Merge pull request #2035 from juj/html5_events1.9.4

HTML5 Events API.

1 files changed, 474 insertions, 0 deletions

diff --git a/tests/test_html5.c b/tests/test_html5.c
new file mode 100644
index 00000000..77ddea98
--- /dev/null
+++ b/tests/test_html5.c
@@ -0,0 +1,474 @@
+#include <stdio.h>
+#include <emscripten.h>
+#include <string.h>
+#include <emscripten/html5.h>
+
+static inline const char *emscripten_event_type_to_string(int eventType) {
+  const char *events[] = { "(invalid)", "(none)", "keypress", "keydown", "keyup", "click", "mousedown", "mouseup", "dblclick", "mousemove", "wheel", "resize", 
+    "scroll", "blur", "focus", "focusin", "focusout", "deviceorientation", "devicemotion", "orientationchange", "fullscreenchange", "pointerlockchange", 
+    "visibilitychange", "touchstart", "touchend", "touchmove", "touchcancel", "gamepadconnected", "gamepaddisconnected", "beforeunload", 
+    "batterychargingchange", "batterylevelchange", "webglcontextlost", "webglcontextrestored", "(invalid)" };
+  ++eventType;
+  if (eventType < 0) eventType = 0;
+  if (eventType >= sizeof(events)/sizeof(events[0])) eventType = sizeof(events)/sizeof(events[0])-1;
+  return events[eventType];
+}
+
+const char *emscripten_result_to_string(EMSCRIPTEN_RESULT result) {
+  if (result == EMSCRIPTEN_RESULT_SUCCESS) return "EMSCRIPTEN_RESULT_SUCCESS";
+  if (result == EMSCRIPTEN_RESULT_DEFERRED) return "EMSCRIPTEN_RESULT_DEFERRED";
+  if (result == EMSCRIPTEN_RESULT_NOT_SUPPORTED) return "EMSCRIPTEN_RESULT_NOT_SUPPORTED";
+  if (result == EMSCRIPTEN_RESULT_FAILED_NOT_DEFERRED) return "EMSCRIPTEN_RESULT_FAILED_NOT_DEFERRED";
+  if (result == EMSCRIPTEN_RESULT_INVALID_TARGET) return "EMSCRIPTEN_RESULT_INVALID_TARGET";
+  if (result == EMSCRIPTEN_RESULT_UNKNOWN_TARGET) return "EMSCRIPTEN_RESULT_UNKNOWN_TARGET";
+  if (result == EMSCRIPTEN_RESULT_INVALID_PARAM) return "EMSCRIPTEN_RESULT_INVALID_PARAM";
+  if (result == EMSCRIPTEN_RESULT_FAILED) return "EMSCRIPTEN_RESULT_FAILED";
+  if (result == EMSCRIPTEN_RESULT_NO_DATA) return "EMSCRIPTEN_RESULT_NO_DATA";
+  return "Unknown EMSCRIPTEN_RESULT!";
+}
+
+#define TEST_RESULT(x) if (ret != EMSCRIPTEN_RESULT_SUCCESS) printf("%s returned %s.\n", #x, emscripten_result_to_string(ret));
+
+// The event handler functions can return 1 to suppress the event and disable the default action. That calls event.preventDefault();
+// Returning 0 signals that the event was not consumed by the code, and will allow the event to pass on and bubble up normally.
