src/video/emscripten/SDL_emscriptenevents.c
author Charlie Birks <admin@daftgames.net>
Wed, 24 May 2017 14:04:39 +0100
changeset 11025 2215b66794ba
parent 11024 32026cc5015a
child 11034 fcb1f3161d2e
permissions -rw-r--r--
Emscripten: Prevent default on arrow keys
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 
    23 #include "../../SDL_internal.h"
    24 
    25 #if SDL_VIDEO_DRIVER_EMSCRIPTEN
    26 
    27 #include <emscripten/html5.h>
    28 
    29 #include "../../events/SDL_events_c.h"
    30 #include "../../events/SDL_keyboard_c.h"
    31 #include "../../events/SDL_touch_c.h"
    32 
    33 #include "SDL_emscriptenevents.h"
    34 #include "SDL_emscriptenvideo.h"
    35 
    36 #include "SDL_hints.h"
    37 
    38 #define FULLSCREEN_MASK ( SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN )
    39 
    40 /*
    41 .keyCode to scancode
    42 https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent
    43 https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode
    44 */
    45 static const SDL_Scancode emscripten_scancode_table[] = {
    46     /*  0 */    SDL_SCANCODE_UNKNOWN,
    47     /*  1 */    SDL_SCANCODE_UNKNOWN,
    48     /*  2 */    SDL_SCANCODE_UNKNOWN,
    49     /*  3 */    SDL_SCANCODE_CANCEL,
    50     /*  4 */    SDL_SCANCODE_UNKNOWN,
    51     /*  5 */    SDL_SCANCODE_UNKNOWN,
    52     /*  6 */    SDL_SCANCODE_HELP,
    53     /*  7 */    SDL_SCANCODE_UNKNOWN,
    54     /*  8 */    SDL_SCANCODE_BACKSPACE,
    55     /*  9 */    SDL_SCANCODE_TAB,
    56     /*  10 */   SDL_SCANCODE_UNKNOWN,
    57     /*  11 */   SDL_SCANCODE_UNKNOWN,
    58     /*  12 */   SDL_SCANCODE_UNKNOWN,
    59     /*  13 */   SDL_SCANCODE_RETURN,
    60     /*  14 */   SDL_SCANCODE_UNKNOWN,
    61     /*  15 */   SDL_SCANCODE_UNKNOWN,
    62     /*  16 */   SDL_SCANCODE_LSHIFT,
    63     /*  17 */   SDL_SCANCODE_LCTRL,
    64     /*  18 */   SDL_SCANCODE_LALT,
    65     /*  19 */   SDL_SCANCODE_PAUSE,
    66     /*  20 */   SDL_SCANCODE_CAPSLOCK,
    67     /*  21 */   SDL_SCANCODE_UNKNOWN,
    68     /*  22 */   SDL_SCANCODE_UNKNOWN,
    69     /*  23 */   SDL_SCANCODE_UNKNOWN,
    70     /*  24 */   SDL_SCANCODE_UNKNOWN,
    71     /*  25 */   SDL_SCANCODE_UNKNOWN,
    72     /*  26 */   SDL_SCANCODE_UNKNOWN,
    73     /*  27 */   SDL_SCANCODE_ESCAPE,
    74     /*  28 */   SDL_SCANCODE_UNKNOWN,
    75     /*  29 */   SDL_SCANCODE_UNKNOWN,
    76     /*  30 */   SDL_SCANCODE_UNKNOWN,
    77     /*  31 */   SDL_SCANCODE_UNKNOWN,
    78     /*  32 */   SDL_SCANCODE_SPACE,
    79     /*  33 */   SDL_SCANCODE_PAGEUP,
    80     /*  34 */   SDL_SCANCODE_PAGEDOWN,
    81     /*  35 */   SDL_SCANCODE_END,
    82     /*  36 */   SDL_SCANCODE_HOME,
    83     /*  37 */   SDL_SCANCODE_LEFT,
    84     /*  38 */   SDL_SCANCODE_UP,
    85     /*  39 */   SDL_SCANCODE_RIGHT,
    86     /*  40 */   SDL_SCANCODE_DOWN,
    87     /*  41 */   SDL_SCANCODE_UNKNOWN,
    88     /*  42 */   SDL_SCANCODE_UNKNOWN,
    89     /*  43 */   SDL_SCANCODE_UNKNOWN,
    90     /*  44 */   SDL_SCANCODE_UNKNOWN,
    91     /*  45 */   SDL_SCANCODE_INSERT,
    92     /*  46 */   SDL_SCANCODE_DELETE,
    93     /*  47 */   SDL_SCANCODE_UNKNOWN,
    94     /*  48 */   SDL_SCANCODE_0,
    95     /*  49 */   SDL_SCANCODE_1,
    96     /*  50 */   SDL_SCANCODE_2,
    97     /*  51 */   SDL_SCANCODE_3,
    98     /*  52 */   SDL_SCANCODE_4,
    99     /*  53 */   SDL_SCANCODE_5,
   100     /*  54 */   SDL_SCANCODE_6,
   101     /*  55 */   SDL_SCANCODE_7,
   102     /*  56 */   SDL_SCANCODE_8,
   103     /*  57 */   SDL_SCANCODE_9,
   104     /*  58 */   SDL_SCANCODE_UNKNOWN,
   105     /*  59 */   SDL_SCANCODE_SEMICOLON,
   106     /*  60 */   SDL_SCANCODE_UNKNOWN,
   107     /*  61 */   SDL_SCANCODE_EQUALS,
