src/ui/edit_field.c

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