DoubleTapReloadRecognizer.java

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

package com.facebook.react.devsupport;

import android.os.Handler;
import android.view.KeyEvent;
import android.view.View;
import android.widget.EditText;

/**
 * A class allows recognizing double key tap of "R", used to reload JS in
 * {@link AbstractReactActivity}, {@link RedBoxDialog} and {@link ReactActivity}.
 */
public class DoubleTapReloadRecognizer {
  private boolean mDoRefresh = false;
  private static final long DOUBLE_TAP_DELAY = 200;

  public boolean didDoubleTapR(int keyCode, View view) {
    if (keyCode == KeyEvent.KEYCODE_R && !(view instanceof EditText)) {
      if (mDoRefresh) {
        mDoRefresh = false;
        return true;
      } else {
        mDoRefresh = true;
        new Handler().postDelayed(
          new Runnable() {
            @Override
            public void run() {
              mDoRefresh = false;
            }
          },
          DOUBLE_TAP_DELAY);
      }
    }
    return false;
  }
}