727#ifndef STB_TEXTEDIT_KEYTYPE
728#define STB_TEXTEDIT_KEYTYPE int
729#endif
730
731// API key: process a keyboard input
732static void stb_textedit_key(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_KEYTYPE key)
733{
734retry:
735 switch (key) {
736 default: {
737 int c = STB_TEXTEDIT_KEYTOTEXT(key);
738 if (c > 0) {
739 STB_TEXTEDIT_CHARTYPE ch = (STB_TEXTEDIT_CHARTYPE) c;
740
741 // can't add newline in single-line mode
742 if (c == '\n' && state->single_line)
743 break;
744
745 if (state->insert_mode && !STB_TEXT_HAS_SELECTION(state) && state->cursor < STB_TEXTEDIT_STRINGLEN(str)) {
746 stb_text_makeundo_replace(str, state, state->cursor, 1, 1);
747 STB_TEXTEDIT_DELETECHARS(str, state->cursor, 1);
748 if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, &ch, 1)) {
749 ++state->cursor;
750 state->has_preferred_x = 0;
751 }
752 } else {
753 stb_textedit_delete_selection(str,state); // implicitly clamps
754 if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, &ch, 1)) {
755 stb_text_makeundo_insert(state, state->cursor, 1);
756 ++state->cursor;
757 state->has_preferred_x = 0;
758 }
759 }
760 }
761 break;
762 }
763
764#ifdef STB_TEXTEDIT_K_INSERT
765 case STB_TEXTEDIT_K_INSERT:
766 state->insert_mode = !state->insert_mode;
767 break;
768#endif
769
770 case STB_TEXTEDIT_K_UNDO:
771 stb_text_undo(str, state);
772 state->has_preferred_x = 0;
773 break;
774
775 case STB_TEXTEDIT_K_REDO:
776 stb_text_redo(str, state);
777 state->has_preferred_x = 0;
778 break;
779
780 case STB_TEXTEDIT_K_LEFT:
781 // if currently there's a selection, move cursor to start of selection
782 if (STB_TEXT_HAS_SELECTION(state))
783 stb_textedit_move_to_first(state);
784 else
785 if (state->cursor > 0)
786 --state->cursor;
787 state->has_preferred_x = 0;
788 break;
789
790 case STB_TEXTEDIT_K_RIGHT:
791 // if currently there's a selection, move cursor to end of selection
792 if (STB_TEXT_HAS_SELECTION(state))
793 stb_textedit_move_to_last(str, state);
794 else
795 ++state->cursor;
796 stb_textedit_clamp(str, state);
797 state->has_preferred_x = 0;
798 break;
799
800 case STB_TEXTEDIT_K_LEFT | STB_TEXTEDIT_K_SHIFT:
801 stb_textedit_clamp(str, state);
802 stb_textedit_prep_selection_at_cursor(state);
803 // move selection left
804 if (state->select_end > 0)
805 --state->select_end;
806 state->cursor = state->select_end;
807 state->has_preferred_x = 0;
808 break;
809
810#ifdef STB_TEXTEDIT_MOVEWORDLEFT
811 case STB_TEXTEDIT_K_WORDLEFT:
812 if (STB_TEXT_HAS_SELECTION(state))
813 stb_textedit_move_to_first(state);
814 else {
815 state->cursor = STB_TEXTEDIT_MOVEWORDLEFT(str, state->cursor);
816 stb_textedit_clamp( str, state );
817 }
818 break;
819
820 case STB_TEXTEDIT_K_WORDLEFT | STB_TEXTEDIT_K_SHIFT:
821 if( !STB_TEXT_HAS_SELECTION( state ) )
822 stb_textedit_prep_selection_at_cursor(state);
823
824 state->cursor = STB_TEXTEDIT_MOVEWORDLEFT(str, state->cursor);
