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// stb_textedit.h - v1.3 - public domain - Sean Barrett
// Development of this library was sponsored by RAD Game Tools
//
// This C header file implements the guts of a multi-line text-editing
// widget; you implement display, word-wrapping, and low-level string
// insertion/deletion, and stb_textedit will map user inputs into
// insertions & deletions, plus updates to the cursor position,
// selection state, and undo state.
//
// It is intended for use in games and other systems that need to build
// their own custom widgets and which do not have heavy text-editing
// requirements (this library is not recommended for use for editing large
// texts, as its performance does not scale and it has limited undo).
//
// Non-trivial behaviors are modelled after Windows text controls.
//
//
// LICENSE
//
// This software has been placed in the public domain by its author.
// Where that dedication is not recognized, you are granted a perpetual,
// irrevocable license to copy and modify this file as you see fit.
//
//
// DEPENDENCIES
//
// Uses the C runtime function 'memmove'. Uses no other functions.
// Performs no runtime allocations.
//
//
// VERSION HISTORY
//
// 1.3 (2013-06-19) fix mouse clicking to round to nearest char boundary
// 1.2 (2013-05-27) fix some RAD types that had crept into the new code
// 1.1 (2013-12-15) move-by-word (requires STB_TEXTEDIT_IS_SPACE )
// 1.0 (2012-07-26) improve documentation, initial public release
// 0.3 (2012-02-24) bugfixes, single-line mode; insert mode
// 0.2 (2011-11-28) fixes to undo/redo
// 0.1 (2010-07-08) initial version
//
// ADDITIONAL CONTRIBUTORS
//
// Ulf Winklemann: move-by-word in 1.1
// Scott Graham: mouse selectiom bugfix in 1.3
//
// USAGE
//
// This file behaves differently depending on what symbols you define
// before including it.
//
//
// Header-file mode:
//
// If you do not define STB_TEXTEDIT_IMPLEMENTATION before including this,
// it will operate in "header file" mode. In this mode, it declares a
// single public symbol, STB_TexteditState, which encapsulates the current
// state of a text widget (except for the string, which you will store
// separately).
//
// To compile in this mode, you must define STB_TEXTEDIT_CHARTYPE to a
// primitive type that defines a single character (e.g. char, wchar_t, etc).
//
// To save space or increase undo-ability, you can optionally define the
// following things that are used by the undo system:
//
// STB_TEXTEDIT_POSITIONTYPE small int type encoding a valid cursor position
// STB_TEXTEDIT_UNDOSTATECOUNT the number of undo states to allow
// STB_TEXTEDIT_UNDOCHARCOUNT the number of characters to store in the undo buffer
//
// If you don't define these, they are set to permissive types and
// moderate sizes. The undo system does no memory allocations, so
// it grows STB_TexteditState by the worst-case storage which is (in bytes):
//
// [4 + sizeof(STB_TEXTEDIT_POSITIONTYPE)] * STB_TEXTEDIT_UNDOSTATE_COUNT
// + sizeof(STB_TEXTEDIT_CHARTYPE) * STB_TEXTEDIT_UNDOCHAR_COUNT
//
//
// Implementation mode:
//
// If you define STB_TEXTEDIT_IMPLEMENTATION before including this, it
// will compile the implementation of the text edit widget, depending
// on a large number of symbols which must be defined before the include.
//
// The implementation is defined only as static functions. You will then
// need to provide your own APIs in the same file which will access the
// static functions.
//
// The basic concept is that you provide a "string" object which
// behaves like an array of characters. stb_textedit uses indices to
// refer to positions in the string, implicitly representing positions
// in the displayed textedit. This is true for both plain text and
// rich text; even with rich text stb_truetype interacts with your
// code as if there was an array of all the displayed characters.
