1 /***************************************************************************
2 * Copyright (c) 2024 Microsoft Corporation
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the MIT License which is available at
6 * https://opensource.org/licenses/MIT.
7 *
8 * SPDX-License-Identifier: MIT
9 **************************************************************************/
10
11
12 /**************************************************************************/
13 /**************************************************************************/
14 /** */
15 /** GUIX Component */
16 /** */
17 /** Multi Line Text Input Management (Multi Line Text Input) */
18 /** */
19 /**************************************************************************/
20
21 #define GX_SOURCE_CODE
22
23
24 /* Include necessary system files. */
25
26 #include "gx_api.h"
27 #include "gx_system.h"
28 #include "gx_multi_line_text_input.h"
29 #include "gx_multi_line_text_view.h"
30 #include "gx_window.h"
31 #include "gx_widget.h"
32 #include "gx_utility.h"
33 #include "gx_scrollbar.h"
34
35 /**************************************************************************/
36 /* */
37 /* FUNCTION RELEASE */
38 /* */
39 /* _gx_multi_line_text_input_backspace PORTABLE C */
40 /* 6.1.7 */
41 /* AUTHOR */
42 /* */
43 /* Kenneth Maxwell, Microsoft Corporation */
44 /* */
45 /* DESCRIPTION */
46 /* */
47 /* This function deletes a character before the cursor. */
48 /* */
49 /* INPUT */
50 /* */
51 /* text_input Multi line text input widget */
52 /* control block */
53 /* */
54 /* OUTPUT */
55 /* */
56 /* None */
57 /* */
58 /* CALLS */
59 /* */
60 /* _gx_widget_font_get Retrieve font */
61 /* _gx_utility_rectangle_resize Increase/Shrink rectangle with*/
62 /* specified value */
63 /* _gx_utility_utf8_string_character_get Parses utf8 string to */
64 /* multi-byte glyph */
65 /* _gx_utility_string_length_check Test string length */
66 /* _gx_window_scrollbar_find Find scrollbar for a window */
67 /* _gx_window_client_width_get Get client width */
68 /* _gx_scrollbar_reset Reset scrollbar information */
69 /* _gx_multi_line_text_view_line_cache_update */
70 /* Update line cache */
71 /* _gx_multi_line_text_view_display_info_get */
72 /* Get the number of characters */
73 /* that a line can display */
74 /* _gx_multi_line_text_input_char_remove Remove a character */
75 /* _gx_multi_line_text_input_cursor_pos_update */
76 /* Update cursor position */
77 /* according to insert index */
78 /* _gx_multi_line_text_view_string_total_rows_compute */
79 /* _gx_system_string_width_get Get string width */
80 /* _gx_system_dirty_partial_add Add one dirty area to dirty */
81 /* list */
82 /* */
83 /* */
84 /* CALLED BY */
85 /* */
86 /* _gx_multi_line_text_input_keydown_process */
87 /* */
88 /* RELEASE HISTORY */
89 /* */
90 /* DATE NAME DESCRIPTION */
91 /* */
92 /* 05-19-2020 Kenneth Maxwell Initial Version 6.0 */
93 /* 09-30-2020 Kenneth Maxwell Modified comment(s), */
94 /* resulting in version 6.1 */
95 /* 06-02-2021 Kenneth Maxwell Modified comment(s), */
96 /* removed unused variable */
97 /* assignment, */
98 /* resulting in version 6.1.7 */
99 /* */
100 /**************************************************************************/
_gx_multi_line_text_input_backspace(GX_MULTI_LINE_TEXT_INPUT * text_input)101 UINT _gx_multi_line_text_input_backspace(GX_MULTI_LINE_TEXT_INPUT *text_input)
102 {
103 GX_TEXT_INPUT_CURSOR *cursor_ptr = &text_input -> gx_multi_line_text_input_cursor_instance;
104 GX_MULTI_LINE_TEXT_VIEW *view = (GX_MULTI_LINE_TEXT_VIEW *)text_input;
105 GX_FONT *font;
106 GX_RECTANGLE client;
107 GX_RECTANGLE dirty_rect;
108 UINT insert_pos;
109 INT shift;
110 INT last_visible_line;
111 GX_VALUE line_height;
112 GX_VALUE delete_width;
113 UINT old_text_rows;
114 UINT glyph_len = 1;
115 GX_STRING string;
116 GX_SCROLLBAR *scroll;
117 UINT start_mark = text_input -> gx_multi_line_text_input_start_mark;
118 UINT end_mark = text_input -> gx_multi_line_text_input_end_mark;
119
120 if (end_mark < start_mark)
121 {
122 return _gx_multi_line_text_input_delete(text_input);
123 }
124
125 insert_pos = text_input -> gx_multi_line_text_input_text_insert_position;
126
127 if (insert_pos > 0)
128 {