+EM_BOOL key_callback(int eventType, const EmscriptenKeyboardEvent *e, void *userData)
+{
+  printf("%s, key: \"%s\", code: \"%s\", location: %lu,%s%s%s%s repeat: %d, locale: \"%s\", char: \"%s\", charCode: %lu, keyCode: %lu, which: %lu\n",
+    emscripten_event_type_to_string(eventType), e->key, e->code, e->location, 
+    e->ctrlKey ? " CTRL" : "", e->shiftKey ? " SHIFT" : "", e->altKey ? " ALT" : "", e->metaKey ? " META" : "", 
+    e->repeat, e->locale, e->charValue, e->charCode, e->keyCode, e->which);
+
+  if (eventType == EMSCRIPTEN_EVENT_KEYPRESS && (!strcmp(e->key, "f") || e->which == 102)) {
+    EmscriptenFullscreenChangeEvent fsce;
+    EMSCRIPTEN_RESULT ret = emscripten_get_fullscreen_status(&fsce);
+    TEST_RESULT(emscripten_get_fullscreen_status);
+    if (!fsce.isFullscreen) {
+      printf("Requesting fullscreen..\n");
+      ret = emscripten_request_fullscreen(0, 1);
+      TEST_RESULT(emscripten_request_fullscreen);
+    } else {
+      printf("Exiting fullscreen..\n");
+      ret = emscripten_exit_fullscreen();
+      TEST_RESULT(emscripten_exit_fullscreen);
+      ret = emscripten_get_fullscreen_status(&fsce);
+      TEST_RESULT(emscripten_get_fullscreen_status);
+      if (fsce.isFullscreen) {
+        fprintf(stderr, "Fullscreen exit did not work!\n");
+      }
+    }
+  }
+
+  if (eventType == EMSCRIPTEN_EVENT_KEYPRESS && (!strcmp(e->key, "p") || e->which == 112)) {
+    EmscriptenPointerlockChangeEvent plce;
+    EMSCRIPTEN_RESULT ret = emscripten_get_pointerlock_status(&plce);
+    TEST_RESULT(emscripten_get_pointerlock_status);
+    if (!plce.isActive) {
+      printf("Requesting pointer lock..\n");
+      ret = emscripten_request_pointerlock(0, 1);
+      TEST_RESULT(emscripten_request_pointerlock);
+    } else {
+      printf("Exiting pointer lock..\n");
+      ret = emscripten_exit_pointerlock();
+      TEST_RESULT(emscripten_exit_pointerlock);
+      ret = emscripten_get_pointerlock_status(&plce);
+      TEST_RESULT(emscripten_get_pointerlock_status);
+      if (plce.isActive) {
+        fprintf(stderr, "Pointer lock exit did not work!\n");
+      }
+    }
+  }
+
+  return 0;
+}
+
+EM_BOOL mouse_callback(int eventType, const EmscriptenMouseEvent *e, void *userData)
+{
+  printf("%s, screen: (%ld,%ld), client: (%ld,%ld),%s%s%s%s button: %hu, buttons: %hu, movement: (%ld,%ld), canvas: (%ld,%ld)\n",
+    emscripten_event_type_to_string(eventType), e->screenX, e->screenY, e->clientX, e->clientY,
+    e->ctrlKey ? " CTRL" : "", e->shiftKey ? " SHIFT" : "", e->altKey ? " ALT" : "", e->metaKey ? " META" : "", 
+    e->button, e->buttons, e->movementX, e->movementY, e->canvasX, e->canvasY);
+
+  return 0;
+}
+
+EM_BOOL wheel_callback(int eventType, const EmscriptenWheelEvent *e, void *userData)
+{
+  printf("%s, screen: (%ld,%ld), client: (%ld,%ld),%s%s%s%s button: %hu, buttons: %hu, canvas: (%ld,%ld), delta:(%g,%g,%g), deltaMode:%lu\n",
+    emscripten_event_type_to_string(eventType), e->mouse.screenX, e->mouse.screenY, e->mouse.clientX, e->mouse.clientY,
+    e->mouse.ctrlKey ? " CTRL" : "", e->mouse.shiftKey ? " SHIFT" : "", e->mouse.altKey ? " ALT" : "", e->mouse.metaKey ? " META" : "", 
+    e->mouse.button, e->mouse.buttons, e->mouse.canvasX, e->mouse.canvasY,
+    (float)e->deltaX, (float)e->deltaY, (float)e->deltaZ, e->deltaMode);
+
+  return 0;
+}
+
+EM_BOOL uievent_callback(int eventType, const EmscriptenUiEvent *e, void *userData)
+{
+  printf("%s, detail: %ld, document.body.client size: (%d,%d), window.inner size: (%d,%d), scrollPos: (%d, %d)\n",
+    emscripten_event_type_to_string(eventType), e->detail, e->documentBodyClientWidth, e->documentBodyClientHeight,
+    e->windowInnerWidth, e->windowInnerHeight, e->scrollTop, e->scrollLeft);
+
+  return 0;
+}
+