   108     /*  62 */   SDL_SCANCODE_UNKNOWN,
   109     /*  63 */   SDL_SCANCODE_UNKNOWN,
   110     /*  64 */   SDL_SCANCODE_UNKNOWN,
   111     /*  65 */   SDL_SCANCODE_A,
   112     /*  66 */   SDL_SCANCODE_B,
   113     /*  67 */   SDL_SCANCODE_C,
   114     /*  68 */   SDL_SCANCODE_D,
   115     /*  69 */   SDL_SCANCODE_E,
   116     /*  70 */   SDL_SCANCODE_F,
   117     /*  71 */   SDL_SCANCODE_G,
   118     /*  72 */   SDL_SCANCODE_H,
   119     /*  73 */   SDL_SCANCODE_I,
   120     /*  74 */   SDL_SCANCODE_J,
   121     /*  75 */   SDL_SCANCODE_K,
   122     /*  76 */   SDL_SCANCODE_L,
   123     /*  77 */   SDL_SCANCODE_M,
   124     /*  78 */   SDL_SCANCODE_N,
   125     /*  79 */   SDL_SCANCODE_O,
   126     /*  80 */   SDL_SCANCODE_P,
   127     /*  81 */   SDL_SCANCODE_Q,
   128     /*  82 */   SDL_SCANCODE_R,
   129     /*  83 */   SDL_SCANCODE_S,
   130     /*  84 */   SDL_SCANCODE_T,
   131     /*  85 */   SDL_SCANCODE_U,
   132     /*  86 */   SDL_SCANCODE_V,
   133     /*  87 */   SDL_SCANCODE_W,
   134     /*  88 */   SDL_SCANCODE_X,
   135     /*  89 */   SDL_SCANCODE_Y,
   136     /*  90 */   SDL_SCANCODE_Z,
   137     /*  91 */   SDL_SCANCODE_LGUI,
   138     /*  92 */   SDL_SCANCODE_UNKNOWN,
   139     /*  93 */   SDL_SCANCODE_APPLICATION,
   140     /*  94 */   SDL_SCANCODE_UNKNOWN,
   141     /*  95 */   SDL_SCANCODE_UNKNOWN,
   142     /*  96 */   SDL_SCANCODE_KP_0,
   143     /*  97 */   SDL_SCANCODE_KP_1,
   144     /*  98 */   SDL_SCANCODE_KP_2,
   145     /*  99 */   SDL_SCANCODE_KP_3,
   146     /* 100 */   SDL_SCANCODE_KP_4,
   147     /* 101 */   SDL_SCANCODE_KP_5,
   148     /* 102 */   SDL_SCANCODE_KP_6,
   149     /* 103 */   SDL_SCANCODE_KP_7,
   150     /* 104 */   SDL_SCANCODE_KP_8,
   151     /* 105 */   SDL_SCANCODE_KP_9,
   152     /* 106 */   SDL_SCANCODE_KP_MULTIPLY,
   153     /* 107 */   SDL_SCANCODE_KP_PLUS,
   154     /* 108 */   SDL_SCANCODE_UNKNOWN,
   155     /* 109 */   SDL_SCANCODE_KP_MINUS,
   156     /* 110 */   SDL_SCANCODE_KP_PERIOD,
   157     /* 111 */   SDL_SCANCODE_KP_DIVIDE,
   158     /* 112 */   SDL_SCANCODE_F1,
   159     /* 113 */   SDL_SCANCODE_F2,
   160     /* 114 */   SDL_SCANCODE_F3,
   161     /* 115 */   SDL_SCANCODE_F4,
   162     /* 116 */   SDL_SCANCODE_F5,
   163     /* 117 */   SDL_SCANCODE_F6,
   164     /* 118 */   SDL_SCANCODE_F7,
   165     /* 119 */   SDL_SCANCODE_F8,
   166     /* 120 */   SDL_SCANCODE_F9,
   167     /* 121 */   SDL_SCANCODE_F10,
   168     /* 122 */   SDL_SCANCODE_F11,
   169     /* 123 */   SDL_SCANCODE_F12,
   170     /* 124 */   SDL_SCANCODE_F13,
   171     /* 125 */   SDL_SCANCODE_F14,
   172     /* 126 */   SDL_SCANCODE_F15,
   173     /* 127 */   SDL_SCANCODE_F16,
   174     /* 128 */   SDL_SCANCODE_F17,
   175     /* 129 */   SDL_SCANCODE_F18,
   176     /* 130 */   SDL_SCANCODE_F19,
   177     /* 131 */   SDL_SCANCODE_F20,
   178     /* 132 */   SDL_SCANCODE_F21,
   179     /* 133 */   SDL_SCANCODE_F22,
   180     /* 134 */   SDL_SCANCODE_F23,
   181     /* 135 */   SDL_SCANCODE_F24,
   182     /* 136 */   SDL_SCANCODE_UNKNOWN,
   183     /* 137 */   SDL_SCANCODE_UNKNOWN,
   184     /* 138 */   SDL_SCANCODE_UNKNOWN,
   185     /* 139 */   SDL_SCANCODE_UNKNOWN,
   186     /* 140 */   SDL_SCANCODE_UNKNOWN,
   187     /* 141 */   SDL_SCANCODE_UNKNOWN,
   188     /* 142 */   SDL_SCANCODE_UNKNOWN,
   189     /* 143 */   SDL_SCANCODE_UNKNOWN,
   190     /* 144 */   SDL_SCANCODE_NUMLOCKCLEAR,
   191     /* 145 */   SDL_SCANCODE_SCROLLLOCK,
   192     /* 146 */   SDL_SCANCODE_UNKNOWN,
   193     /* 147 */   SDL_SCANCODE_UNKNOWN,
   194     /* 148 */   SDL_SCANCODE_UNKNOWN,
   195     /* 149 */   SDL_SCANCODE_UNKNOWN,
   196     /* 150 */   SDL_SCANCODE_UNKNOWN,
   197     /* 151 */   SDL_SCANCODE_UNKNOWN,
