src/video/emscripten/SDL_emscriptenevents.c
author Sylvain Beucler <beuc@beuc.net>
Tue, 29 Jan 2019 12:14:44 +0000
changeset 12572 397aa57185c4
parent 12570 bb39a14d510c
child 12573 296d155a8ce5
permissions -rw-r--r--
Emscripten: fix duplicate mousebuttonup/mousebuttondown events when touch events are disabled
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2019 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, (float)wheelEvent->deltaX, (float)-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, SDL_TOUCH_DEVICE_DIRECT, "") < 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             /* disable browser scrolling/pinch-to-zoom if app handles touch events */
   462             if (!preventDefault && SDL_GetEventState(SDL_FINGERDOWN) == SDL_ENABLE) {
   463                 preventDefault = 1;
   464             }
   465         } else if (eventType == EMSCRIPTEN_EVENT_TOUCHMOVE) {
   466             if ((window_data->finger_touching) && (window_data->first_finger == id)) {
   467                 SDL_SendMouseMotion(window_data->window, SDL_TOUCH_MOUSEID, 0, mx, my);
   468             }
   469             SDL_SendTouchMotion(deviceId, id, x, y, 1.0f);
   470         } else {
   471             if ((window_data->finger_touching) && (window_data->first_finger == id)) {
   472                 SDL_SendMouseButton(window_data->window, SDL_TOUCH_MOUSEID, SDL_RELEASED, SDL_BUTTON_LEFT);
   473                 window_data->finger_touching = SDL_FALSE;
   474             }
   475             SDL_SendTouch(deviceId, id, SDL_FALSE, x, y, 1.0f);
   476 
   477             /* block browser's simulated mousedown/mouseup on touchscreen devices */
   478             preventDefault = 1;
   479         }
   480     }
   481 
   482     return preventDefault;
   483 }
   484 
   485 static EM_BOOL
   486 Emscripten_HandleKey(int eventType, const EmscriptenKeyboardEvent *keyEvent, void *userData)
   487 {
   488     Uint32 scancode;
   489     SDL_bool prevent_default;
   490     SDL_bool is_nav_key;
   491 
   492     /* .keyCode is deprecated, but still the most reliable way to get keys */
   493     if (keyEvent->keyCode < SDL_arraysize(emscripten_scancode_table)) {
   494         scancode = emscripten_scancode_table[keyEvent->keyCode];
   495 
   496         if (scancode != SDL_SCANCODE_UNKNOWN) {
   497 
   498             if (keyEvent->location == DOM_KEY_LOCATION_RIGHT) {
   499                 switch (scancode) {
   500                     case SDL_SCANCODE_LSHIFT:
   501                         scancode = SDL_SCANCODE_RSHIFT;
   502                         break;
   503                     case SDL_SCANCODE_LCTRL:
   504                         scancode = SDL_SCANCODE_RCTRL;
   505                         break;
   506                     case SDL_SCANCODE_LALT:
   507                         scancode = SDL_SCANCODE_RALT;
   508                         break;
   509                     case SDL_SCANCODE_LGUI:
   510                         scancode = SDL_SCANCODE_RGUI;
   511                         break;
   512                 }
   513             }
   514             SDL_SendKeyboardKey(eventType == EMSCRIPTEN_EVENT_KEYDOWN ? SDL_PRESSED : SDL_RELEASED, scancode);
   515         }
   516     }
   517 
   518     prevent_default = SDL_GetEventState(eventType == EMSCRIPTEN_EVENT_KEYDOWN ? SDL_KEYDOWN : SDL_KEYUP) == SDL_ENABLE;
   519 
   520     /* if TEXTINPUT events are enabled we can't prevent keydown or we won't get keypress
   521      * we need to ALWAYS prevent backspace and tab otherwise chrome takes action and does bad navigation UX
   522      */
   523     is_nav_key = keyEvent->keyCode == 8 /* backspace */ ||
   524                  keyEvent->keyCode == 9 /* tab */ ||
   525                  keyEvent->keyCode == 37 /* left */ ||
   526                  keyEvent->keyCode == 38 /* up */ ||
   527                  keyEvent->keyCode == 39 /* right */ ||