+EM_BOOL focusevent_callback(int eventType, const EmscriptenFocusEvent *e, void *userData)
+{
+  printf("%s, nodeName: \"%s\", id: \"%s\"\n", emscripten_event_type_to_string(eventType), e->nodeName, e->id[0] == '\0' ? "(empty string)" : e->id);
+
+  return 0;
+}
+
+EM_BOOL deviceorientation_callback(int eventType, const EmscriptenDeviceOrientationEvent *e, void *userData)
+{
+  printf("%s, (%g, %g, %g)\n", emscripten_event_type_to_string(eventType), e->alpha, e->beta, e->gamma);
+
+  return 0;
+}
+
+EM_BOOL devicemotion_callback(int eventType, const EmscriptenDeviceMotionEvent *e, void *userData)
+{
+  printf("%s, accel: (%g, %g, %g), accelInclGravity: (%g, %g, %g), rotationRate: (%g, %g, %g)\n", 
+    emscripten_event_type_to_string(eventType), 
+    e->accelerationX, e->accelerationY, e->accelerationZ,
+    e->accelerationIncludingGravityX, e->accelerationIncludingGravityY, e->accelerationIncludingGravityZ,
+    e->rotationRateAlpha, e->rotationRateBeta, e->rotationRateGamma);
+
+  return 0;
+}
+
+EM_BOOL orientationchange_callback(int eventType, const EmscriptenOrientationChangeEvent *e, void *userData)
+{
+  printf("%s, orientationAngle: %d, orientationIndex: %d\n", emscripten_event_type_to_string(eventType), e->orientationAngle, e->orientationIndex);
+
+  return 0;
+}
+
+EM_BOOL fullscreenchange_callback(int eventType, const EmscriptenFullscreenChangeEvent *e, void *userData)
+{
+  printf("%s, isFullscreen: %d, fullscreenEnabled: %d, fs element nodeName: \"%s\", fs element id: \"%s\"\n",
+    emscripten_event_type_to_string(eventType), e->isFullscreen, e->fullscreenEnabled, e->nodeName, e->id);
+
+  return 0;
+}
+
+EM_BOOL pointerlockchange_callback(int eventType, const EmscriptenPointerlockChangeEvent *e, void *userData)
+{
+  printf("%s, isActive: %d, pointerlock element nodeName: \"%s\", id: \"%s\"\n",
+    emscripten_event_type_to_string(eventType), e->isActive, e->nodeName, e->id);
+
+  return 0;
+}
+
+EM_BOOL visibilitychange_callback(int eventType, const EmscriptenVisibilityChangeEvent *e, void *userData)
+{
+  printf("%s, hidden: %d, visibilityState: %d\n", emscripten_event_type_to_string(eventType), e->hidden, e->visibilityState);
+
+  return 0;
+}
+
+EM_BOOL touch_callback(int eventType, const EmscriptenTouchEvent *e, void *userData)
+{
+  printf("%s, numTouches: %d %s%s%s%s\n",
+    emscripten_event_type_to_string(eventType), e->numTouches,
+    e->ctrlKey ? " CTRL" : "", e->shiftKey ? " SHIFT" : "", e->altKey ? " ALT" : "", e->metaKey ? " META" : "");
+  for(int i = 0; i < e->numTouches; ++i)
+  {
+    const EmscriptenTouchPoint *t = &e->touches[i];
+    printf("  %ld: screen: (%ld,%ld), client: (%ld,%ld), page: (%ld,%ld), isChanged: %d, onTarget: %d, canvas: (%ld, %ld)\n",
+      t->identifier, t->screenX, t->screenY, t->clientX, t->clientY, t->pageX, t->pageY, t->isChanged, t->onTarget, t->canvasX, t->canvasY);
+  }
+  
+  return 0;
+}
+
+EM_BOOL gamepad_callback(int eventType, const EmscriptenGamepadEvent *e, void *userData)
+{
+  printf("%s: timeStamp: %g, connected: %d, index: %ld, numAxes: %d, numButtons: %d, id: \"%s\", mapping: \"%s\"\n",
+    eventType != 0 ? emscripten_event_type_to_string(eventType) : "Gamepad state", e->timestamp, e->connected, e->index, 
+    e->numAxes, e->numButtons, e->id, e->mapping);
+
+  if (e->connected)
+  {
+    for(int i = 0; i < e->numAxes; ++i)
+      printf("Axis %d: %g\n", i, e->axis[i]);
+
+    for(int i = 0; i < e->numButtons; ++i)
+      printf("Button %d: Digital: %d, Analog: %g\n", i, e->digitalButton[i], e->analogButton[i]);
+  }
+
+  return 0;
+}
+
+const char *beforeunload_callback(int eventType, const void *reserved, void *userData)
+{
+#ifdef REPORT_RESULT
+  return ""; // For test harness, don't show a confirmation dialog to not block and keep the test runner automated.