   198     /* 152 */   SDL_SCANCODE_UNKNOWN,
   199     /* 153 */   SDL_SCANCODE_UNKNOWN,
   200     /* 154 */   SDL_SCANCODE_UNKNOWN,
   201     /* 155 */   SDL_SCANCODE_UNKNOWN,
   202     /* 156 */   SDL_SCANCODE_UNKNOWN,
   203     /* 157 */   SDL_SCANCODE_UNKNOWN,
   204     /* 158 */   SDL_SCANCODE_UNKNOWN,
   205     /* 159 */   SDL_SCANCODE_UNKNOWN,
   206     /* 160 */   SDL_SCANCODE_UNKNOWN,
   207     /* 161 */   SDL_SCANCODE_UNKNOWN,
   208     /* 162 */   SDL_SCANCODE_UNKNOWN,
   209     /* 163 */   SDL_SCANCODE_UNKNOWN,
   210     /* 164 */   SDL_SCANCODE_UNKNOWN,
   211     /* 165 */   SDL_SCANCODE_UNKNOWN,
   212     /* 166 */   SDL_SCANCODE_UNKNOWN,
   213     /* 167 */   SDL_SCANCODE_UNKNOWN,
   214     /* 168 */   SDL_SCANCODE_UNKNOWN,
   215     /* 169 */   SDL_SCANCODE_UNKNOWN,
   216     /* 170 */   SDL_SCANCODE_UNKNOWN,
   217     /* 171 */   SDL_SCANCODE_UNKNOWN,
   218     /* 172 */   SDL_SCANCODE_UNKNOWN,
   219     /* 173 */   SDL_SCANCODE_MINUS, /*FX*/
   220     /* 174 */   SDL_SCANCODE_VOLUMEDOWN, /*IE, Chrome*/
   221     /* 175 */   SDL_SCANCODE_VOLUMEUP, /*IE, Chrome*/
   222     /* 176 */   SDL_SCANCODE_AUDIONEXT, /*IE, Chrome*/
   223     /* 177 */   SDL_SCANCODE_AUDIOPREV, /*IE, Chrome*/
   224     /* 178 */   SDL_SCANCODE_UNKNOWN,
   225     /* 179 */   SDL_SCANCODE_AUDIOPLAY, /*IE, Chrome*/
   226     /* 180 */   SDL_SCANCODE_UNKNOWN,
   227     /* 181 */   SDL_SCANCODE_AUDIOMUTE, /*FX*/
   228     /* 182 */   SDL_SCANCODE_VOLUMEDOWN, /*FX*/
   229     /* 183 */   SDL_SCANCODE_VOLUMEUP, /*FX*/
   230     /* 184 */   SDL_SCANCODE_UNKNOWN,
   231     /* 185 */   SDL_SCANCODE_UNKNOWN,
   232     /* 186 */   SDL_SCANCODE_SEMICOLON, /*IE, Chrome, D3E legacy*/
   233     /* 187 */   SDL_SCANCODE_EQUALS, /*IE, Chrome, D3E legacy*/
   234     /* 188 */   SDL_SCANCODE_COMMA,
   235     /* 189 */   SDL_SCANCODE_MINUS, /*IE, Chrome, D3E legacy*/
   236     /* 190 */   SDL_SCANCODE_PERIOD,
   237     /* 191 */   SDL_SCANCODE_SLASH,
   238     /* 192 */   SDL_SCANCODE_GRAVE, /*FX, D3E legacy (SDL_SCANCODE_APOSTROPHE in IE/Chrome)*/
   239     /* 193 */   SDL_SCANCODE_UNKNOWN,
   240     /* 194 */   SDL_SCANCODE_UNKNOWN,
   241     /* 195 */   SDL_SCANCODE_UNKNOWN,
   242     /* 196 */   SDL_SCANCODE_UNKNOWN,
   243     /* 197 */   SDL_SCANCODE_UNKNOWN,
   244     /* 198 */   SDL_SCANCODE_UNKNOWN,
   245     /* 199 */   SDL_SCANCODE_UNKNOWN,
   246     /* 200 */   SDL_SCANCODE_UNKNOWN,
   247     /* 201 */   SDL_SCANCODE_UNKNOWN,
   248     /* 202 */   SDL_SCANCODE_UNKNOWN,
   249     /* 203 */   SDL_SCANCODE_UNKNOWN,
   250     /* 204 */   SDL_SCANCODE_UNKNOWN,
   251     /* 205 */   SDL_SCANCODE_UNKNOWN,
   252     /* 206 */   SDL_SCANCODE_UNKNOWN,
   253     /* 207 */   SDL_SCANCODE_UNKNOWN,
   254     /* 208 */   SDL_SCANCODE_UNKNOWN,
   255     /* 209 */   SDL_SCANCODE_UNKNOWN,
   256     /* 210 */   SDL_SCANCODE_UNKNOWN,
   257     /* 211 */   SDL_SCANCODE_UNKNOWN,
   258     /* 212 */   SDL_SCANCODE_UNKNOWN,
   259     /* 213 */   SDL_SCANCODE_UNKNOWN,
   260     /* 214 */   SDL_SCANCODE_UNKNOWN,
   261     /* 215 */   SDL_SCANCODE_UNKNOWN,
   262     /* 216 */   SDL_SCANCODE_UNKNOWN,
   263     /* 217 */   SDL_SCANCODE_UNKNOWN,
   264     /* 218 */   SDL_SCANCODE_UNKNOWN,
   265     /* 219 */   SDL_SCANCODE_LEFTBRACKET,
   266     /* 220 */   SDL_SCANCODE_BACKSLASH,
   267     /* 221 */   SDL_SCANCODE_RIGHTBRACKET,
   268     /* 222 */   SDL_SCANCODE_APOSTROPHE, /*FX, D3E legacy*/
   269 };
   270 
   271 
   272 /* "borrowed" from SDL_windowsevents.c */
   273 static int
   274 Emscripten_ConvertUTF32toUTF8(Uint32 codepoint, char * text)
   275 {
   276     if (codepoint <= 0x7F) {
   277         text[0] = (char) codepoint;
   278         text[1] = '\0';
   279     } else if (codepoint <= 0x7FF) {
