src/video/emscripten/SDL_emscriptenevents.c
author Patrick Monaghan <pat@patsown.com>
Wed, 24 May 2017 14:04:25 +0100
changeset 11024 32026cc5015a
parent 11003 ced20e690a19
child 11025 2215b66794ba
permissions -rw-r--r--
Emscripten: fixed incorrect conversion of touch motion events to mouse motion events
     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     if (eventType == EMSCRIPTEN_EVENT_KEYDOWN && SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE && keyEvent->keyCode != 8 /* backspace */ && keyEvent->keyCode != 9 /* tab */)
   526         prevent_default = SDL_FALSE;
   527 
   528     return prevent_default;
   529 }
   530 
   531 static EM_BOOL
   532 Emscripten_HandleKeyPress(int eventType, const EmscriptenKeyboardEvent *keyEvent, void *userData)
   533 {
   534     char text[5];
   535     if (Emscripten_ConvertUTF32toUTF8(keyEvent->charCode, text)) {
   536         SDL_SendKeyboardText(text);
   537     }
   538     return SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE;
   539 }
   540 
   541 static EM_BOOL
   542 Emscripten_HandleFullscreenChange(int eventType, const EmscriptenFullscreenChangeEvent *fullscreenChangeEvent, void *userData)
   543 {
   544     SDL_WindowData *window_data = userData;
   545     if(fullscreenChangeEvent->isFullscreen)
   546     {
   547         window_data->window->flags |= window_data->requested_fullscreen_mode;
   548 
   549         window_data->requested_fullscreen_mode = 0;
   550 
   551         if(!window_data->requested_fullscreen_mode)
   552             window_data->window->flags |= SDL_WINDOW_FULLSCREEN; /*we didn't reqest fullscreen*/
   553     }
   554     else
   555     {
   556         window_data->window->flags &= ~FULLSCREEN_MASK;
   557     }
   558 
   559     return 0;
   560 }
   561 
   562 static EM_BOOL
   563 Emscripten_HandleResize(int eventType, const EmscriptenUiEvent *uiEvent, void *userData)
   564 {
   565     SDL_WindowData *window_data = userData;
   566 
   567     /* update pixel ratio */
   568     if (window_data->window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
   569         window_data->pixel_ratio = emscripten_get_device_pixel_ratio();
   570     }
   571 
   572     if(!(window_data->window->flags & FULLSCREEN_MASK))
   573     {
   574         /* this will only work if the canvas size is set through css */
   575         if(window_data->window->flags & SDL_WINDOW_RESIZABLE)
   576         {
   577             double w = window_data->window->w;
   578             double h = window_data->window->h;
   579 
   580             if(window_data->external_size) {
   581                 emscripten_get_element_css_size(NULL, &w, &h);
   582             }
   583 
   584             emscripten_set_canvas_size(w * window_data->pixel_ratio, h * window_data->pixel_ratio);
   585 
   586             /* set_canvas_size unsets this */
   587             if (!window_data->external_size && window_data->pixel_ratio != 1.0f) {
   588                 emscripten_set_element_css_size(NULL, w, h);
   589             }
   590 
   591             SDL_SendWindowEvent(window_data->window, SDL_WINDOWEVENT_RESIZED, w, h);
   592         }
   593     }
   594 
   595     return 0;
   596 }
   597 
   598 EM_BOOL
   599 Emscripten_HandleCanvasResize(int eventType, const void *reserved, void *userData)
   600 {
   601     /*this is used during fullscreen changes*/
   602     SDL_WindowData *window_data = userData;
   603 
   604     if(window_data->fullscreen_resize)
   605     {
   606         double css_w, css_h;
   607         emscripten_get_element_css_size(NULL, &css_w, &css_h);
   608         SDL_SendWindowEvent(window_data->window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
   609     }
   610 
   611     return 0;
   612 }
   613 
   614 static EM_BOOL
   615 Emscripten_HandleVisibilityChange(int eventType, const EmscriptenVisibilityChangeEvent *visEvent, void *userData)
   616 {
   617     SDL_WindowData *window_data = userData;
   618     SDL_SendWindowEvent(window_data->window, visEvent->hidden ? SDL_WINDOWEVENT_HIDDEN : SDL_WINDOWEVENT_SHOWN, 0, 0);
