src/game/edit_field.c

   1 #include <assert.h>
   2
   3 #include "edit_field.h"
   4 #include "game/sprite_font.h"
   5 #include "sdl/renderer.h"
   6 #include "system/error.h"
   7 #include "system/lt.h"
   8
   9 #define BUFFER_CAPACITY 256
  10
  11 struct Edit_field
  12 {
  13     Lt *lt;
  14     char *buffer;
  15     size_t buffer_size;
  16     size_t cursor;
  17     const Sprite_font *font;
  18     Vec font_size;
  19     Color font_color;
  20 };
  21
  22 static void edit_field_left(Edit_field *edit_field);
  23 static void edit_field_right(Edit_field *edit_field);
  24 static void edit_field_backspace(Edit_field *edit_field);
  25 static void edit_field_delete(Edit_field *edit_field);
  26 static void edit_field_insert_char(Edit_field *edit_field, char c);
  27
  28 Edit_field *create_edit_field(const Sprite_font *font,
  29                                 Vec font_size,
  30                                 Color font_color)
  31 {
  32     assert(font);
  33
  34     Lt *lt = create_lt();
  35
  36     if (lt == NULL) {
  37         return NULL;
  38     }
  39
  40     Edit_field *const edit_field = PUSH_LT(lt, malloc(sizeof(Edit_field)), free);
  41     if (edit_field == NULL) {
  42         throw_error(ERROR_TYPE_LIBC);
  43         RETURN_LT(lt, NULL);
  44     }
  45     edit_field->lt = lt;
  46
  47     edit_field->buffer = PUSH_LT(lt, malloc(sizeof(char) * (BUFFER_CAPACITY + 10)), free);
  48     if (edit_field->buffer == NULL) {
  49         throw_error(ERROR_TYPE_LIBC);
  50         RETURN_LT(lt, NULL);
  51     }
  52
  53     edit_field->buffer_size = 0;
  54     edit_field->cursor = 0;
  55     edit_field->font = font;
  56     edit_field->font_size = font_size;
  57     edit_field->font_color = font_color;
  58
  59     edit_field->buffer[edit_field->buffer_size] = 0;
  60
  61     return edit_field;
  62 }
  63
  64 void destroy_edit_field(Edit_field *edit_field)
  65 {
  66     assert(edit_field);
  67     RETURN_LT0(edit_field->lt);
  68 }
  69
  70 int edit_field_render(const Edit_field *edit_field,
  71                       SDL_Renderer *renderer,
  72                       Point position)
  73 {
  74     assert(edit_field);
  75     assert(renderer);
  76
  77     const float cursor_y_overflow = 10.0f;
  78     const float cursor_width = 2.0f;
  79
  80     if (sprite_font_render_text(edit_field->font,
  81                                 renderer,
  82                                 position,
  83                                 edit_field->font_size,
  84                                 edit_field->font_color,
  85                                 edit_field->buffer) < 0) {
  86         return -1;
  87     }
  88
  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     assert(edit_field);
 106     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             edit_field_insert_char(edit_field, (char) event->key.keysym.sym);
 129         }
 130         }
 131         break;
 132
 133     default: {}
 134     }
 135
 136     return 0;
 137 }
 138
 139 const char *edit_field_as_text(const Edit_field *edit_field)
 140 {
 141     assert(edit_field);
 142     return edit_field->buffer;
 143 }
 144
 145 static void edit_field_left(Edit_field *edit_field)
 146 {
 147     if (edit_field->cursor > 0) {
 148         edit_field->cursor--;
 149     }
 150 }
 151
 152 static void edit_field_right(Edit_field *edit_field)
 153 {
 154     assert(edit_field);
 155     if (edit_field->cursor < edit_field->buffer_size) {
 156         edit_field->cursor++;
 157     }
 158 }
 159
 160 static void edit_field_backspace(Edit_field *edit_field)
 161 {
 162     assert(edit_field);
 163
 164     if (edit_field->cursor == 0) {
 165         return;
 166     }
 167
 168     for (size_t i = edit_field->cursor; i < edit_field->buffer_size; ++i) {
 169         edit_field->buffer[i - 1] = edit_field->buffer[i];
 170     }
 171
 172     edit_field->cursor--;
 173     edit_field->buffer[--edit_field->buffer_size] = 0;
 174 }
 175
 176 static void edit_field_delete(Edit_field *edit_field)
 177 {
 178     assert(edit_field);
 179
 180     if (edit_field->cursor >= edit_field->buffer_size) {
 181         return;
 182     }
 183
 184     for (size_t i = edit_field->cursor; i < edit_field->buffer_size; ++i) {
 185         edit_field->buffer[i] = edit_field->buffer[i + 1];
 186     }
 187
 188     edit_field->buffer[--edit_field->buffer_size] = 0;
 189 }
 190
 191 static void edit_field_insert_char(Edit_field *edit_field, char c)
 192 {
 193     assert(edit_field);
 194
 195     if (edit_field->buffer_size >= BUFFER_CAPACITY) {
 196         return;
 197     }
 198
 199     for (int64_t i = (int64_t) edit_field->buffer_size - 1; i >= (int64_t) edit_field->cursor; --i) {
 200         edit_field->buffer[i + 1] = edit_field->buffer[i];
 201     }
 202
 203     edit_field->buffer[edit_field->cursor++] = c;
 204     edit_field->buffer[++edit_field->buffer_size] = 0;
 205 }