   280         text[0] = 0xC0 | (char) ((codepoint >> 6) & 0x1F);
   281         text[1] = 0x80 | (char) (codepoint & 0x3F);
   282         text[2] = '\0';
   283     } else if (codepoint <= 0xFFFF) {
   284         text[0] = 0xE0 | (char) ((codepoint >> 12) & 0x0F);
   285         text[1] = 0x80 | (char) ((codepoint >> 6) & 0x3F);
   286         text[2] = 0x80 | (char) (codepoint & 0x3F);
   287         text[3] = '\0';
   288     } else if (codepoint <= 0x10FFFF) {
   289         text[0] = 0xF0 | (char) ((codepoint >> 18) & 0x0F);
   290         text[1] = 0x80 | (char) ((codepoint >> 12) & 0x3F);
   291         text[2] = 0x80 | (char) ((codepoint >> 6) & 0x3F);
   292         text[3] = 0x80 | (char) (codepoint & 0x3F);
   293         text[4] = '\0';
   294     } else {
   295         return SDL_FALSE;
   296     }
   297     return SDL_TRUE;
   298 }
   299 
   300 static EM_BOOL
   301 Emscripten_HandlePointerLockChange(int eventType, const EmscriptenPointerlockChangeEvent *changeEvent, void *userData)
   302 {
   303     SDL_WindowData *window_data = (SDL_WindowData *) userData;
   304     /* keep track of lock losses, so we can regrab if/when appropriate. */
   305     window_data->has_pointer_lock = changeEvent->isActive;
   306     return 0;
   307 }
   308 
   309 
   310 static EM_BOOL
   311 Emscripten_HandleMouseMove(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData)
   312 {
   313     SDL_WindowData *window_data = userData;
   314     const int isPointerLocked = window_data->has_pointer_lock;
   315     int mx, my;
   316     static double residualx = 0, residualy = 0;
   317 
   318     /* rescale (in case canvas is being scaled)*/
   319     double client_w, client_h, xscale, yscale;
   320     emscripten_get_element_css_size(NULL, &client_w, &client_h);
   321     xscale = window_data->window->w / client_w;
   322     yscale = window_data->window->h / client_h;
   323 
   324     if (isPointerLocked) {
   325         residualx += mouseEvent->movementX * xscale;
   326         residualy += mouseEvent->movementY * yscale;
   327         /* Let slow sub-pixel motion accumulate. Don't lose it. */
   328         mx = residualx;
   329         residualx -= mx;
   330         my = residualy;
   331         residualy -= my;
   332     } else {
   333         mx = mouseEvent->canvasX * xscale;
   334         my = mouseEvent->canvasY * yscale;
   335     }
   336 
   337     SDL_SendMouseMotion(window_data->window, 0, isPointerLocked, mx, my);
   338     return 0;
   339 }
   340 
   341 static EM_BOOL
   342 Emscripten_HandleMouseButton(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData)
   343 {
   344     SDL_WindowData *window_data = userData;
   345     Uint8 sdl_button;
   346     Uint8 sdl_button_state;
   347     SDL_EventType sdl_event_type;
   348 
   349     switch (mouseEvent->button) {
   350         case 0:
   351             sdl_button = SDL_BUTTON_LEFT;
   352             break;
   353         case 1:
   354             sdl_button = SDL_BUTTON_MIDDLE;
   355             break;
   356         case 2:
   357             sdl_button = SDL_BUTTON_RIGHT;
   358             break;
   359         default:
   360             return 0;
   361     }
   362 
   363     if (eventType == EMSCRIPTEN_EVENT_MOUSEDOWN) {
   364         if (SDL_GetMouse()->relative_mode && !window_data->has_pointer_lock) {
   365             emscripten_request_pointerlock(NULL, 0);  /* try to regrab lost pointer lock. */
   366         }
   367         sdl_button_state = SDL_PRESSED;
   368         sdl_event_type = SDL_MOUSEBUTTONDOWN;
   369     } else {
   370         sdl_button_state = SDL_RELEASED;
   371         sdl_event_type = SDL_MOUSEBUTTONUP;
   372     }