825 state->select_end = state->cursor;
826
827 stb_textedit_clamp( str, state );
828 break;
829#endif
830
831#ifdef STB_TEXTEDIT_MOVEWORDRIGHT
832 case STB_TEXTEDIT_K_WORDRIGHT:
833 if (STB_TEXT_HAS_SELECTION(state))
834 stb_textedit_move_to_last(str, state);
835 else {
836 state->cursor = STB_TEXTEDIT_MOVEWORDRIGHT(str, state->cursor);
837 stb_textedit_clamp( str, state );
838 }
839 break;
840
841 case STB_TEXTEDIT_K_WORDRIGHT | STB_TEXTEDIT_K_SHIFT:
842 if( !STB_TEXT_HAS_SELECTION( state ) )
843 stb_textedit_prep_selection_at_cursor(state);
844
845 state->cursor = STB_TEXTEDIT_MOVEWORDRIGHT(str, state->cursor);
846 state->select_end = state->cursor;
847
848 stb_textedit_clamp( str, state );
849 break;
850#endif
851
852 case STB_TEXTEDIT_K_RIGHT | STB_TEXTEDIT_K_SHIFT:
853 stb_textedit_prep_selection_at_cursor(state);
854 // move selection right
855 ++state->select_end;
856 stb_textedit_clamp(str, state);
857 state->cursor = state->select_end;
858 state->has_preferred_x = 0;
859 break;
860
861 case STB_TEXTEDIT_K_DOWN:
862 case STB_TEXTEDIT_K_DOWN | STB_TEXTEDIT_K_SHIFT:
863 case STB_TEXTEDIT_K_PGDOWN:
864 case STB_TEXTEDIT_K_PGDOWN | STB_TEXTEDIT_K_SHIFT: {
865 StbFindState find;
866 StbTexteditRow row;
867 int i, j, sel = (key & STB_TEXTEDIT_K_SHIFT) != 0;
868 int is_page = (key & ~STB_TEXTEDIT_K_SHIFT) == STB_TEXTEDIT_K_PGDOWN;
869 int row_count = is_page ? state->row_count_per_page : 1;
870
871 if (!is_page && state->single_line) {
872 // on windows, up&down in single-line behave like left&right
873 key = STB_TEXTEDIT_K_RIGHT | (key & STB_TEXTEDIT_K_SHIFT);
874 goto retry;
875 }
876
877 if (sel)
878 stb_textedit_prep_selection_at_cursor(state);
879 else if (STB_TEXT_HAS_SELECTION(state))
880 stb_textedit_move_to_last(str, state);
881
882 // compute current position of cursor point
883 stb_textedit_clamp(str, state);
884 stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
885
886 for (j = 0; j < row_count; ++j) {
887 float x, goal_x = state->has_preferred_x ? state->preferred_x : find.x;
888 int start = find.first_char + find.length;
889
890 if (find.length == 0)
891 break;
892
893 // [DEAR IMGUI]
894 // going down while being on the last line shouldn't bring us to that line end
895 if (STB_TEXTEDIT_GETCHAR(str, find.first_char + find.length - 1) != STB_TEXTEDIT_NEWLINE)
896 break;
897
898 // now find character position down a row
899 state->cursor = start;
900 STB_TEXTEDIT_LAYOUTROW(&row, str, state->cursor);
901 x = row.x0;
902 for (i=0; i < row.num_chars; ++i) {
903 float dx = STB_TEXTEDIT_GETWIDTH(str, start, i);
904 #ifdef STB_TEXTEDIT_GETWIDTH_NEWLINE
905 if (dx == STB_TEXTEDIT_GETWIDTH_NEWLINE)
906 break;
907 #endif
908 x += dx;
909 if (x > goal_x)
910 break;
911 ++state->cursor;
912 }
913 stb_textedit_clamp(str, state);
914
915 state->has_preferred_x = 1;
916 state->preferred_x = goal_x;
917
918 if (sel)
919 state->select_end = state->cursor;
