tests/canvas_focus.c

/*
 * Copyright 2017 The Emscripten Authors.  All rights reserved.
 * Emscripten is available under two separate licenses, the MIT license and the
 * University of Illinois/NCSA Open Source License.  Both these licenses can be
 * found in the LICENSE file.
 */

#include <emscripten/html5.h>
#include <emscripten/key_codes.h>
#include <emscripten.h>
#include <stdio.h>
#include <string.h>

EM_BOOL key_callback(int eventType, const EmscriptenKeyboardEvent *e, void *userData)
{
  static int i = 0;
  printf("key_callback %d\n", i);
  i++;
#ifdef REPORT_RESULT
  REPORT_RESULT(1);
#endif
  return 0;
}

int main()
{
  emscripten_set_keypress_callback("#canvas", 0, 1, key_callback);
  EM_ASM({
    var event = new KeyboardEvent("keypress", { 'keyCode': 38, 'charCode': 38, 'view': window, 'bubbles': true, 'cancelable': true });
    // Focus, then send an event, same as if the user clicked on it for focus.
    Module.canvas.focus();
    document.activeElement.dispatchEvent(event);
    noExitRuntime = true;
  });
}