   528                  keyEvent->keyCode == 40 /* down */;
   529 
   530     if (eventType == EMSCRIPTEN_EVENT_KEYDOWN && SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE && !is_nav_key)
   531         prevent_default = SDL_FALSE;
   532 
   533     return prevent_default;
   534 }
   535 
   536 static EM_BOOL
   537 Emscripten_HandleKeyPress(int eventType, const EmscriptenKeyboardEvent *keyEvent, void *userData)
   538 {
   539     char text[5];
   540     if (Emscripten_ConvertUTF32toUTF8(keyEvent->charCode, text)) {
   541         SDL_SendKeyboardText(text);
   542     }
   543     return SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE;
   544 }
   545 
   546 static EM_BOOL
   547 Emscripten_HandleFullscreenChange(int eventType, const EmscriptenFullscreenChangeEvent *fullscreenChangeEvent, void *userData)
   548 {
   549     SDL_WindowData *window_data = userData;
   550     SDL_VideoDisplay *display;
   551 
   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         /* reset fullscreen window if the browser left fullscreen */
   566         display = SDL_GetDisplayForWindow(window_data->window);
   567 
   568         if (display->fullscreen_window == window_data->window) {
   569             display->fullscreen_window = NULL;
   570         }
   571     }
   572 
   573     return 0;
   574 }
   575 
   576 static EM_BOOL
   577 Emscripten_HandleResize(int eventType, const EmscriptenUiEvent *uiEvent, void *userData)
   578 {
   579     SDL_WindowData *window_data = userData;
   580 
   581     /* update pixel ratio */
   582     if (window_data->window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
   583         window_data->pixel_ratio = emscripten_get_device_pixel_ratio();
   584     }
   585 
   586     if(!(window_data->window->flags & FULLSCREEN_MASK))
   587     {
   588         /* this will only work if the canvas size is set through css */
   589         if(window_data->window->flags & SDL_WINDOW_RESIZABLE)
   590         {
   591             double w = window_data->window->w;
   592             double h = window_data->window->h;
   593 
   594             if(window_data->external_size) {
   595                 emscripten_get_element_css_size(NULL, &w, &h);
   596             }
   597 
   598             emscripten_set_canvas_size(w * window_data->pixel_ratio, h * window_data->pixel_ratio);
   599 
   600             /* set_canvas_size unsets this */
   601             if (!window_data->external_size && window_data->pixel_ratio != 1.0f) {
   602                 emscripten_set_element_css_size(NULL, w, h);
   603             }
   604 
   605             SDL_SendWindowEvent(window_data->window, SDL_WINDOWEVENT_RESIZED, w, h);
   606         }
   607     }
   608 
   609     return 0;
   610 }
   611 
   612 EM_BOOL
   613 Emscripten_HandleCanvasResize(int eventType, const void *reserved, void *userData)
   614 {
   615     /*this is used during fullscreen changes*/
   616     SDL_WindowData *window_data = userData;
   617 
   618     if(window_data->fullscreen_resize)
   619     {
   620         double css_w, css_h;
   621         emscripten_get_element_css_size(NULL, &css_w, &css_h);
   622         SDL_SendWindowEvent(window_data->window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
   623     }
   624 
   625     return 0;
   626 }
   627 
   628 static EM_BOOL
   629 Emscripten_HandleVisibilityChange(int eventType, const EmscriptenVisibilityChangeEvent *visEvent, void *userData)
   630 {
   631     SDL_WindowData *window_data = userData;
   632     SDL_SendWindowEvent(window_data->window, visEvent->hidden ? SDL_WINDOWEVENT_HIDDEN : SDL_WINDOWEVENT_SHOWN, 0, 0);
   633     return 0;
   634 }
   635 
   636 void
   637 Emscripten_RegisterEventHandlers(SDL_WindowData *data)
   638 {
   639     const char *keyElement;
   640 
   641     /* There is only one window and that window is the canvas */