920
921 // go to next line
922 find.first_char = find.first_char + find.length;
923 find.length = row.num_chars;
924 }
925 break;
926 }
927
928 case STB_TEXTEDIT_K_UP:
929 case STB_TEXTEDIT_K_UP | STB_TEXTEDIT_K_SHIFT:
930 case STB_TEXTEDIT_K_PGUP:
931 case STB_TEXTEDIT_K_PGUP | STB_TEXTEDIT_K_SHIFT: {
932 StbFindState find;
933 StbTexteditRow row;
934 int i, j, prev_scan, sel = (key & STB_TEXTEDIT_K_SHIFT) != 0;
935 int is_page = (key & ~STB_TEXTEDIT_K_SHIFT) == STB_TEXTEDIT_K_PGUP;
936 int row_count = is_page ? state->row_count_per_page : 1;
937
938 if (!is_page && state->single_line) {
939 // on windows, up&down become left&right
940 key = STB_TEXTEDIT_K_LEFT | (key & STB_TEXTEDIT_K_SHIFT);
941 goto retry;
942 }
943
944 if (sel)
945 stb_textedit_prep_selection_at_cursor(state);
946 else if (STB_TEXT_HAS_SELECTION(state))
947 stb_textedit_move_to_first(state);
948
949 // compute current position of cursor point
950 stb_textedit_clamp(str, state);
951 stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
952
953 for (j = 0; j < row_count; ++j) {
954 float x, goal_x = state->has_preferred_x ? state->preferred_x : find.x;
955
956 // can only go up if there's a previous row
957 if (find.prev_first == find.first_char)
958 break;
959
960 // now find character position up a row
961 state->cursor = find.prev_first;
962 STB_TEXTEDIT_LAYOUTROW(&row, str, state->cursor);
963 x = row.x0;
964 for (i=0; i < row.num_chars; ++i) {
965 float dx = STB_TEXTEDIT_GETWIDTH(str, find.prev_first, i);
966 #ifdef STB_TEXTEDIT_GETWIDTH_NEWLINE
967 if (dx == STB_TEXTEDIT_GETWIDTH_NEWLINE)
968 break;
969 #endif
970 x += dx;
971 if (x > goal_x)
972 break;
973 ++state->cursor;
974 }
975 stb_textedit_clamp(str, state);
976
977 state->has_preferred_x = 1;
978 state->preferred_x = goal_x;
979
980 if (sel)
981 state->select_end = state->cursor;
982
983 // go to previous line
984 // (we need to scan previous line the hard way. maybe we could expose this as a new API function?)
985 prev_scan = find.prev_first > 0 ? find.prev_first - 1 : 0;
986 while (prev_scan > 0 && STB_TEXTEDIT_GETCHAR(str, prev_scan - 1) != STB_TEXTEDIT_NEWLINE)
987 --prev_scan;
988 find.first_char = find.prev_first;
989 find.prev_first = prev_scan;
990 }
991 break;
992 }
993
994 case STB_TEXTEDIT_K_DELETE:
995 case STB_TEXTEDIT_K_DELETE | STB_TEXTEDIT_K_SHIFT:
996 if (STB_TEXT_HAS_SELECTION(state))
997 stb_textedit_delete_selection(str, state);
998 else {
999 int n = STB_TEXTEDIT_STRINGLEN(str);
1000 if (state->cursor < n)
1001 stb_textedit_delete(str, state, state->cursor, 1);
1002 }
1003 state->has_preferred_x = 0;
1004 break;
1005
1006 case STB_TEXTEDIT_K_BACKSPACE:
1007 case STB_TEXTEDIT_K_BACKSPACE | STB_TEXTEDIT_K_SHIFT:
1008 if (STB_TEXT_HAS_SELECTION(state))
1009 stb_textedit_delete_selection(str, state);
1010 else {
1011 stb_textedit_clamp(str, state);
1012 if (state->cursor > 0) {