   373     SDL_SendMouseButton(window_data->window, 0, sdl_button_state, sdl_button);
   374     return SDL_GetEventState(sdl_event_type) == SDL_ENABLE;
   375 }
   376 
   377 static EM_BOOL
   378 Emscripten_HandleMouseFocus(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData)
   379 {
   380     SDL_WindowData *window_data = userData;
   381 
   382     int mx = mouseEvent->canvasX, my = mouseEvent->canvasY;
   383     const int isPointerLocked = window_data->has_pointer_lock;
   384 
   385     if (!isPointerLocked) {
   386         /* rescale (in case canvas is being scaled)*/
   387         double client_w, client_h;
   388         emscripten_get_element_css_size(NULL, &client_w, &client_h);
   389 
   390         mx = mx * (window_data->window->w / client_w);
   391         my = my * (window_data->window->h / client_h);
   392         SDL_SendMouseMotion(window_data->window, 0, isPointerLocked, mx, my);
   393     }
   394 
   395     SDL_SetMouseFocus(eventType == EMSCRIPTEN_EVENT_MOUSEENTER ? window_data->window : NULL);
   396     return SDL_GetEventState(SDL_WINDOWEVENT) == SDL_ENABLE;
   397 }
   398 
   399 static EM_BOOL
   400 Emscripten_HandleWheel(int eventType, const EmscriptenWheelEvent *wheelEvent, void *userData)
   401 {
   402     SDL_WindowData *window_data = userData;
   403     SDL_SendMouseWheel(window_data->window, 0, wheelEvent->deltaX, -wheelEvent->deltaY, SDL_MOUSEWHEEL_NORMAL);
   404     return SDL_GetEventState(SDL_MOUSEWHEEL) == SDL_ENABLE;
   405 }
   406 
   407 static EM_BOOL
   408 Emscripten_HandleFocus(int eventType, const EmscriptenFocusEvent *wheelEvent, void *userData)
   409 {
   410     SDL_WindowData *window_data = userData;
   411     /* If the user switches away while keys are pressed (such as
   412      * via Alt+Tab), key release events won't be received. */
   413     if (eventType == EMSCRIPTEN_EVENT_BLUR) {
   414         SDL_ResetKeyboard();
   415     }
   416 
   417 
   418     SDL_SendWindowEvent(window_data->window, eventType == EMSCRIPTEN_EVENT_FOCUS ? SDL_WINDOWEVENT_FOCUS_GAINED : SDL_WINDOWEVENT_FOCUS_LOST, 0, 0);
   419     return SDL_GetEventState(SDL_WINDOWEVENT) == SDL_ENABLE;
   420 }
   421 
   422 static EM_BOOL
   423 Emscripten_HandleTouch(int eventType, const EmscriptenTouchEvent *touchEvent, void *userData)
   424 {
   425     SDL_WindowData *window_data = userData;
   426     int i;
   427     double client_w, client_h;
   428     int preventDefault = 0;
   429 
   430     SDL_TouchID deviceId = 1;
   431     if (SDL_AddTouch(deviceId, "") < 0) {
   432          return 0;
   433     }
   434 
   435     emscripten_get_element_css_size(NULL, &client_w, &client_h);
   436 
   437     for (i = 0; i < touchEvent->numTouches; i++) {
   438         SDL_FingerID id;
   439         float x, y;
   440         int mx, my;
   441 
   442         if (!touchEvent->touches[i].isChanged)
   443             continue;
   444 
   445         id = touchEvent->touches[i].identifier;
   446         x = touchEvent->touches[i].canvasX / client_w;
   447         y = touchEvent->touches[i].canvasY / client_h;
   448 
   449         mx = x * window_data->window->w;
   450         my = y * window_data->window->h;
   451 
   452         if (eventType == EMSCRIPTEN_EVENT_TOUCHSTART) {
   453             if (!window_data->finger_touching) {
   454                 window_data->finger_touching = SDL_TRUE;
   455                 window_data->first_finger = id;
   456                 SDL_SendMouseMotion(window_data->window, SDL_TOUCH_MOUSEID, 0, mx, my);
   457                 SDL_SendMouseButton(window_data->window, SDL_TOUCH_MOUSEID, SDL_PRESSED, SDL_BUTTON_LEFT);
   458             }
   459             SDL_SendTouch(deviceId, id, SDL_TRUE, x, y, 1.0f);
   460 