   642     emscripten_set_mousemove_callback("#canvas", data, 0, Emscripten_HandleMouseMove);
   643 
   644     emscripten_set_mousedown_callback("#canvas", data, 0, Emscripten_HandleMouseButton);
   645     emscripten_set_mouseup_callback("#document", data, 0, Emscripten_HandleMouseButton);
   646 
   647     emscripten_set_mouseenter_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
   648     emscripten_set_mouseleave_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
   649 
   650     emscripten_set_wheel_callback("#canvas", data, 0, Emscripten_HandleWheel);
   651 
   652     emscripten_set_focus_callback("#window", data, 0, Emscripten_HandleFocus);
   653     emscripten_set_blur_callback("#window", data, 0, Emscripten_HandleFocus);
   654 
   655     emscripten_set_touchstart_callback("#canvas", data, 0, Emscripten_HandleTouch);
   656     emscripten_set_touchend_callback("#canvas", data, 0, Emscripten_HandleTouch);
   657     emscripten_set_touchmove_callback("#canvas", data, 0, Emscripten_HandleTouch);
   658     emscripten_set_touchcancel_callback("#canvas", data, 0, Emscripten_HandleTouch);
   659 
   660     emscripten_set_pointerlockchange_callback("#document", data, 0, Emscripten_HandlePointerLockChange);
   661 
   662     /* Keyboard events are awkward */
   663     keyElement = SDL_GetHint(SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT);
   664     if (!keyElement) keyElement = "#window";
   665 
   666     emscripten_set_keydown_callback(keyElement, data, 0, Emscripten_HandleKey);
   667     emscripten_set_keyup_callback(keyElement, data, 0, Emscripten_HandleKey);
   668     emscripten_set_keypress_callback(keyElement, data, 0, Emscripten_HandleKeyPress);
   669 
   670     emscripten_set_fullscreenchange_callback("#document", data, 0, Emscripten_HandleFullscreenChange);
   671 
   672     emscripten_set_resize_callback("#window", data, 0, Emscripten_HandleResize);
   673 
   674     emscripten_set_visibilitychange_callback(data, 0, Emscripten_HandleVisibilityChange);
   675 }
   676 
   677 void
   678 Emscripten_UnregisterEventHandlers(SDL_WindowData *data)
   679 {
   680     const char *target;
   681 
   682     /* only works due to having one window */
   683     emscripten_set_mousemove_callback("#canvas", NULL, 0, NULL);
   684 
   685     emscripten_set_mousedown_callback("#canvas", NULL, 0, NULL);
   686     emscripten_set_mouseup_callback("#document", NULL, 0, NULL);
   687 
   688     emscripten_set_mouseenter_callback("#canvas", NULL, 0, NULL);
   689     emscripten_set_mouseleave_callback("#canvas", NULL, 0, NULL);
   690 
   691     emscripten_set_wheel_callback("#canvas", NULL, 0, NULL);
   692 
   693     emscripten_set_focus_callback("#window", NULL, 0, NULL);
   694     emscripten_set_blur_callback("#window", NULL, 0, NULL);
   695 
   696     emscripten_set_touchstart_callback("#canvas", NULL, 0, NULL);
   697     emscripten_set_touchend_callback("#canvas", NULL, 0, NULL);
   698     emscripten_set_touchmove_callback("#canvas", NULL, 0, NULL);
   699     emscripten_set_touchcancel_callback("#canvas", NULL, 0, NULL);
   700 
   701     emscripten_set_pointerlockchange_callback("#document", NULL, 0, NULL);
   702 
   703     target = SDL_GetHint(SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT);
   704     if (!target) {
   705         target = "#window";
   706     }
   707 
   708     emscripten_set_keydown_callback(target, NULL, 0, NULL);
   709     emscripten_set_keyup_callback(target, NULL, 0, NULL);
   710     emscripten_set_keypress_callback(target, NULL, 0, NULL);
   711 
   712     emscripten_set_fullscreenchange_callback("#document", NULL, 0, NULL);
   713 
   714     emscripten_set_resize_callback("#window", NULL, 0, NULL);
   715 
   716     emscripten_set_visibilitychange_callback(NULL, 0, NULL);
   717 }
   718 
   719 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */
   720 
   721 /* vi: set ts=4 sw=4 expandtab: */