   619     return 0;
   620 }
   621 
   622 void
   623 Emscripten_RegisterEventHandlers(SDL_WindowData *data)
   624 {
   625     /* There is only one window and that window is the canvas */
   626     emscripten_set_mousemove_callback("#canvas", data, 0, Emscripten_HandleMouseMove);
   627 
   628     emscripten_set_mousedown_callback("#canvas", data, 0, Emscripten_HandleMouseButton);
   629     emscripten_set_mouseup_callback("#document", data, 0, Emscripten_HandleMouseButton);
   630 
   631     emscripten_set_mouseenter_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
   632     emscripten_set_mouseleave_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
   633 
   634     emscripten_set_wheel_callback("#canvas", data, 0, Emscripten_HandleWheel);
   635 
   636     emscripten_set_focus_callback("#window", data, 0, Emscripten_HandleFocus);
   637     emscripten_set_blur_callback("#window", data, 0, Emscripten_HandleFocus);
   638 
   639     emscripten_set_touchstart_callback("#canvas", data, 0, Emscripten_HandleTouch);
   640     emscripten_set_touchend_callback("#canvas", data, 0, Emscripten_HandleTouch);
   641     emscripten_set_touchmove_callback("#canvas", data, 0, Emscripten_HandleTouch);
   642     emscripten_set_touchcancel_callback("#canvas", data, 0, Emscripten_HandleTouch);
   643 
   644     emscripten_set_pointerlockchange_callback(NULL, data, 0, Emscripten_HandlePointerLockChange);
   645 
   646     /* Keyboard events are awkward */
   647     const char *keyElement = SDL_GetHint(SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT);
   648     if (!keyElement) keyElement = "#window";
   649 
   650     emscripten_set_keydown_callback(keyElement, data, 0, Emscripten_HandleKey);
   651     emscripten_set_keyup_callback(keyElement, data, 0, Emscripten_HandleKey);
   652     emscripten_set_keypress_callback(keyElement, data, 0, Emscripten_HandleKeyPress);
   653 
   654     emscripten_set_fullscreenchange_callback("#document", data, 0, Emscripten_HandleFullscreenChange);
   655 
   656     emscripten_set_resize_callback("#window", data, 0, Emscripten_HandleResize);
   657 
   658     emscripten_set_visibilitychange_callback(data, 0, Emscripten_HandleVisibilityChange);
   659 }
   660 
   661 void
   662 Emscripten_UnregisterEventHandlers(SDL_WindowData *data)
   663 {
   664     /* only works due to having one window */
   665     emscripten_set_mousemove_callback("#canvas", NULL, 0, NULL);
   666 
   667     emscripten_set_mousedown_callback("#canvas", NULL, 0, NULL);
   668     emscripten_set_mouseup_callback("#document", NULL, 0, NULL);
   669 
   670     emscripten_set_mouseenter_callback("#canvas", NULL, 0, NULL);
   671     emscripten_set_mouseleave_callback("#canvas", NULL, 0, NULL);
   672 
   673     emscripten_set_wheel_callback("#canvas", NULL, 0, NULL);
   674 
   675     emscripten_set_focus_callback("#window", NULL, 0, NULL);
   676     emscripten_set_blur_callback("#window", NULL, 0, NULL);
   677 
   678     emscripten_set_touchstart_callback("#canvas", NULL, 0, NULL);
   679     emscripten_set_touchend_callback("#canvas", NULL, 0, NULL);
   680     emscripten_set_touchmove_callback("#canvas", NULL, 0, NULL);
   681     emscripten_set_touchcancel_callback("#canvas", NULL, 0, NULL);
   682 
   683     emscripten_set_pointerlockchange_callback(NULL, NULL, 0, NULL);
   684 
   685     const char *target = SDL_GetHint(SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT);
   686     if (!target) {
   687         target = "#window";
   688     }
   689 
   690     emscripten_set_keydown_callback(target, NULL, 0, NULL);
   691     emscripten_set_keyup_callback(target, NULL, 0, NULL);
   692     emscripten_set_keypress_callback(target, NULL, 0, NULL);
   693 
   694     emscripten_set_fullscreenchange_callback("#document", NULL, 0, NULL);
   695 
   696     emscripten_set_resize_callback("#window", NULL, 0, NULL);
   697 
   698     emscripten_set_visibilitychange_callback(NULL, 0, NULL);
   699 }
   700 
   701 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */
   702 
   703 /* vi: set ts=4 sw=4 expandtab: */