//
// Symbols that must be the same in header-file and implementation mode:
//
// STB_TEXTEDIT_CHARTYPE the character type
// STB_TEXTEDIT_POSITIONTYPE small type that a valid cursor position
// STB_TEXTEDIT_UNDOSTATECOUNT the number of undo states to allow
// STB_TEXTEDIT_UNDOCHARCOUNT the number of characters to store in the undo buffer
//
// Symbols you must define for implementation mode:
//
// STB_TEXTEDIT_STRING the type of object representing a string being edited,
// typically this is a wrapper object with other data you need
//
// STB_TEXTEDIT_STRINGLEN(obj) the length of the string (ideally O(1))
// STB_TEXTEDIT_LAYOUTROW(&r,obj,n) returns the results of laying out a line of characters
// starting from character #n (see discussion below)
// STB_TEXTEDIT_GETWIDTH(obj,n,i) returns the pixel delta from the xpos of the i'th character
// to the xpos of the i+1'th char for a line of characters
// starting at character #n (i.e. accounts for kerning
// with previous char)
// STB_TEXTEDIT_KEYTOTEXT(k) maps a keyboard input to an insertable character
// (return type is int, -1 means not valid to insert)
// STB_TEXTEDIT_GETCHAR(obj,i) returns the i'th character of obj, 0-based
// STB_TEXTEDIT_NEWLINE the character returned by _GETCHAR() we recognize
// as manually wordwrapping for end-of-line positioning
//
// STB_TEXTEDIT_DELETECHARS(obj,i,n) delete n characters starting at i
// STB_TEXTEDIT_INSERTCHARS(obj,i,c*,n) insert n characters at i (pointed to by STB_TEXTEDIT_CHARTYPE*)
//
// STB_TEXTEDIT_K_SHIFT a power of two that is or'd in to a keyboard input to represent the shift key
//
// STB_TEXTEDIT_K_LEFT keyboard input to move cursor left
// STB_TEXTEDIT_K_RIGHT keyboard input to move cursor right
// STB_TEXTEDIT_K_UP keyboard input to move cursor up
// STB_TEXTEDIT_K_DOWN keyboard input to move cursor down
// STB_TEXTEDIT_K_LINESTART keyboard input to move cursor to start of line // e.g. HOME
// STB_TEXTEDIT_K_LINEEND keyboard input to move cursor to end of line // e.g. END
// STB_TEXTEDIT_K_TEXTSTART keyboard input to move cursor to start of text // e.g. ctrl-HOME
// STB_TEXTEDIT_K_TEXTEND keyboard input to move cursor to end of text // e.g. ctrl-END
// STB_TEXTEDIT_K_DELETE keyboard input to delete selection or character under cursor
// STB_TEXTEDIT_K_BACKSPACE keyboard input to delete selection or character left of cursor
// STB_TEXTEDIT_K_UNDO keyboard input to perform undo
// STB_TEXTEDIT_K_REDO keyboard input to perform redo
//
// Optional:
// STB_TEXTEDIT_K_INSERT keyboard input to toggle insert mode
// STB_TEXTEDIT_IS_SPACE(ch) true if character is whitespace (e.g. 'isspace'),
// required for WORDLEFT/WORDRIGHT
// STB_TEXTEDIT_K_WORDLEFT keyboard input to move cursor left one word // e.g. ctrl-LEFT
// STB_TEXTEDIT_K_WORDRIGHT keyboard input to move cursor right one word // e.g. ctrl-RIGHT
//
// Todo:
// STB_TEXTEDIT_K_PGUP keyboard input to move cursor up a page
// STB_TEXTEDIT_K_PGDOWN keyboard input to move cursor down a page
//
// Keyboard input must be encoded as a single integer value; e.g. a character code
// and some bitflags that represent shift states. to simplify the interface, SHIFT must
// be a bitflag, so we can test the shifted state of cursor movements to allow selection,
// i.e. (STB_TEXTED_K_RIGHT|STB_TEXTEDIT_K_SHIFT) should be shifted right-arrow.
//
// You can encode other things, such as CONTROL or ALT, in additional bits, and
// then test for their presence in e.g. STB_TEXTEDIT_K_WORDLEFT. For example,
// my Windows implementations add an additional CONTROL bit, and an additional KEYDOWN
// bit. Then all of the STB_TEXTEDIT_K_ values bitwise-or in the KEYDOWN bit,
// and I pass both WM_KEYDOWN and WM_CHAR events to the "key" function in the
// API below. The control keys will only match WM_KEYDOWN events because of the
// keydown bit I add, and STB_TEXTEDIT_KEYTOTEXT only tests for the KEYDOWN
// bit so it only decodes WM_CHAR events.
//
// STB_TEXTEDIT_LAYOUTROW returns information about the shape of one displayed
// row of characters assuming they start on the i'th character--the width and
// the height and the number of characters consumed. This allows this library
// to traverse the entire layout incrementally. You need to compute word-wrapping
// here.
//
// Each textfield keeps its own insert mode state, which is not how normal
// applications work. To keep an app-wide insert mode, update/copy the
// "insert_mode" field of STB_TexteditState before/after calling API functions.
//
// API
//
// void stb_textedit_initialize_state(STB_TexteditState *state, int is_single_line)
//
// void stb_textedit_click(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
// void stb_textedit_drag(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
// int stb_textedit_cut(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
// int stb_textedit_paste(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_CHARTYPE *text, int len)
// void stb_textedit_key(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int key)
//
// Each of these functions potentially updates the string and updates the
// state.
//
// initialize_state:
// set the textedit state to a known good default state when initially
// constructing the textedit.
//
// click:
// call this with the mouse x,y on a mouse down; it will update the cursor
// and reset the selection start/end to the cursor point. the x,y must
// be relative to the text widget, with (0,0) being the top left.
//
// drag:
// call this with the mouse x,y on a mouse drag/up; it will update the
// cursor and the selection end point
//
// cut:
// call this to delete the current selection; returns true if there was
// one. you should FIRST copy the current selection to the system paste buffer.
// (To copy, just copy the current selection out of the string yourself.)
//
// paste:
// call this to paste text at the current cursor point or over the current
// selection if there is one.
//
// key:
// call this for keyboard inputs sent to the textfield. you can use it
// for "key down" events or for "translated" key events. if you need to
// do both (as in Win32), or distinguish Unicode characters from control
// inputs, set a high bit to distinguish the two; then you can define the
// various definitions like STB_TEXTEDIT_K_LEFT have the is-key-event bit
// set, and make STB_TEXTEDIT_KEYTOCHAR check that the is-key-event bit is
// clear.
//
// When rendering, you can read the cursor position and selection state from
// the STB_TexteditState.