   461             if (!preventDefault && SDL_GetEventState(SDL_FINGERDOWN) == SDL_ENABLE) {
   462                 preventDefault = 1;
   463             }
   464         } else if (eventType == EMSCRIPTEN_EVENT_TOUCHMOVE) {
   465             if ((window_data->finger_touching) && (window_data->first_finger == id)) {
   466                 SDL_SendMouseMotion(window_data->window, SDL_TOUCH_MOUSEID, 0, mx, my);
   467             }
   468             SDL_SendTouchMotion(deviceId, id, x, y, 1.0f);
   469 
   470             if (!preventDefault && SDL_GetEventState(SDL_FINGERMOTION) == SDL_ENABLE) {
   471                 preventDefault = 1;
   472             }
   473         } else {
   474             if ((window_data->finger_touching) && (window_data->first_finger == id)) {
   475                 SDL_SendMouseButton(window_data->window, SDL_TOUCH_MOUSEID, SDL_RELEASED, SDL_BUTTON_LEFT);
   476                 window_data->finger_touching = SDL_FALSE;
   477             }
   478             SDL_SendTouch(deviceId, id, SDL_FALSE, x, y, 1.0f);
   479 
   480             if (!preventDefault && SDL_GetEventState(SDL_FINGERUP) == SDL_ENABLE) {
   481                 preventDefault = 1;
   482             }
   483         }
   484     }
   485 
   486     return preventDefault;
   487 }
   488 
   489 static EM_BOOL
   490 Emscripten_HandleKey(int eventType, const EmscriptenKeyboardEvent *keyEvent, void *userData)
   491 {
   492     Uint32 scancode;
   493 
   494     /* .keyCode is deprecated, but still the most reliable way to get keys */
   495     if (keyEvent->keyCode < SDL_arraysize(emscripten_scancode_table)) {
   496         scancode = emscripten_scancode_table[keyEvent->keyCode];
   497 
   498         if (scancode != SDL_SCANCODE_UNKNOWN) {
   499 
   500             if (keyEvent->location == DOM_KEY_LOCATION_RIGHT) {
   501                 switch (scancode) {
   502                     case SDL_SCANCODE_LSHIFT:
   503                         scancode = SDL_SCANCODE_RSHIFT;
   504                         break;
   505                     case SDL_SCANCODE_LCTRL:
   506                         scancode = SDL_SCANCODE_RCTRL;
   507                         break;
   508                     case SDL_SCANCODE_LALT:
   509                         scancode = SDL_SCANCODE_RALT;
   510                         break;
   511                     case SDL_SCANCODE_LGUI:
   512                         scancode = SDL_SCANCODE_RGUI;
   513                         break;
   514                 }
   515             }
   516             SDL_SendKeyboardKey(eventType == EMSCRIPTEN_EVENT_KEYDOWN ? SDL_PRESSED : SDL_RELEASED, scancode);
   517         }
   518     }
   519 
   520     SDL_bool prevent_default = SDL_GetEventState(eventType == EMSCRIPTEN_EVENT_KEYDOWN ? SDL_KEYDOWN : SDL_KEYUP) == SDL_ENABLE;
   521 
   522     /* if TEXTINPUT events are enabled we can't prevent keydown or we won't get keypress
   523      * we need to ALWAYS prevent backspace and tab otherwise chrome takes action and does bad navigation UX
   524      */
   525     SDL_bool is_nav_key = keyEvent->keyCode == 8 /* backspace */ ||
   526                           keyEvent->keyCode == 9 /* tab */ ||
   527                           keyEvent->keyCode == 37 /* left */ ||
   528                           keyEvent->keyCode == 38 /* up */ ||
   529                           keyEvent->keyCode == 39 /* right */ ||
   530                           keyEvent->keyCode == 40 /* down */;
   531 
   532     if (eventType == EMSCRIPTEN_EVENT_KEYDOWN && SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE && !is_nav_key)
   533         prevent_default = SDL_FALSE;
   534 
   535     return prevent_default;
   536 }
   537 
   538 static EM_BOOL
