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(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 const char *edit_field_as_text(const Edit_field *edit_field)
  95 {
  96     trace_assert(edit_field);
  97     return edit_field->buffer;
  98 }
  99
 100 static void edit_field_left(Edit_field *edit_field)
 101 {
 102     if (edit_field->cursor > 0) {
 103         edit_field->cursor--;
 104     }
 105 }
 106
 107 static void edit_field_right(Edit_field *edit_field)
 108 {
 109     trace_assert(edit_field);
 110     if (edit_field->cursor < edit_field->buffer_size) {
 111         edit_field->cursor++;
 112     }
 113 }
 114
 115 static void edit_field_backspace(Edit_field *edit_field)
 116 {
 117     trace_assert(edit_field);
 118
 119     if (edit_field->cursor == 0) {
 120         return;
 121     }
 122
 123     for (size_t i = edit_field->cursor; i < edit_field->buffer_size; ++i) {
 124         edit_field->buffer[i - 1] = edit_field->buffer[i];
 125     }
 126
 127     edit_field->cursor--;
 128     edit_field->buffer[--edit_field->buffer_size] = 0;
 129 }
 130
 131 static void edit_field_delete(Edit_field *edit_field)
 132 {
 133     trace_assert(edit_field);
 134
 135     if (edit_field->cursor >= edit_field->buffer_size) {
 136         return;
 137     }
 138
 139     for (size_t i = edit_field->cursor; i < edit_field->buffer_size; ++i) {
 140         edit_field->buffer[i] = edit_field->buffer[i + 1];
 141     }
 142
 143     edit_field->buffer[--edit_field->buffer_size] = 0;
 144 }
 145
 146 static void edit_field_insert_char(Edit_field *edit_field, char c)
 147 {
 148     trace_assert(edit_field);
 149
 150     if (edit_field->buffer_size >= BUFFER_CAPACITY) {
 151         return;
 152     }
 153
 154     for (int64_t i = (int64_t) edit_field->buffer_size - 1; i >= (int64_t) edit_field->cursor; --i) {
 155         edit_field->buffer[i + 1] = edit_field->buffer[i];
 156     }
 157
 158     edit_field->buffer[edit_field->cursor++] = c;
 159     edit_field->buffer[++edit_field->buffer_size] = 0;
 160 }
 161
 162 void edit_field_clean(Edit_field *edit_field)
 163 {
 164     trace_assert(edit_field);
 165
 166     edit_field->cursor = 0;
 167     edit_field->buffer_size = 0;
 168     edit_field->buffer[0] = 0;
 169 }
 170
 171 void edit_field_replace(Edit_field *edit_field, const char *text)
 172 {
 173     trace_assert(edit_field);
 174
 175     edit_field_clean(edit_field);
 176
 177     if (text == NULL) {
 178         return;
 179     }
 180
 181     size_t n = strlen(text);
 182     for (size_t i = 0; i < n; ++i) {
 183         edit_field_insert_char(edit_field, text[i]);
 184     }
 185 }
 186
 187 int edit_field_keyboard(Edit_field *edit_field,
 188                         const SDL_KeyboardEvent *key)
 189 {
 190     trace_assert(edit_field);
 191     trace_assert(key);
 192
 193     if (key->type == SDL_KEYDOWN) {
 194         switch (key->keysym.sym) {
 195         case SDLK_LEFT:
 196             edit_field_left(edit_field);
 197             break;
 198
 199         case SDLK_RIGHT:
 200             edit_field_right(edit_field);
 201             break;
 202
 203         case SDLK_BACKSPACE:
 204             edit_field_backspace(edit_field);
 205             break;
 206
 207         case SDLK_DELETE:
 208             edit_field_delete(edit_field);
 209             break;
 210
 211         default: {}
 212         }
 213     }
 214
 215     return 0;
 216 }
 217
 218 int edit_field_text_input(Edit_field *edit_field,
 219                           const SDL_TextInputEvent *text_input)
 220 {
 221     trace_assert(edit_field);
 222     trace_assert(text_input);
 223
 224     size_t n = strlen(text_input->text);
 225     for (size_t i = 0; i < n; ++i) {
 226         edit_field_insert_char(edit_field, text_input->text[i]);
 227     }
 228
 229     return 0;
 230 }