1013 stb_textedit_delete(str, state, state->cursor-1, 1);
1014 --state->cursor;
1015 }
1016 }
1017 state->has_preferred_x = 0;
1018 break;
1019
1020#ifdef STB_TEXTEDIT_K_TEXTSTART2
1021 case STB_TEXTEDIT_K_TEXTSTART2:
1022#endif
1023 case STB_TEXTEDIT_K_TEXTSTART:
1024 state->cursor = state->select_start = state->select_end = 0;
1025 state->has_preferred_x = 0;
1026 break;
1027
1028#ifdef STB_TEXTEDIT_K_TEXTEND2
1029 case STB_TEXTEDIT_K_TEXTEND2:
1030#endif
1031 case STB_TEXTEDIT_K_TEXTEND:
1032 state->cursor = STB_TEXTEDIT_STRINGLEN(str);
1033 state->select_start = state->select_end = 0;
1034 state->has_preferred_x = 0;
1035 break;
1036
1037#ifdef STB_TEXTEDIT_K_TEXTSTART2
1038 case STB_TEXTEDIT_K_TEXTSTART2 | STB_TEXTEDIT_K_SHIFT:
1039#endif
1040 case STB_TEXTEDIT_K_TEXTSTART | STB_TEXTEDIT_K_SHIFT:
1041 stb_textedit_prep_selection_at_cursor(state);
1042 state->cursor = state->select_end = 0;
1043 state->has_preferred_x = 0;
1044 break;
1045
1046#ifdef STB_TEXTEDIT_K_TEXTEND2
1047 case STB_TEXTEDIT_K_TEXTEND2 | STB_TEXTEDIT_K_SHIFT:
1048#endif
1049 case STB_TEXTEDIT_K_TEXTEND | STB_TEXTEDIT_K_SHIFT:
1050 stb_textedit_prep_selection_at_cursor(state);
1051 state->cursor = state->select_end = STB_TEXTEDIT_STRINGLEN(str);
1052 state->has_preferred_x = 0;
1053 break;
1054
1055
1056#ifdef STB_TEXTEDIT_K_LINESTART2
1057 case STB_TEXTEDIT_K_LINESTART2:
1058#endif
1059 case STB_TEXTEDIT_K_LINESTART:
1060 stb_textedit_clamp(str, state);
1061 stb_textedit_move_to_first(state);
1062 if (state->single_line)
1063 state->cursor = 0;
1064 else while (state->cursor > 0 && STB_TEXTEDIT_GETCHAR(str, state->cursor-1) != STB_TEXTEDIT_NEWLINE)
1065 --state->cursor;
1066 state->has_preferred_x = 0;
1067 break;
1068
1069#ifdef STB_TEXTEDIT_K_LINEEND2
1070 case STB_TEXTEDIT_K_LINEEND2:
1071#endif
1072 case STB_TEXTEDIT_K_LINEEND: {
1073 int n = STB_TEXTEDIT_STRINGLEN(str);
1074 stb_textedit_clamp(str, state);
1075 stb_textedit_move_to_first(state);
1076 if (state->single_line)
1077 state->cursor = n;
1078 else while (state->cursor < n && STB_TEXTEDIT_GETCHAR(str, state->cursor) != STB_TEXTEDIT_NEWLINE)
1079 ++state->cursor;
1080 state->has_preferred_x = 0;
1081 break;
1082 }
1083
1084#ifdef STB_TEXTEDIT_K_LINESTART2
1085 case STB_TEXTEDIT_K_LINESTART2 | STB_TEXTEDIT_K_SHIFT:
1086#endif
1087 case STB_TEXTEDIT_K_LINESTART | STB_TEXTEDIT_K_SHIFT:
1088 stb_textedit_clamp(str, state);
1089 stb_textedit_prep_selection_at_cursor(state);
1090 if (state->single_line)
1091 state->cursor = 0;
1092 else while (state->cursor > 0 && STB_TEXTEDIT_GETCHAR(str, state->cursor-1) != STB_TEXTEDIT_NEWLINE)
1093 --state->cursor;
1094 state->select_end = state->cursor;
1095 state->has_preferred_x = 0;
1096 break;
1097
1098#ifdef STB_TEXTEDIT_K_LINEEND2
1099 case STB_TEXTEDIT_K_LINEEND2 | STB_TEXTEDIT_K_SHIFT:
1100#endif
1101 case STB_TEXTEDIT_K_LINEEND | STB_TEXTEDIT_K_SHIFT: {