   539 Emscripten_HandleKeyPress(int eventType, const EmscriptenKeyboardEvent *keyEvent, void *userData)
   540 {
   541     char text[5];
   542     if (Emscripten_ConvertUTF32toUTF8(keyEvent->charCode, text)) {
   543         SDL_SendKeyboardText(text);
   544     }
   545     return SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE;
   546 }
   547 
   548 static EM_BOOL
   549 Emscripten_HandleFullscreenChange(int eventType, const EmscriptenFullscreenChangeEvent *fullscreenChangeEvent, void *userData)
   550 {
   551     SDL_WindowData *window_data = userData;
   552     if(fullscreenChangeEvent->isFullscreen)
   553     {
   554         window_data->window->flags |= window_data->requested_fullscreen_mode;
   555 
   556         window_data->requested_fullscreen_mode = 0;
   557 
   558         if(!window_data->requested_fullscreen_mode)
   559             window_data->window->flags |= SDL_WINDOW_FULLSCREEN; /*we didn't reqest fullscreen*/
   560     }
   561     else
   562     {
   563         window_data->window->flags &= ~FULLSCREEN_MASK;
   564     }
   565 
   566     return 0;
   567 }
   568 
   569 static EM_BOOL
   570 Emscripten_HandleResize(int eventType, const EmscriptenUiEvent *uiEvent, void *userData)
   571 {
   572     SDL_WindowData *window_data = userData;
   573 
   574     /* update pixel ratio */
   575     if (window_data->window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
   576         window_data->pixel_ratio = emscripten_get_device_pixel_ratio();
   577     }
   578 
   579     if(!(window_data->window->flags & FULLSCREEN_MASK))
   580     {
   581         /* this will only work if the canvas size is set through css */
   582         if(window_data->window->flags & SDL_WINDOW_RESIZABLE)
   583         {
   584             double w = window_data->window->w;
   585             double h = window_data->window->h;
   586 
   587             if(window_data->external_size) {
   588                 emscripten_get_element_css_size(NULL, &w, &h);
   589             }
   590 
   591             emscripten_set_canvas_size(w * window_data->pixel_ratio, h * window_data->pixel_ratio);
   592 
   593             /* set_canvas_size unsets this */
   594             if (!window_data->external_size && window_data->pixel_ratio != 1.0f) {
   595                 emscripten_set_element_css_size(NULL, w, h);
   596             }
   597 
   598             SDL_SendWindowEvent(window_data->window, SDL_WINDOWEVENT_RESIZED, w, h);
   599         }
   600     }
   601 
   602     return 0;
   603 }
   604 
   605 EM_BOOL
   606 Emscripten_HandleCanvasResize(int eventType, const void *reserved, void *userData)
   607 {
   608     /*this is used during fullscreen changes*/
   609     SDL_WindowData *window_data = userData;
   610 
   611     if(window_data->fullscreen_resize)
   612     {
   613         double css_w, css_h;
   614         emscripten_get_element_css_size(NULL, &css_w, &css_h);
   615         SDL_SendWindowEvent(window_data->window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
   616     }
   617 
   618     return 0;
   619 }
   620 
   621 static EM_BOOL
   622 Emscripten_HandleVisibilityChange(int eventType, const EmscriptenVisibilityChangeEvent *visEvent, void *userData)
   623 {
   624     SDL_WindowData *window_data = userData;
   625     SDL_SendWindowEvent(window_data->window, visEvent->hidden ? SDL_WINDOWEVENT_HIDDEN : SDL_WINDOWEVENT_SHOWN, 0, 0);
   626     return 0;
   627 }
   628 
   629 void
   630 Emscripten_RegisterEventHandlers(SDL_WindowData *data)
   631 {
   632     /* There is only one window and that window is the canvas */
   633     emscripten_set_mousemove_callback("#canvas", data, 0, Emscripten_HandleMouseMove);
   634 
   635     emscripten_set_mousedown_callback("#canvas", data, 0, Emscripten_HandleMouseButton);