+#else
+  return "Do you really want to leave the page?";
+#endif
+}
+
+void formatTime(char *str, int seconds)
+{
+  int h = seconds / (60*60);
+  seconds -= h*60*60;
+  int m = seconds / 60;
+  seconds -= m*60;
+  if (h > 0)
+  {
+    sprintf(str, "%dh:%02dm:%02ds", h, m, seconds);
+  }
+  else
+  {
+    sprintf(str, "%02dm:%02ds", m, seconds);
+  }
+}
+
+EM_BOOL battery_callback(int eventType, const EmscriptenBatteryEvent *e, void *userData)
+{
+  char t1[64];
+  formatTime(t1, (int)e->chargingTime);
+  char t2[64];
+  formatTime(t2, (int)e->dischargingTime);
+  printf("%s: chargingTime: %s, dischargingTime: %s, level: %g%%, charging: %d\n",
+    emscripten_event_type_to_string(eventType), t1, t2, e->level*100, e->charging);
+
+  return 0;
+}
+
+EM_BOOL webglcontext_callback(int eventType, const void *reserved, void *userData)
+{
+  printf("%s.\n", emscripten_event_type_to_string(eventType));
+
+  return 0;
+}
+
+EmscriptenGamepadEvent prevState[32];
+int prevNumGamepads = 0;
+
+void mainloop()
+{
+  int numGamepads = emscripten_get_num_gamepads();
+  if (numGamepads != prevNumGamepads)
+  {
+    if (numGamepads == EMSCRIPTEN_RESULT_NOT_SUPPORTED) {
+      printf("emscripten_get_num_gamepads returned EMSCRIPTEN_RESULT_NOT_SUPPORTED.\n");
+      emscripten_cancel_main_loop();
+      return;
+    } else {
+      printf("Number of connected gamepads: %d\n", numGamepads);
+    }
+    prevNumGamepads = numGamepads;
+  }
+
+  for(int i = 0; i < numGamepads && i < 32; ++i)
+  {
+    EmscriptenGamepadEvent ge;
+    int failed = emscripten_get_gamepad_status(i, &ge);
+    if (!failed)
+    {
+      int g = ge.index;
+      for(int j = 0; j < ge.numAxes; ++j)
+      {
+        if (ge.axis[j] != prevState[g].axis[j])
+          printf("Gamepad %d, axis %d: %g\n", g, j, ge.axis[j]);
+      }
+
+      for(int j = 0; j < ge.numButtons; ++j)
+      {
+        if (ge.analogButton[j] != prevState[g].analogButton[j] || ge.digitalButton[j] != prevState[g].digitalButton[j])
+          printf("Gamepad %d, button %d: Digital: %d, Analog: %g\n", g, j, ge.digitalButton[j], ge.analogButton[j]);
+      }
+      prevState[g] = ge;
+    }
+  }
+
+}
+
+#ifdef REPORT_RESULT
+void report_result(void *arg)
+{
+  int result = 0;
+  REPORT_RESULT();
+}
+#endif
+
+int main()
+{
+
+  EMSCRIPTEN_RESULT ret = emscripten_set_keypress_callback(0, 0, 1, key_callback);
+  TEST_RESULT(emscripten_set_keypress_callback);
+  ret = emscripten_set_keydown_callback(0, 0, 1, key_callback);
+  TEST_RESULT(emscripten_set_keydown_callback);
+  ret = emscripten_set_keyup_callback(0, 0, 1, key_callback);
+  TEST_RESULT(emscripten_set_keyup_callback);
+
+  ret = emscripten_set_click_callback(0, 0, 1, mouse_callback);
+  TEST_RESULT(emscripten_set_click_callback);
+  ret = emscripten_set_mousedown_callback(0, 0, 1, mouse_callback);
+  TEST_RESULT(emscripten_set_mousedown_callback);
+  ret = emscripten_set_mouseup_callback(0, 0, 1, mouse_callback);
+  TEST_RESULT(emscripten_set_mouseup_callback);
+  ret = emscripten_set_dblclick_callback(0, 0, 1, mouse_callback);
+  TEST_RESULT(emscripten_set_dblclick_callback);
+  ret = emscripten_set_mousemove_callback(0, 0, 1, mouse_callback);
