src/ui/edit_field.c

   1 #include <stdbool.h>
   2
   3 #include "edit_field.h"
   4 #include "game/camera.h"
   5 #include "game/sprite_font.h"
   6 #include "sdl/renderer.h"
   7 #include "system/lt.h"
   8 #include "system/nth_alloc.h"
   9 #include "system/stacktrace.h"
  10
  11 #define BUFFER_CAPACITY 256
  12
  13 struct Edit_field
  14 {
  15     Lt *lt;
  16     char *buffer;
  17     size_t buffer_size;
  18     size_t cursor;
  19     Vec font_size;
  20     Color font_color;
  21 };
  22
  23 static void edit_field_left(Edit_field *edit_field);
  24 static void edit_field_right(Edit_field *edit_field);
  25 static void edit_field_backspace(Edit_field *edit_field);
  26 static void edit_field_delete(Edit_field *edit_field);
  27 static void edit_field_insert_char(Edit_field *edit_field, char c);
  28
  29 Edit_field *create_edit_field(Vec font_size,
  30                               Color font_color)
  31 {
  32     Lt *lt = create_lt();
  33
  34     Edit_field *const edit_field = PUSH_LT(lt, nth_calloc(1, sizeof(Edit_field)), free);
  35     if (edit_field == NULL) {
  36         RETURN_LT(lt, NULL);
  37     }
  38     edit_field->lt = lt;
  39
  40     edit_field->buffer = PUSH_LT(lt, nth_calloc(1, sizeof(char) * (BUFFER_CAPACITY + 10)), free);
  41     if (edit_field->buffer == NULL) {
  42         RETURN_LT(lt, NULL);
  43     }
  44
  45     edit_field->buffer_size = 0;
  46     edit_field->cursor = 0;
  47     edit_field->font_size = font_size;
  48     edit_field->font_color = font_color;
  49
  50     edit_field->buffer[edit_field->buffer_size] = 0;
  51
  52     return edit_field;
  53 }
  54
  55 void destroy_edit_field(Edit_field *edit_field)
  56 {
  57     trace_assert(edit_field);
  58     RETURN_LT0(edit_field->lt);
  59 }
  60
  61 int edit_field_render_screen(const Edit_field *edit_field,
  62                              Camera *camera,
  63                              Point screen_position)
  64 {
  65     trace_assert(edit_field);
  66     trace_assert(camera);
  67
  68     const float cursor_y_overflow = 10.0f;
  69     const float cursor_width = 2.0f;
  70
  71     if (camera_render_text_screen(
  72             camera,
  73             edit_field->buffer,
  74             edit_field->font_size,
  75             edit_field->font_color,
  76             screen_position) < 0) {
  77         return -1;
  78     }
  79
  80     /* TODO(#363): the size of the cursor does not correspond to font size */
  81     if (camera_fill_rect_screen(
  82             camera,
  83             rect(screen_position.x + (float) edit_field->cursor * (float) FONT_CHAR_WIDTH * edit_field->font_size.x,
  84                  screen_position.y - cursor_y_overflow,
  85                  cursor_width,
  86                  FONT_CHAR_HEIGHT * edit_field->font_size.y + cursor_y_overflow * 2.0f),
  87             edit_field->font_color) < 0) {
  88         return -1;
  89     }
  90
  91     return 0;
  92 }
  93
  94 int edit_field_render_world(const Edit_field *edit_field,
  95                             Camera *camera,
  96                             Point world_position)
  97 {
  98     trace_assert(edit_field);
  99     trace_assert(camera);
 100
 101     const float cursor_y_overflow = 10.0f;
 102     const float cursor_width = 2.0f;
 103
 104     if (camera_render_text(
 105             camera,
 106             edit_field->buffer,
 107             edit_field->font_size,
 108             edit_field->font_color,
 109             world_position) < 0) {
 110         return -1;
 111     }
 112
 113     if (camera_fill_rect(
 114             camera,
 115             rect(world_position.x + (float) edit_field->cursor * (float) FONT_CHAR_WIDTH * edit_field->font_size.x,
 116                  world_position.y - cursor_y_overflow,