1102 int n = STB_TEXTEDIT_STRINGLEN(str);
1103 stb_textedit_clamp(str, state);
1104 stb_textedit_prep_selection_at_cursor(state);
1105 if (state->single_line)
1106 state->cursor = n;
1107 else while (state->cursor < n && STB_TEXTEDIT_GETCHAR(str, state->cursor) != STB_TEXTEDIT_NEWLINE)
1108 ++state->cursor;
1109 state->select_end = state->cursor;
1110 state->has_preferred_x = 0;
1111 break;
1112 }
1113 }
1114}
1115
1116/////////////////////////////////////////////////////////////////////////////
1117//
1118// Undo processing
1119//
1120// @OPTIMIZE: the undo/redo buffer should be circular
1121
1122static void stb_textedit_flush_redo(StbUndoState *state)
1123{
1124 state->redo_point = STB_TEXTEDIT_UNDOSTATECOUNT;
1125 state->redo_char_point = STB_TEXTEDIT_UNDOCHARCOUNT;
1126}
1127
1128// discard the oldest entry in the undo list
1129static void stb_textedit_discard_undo(StbUndoState *state)
1130{
1131 if (state->undo_point > 0) {
1132 // if the 0th undo state has characters, clean those up
1133 if (state->undo_rec[0].char_storage >= 0) {
1134 int n = state->undo_rec[0].insert_length, i;
1135 // delete n characters from all other records
1136 state->undo_char_point -= n;
1137 STB_TEXTEDIT_memmove(state->undo_char, state->undo_char + n, (size_t) (state->undo_char_point*sizeof(STB_TEXTEDIT_CHARTYPE)));
1138 for (i=0; i < state->undo_point; ++i)
1139 if (state->undo_rec[i].char_storage >= 0)
1140 state->undo_rec[i].char_storage -= n; // @OPTIMIZE: get rid of char_storage and infer it
1141 }
1142 --state->undo_point;
1143 STB_TEXTEDIT_memmove(state->undo_rec, state->undo_rec+1, (size_t) (state->undo_point*sizeof(state->undo_rec[0])));
1144 }
1145}
1146
1147// discard the oldest entry in the redo list--it's bad if this
1148// ever happens, but because undo & redo have to store the actual
1149// characters in different cases, the redo character buffer can
1150// fill up even though the undo buffer didn't
1151static void stb_textedit_discard_redo(StbUndoState *state)
1152{
1153 int k = STB_TEXTEDIT_UNDOSTATECOUNT-1;
1154
1155 if (state->redo_point <= k) {
1156 // if the k'th undo state has characters, clean those up
1157 if (state->undo_rec[k].char_storage >= 0) {
1158 int n = state->undo_rec[k].insert_length, i;
1159 // move the remaining redo character data to the end of the buffer
1160 state->redo_char_point += n;
1161 STB_TEXTEDIT_memmove(state->undo_char + state->redo_char_point, state->undo_char + state->redo_char_point-n, (size_t) ((STB_TEXTEDIT_UNDOCHARCOUNT - state->redo_char_point)*sizeof(STB_TEXTEDIT_CHARTYPE)));
1162 // adjust the position of all the other records to account for above memmove
1163 for (i=state->redo_point; i < k; ++i)
1164 if (state->undo_rec[i].char_storage >= 0)
1165 state->undo_rec[i].char_storage += n;
1166 }
1167 // now move all the redo records towards the end of the buffer; the first one is at 'redo_point'
1168 // [DEAR IMGUI]
