HelpActivity.java

/*
 * Copyright 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing.client.android;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.webkit.WebView;

/**
 * An HTML-based help screen.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class HelpActivity extends Activity {

  private static final String BASE_URL =
      "file:///android_asset/html-" + LocaleManager.getTranslatedAssetLanguage() + '/';

  private WebView webView;

  @Override
  protected void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.help);

    webView = (WebView) findViewById(R.id.help_contents);

    if (icicle == null) {
      webView.loadUrl(BASE_URL + "index.html");
    } else {
      webView.restoreState(icicle);
    }
  }

  @Override
  protected void onSaveInstanceState(Bundle state) {
    String url = webView.getUrl();
    if (url != null && !url.isEmpty()) {
      webView.saveState(state);
    }
  }

  @Override
  public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK && webView.canGoBack()) {
      webView.goBack();
      return true;
    }
    return super.onKeyDown(keyCode, event);
  }

}