   636     emscripten_set_mouseup_callback("#document", data, 0, Emscripten_HandleMouseButton);
   637 
   638     emscripten_set_mouseenter_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
   639     emscripten_set_mouseleave_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
   640 
   641     emscripten_set_wheel_callback("#canvas", data, 0, Emscripten_HandleWheel);
   642 
   643     emscripten_set_focus_callback("#window", data, 0, Emscripten_HandleFocus);
   644     emscripten_set_blur_callback("#window", data, 0, Emscripten_HandleFocus);
   645 
   646     emscripten_set_touchstart_callback("#canvas", data, 0, Emscripten_HandleTouch);
   647     emscripten_set_touchend_callback("#canvas", data, 0, Emscripten_HandleTouch);
   648     emscripten_set_touchmove_callback("#canvas", data, 0, Emscripten_HandleTouch);
   649     emscripten_set_touchcancel_callback("#canvas", data, 0, Emscripten_HandleTouch);
   650 
   651     emscripten_set_pointerlockchange_callback(NULL, data, 0, Emscripten_HandlePointerLockChange);
   652 
   653     /* Keyboard events are awkward */
   654     const char *keyElement = SDL_GetHint(SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT);
   655     if (!keyElement) keyElement = "#window";
   656 
   657     emscripten_set_keydown_callback(keyElement, data, 0, Emscripten_HandleKey);
   658     emscripten_set_keyup_callback(keyElement, data, 0, Emscripten_HandleKey);
   659     emscripten_set_keypress_callback(keyElement, data, 0, Emscripten_HandleKeyPress);
   660 
   661     emscripten_set_fullscreenchange_callback("#document", data, 0, Emscripten_HandleFullscreenChange);
   662 
   663     emscripten_set_resize_callback("#window", data, 0, Emscripten_HandleResize);
   664 
   665     emscripten_set_visibilitychange_callback(data, 0, Emscripten_HandleVisibilityChange);
   666 }
   667 
   668 void
   669 Emscripten_UnregisterEventHandlers(SDL_WindowData *data)
   670 {
   671     /* only works due to having one window */
   672     emscripten_set_mousemove_callback("#canvas", NULL, 0, NULL);
   673 
   674     emscripten_set_mousedown_callback("#canvas", NULL, 0, NULL);
   675     emscripten_set_mouseup_callback("#document", NULL, 0, NULL);
   676 
   677     emscripten_set_mouseenter_callback("#canvas", NULL, 0, NULL);
   678     emscripten_set_mouseleave_callback("#canvas", NULL, 0, NULL);
   679 
   680     emscripten_set_wheel_callback("#canvas", NULL, 0, NULL);
   681 
   682     emscripten_set_focus_callback("#window", NULL, 0, NULL);
   683     emscripten_set_blur_callback("#window", NULL, 0, NULL);
   684 
   685     emscripten_set_touchstart_callback("#canvas", NULL, 0, NULL);
   686     emscripten_set_touchend_callback("#canvas", NULL, 0, NULL);
   687     emscripten_set_touchmove_callback("#canvas", NULL, 0, NULL);
   688     emscripten_set_touchcancel_callback("#canvas", NULL, 0, NULL);
   689 
   690     emscripten_set_pointerlockchange_callback(NULL, NULL, 0, NULL);
   691 
   692     const char *target = SDL_GetHint(SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT);
   693     if (!target) {
   694         target = "#window";
   695     }
   696 
   697     emscripten_set_keydown_callback(target, NULL, 0, NULL);
   698     emscripten_set_keyup_callback(target, NULL, 0, NULL);
   699     emscripten_set_keypress_callback(target, NULL, 0, NULL);
   700 
   701     emscripten_set_fullscreenchange_callback("#document", NULL, 0, NULL);
   702 
   703     emscripten_set_resize_callback("#window", NULL, 0, NULL);
   704 
   705     emscripten_set_visibilitychange_callback(NULL, 0, NULL);
   706 }
   707 
   708 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */
   709 
   710 /* vi: set ts=4 sw=4 expandtab: */