1169 size_t move_size = (size_t)((STB_TEXTEDIT_UNDOSTATECOUNT - state->redo_point - 1) * sizeof(state->undo_rec[0]));
1170 const char* buf_begin = (char*)state->undo_rec; (void)buf_begin;
1171 const char* buf_end = (char*)state->undo_rec + sizeof(state->undo_rec); (void)buf_end;
1172 IM_ASSERT(((char*)(state->undo_rec + state->redo_point)) >= buf_begin);
1173 IM_ASSERT(((char*)(state->undo_rec + state->redo_point + 1) + move_size) <= buf_end);
1174 STB_TEXTEDIT_memmove(state->undo_rec + state->redo_point+1, state->undo_rec + state->redo_point, move_size);
1175
1176 // now move redo_point to point to the new one
1177 ++state->redo_point;
1178 }
1179}
1180
1181static StbUndoRecord *stb_text_create_undo_record(StbUndoState *state, int numchars)
1182{
1183 // any time we create a new undo record, we discard redo
1184 stb_textedit_flush_redo(state);
1185
1186 // if we have no free records, we have to make room, by sliding the
1187 // existing records down
1188 if (state->undo_point == STB_TEXTEDIT_UNDOSTATECOUNT)
1189 stb_textedit_discard_undo(state);
1190
1191 // if the characters to store won't possibly fit in the buffer, we can't undo
1192 if (numchars > STB_TEXTEDIT_UNDOCHARCOUNT) {
1193 state->undo_point = 0;
1194 state->undo_char_point = 0;
1195 return NULL;
1196 }
1197
1198 // if we don't have enough free characters in the buffer, we have to make room
1199 while (state->undo_char_point + numchars > STB_TEXTEDIT_UNDOCHARCOUNT)
1200 stb_textedit_discard_undo(state);
1201
1202 return &state->undo_rec[state->undo_point++];
1203}
1204
1205static STB_TEXTEDIT_CHARTYPE *stb_text_createundo(StbUndoState *state, int pos, int insert_len, int delete_len)
1206{
1207 StbUndoRecord *r = stb_text_create_undo_record(state, insert_len);
1208 if (r == NULL)
1209 return NULL;
1210
1211 r->where = pos;
1212 r->insert_length = (STB_TEXTEDIT_POSITIONTYPE) insert_len;
1213 r->delete_length = (STB_TEXTEDIT_POSITIONTYPE) delete_len;
1214
1215 if (insert_len == 0) {
1216 r->char_storage = -1;
1217 return NULL;
1218 } else {
1219 r->char_storage = state->undo_char_point;
1220 state->undo_char_point += insert_len;
1221 return &state->undo_char[r->char_storage];
1222 }
1223}
1224
1225static void stb_text_undo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
1226{
1227 StbUndoState *s = &state->undostate;
1228 StbUndoRecord u, *r;
1229 if (s->undo_point == 0)
1230 return;
1231
1232 // we need to do two things: apply the undo record, and create a redo record
1233 u = s->undo_rec[s->undo_point-1];
1234 r = &s->undo_rec[s->redo_point-1];
1235 r->char_storage = -1;
1236
1237 r->insert_length = u.delete_length;
1238 r->delete_length = u.insert_length;
1239 r->where = u.where;
1240
1241 if (u.delete_length) {
1242 // if the undo record says to delete characters, then the redo record will
1243 // need to re-insert the characters that get deleted, so we need to store
1244 // them.