+  TEST_RESULT(emscripten_set_mousemove_callback);
+
+  ret = emscripten_set_wheel_callback(0, 0, 1, wheel_callback);
+  TEST_RESULT(emscripten_set_wheel_callback);
+
+  ret = emscripten_set_resize_callback(0, 0, 1, uievent_callback);
+  TEST_RESULT(emscripten_set_resize_callback);
+  ret = emscripten_set_scroll_callback(0, 0, 1, uievent_callback);
+  TEST_RESULT(emscripten_set_scroll_callback);
+
+  ret = emscripten_set_blur_callback(0, 0, 1, focusevent_callback);
+  TEST_RESULT(emscripten_set_blur_callback);
+  ret = emscripten_set_focus_callback(0, 0, 1, focusevent_callback);
+  TEST_RESULT(emscripten_set_focus_callback);
+  ret = emscripten_set_focusin_callback(0, 0, 1, focusevent_callback);
+  TEST_RESULT(emscripten_set_focusin_callback);
+  ret = emscripten_set_focusout_callback(0, 0, 1, focusevent_callback);
+  TEST_RESULT(emscripten_set_focusout_callback);
+
+  ret = emscripten_set_deviceorientation_callback(0, 1, deviceorientation_callback);
+  TEST_RESULT(emscripten_set_deviceorientation_callback);
+  ret = emscripten_set_devicemotion_callback(0, 1, devicemotion_callback);
+  TEST_RESULT(emscripten_set_devicemotion_callback);
+
+  ret = emscripten_set_orientationchange_callback(0, 1, orientationchange_callback);
+  TEST_RESULT(emscripten_set_orientationchange_callback);
+
+  // Test the polling of orientation.
+  EmscriptenOrientationChangeEvent oce;
+  ret = emscripten_get_orientation_status(&oce);
+  TEST_RESULT(emscripten_get_orientation_status);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("The current orientation is:\n");
+    orientationchange_callback(EMSCRIPTEN_EVENT_ORIENTATIONCHANGE, &oce, 0);
+  }
+
+  int newOrientation = (oce.orientationIndex == EMSCRIPTEN_ORIENTATION_PORTRAIT_PRIMARY 
+  || oce.orientationIndex == EMSCRIPTEN_ORIENTATION_PORTRAIT_SECONDARY) ? EMSCRIPTEN_ORIENTATION_LANDSCAPE_PRIMARY : EMSCRIPTEN_ORIENTATION_PORTRAIT_PRIMARY;
+  // Test locking of orientation.
+  ret = emscripten_lock_orientation(newOrientation);
+  TEST_RESULT(emscripten_lock_orientation);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("Locked orientation to state %d.\n", newOrientation);
+  }
+
+  ret = emscripten_get_orientation_status(&oce);
+  TEST_RESULT(emscripten_get_orientation_status);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("The current orientation is after locking:\n");
+    orientationchange_callback(18, &oce, 0);
+  }
+
+  ret = emscripten_unlock_orientation();
+  TEST_RESULT(emscripten_unlock_orientation);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("Unlocked orientation.\n");
+  }
+
+  EmscriptenFullscreenChangeEvent fsce;
+  ret = emscripten_get_fullscreen_status(&fsce);
+  TEST_RESULT(emscripten_get_fullscreen_status);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("The current fullscreen status is:\n");
+    fullscreenchange_callback(EMSCRIPTEN_EVENT_FULLSCREENCHANGE, &fsce, 0);
+  }
+
+  ret = emscripten_set_fullscreenchange_callback(0, 0, 1, fullscreenchange_callback);
+  TEST_RESULT(emscripten_set_fullscreenchange_callback);
+
+  // These won't do anything, since fullscreen must be requested in an event handler,
+  // but call these anyways to confirm that they don't crash in an exception in the test suite.