//
//
// Notes:
//
// This is designed to be usable in IMGUI, so it allows for the possibility of
// running in an IMGUI that has NOT cached the multi-line layout. For this
// reason, it provides an interface that is compatible with computing the
// layout incrementally--we try to make sure we make as few passes through
// as possible. (For example, to locate the mouse pointer in the text, we
// could define functions that return the X and Y positions of characters
// and binary search Y and then X, but if we're doing dynamic layout this
// will run the layout algorithm many times, so instead we manually search
// forward in one pass. Similar logic applies to e.g. up-arrow and
// down-arrow movement.)
//
// If it's run in a widget that *has* cached the layout, then this is less
// efficient, but it's not horrible on modern computers. But you wouldn't
// want to edit million-line files with it.
////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////
////
//// Header-file mode
////
////
#ifndef INCLUDE_STB_TEXTEDIT_H
#define INCLUDE_STB_TEXTEDIT_H
////////////////////////////////////////////////////////////////////////
//
// STB_TexteditState
//
// Definition of STB_TexteditState which you should store
// per-textfield; it includes cursor position, selection state,
// and undo state.
//
#ifndef STB_TEXTEDIT_UNDOSTATECOUNT
#define STB_TEXTEDIT_UNDOSTATECOUNT 99
#endif
#ifndef STB_TEXTEDIT_UNDOCHARCOUNT
#define STB_TEXTEDIT_UNDOCHARCOUNT 999
#endif
#ifndef STB_TEXTEDIT_CHARTYPE
#define STB_TEXTEDIT_CHARTYPE int
#endif
#ifndef STB_TEXTEDIT_POSITIONTYPE
#define STB_TEXTEDIT_POSITIONTYPE int
#endif
typedef struct
{
// private data
STB_TEXTEDIT_POSITIONTYPE where;
short insert_length;
short delete_length;
short char_storage;
} StbUndoRecord;
typedef struct
{
// private data
StbUndoRecord undo_rec [STB_TEXTEDIT_UNDOSTATECOUNT];
STB_TEXTEDIT_CHARTYPE undo_char[STB_TEXTEDIT_UNDOCHARCOUNT];
short undo_point, redo_point;
short undo_char_point, redo_char_point;
} StbUndoState;
typedef struct
{
/////////////////////
//
// public data
//
int cursor;
// position of the text cursor within the string
int select_start; // selection start point
int select_end;
// selection start and end point in characters; if equal, no selection.
// note that start may be less than or greater than end (e.g. when
// dragging the mouse, start is where the initial click was, and you
// can drag in either direction)
unsigned char insert_mode;
// each textfield keeps its own insert mode state. to keep an app-wide
// insert mode, copy this value in/out of the app state
/////////////////////
//
// private data
//
unsigned char cursor_at_end_of_line; // not implemented yet
unsigned char initialized;
unsigned char has_preferred_x;
unsigned char single_line;
unsigned char padding1, padding2, padding3;
float preferred_x; // this determines where the cursor up/down tries to seek to along x
StbUndoState undostate;
} STB_TexteditState;
////////////////////////////////////////////////////////////////////////
//
// StbTexteditRow
//
// Result of layout query, used by stb_textedit to determine where
// the text in each row is.
// result of layout query
typedef struct
{
float x0,x1; // starting x location, end x location (allows for align=right, etc)
float baseline_y_delta; // position of baseline relative to previous row's baseline
float ymin,ymax; // height of row above and below baseline
int num_chars;
} StbTexteditRow;
#endif //INCLUDE_STB_TEXTEDIT_H
////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////
////
//// Implementation mode
////
////
// implementation isn't include-guarded, since it might have indirectly
// included just the "header" portion
#ifdef STB_TEXTEDIT_IMPLEMENTATION
#include <string.h> // memmove
/////////////////////////////////////////////////////////////////////////////
//
// Mouse input handling
//
// traverse the layout to locate the nearest character to a display position
static int stb_text_locate_coord(STB_TEXTEDIT_STRING *str, float x, float y)
{
StbTexteditRow r;
int n = STB_TEXTEDIT_STRINGLEN(str);
float base_y = 0, prev_x;
int i=0, k;
if (y < 0)
return 0;
r.x0 = r.x1 = 0;
r.ymin = r.ymax = 0;
r.num_chars = 0;
// search rows to find one that straddles 'y'
while (i < n) {
STB_TEXTEDIT_LAYOUTROW(&r, str, i);
if (r.num_chars <= 0)
return n;
if (y < base_y + r.ymax)
break;
i += r.num_chars;
base_y += r.baseline_y_delta;
}
// below all text, return 'after' last character
if (i >= n)
return n;
// check if it's before the beginning of the line
if (x < r.x0)
return i;
// check if it's before the end of the line
if (x < r.x1) {
// search characters in row for one that straddles 'x'
k = i;
prev_x = r.x0;
for (i=0; i < r.num_chars; ++i) {
float w = STB_TEXTEDIT_GETWIDTH(str, k, i);
if (x < prev_x+w) {
if (x < prev_x+w/2)
return k+i;
else
return k+i+1;
}
prev_x += w;
}
// shouldn't happen, but if it does, fall through to end-of-line case
}
// if the last character is a newline, return that. otherwise return 'after' the last character