1245
1246 // there are three cases:
1247 // there's enough room to store the characters
1248 // characters stored for *redoing* don't leave room for redo
1249 // characters stored for *undoing* don't leave room for redo
1250 // if the last is true, we have to bail
1251
1252 if (s->undo_char_point + u.delete_length >= STB_TEXTEDIT_UNDOCHARCOUNT) {
1253 // the undo records take up too much character space; there's no space to store the redo characters
1254 r->insert_length = 0;
1255 } else {
1256 int i;
1257
1258 // there's definitely room to store the characters eventually
1259 while (s->undo_char_point + u.delete_length > s->redo_char_point) {
1260 // should never happen:
1261 if (s->redo_point == STB_TEXTEDIT_UNDOSTATECOUNT)
1262 return;
1263 // there's currently not enough room, so discard a redo record
1264 stb_textedit_discard_redo(s);
1265 }
1266 r = &s->undo_rec[s->redo_point-1];
1267
1268 r->char_storage = s->redo_char_point - u.delete_length;
1269 s->redo_char_point = s->redo_char_point - u.delete_length;
1270
1271 // now save the characters
1272 for (i=0; i < u.delete_length; ++i)
1273 s->undo_char[r->char_storage + i] = STB_TEXTEDIT_GETCHAR(str, u.where + i);
1274 }
1275
1276 // now we can carry out the deletion
1277 STB_TEXTEDIT_DELETECHARS(str, u.where, u.delete_length);
1278 }
1279
1280 // check type of recorded action:
1281 if (u.insert_length) {
1282 // easy case: was a deletion, so we need to insert n characters
1283 STB_TEXTEDIT_INSERTCHARS(str, u.where, &s->undo_char[u.char_storage], u.insert_length);
1284 s->undo_char_point -= u.insert_length;
1285 }
1286
1287 state->cursor = u.where + u.insert_length;
1288
1289 s->undo_point--;
1290 s->redo_point--;
1291}
1292
1293static void stb_text_redo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
1294{
1295 StbUndoState *s = &state->undostate;
1296 StbUndoRecord *u, r;
1297 if (s->redo_point == STB_TEXTEDIT_UNDOSTATECOUNT)
1298 return;
1299
1300 // we need to do two things: apply the redo record, and create an undo record
1301 u = &s->undo_rec[s->undo_point];
1302 r = s->undo_rec[s->redo_point];
1303
1304 // we KNOW there must be room for the undo record, because the redo record
1305 // was derived from an undo record
1306
1307 u->delete_length = r.insert_length;
1308 u->insert_length = r.delete_length;
1309 u->where = r.where;
1310 u->char_storage = -1;
1311
1312 if (r.delete_length) {
1313 // the redo record requires us to delete characters, so the undo record
1314 // needs to store the characters
1315
1316 if (s->undo_char_point + u->insert_length > s->redo_char_point) {
1317 u->insert_length = 0;
1318 u->delete_length = 0;
1319 } else {
1320 int i;
1321 u->char_storage = s->undo_char_point;
1322 s->undo_char_point = s->undo_char_point + u->insert_length;
1323
1324 // now save the characters
1325 for (i=0; i < u->insert_length; ++i)
1326 s->undo_char[u->char_storage + i] = STB_TEXTEDIT_GETCHAR(str, u->where + i);
1327 }
1328
1329 STB_TEXTEDIT_DELETECHARS(str, r.where, r.delete_length);
1330 }
1331
1332 if (r.insert_length) {
1333 // easy case: need to insert n characters
1334 STB_TEXTEDIT_INSERTCHARS(str, r.where, &s->undo_char[r.char_storage], r.insert_length);
1335 s->redo_char_point += r.insert_length;
1336 }
1337
1338 state->cursor = r.where + r.insert_length;
1339
1340 s->undo_point++;
1341 s->redo_point++;
1342}
1343
1344static void stb_text_makeundo_insert(STB_TexteditState *state, int where, int length)
1345{
1346 stb_text_createundo(&state->undostate, where, 0, length);
1347}
1348
1349static void stb_text_makeundo_delete(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int length)
1350{
1351 int i;
1352 STB_TEXTEDIT_CHARTYPE *p = stb_text_createundo(&state->undostate, where, length, 0);
1353 if (p) {
1354 for (i=0; i < length; ++i)
1355 p[i] = STB_TEXTEDIT_GETCHAR(str, where+i);
1356 }
1357}
1358
1359static void stb_text_makeundo_replace(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int old_length, int new_length)
1360{
1361 int i;
1362 STB_TEXTEDIT_CHARTYPE *p = stb_text_createundo(&state->undostate, where, old_length, new_length);