 117                  cursor_width,
 118                  FONT_CHAR_HEIGHT * edit_field->font_size.y + cursor_y_overflow * 2.0f),
 119             edit_field->font_color) < 0) {
 120         return -1;
 121     }
 122
 123     return 0;
 124 }
 125
 126 const char *edit_field_as_text(const Edit_field *edit_field)
 127 {
 128     trace_assert(edit_field);
 129     return edit_field->buffer;
 130 }
 131
 132 static void edit_field_left(Edit_field *edit_field)
 133 {
 134     if (edit_field->cursor > 0) {
 135         edit_field->cursor--;
 136     }
 137 }
 138
 139 static void edit_field_right(Edit_field *edit_field)
 140 {
 141     trace_assert(edit_field);
 142     if (edit_field->cursor < edit_field->buffer_size) {
 143         edit_field->cursor++;
 144     }
 145 }
 146
 147 static void edit_field_backspace(Edit_field *edit_field)
 148 {
 149     trace_assert(edit_field);
 150
 151     if (edit_field->cursor == 0) {
 152         return;
 153     }
 154
 155     for (size_t i = edit_field->cursor; i < edit_field->buffer_size; ++i) {
 156         edit_field->buffer[i - 1] = edit_field->buffer[i];
 157     }
 158
 159     edit_field->cursor--;
 160     edit_field->buffer[--edit_field->buffer_size] = 0;
 161 }
 162
 163 static void edit_field_delete(Edit_field *edit_field)
 164 {
 165     trace_assert(edit_field);
 166
 167     if (edit_field->cursor >= edit_field->buffer_size) {
 168         return;
 169     }
 170
 171     for (size_t i = edit_field->cursor; i < edit_field->buffer_size; ++i) {
 172         edit_field->buffer[i] = edit_field->buffer[i + 1];
 173     }
 174
 175     edit_field->buffer[--edit_field->buffer_size] = 0;
 176 }
 177
 178 static void edit_field_insert_char(Edit_field *edit_field, char c)
 179 {
 180     trace_assert(edit_field);
 181
 182     if (edit_field->buffer_size >= BUFFER_CAPACITY) {
 183         return;
 184     }
 185
 186     for (int64_t i = (int64_t) edit_field->buffer_size - 1; i >= (int64_t) edit_field->cursor; --i) {
 187         edit_field->buffer[i + 1] = edit_field->buffer[i];
 188     }
 189
 190     edit_field->buffer[edit_field->cursor++] = c;
 191     edit_field->buffer[++edit_field->buffer_size] = 0;
 192 }
 193
 194 void edit_field_clean(Edit_field *edit_field)
 195 {
 196     trace_assert(edit_field);
 197
 198     edit_field->cursor = 0;
 199     edit_field->buffer_size = 0;
 200     edit_field->buffer[0] = 0;
 201 }
 202
 203 void edit_field_replace(Edit_field *edit_field, const char *text)
 204 {
 205     trace_assert(edit_field);
 206
 207     edit_field_clean(edit_field);
 208
 209     if (text == NULL) {
 210         return;
 211     }
 212
 213     size_t n = strlen(text);
 214     for (size_t i = 0; i < n; ++i) {
 215         edit_field_insert_char(edit_field, text[i]);
 216     }
 217 }
 218
 219 int edit_field_event(Edit_field *edit_field, const SDL_Event *event)
 220 {
 221     trace_assert(edit_field);
 222     trace_assert(event);
 223
 224     switch (event->type) {
 225     case SDL_KEYDOWN: {
 226         switch (event->key.keysym.sym) {
 227         case SDLK_LEFT:
 228             edit_field_left(edit_field);
 229             break;
 230
 231         case SDLK_RIGHT:
 232             edit_field_right(edit_field);
 233             break;
 234
 235         case SDLK_BACKSPACE:
 236             edit_field_backspace(edit_field);
 237             break;
 238
 239         case SDLK_DELETE:
 240             edit_field_delete(edit_field);
 241             break;
 242         }
 243     } break;
 244
 245     case SDL_TEXTINPUT: {
 246         size_t n = strlen(event->text.text);
 247         for (size_t i = 0; i < n; ++i) {
 248             edit_field_insert_char(edit_field, event->text.text[i]);
 249         }
 250     } break;
 251     }
 252
 253     return 0;
 254 }