if (STB_TEXTEDIT_GETCHAR(str, i+r.num_chars-1) == STB_TEXTEDIT_NEWLINE)
return i+r.num_chars-1;
else
return i+r.num_chars;
}
// API click: on mouse down, move the cursor to the clicked location, and reset the selection
static void stb_textedit_click(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
{
state->cursor = stb_text_locate_coord(str, x, y);
state->select_start = state->cursor;
state->select_end = state->cursor;
state->has_preferred_x = 0;
}
// API drag: on mouse drag, move the cursor and selection endpoint to the clicked location
static void stb_textedit_drag(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, float x, float y)
{
int p = stb_text_locate_coord(str, x, y);
state->cursor = state->select_end = p;
}
/////////////////////////////////////////////////////////////////////////////
//
// Keyboard input handling
//
// forward declarations
static void stb_text_undo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state);
static void stb_text_redo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state);
static void stb_text_makeundo_delete(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int length);
static void stb_text_makeundo_insert(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int length);
static void stb_text_makeundo_replace(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int old_length, int new_length);
typedef struct
{
float x,y; // position of n'th character
float height; // height of line
int first_char, length; // first char of row, and length
int prev_first; // first char of previous row
} StbFindState;
// find the x/y location of a character, and remember info about the previous row in
// case we get a move-up event (for page up, we'll have to rescan)
static void stb_textedit_find_charpos(StbFindState *find, STB_TEXTEDIT_STRING *str, int n, int single_line)
{
StbTexteditRow r;
int prev_start = 0;
int z = STB_TEXTEDIT_STRINGLEN(str);
int i=0, first;
if (n == z) {
// if it's at the end, then find the last line -- simpler than trying to
// explicitly handle this case in the regular code
if (single_line) {
STB_TEXTEDIT_LAYOUTROW(&r, str, 0);
find->y = 0;
find->first_char = 0;
find->length = z;
find->height = r.ymax - r.ymin;
find->x = r.x1;
} else {
find->y = 0;
find->x = 0;
find->height = 1;
while (i < z) {
STB_TEXTEDIT_LAYOUTROW(&r, str, i);
prev_start = i;
i += r.num_chars;
}
find->first_char = i;
find->length = 0;
find->prev_first = prev_start;
}
return;
}
// search rows to find the one that straddles character n
find->y = 0;
for(;;) {
STB_TEXTEDIT_LAYOUTROW(&r, str, i);
if (n < i + r.num_chars)
break;
prev_start = i;
i += r.num_chars;
find->y += r.baseline_y_delta;
}
find->first_char = first = i;
find->length = r.num_chars;
find->height = r.ymax - r.ymin;
find->prev_first = prev_start;
// now scan to find xpos
find->x = r.x0;
i = 0;
for (i=0; first+i < n; ++i)
find->x += STB_TEXTEDIT_GETWIDTH(str, first, i);
}
#define STB_TEXT_HAS_SELECTION(s) ((s)->select_start != (s)->select_end)
// make the selection/cursor state valid if client altered the string
static void stb_textedit_clamp(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
{
int n = STB_TEXTEDIT_STRINGLEN(str);
if (STB_TEXT_HAS_SELECTION(state)) {
if (state->select_start > n) state->select_start = n;
if (state->select_end > n) state->select_end = n;
// if clamping forced them to be equal, move the cursor to match
if (state->select_start == state->select_end)
state->cursor = state->select_start;
}
if (state->cursor > n) state->cursor = n;
}
// delete characters while updating undo
static void stb_textedit_delete(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int len)
{
stb_text_makeundo_delete(str, state, where, len);
STB_TEXTEDIT_DELETECHARS(str, where, len);
state->has_preferred_x = 0;
}
// delete the section
static void stb_textedit_delete_selection(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
{
stb_textedit_clamp(str, state);
if (STB_TEXT_HAS_SELECTION(state)) {
if (state->select_start < state->select_end) {
stb_textedit_delete(str, state, state->select_start, state->select_end - state->select_start);
state->select_end = state->cursor = state->select_start;
} else {
stb_textedit_delete(str, state, state->select_end, state->select_start - state->select_end);
state->select_start = state->cursor = state->select_end;
}
state->has_preferred_x = 0;
}
}
// canoncialize the selection so start <= end
static void stb_textedit_sortselection(STB_TexteditState *state)
{
if (state->select_end < state->select_start) {
int temp = state->select_end;
state->select_end = state->select_start;
state->select_start = temp;
}
}
// move cursor to first character of selection
static void stb_textedit_move_to_first(STB_TexteditState *state)
{
if (STB_TEXT_HAS_SELECTION(state)) {
stb_textedit_sortselection(state);
state->cursor = state->select_start;
state->select_end = state->select_start;
state->has_preferred_x = 0;
}
}