+  ret = emscripten_request_fullscreen(0, 1);
+  TEST_RESULT(emscripten_request_fullscreen);
+  ret = emscripten_exit_fullscreen();
+  TEST_RESULT(emscripten_exit_fullscreen);
+
+  EmscriptenPointerlockChangeEvent plce;
+  ret = emscripten_get_pointerlock_status(&plce);
+  TEST_RESULT(emscripten_get_pointerlock_status);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("The current pointerlock status is:\n");
+    pointerlockchange_callback(EMSCRIPTEN_EVENT_POINTERLOCKCHANGE, &plce, 0);
+  }
+
+  ret = emscripten_set_pointerlockchange_callback(0, 0, 1, pointerlockchange_callback);
+  TEST_RESULT(emscripten_set_pointerlockchange_callback);
+
+  // These won't do anything, since pointer lock must be requested in an event handler,
+  // but call these anyways to confirm that they don't crash in an exception in the test suite.
+  ret = emscripten_request_pointerlock(0, 1);
+  TEST_RESULT(emscripten_request_pointerlock);
+  ret = emscripten_exit_pointerlock();
+  TEST_RESULT(emscripten_exit_pointerlock);
+
+  int vibratePattern[] = {
+    150, 500, 
+    300, 500, 
+    450
+  };
+  ret = emscripten_vibrate_pattern(vibratePattern, sizeof(vibratePattern)/sizeof(vibratePattern[0]));
+  TEST_RESULT(emscripten_vibrate_pattern);
+
+  EmscriptenVisibilityChangeEvent vce;
+  ret = emscripten_get_visibility_status(&vce);
+  TEST_RESULT(emscripten_get_visibility_status);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("Current visibility status:\n");
+    visibilitychange_callback(EMSCRIPTEN_EVENT_VISIBILITYCHANGE, &vce, 0);
+  }
+
+  ret = emscripten_set_visibilitychange_callback(0, 1, visibilitychange_callback);
+  TEST_RESULT(emscripten_set_visibilitychange_callback);
+
+  ret = emscripten_set_touchstart_callback(0, 0, 1, touch_callback);
+  TEST_RESULT(emscripten_set_touchstart_callback);
+  ret = emscripten_set_touchend_callback(0, 0, 1, touch_callback);
+  TEST_RESULT(emscripten_set_touchend_callback);
+  ret = emscripten_set_touchmove_callback(0, 0, 1, touch_callback);
+  TEST_RESULT(emscripten_set_touchmove_callback);
+  ret = emscripten_set_touchcancel_callback(0, 0, 1, touch_callback);
+  TEST_RESULT(emscripten_set_touchcancel_callback);
+
+  ret = emscripten_set_gamepadconnected_callback(0, 1, gamepad_callback);
+  TEST_RESULT(emscripten_set_gamepadconnected_callback);
+  ret = emscripten_set_gamepaddisconnected_callback(0, 1, gamepad_callback);
+  TEST_RESULT(emscripten_set_gamepaddisconnected_callback);
+
+  emscripten_set_main_loop(mainloop, 10, 0);
+
+  ret = emscripten_set_beforeunload_callback(0, beforeunload_callback);
+  TEST_RESULT(emscripten_set_beforeunload_callback);
+
+  ret = emscripten_set_batterychargingchange_callback(0, battery_callback);
+  TEST_RESULT(emscripten_set_batterychargingchange_callback);
+  ret = emscripten_set_batterylevelchange_callback(0, battery_callback);
+  TEST_RESULT(emscripten_set_batterylevelchange_callback);
+
+  EmscriptenBatteryEvent bs;
+  ret = emscripten_get_battery_status(&bs);
+  TEST_RESULT(emscripten_get_battery_status);
+  if (ret == EMSCRIPTEN_RESULT_SUCCESS) {
+    printf("Current battery status:\n");
+    battery_callback(EMSCRIPTEN_EVENT_BATTERYLEVELCHANGE, &bs, 0);
+  }
+
+  ret = emscripten_set_webglcontextlost_callback(0, 0, 1, webglcontext_callback);
+  TEST_RESULT(emscripten_set_webglcontextlost_callback);
+  ret = emscripten_set_webglcontextrestored_callback(0, 0, 1, webglcontext_callback);
+  TEST_RESULT(emscripten_set_webglcontextrestored_callback);
+
+  /* For the events to function, one must either call emscripten_set_main_loop or enable Module.noExitRuntime by some other means. 
+     Otherwise the application will exit after leaving main(), and the atexit handlers will clean up all event hooks (by design). */
+  EM_ASM(Module['noExitRuntime'] = true);
+  
+#ifdef REPORT_RESULT
+  // Keep the page running for a moment.
+  emscripten_async_call(report_result, 0, 5000);
+#endif
+  return 0;
+}