1363 if (p) {
1364 for (i=0; i < old_length; ++i)
1365 p[i] = STB_TEXTEDIT_GETCHAR(str, where+i);
1366 }
1367}
1368
1369// reset the state to default
1370static void stb_textedit_clear_state(STB_TexteditState *state, int is_single_line)
1371{
1372 state->undostate.undo_point = 0;
1373 state->undostate.undo_char_point = 0;
1374 state->undostate.redo_point = STB_TEXTEDIT_UNDOSTATECOUNT;
1375 state->undostate.redo_char_point = STB_TEXTEDIT_UNDOCHARCOUNT;
1376 state->select_end = state->select_start = 0;
1377 state->cursor = 0;
1378 state->has_preferred_x = 0;
1379 state->preferred_x = 0;
1380 state->cursor_at_end_of_line = 0;
1381 state->initialized = 1;
1382 state->single_line = (unsigned char) is_single_line;
1383 state->insert_mode = 0;
1384 state->row_count_per_page = 0;
1385}
1386
1387// API initialize
1388static void stb_textedit_initialize_state(STB_TexteditState *state, int is_single_line)
1389{
1390 stb_textedit_clear_state(state, is_single_line);
1391}
1392
1393#if defined(__GNUC__) || defined(__clang__)
1394#pragma GCC diagnostic push
1395#pragma GCC diagnostic ignored "-Wcast-qual"
1396#endif
1397
1398static int stb_textedit_paste(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_CHARTYPE const *ctext, int len)
1399{
1400 return stb_textedit_paste_internal(str, state, (STB_TEXTEDIT_CHARTYPE *) ctext, len);
1401}
1402
1403#if defined(__GNUC__) || defined(__clang__)
1404#pragma GCC diagnostic pop
1405#endif
1406
1407#endif//STB_TEXTEDIT_IMPLEMENTATION
1408
1409/*
1410------------------------------------------------------------------------------
1411This software is available under 2 licenses -- choose whichever you prefer.
1412------------------------------------------------------------------------------
1413ALTERNATIVE A - MIT License
1414Copyright (c) 2017 Sean Barrett
1415Permission is hereby granted, free of charge, to any person obtaining a copy of
1416this software and associated documentation files (the "Software"), to deal in
1417the Software without restriction, including without limitation the rights to
1418use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
1419of the Software, and to permit persons to whom the Software is furnished to do
1420so, subject to the following conditions:
1421The above copyright notice and this permission notice shall be included in all
1422copies or substantial portions of the Software.
1423THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
1424IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1425FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
1426AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
1427LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
1428OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
1429SOFTWARE.
1430------------------------------------------------------------------------------
1431ALTERNATIVE B - Public Domain (www.unlicense.org)
1432This is free and unencumbered software released into the public domain.
1433Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
1434software, either in source code form or as a compiled binary, for any purpose,
1435commercial or non-commercial, and by any means.
1436In jurisdictions that recognize copyright laws, the author or authors of this
1437software dedicate any and all copyright interest in the software to the public
1438domain. We make this dedication for the benefit of the public at large and to
1439the detriment of our heirs and successors. We intend this dedication to be an
1440overt act of relinquishment in perpetuity of all present and future rights to
1441this software under copyright law.
1442THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
1443IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1444FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
1445AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
1446ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
1447WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
1448------------------------------------------------------------------------------
1449*/
1450