// move cursor to last character of selection
static void stb_textedit_move_to_last(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
{
if (STB_TEXT_HAS_SELECTION(state)) {
stb_textedit_sortselection(state);
stb_textedit_clamp(str, state);
state->cursor = state->select_end;
state->select_start = state->select_end;
state->has_preferred_x = 0;
}
}
#ifdef STB_TEXTEDIT_IS_SPACE
static int is_word_boundary( STB_TEXTEDIT_STRING *_str, int _idx )
{
return _idx > 0 ? (STB_TEXTEDIT_IS_SPACE( STB_TEXTEDIT_GETCHAR(_str,_idx-1) ) && !STB_TEXTEDIT_IS_SPACE( STB_TEXTEDIT_GETCHAR(_str, _idx) ) ) : 1;
}
static int stb_textedit_move_to_word_previous( STB_TEXTEDIT_STRING *_str, STB_TexteditState *_state )
{
int c = _state->cursor - 1;
while( c >= 0 && !is_word_boundary( _str, c ) )
--c;
if( c < 0 )
c = 0;
return c;
}
static int stb_textedit_move_to_word_next( STB_TEXTEDIT_STRING *_str, STB_TexteditState *_state )
{
const int len = STB_TEXTEDIT_STRINGLEN(_str);
int c = _state->cursor+1;
while( c < len && !is_word_boundary( _str, c ) )
++c;
if( c > len )
c = len;
return c;
}
#endif
// update selection and cursor to match each other
static void stb_textedit_prep_selection_at_cursor(STB_TexteditState *state)
{
if (!STB_TEXT_HAS_SELECTION(state))
state->select_start = state->select_end = state->cursor;
else
state->cursor = state->select_end;
}
// API cut: delete selection
static int stb_textedit_cut(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
{
if (STB_TEXT_HAS_SELECTION(state)) {
stb_textedit_delete_selection(str,state); // implicity clamps
state->has_preferred_x = 0;
return 1;
}
return 0;
}
// API paste: replace existing selection with passed-in text
static int stb_textedit_paste(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_CHARTYPE const *ctext, int len)
{
STB_TEXTEDIT_CHARTYPE *text = (STB_TEXTEDIT_CHARTYPE *) ctext;
// if there's a selection, the paste should delete it
stb_textedit_clamp(str, state);
stb_textedit_delete_selection(str,state);
// try to insert the characters
if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, text, len)) {
stb_text_makeundo_insert(str, state, state->cursor, len);
state->cursor += len;
state->has_preferred_x = 0;
return 1;
}
// remove the undo since we didn't actually insert the characters
if (state->undostate.undo_point)
--state->undostate.undo_point;
return 0;
}
// API key: process a keyboard input
static void stb_textedit_key(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int key)
{
retry:
switch (key) {
default: {
int c = STB_TEXTEDIT_KEYTOTEXT(key);
if (c > 0) {
STB_TEXTEDIT_CHARTYPE ch = (STB_TEXTEDIT_CHARTYPE) c;
// can't add newline in single-line mode
if (c == '\n' && state->single_line)
break;
if (state->insert_mode && !STB_TEXT_HAS_SELECTION(state) && state->cursor < STB_TEXTEDIT_STRINGLEN(str)) {
stb_text_makeundo_replace(str, state, state->cursor, 1, 1);
STB_TEXTEDIT_DELETECHARS(str, state->cursor, 1);
if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, &ch, 1)) {
++state->cursor;
state->has_preferred_x = 0;
}
} else {
stb_textedit_delete_selection(str,state); // implicity clamps
if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, &ch, 1)) {
stb_text_makeundo_insert(str, state, state->cursor, 1);
++state->cursor;
state->has_preferred_x = 0;
}
}
}
break;
}
#ifdef STB_TEXTEDIT_K_INSERT
case STB_TEXTEDIT_K_INSERT:
state->insert_mode = !state->insert_mode;
break;
#endif
case STB_TEXTEDIT_K_UNDO:
stb_text_undo(str, state);
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_REDO:
stb_text_redo(str, state);
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_LEFT:
// if currently there's a selection, move cursor to start of selection
if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_move_to_first(state);
else
if (state->cursor > 0)
--state->cursor;
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_RIGHT:
// if currently there's a selection, move cursor to end of selection
if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_move_to_last(str, state);
else
++state->cursor;
stb_textedit_clamp(str, state);
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_LEFT | STB_TEXTEDIT_K_SHIFT:
stb_textedit_clamp(str, state);
stb_textedit_prep_selection_at_cursor(state);
// move selection left
if (state->select_end > 0)
--state->select_end;
state->cursor = state->select_end;
state->has_preferred_x = 0;
break;
#ifdef STB_TEXTEDIT_IS_SPACE
case STB_TEXTEDIT_K_WORDLEFT:
if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_move_to_first(state);
else {
state->cursor = stb_textedit_move_to_word_previous(str, state);
stb_textedit_clamp( str, state );
}
break;
case STB_TEXTEDIT_K_WORDRIGHT:
if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_move_to_last(str, state);
else {
state->cursor = stb_textedit_move_to_word_next(str, state);
stb_textedit_clamp( str, state );
}
break;
case STB_TEXTEDIT_K_WORDLEFT | STB_TEXTEDIT_K_SHIFT:
if( !STB_TEXT_HAS_SELECTION( state ) )
stb_textedit_prep_selection_at_cursor(state);