129 _gx_widget_font_get((GX_WIDGET *)text_input, text_input -> gx_multi_line_text_view_font_id, &font);
130
131 if (!font)
132 {
133 return GX_FAILURE;
134 }
135
136 if (start_mark != end_mark)
137 {
138 glyph_len = (UINT)GX_ABS((INT)start_mark - (INT)end_mark);
139 text_input -> gx_multi_line_text_input_start_mark = 0;
140 text_input -> gx_multi_line_text_input_end_mark = 0;
141
142 string.gx_string_ptr = &text_input -> gx_multi_line_text_view_text.gx_string_ptr[insert_pos - glyph_len];
143 }
144 else
145 {
146 _gx_multi_line_text_input_cursor_visible(text_input);
147
148 #ifdef GX_UTF8_SUPPORT
149 _gx_utility_utf8_string_backward_character_length_get(&text_input -> gx_multi_line_text_view_text,
150 (INT)(insert_pos - 1), &glyph_len);
151 #endif
152
153 /* Get the character to be deleted. */
154 string.gx_string_ptr = &text_input -> gx_multi_line_text_view_text.gx_string_ptr[insert_pos - glyph_len];
155
156 if (string.gx_string_ptr[0] == GX_KEY_CARRIAGE_RETURN || string.gx_string_ptr[0] == GX_KEY_LINE_FEED)
157 {
158 glyph_len = text_input -> gx_multi_line_text_input_new_line_character_size;
159
160 string.gx_string_ptr = &text_input -> gx_multi_line_text_view_text.gx_string_ptr[insert_pos - glyph_len];
161 }
162 }
163
164 string.gx_string_length = glyph_len;
165
166 /* Get the width of the character to be deleted. */
167 _gx_system_string_width_get_ext(font, &string, &delete_width);
168
169 /* Record old shift value. */
170 shift = text_input -> gx_multi_line_text_view_text_scroll_shift;
171
172 /* Remove character before cursor. */
173 _gx_multi_line_text_input_char_remove(text_input, insert_pos - glyph_len, glyph_len);
174
175 /* Save old text rows. */
176 old_text_rows = text_input -> gx_multi_line_text_view_text_total_rows;
177
178 /* Calculate new text rows. */
179 _gx_multi_line_text_view_string_total_rows_compute((GX_MULTI_LINE_TEXT_VIEW *)text_input);
180
181 if (old_text_rows != text_input -> gx_multi_line_text_view_text_total_rows)
182 {
183 _gx_window_scrollbar_find((GX_WINDOW *)text_input, GX_TYPE_VERTICAL_SCROLL, &scroll);
184 if (scroll)
185 {
186 /* Reset scrollbar. */
187 _gx_scrollbar_reset(scroll, GX_NULL);
188 }
189 else
190 {
191 if (text_input -> gx_multi_line_text_view_text_total_rows >
192 view -> gx_multi_line_text_view_cache_size)
193 {
194 _gx_multi_line_text_view_line_cache_update((GX_MULTI_LINE_TEXT_VIEW *)text_input);
195 }
196 }
197 }
198
199 /* Update text insert position. */
200 text_input -> gx_multi_line_text_input_text_insert_position -= glyph_len;
201
202 client = text_input -> gx_window_client;
203
204 if (text_input -> gx_multi_line_text_view_whitespace)
205 {
206 /* Offset client bounding box. */
207 _gx_utility_rectangle_resize(&client, (GX_VALUE)(-text_input -> gx_multi_line_text_view_whitespace));
208 }
209
210 /* Recalculate cursor position. */
211 _gx_multi_line_text_input_cursor_pos_update(text_input, GX_TRUE);
212
213 if (shift == text_input -> gx_multi_line_text_view_text_scroll_shift)
214 {
215
216 line_height = (GX_VALUE)(font -> gx_font_line_height + text_input -> gx_multi_line_text_view_line_space);
217
218 if (line_height)
219 {
220 /* Calculate dirty area. */
221 dirty_rect = client;
222
223 dirty_rect.gx_rectangle_top = (GX_VALUE)(cursor_ptr -> gx_text_input_cursor_pos.gx_point_y - (line_height << 1));
224
225 /* Calculate last visible line. */
226 last_visible_line = (-text_input -> gx_multi_line_text_view_text_scroll_shift) / line_height;
227 last_visible_line = last_visible_line + (INT)view -> gx_multi_line_text_view_text_visible_rows + 1;
228
229 if (last_visible_line > (INT)text_input -> gx_multi_line_text_view_text_total_rows)
230 {
231 last_visible_line = (INT)text_input -> gx_multi_line_text_view_text_total_rows;
232 }
233
234 shift = (last_visible_line + (INT)old_text_rows - (INT)text_input -> gx_multi_line_text_view_text_total_rows) * line_height + shift;
235 shift += client.gx_rectangle_top;
236
237 if (shift < dirty_rect.gx_rectangle_bottom)
238 {
239 dirty_rect.gx_rectangle_bottom = (GX_VALUE)shift;
240 }
241
242 _gx_system_dirty_partial_add((GX_WIDGET *)text_input, &dirty_rect);
243 }
244 }
245 else
246 {
247 _gx_system_dirty_mark((GX_WIDGET *)text_input);
248 }
249 }
250
251 return GX_SUCCESS;
252 }
253
254