state->cursor = stb_textedit_move_to_word_previous(str, state);
state->select_end = state->cursor;
stb_textedit_clamp( str, state );
break;
case STB_TEXTEDIT_K_WORDRIGHT | STB_TEXTEDIT_K_SHIFT:
if( !STB_TEXT_HAS_SELECTION( state ) )
stb_textedit_prep_selection_at_cursor(state);
state->cursor = stb_textedit_move_to_word_next(str, state);
state->select_end = state->cursor;
stb_textedit_clamp( str, state );
break;
#endif
case STB_TEXTEDIT_K_RIGHT | STB_TEXTEDIT_K_SHIFT:
stb_textedit_prep_selection_at_cursor(state);
// move selection right
++state->select_end;
stb_textedit_clamp(str, state);
state->cursor = state->select_end;
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_DOWN:
case STB_TEXTEDIT_K_DOWN | STB_TEXTEDIT_K_SHIFT: {
StbFindState find;
StbTexteditRow row;
int i, sel = (key & STB_TEXTEDIT_K_SHIFT) != 0;
if (state->single_line) {
// on windows, up&down in single-line behave like left&right
key = STB_TEXTEDIT_K_RIGHT | (key & STB_TEXTEDIT_K_SHIFT);
goto retry;
}
if (sel)
stb_textedit_prep_selection_at_cursor(state);
else if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_move_to_last(str,state);
// compute current position of cursor point
stb_textedit_clamp(str, state);
stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
// now find character position down a row
if (find.length) {
float goal_x = state->has_preferred_x ? state->preferred_x : find.x;
float x;
int start = find.first_char + find.length;
state->cursor = start;
STB_TEXTEDIT_LAYOUTROW(&row, str, state->cursor);
x = row.x0;
for (i=0; i < row.num_chars; ++i) {
float dx = STB_TEXTEDIT_GETWIDTH(str, start, i);
#ifdef STB_TEXTEDIT_GETWIDTH_NEWLINE
if (dx == STB_TEXTEDIT_GETWIDTH_NEWLINE)
break;
#endif
x += dx;
if (x > goal_x)
break;
++state->cursor;
}
stb_textedit_clamp(str, state);
state->has_preferred_x = 1;
state->preferred_x = goal_x;
if (sel)
state->select_end = state->cursor;
}
break;
}
case STB_TEXTEDIT_K_UP:
case STB_TEXTEDIT_K_UP | STB_TEXTEDIT_K_SHIFT: {
StbFindState find;
StbTexteditRow row;
int i, sel = (key & STB_TEXTEDIT_K_SHIFT) != 0;
if (state->single_line) {
// on windows, up&down become left&right
key = STB_TEXTEDIT_K_LEFT | (key & STB_TEXTEDIT_K_SHIFT);
goto retry;
}
if (sel)
stb_textedit_prep_selection_at_cursor(state);
else if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_move_to_first(state);
// compute current position of cursor point
stb_textedit_clamp(str, state);
stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
// can only go up if there's a previous row
if (find.prev_first != find.first_char) {
// now find character position up a row
float goal_x = state->has_preferred_x ? state->preferred_x : find.x;
float x;
state->cursor = find.prev_first;
STB_TEXTEDIT_LAYOUTROW(&row, str, state->cursor);
x = row.x0;
for (i=0; i < row.num_chars; ++i) {
float dx = STB_TEXTEDIT_GETWIDTH(str, find.prev_first, i);
#ifdef STB_TEXTEDIT_GETWIDTH_NEWLINE
if (dx == STB_TEXTEDIT_GETWIDTH_NEWLINE)
break;
#endif
x += dx;
if (x > goal_x)
break;
++state->cursor;
}
stb_textedit_clamp(str, state);
state->has_preferred_x = 1;
state->preferred_x = goal_x;
if (sel)
state->select_end = state->cursor;
}
break;
}
case STB_TEXTEDIT_K_DELETE:
case STB_TEXTEDIT_K_DELETE | STB_TEXTEDIT_K_SHIFT:
if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_delete_selection(str, state);
else {
int n = STB_TEXTEDIT_STRINGLEN(str);
if (state->cursor < n)
stb_textedit_delete(str, state, state->cursor, 1);
}
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_BACKSPACE:
case STB_TEXTEDIT_K_BACKSPACE | STB_TEXTEDIT_K_SHIFT:
if (STB_TEXT_HAS_SELECTION(state))
stb_textedit_delete_selection(str, state);
else {
stb_textedit_clamp(str, state);
if (state->cursor > 0) {
stb_textedit_delete(str, state, state->cursor-1, 1);
--state->cursor;
}
}
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_TEXTSTART:
state->cursor = state->select_start = state->select_end = 0;
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_TEXTEND:
state->cursor = STB_TEXTEDIT_STRINGLEN(str);
state->select_start = state->select_end = 0;
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_TEXTSTART | STB_TEXTEDIT_K_SHIFT:
stb_textedit_prep_selection_at_cursor(state);
state->cursor = state->select_end = 0;
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_TEXTEND | STB_TEXTEDIT_K_SHIFT:
stb_textedit_prep_selection_at_cursor(state);
state->cursor = state->select_end = STB_TEXTEDIT_STRINGLEN(str);
state->has_preferred_x = 0;
break;
case STB_TEXTEDIT_K_LINESTART: {
StbFindState find;
stb_textedit_clamp(str, state);
stb_textedit_move_to_first(state);
stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
state->cursor = find.first_char;
state->has_preferred_x = 0;
break;
}
case STB_TEXTEDIT_K_LINEEND: {
StbFindState find;
stb_textedit_clamp(str, state);
stb_textedit_move_to_first(state);
stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
state->cursor = find.first_char + find.length;
state->has_preferred_x = 0;
break;
}
case STB_TEXTEDIT_K_LINESTART | STB_TEXTEDIT_K_SHIFT: {
StbFindState find;
stb_textedit_clamp(str, state);
stb_textedit_prep_selection_at_cursor(state);
stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
state->cursor = state->select_end = find.first_char;
state->has_preferred_x = 0;
break;
}
case STB_TEXTEDIT_K_LINEEND | STB_TEXTEDIT_K_SHIFT: {
StbFindState find;
stb_textedit_clamp(str, state);
stb_textedit_prep_selection_at_cursor(state);
stb_textedit_find_charpos(&find, str, state->cursor, state->single_line);
state->cursor = state->select_end = find.first_char + find.length;
state->has_preferred_x = 0;
break;
}
// @TODO:
// STB_TEXTEDIT_K_PGUP - move cursor up a page
// STB_TEXTEDIT_K_PGDOWN - move cursor down a page
}
}
/////////////////////////////////////////////////////////////////////////////
//
// Undo processing
//
// @OPTIMIZE: the undo/redo buffer should be circular
static void stb_textedit_flush_redo(StbUndoState *state)
{
state->redo_point = STB_TEXTEDIT_UNDOSTATECOUNT;
state->redo_char_point = STB_TEXTEDIT_UNDOCHARCOUNT;
}
// discard the oldest entry in the undo list
static void stb_textedit_discard_undo(StbUndoState *state)
{
if (state->undo_point > 0) {
// if the 0th undo state has characters, clean those up
if (state->undo_rec[0].char_storage >= 0) {
int n = state->undo_rec[0].insert_length, i;
// delete n characters from all other records
state->undo_char_point = state->undo_char_point - (short) n; // vsnet05
memmove(state->undo_char, state->undo_char + n, state->undo_char_point*sizeof(STB_TEXTEDIT_CHARTYPE));
for (i=0; i < state->undo_point; ++i)
if (state->undo_rec[i].char_storage >= 0)
state->undo_rec[i].char_storage = state->undo_rec[i].char_storage - (short) n; // vsnet05 // @OPTIMIZE: get rid of char_storage and infer it
}
--state->undo_point;
memmove(state->undo_rec, state->undo_rec+1, state->undo_point*sizeof(state->undo_rec[0]));
}
}
// discard the oldest entry in the redo list--it's bad if this
// ever happens, but because undo & redo have to store the actual
// characters in different cases, the redo character buffer can
// fill up even though the undo buffer didn't
static void stb_textedit_discard_redo(StbUndoState *state)
{
int k = STB_TEXTEDIT_UNDOSTATECOUNT-1;
if (state->redo_point <= k) {
// if the k'th undo state has characters, clean those up
if (state->undo_rec[k].char_storage >= 0) {
int n = state->undo_rec[k].insert_length, i;
// delete n characters from all other records
state->redo_char_point = state->redo_char_point + (short) n; // vsnet05
memmove(state->undo_char + state->redo_char_point, state->undo_char + state->redo_char_point-n, (STB_TEXTEDIT_UNDOSTATECOUNT - state->redo_char_point)*sizeof(STB_TEXTEDIT_CHARTYPE));
for (i=state->redo_point; i < k; ++i)
if (state->undo_rec[i].char_storage >= 0)
state->undo_rec[i].char_storage = state->undo_rec[i].char_storage + (short) n; // vsnet05
}
++state->redo_point;
memmove(state->undo_rec + state->redo_point-1, state->undo_rec + state->redo_point, (STB_TEXTEDIT_UNDOSTATECOUNT - state->redo_point)*sizeof(state->undo_rec[0]));
}
}
static StbUndoRecord *stb_text_create_undo_record(StbUndoState *state, int numchars)
{
// any time we create a new undo record, we discard redo
stb_textedit_flush_redo(state);
// if we have no free records, we have to make room, by sliding the
// existing records down
if (state->undo_point == STB_TEXTEDIT_UNDOSTATECOUNT)
stb_textedit_discard_undo(state);
// if the characters to store won't possibly fit in the buffer, we can't undo
if (numchars > STB_TEXTEDIT_UNDOCHARCOUNT) {
state->undo_point = 0;
state->undo_char_point = 0;
return NULL;
}
// if we don't have enough free characters in the buffer, we have to make room
while (state->undo_char_point + numchars > STB_TEXTEDIT_UNDOCHARCOUNT)
stb_textedit_discard_undo(state);
return &state->undo_rec[state->undo_point++];
}
static STB_TEXTEDIT_CHARTYPE *stb_text_createundo(StbUndoState *state, int pos, int insert_len, int delete_len)
{
StbUndoRecord *r = stb_text_create_undo_record(state, insert_len);
if (r == NULL)
return NULL;
r->where = pos;
r->insert_length = (short) insert_len;
r->delete_length = (short) delete_len;
if (insert_len == 0) {
r->char_storage = -1;
return NULL;
} else {
r->char_storage = state->undo_char_point;
state->undo_char_point = state->undo_char_point + (short) insert_len;
return &state->undo_char[r->char_storage];
}
}
static void stb_text_undo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
{
StbUndoState *s = &state->undostate;
StbUndoRecord u, *r;
if (s->undo_point == 0)
return;
// we need to do two things: apply the undo record, and create a redo record
u = s->undo_rec[s->undo_point-1];
r = &s->undo_rec[s->redo_point-1];
r->char_storage = -1;
r->insert_length = u.delete_length;
r->delete_length = u.insert_length;
r->where = u.where;
if (u.delete_length) {
// if the undo record says to delete characters, then the redo record will
// need to re-insert the characters that get deleted, so we need to store
// them.
// there are three cases:
// there's enough room to store the characters
// characters stored for *redoing* don't leave room for redo
// characters stored for *undoing* don't leave room for redo
// if the last is true, we have to bail
if (s->undo_char_point + u.delete_length >= STB_TEXTEDIT_UNDOCHARCOUNT) {
// the undo records take up too much character space; there's no space to store the redo characters
r->insert_length = 0;
} else {
int i;
// there's definitely room to store the characters eventually
while (s->undo_char_point + u.delete_length > s->redo_char_point) {
// there's currently not enough room, so discard a redo record
stb_textedit_discard_redo(s);
// should never happen:
if (s->redo_point == STB_TEXTEDIT_UNDOSTATECOUNT)
return;
}
r = &s->undo_rec[s->redo_point-1];
r->char_storage = s->redo_char_point - u.delete_length;
s->redo_char_point = s->redo_char_point - (short) u.delete_length;
// now save the characters
for (i=0; i < u.delete_length; ++i)
s->undo_char[r->char_storage + i] = STB_TEXTEDIT_GETCHAR(str, u.where + i);
}
// now we can carry out the deletion
STB_TEXTEDIT_DELETECHARS(str, u.where, u.delete_length);
}
// check type of recorded action:
if (u.insert_length) {
// easy case: was a deletion, so we need to insert n characters
STB_TEXTEDIT_INSERTCHARS(str, u.where, &s->undo_char[u.char_storage], u.insert_length);
s->undo_char_point -= u.insert_length;
}
state->cursor = u.where + u.insert_length;
s->undo_point--;
s->redo_point--;
}
static void stb_text_redo(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
{
StbUndoState *s = &state->undostate;
StbUndoRecord *u, r;
if (s->redo_point == STB_TEXTEDIT_UNDOSTATECOUNT)
return;
// we need to do two things: apply the redo record, and create an undo record
u = &s->undo_rec[s->undo_point];
r = s->undo_rec[s->redo_point];
// we KNOW there must be room for the undo record, because the redo record
// was derived from an undo record
u->delete_length = r.insert_length;
u->insert_length = r.delete_length;
u->where = r.where;
u->char_storage = -1;
if (r.delete_length) {
// the redo record requires us to delete characters, so the undo record
// needs to store the characters
if (s->undo_char_point + u->insert_length > s->redo_char_point) {
u->insert_length = 0;
u->delete_length = 0;
} else {
int i;
u->char_storage = s->undo_char_point;
s->undo_char_point = s->undo_char_point + u->insert_length;
// now save the characters
for (i=0; i < u->insert_length; ++i)
s->undo_char[u->char_storage + i] = STB_TEXTEDIT_GETCHAR(str, u->where + i);
}
STB_TEXTEDIT_DELETECHARS(str, r.where, r.delete_length);
}
if (r.insert_length) {
// easy case: need to insert n characters
STB_TEXTEDIT_INSERTCHARS(str, r.where, &s->undo_char[r.char_storage], r.insert_length);
}
state->cursor = r.where + r.insert_length;
s->undo_point++;
s->redo_point++;
}
static void stb_text_makeundo_insert(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int length)
{
stb_text_createundo(&state->undostate, where, 0, length);
}
static void stb_text_makeundo_delete(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int length)
{
int i;
STB_TEXTEDIT_CHARTYPE *p = stb_text_createundo(&state->undostate, where, length, 0);
if (p) {
for (i=0; i < length; ++i)
p[i] = STB_TEXTEDIT_GETCHAR(str, where+i);
}
}
static void stb_text_makeundo_replace(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, int where, int old_length, int new_length)
{
int i;
STB_TEXTEDIT_CHARTYPE *p = stb_text_createundo(&state->undostate, where, old_length, new_length);
if (p) {
for (i=0; i < old_length; ++i)
p[i] = STB_TEXTEDIT_GETCHAR(str, where+i);
}
}
// reset the state to default
static void stb_textedit_clear_state(STB_TexteditState *state, int is_single_line)
{
state->undostate.undo_point = 0;
state->undostate.undo_char_point = 0;
state->undostate.redo_point = STB_TEXTEDIT_UNDOSTATECOUNT;
state->undostate.redo_char_point = STB_TEXTEDIT_UNDOCHARCOUNT;
state->select_end = state->select_start = 0;
state->cursor = 0;
state->has_preferred_x = 0;
state->preferred_x = 0;
state->cursor_at_end_of_line = 0;
state->initialized = 1;
state->single_line = (unsigned char) is_single_line;
state->insert_mode = 0;
}
// API initialize
static void stb_textedit_initialize_state(STB_TexteditState *state, int is_single_line)
{
stb_textedit_clear_state(state, is_single_line);
}
#endif//STB_TEXTEDIT_IMPLEMENTATION