Java tutorial
/** * Copyright (c) 2014, Google Inc. * * 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.android.mail.ui; import android.annotation.TargetApi; import android.app.Activity; import android.app.AlertDialog; import android.app.Dialog; import android.app.DialogFragment; import android.app.Fragment; import android.content.Context; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.print.PrintAttributes; import android.print.PrintDocumentAdapter; import android.print.PrintManager; import android.support.v4.print.PrintHelper; import android.text.TextUtils; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.webkit.WebView; import android.webkit.WebViewClient; import com.android.mail.R; import java.util.Calendar; /** * This fragment shows the Help screen. */ public final class HelpFragment extends Fragment { /** Displays the copyright information, privacy policy or open source licenses. */ private WebView mWebView; // Public no-args constructor needed for fragment re-instantiation public HelpFragment() { } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); final Uri helpUri = getActivity().getIntent().getParcelableExtra(HelpActivity.PARAM_HELP_URL); mWebView.loadUrl(helpUri.toString()); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle state) { setHasOptionsMenu(true); final View view = inflater.inflate(R.layout.help_fragment, container, false); if (view != null) { mWebView = (WebView) view.findViewById(R.id.webview); mWebView.setWebViewClient(new WebViewClient()); if (state != null) { mWebView.restoreState(state); } } return view; } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.help_menu, menu); // if we have no play store URI, hide that menu item final MenuItem viewAppUrlMenuItem = menu.findItem(R.id.view_app_url); if (viewAppUrlMenuItem != null) { final String appUrl = getString(R.string.app_url); viewAppUrlMenuItem.setVisible(!TextUtils.isEmpty(appUrl)); } // printing the content of the webview is only allowed if running on Kitkat or later final MenuItem printItem = menu.findItem(R.id.print_dialog); if (printItem != null) { printItem.setVisible(PrintHelper.systemSupportsPrint()); } } @Override public boolean onOptionsItemSelected(MenuItem item) { final int itemId = item.getItemId(); if (itemId == android.R.id.home) { final Activity activity = getActivity(); if (activity != null) { activity.finish(); } return true; } else if (itemId == R.id.view_app_url) { showAppUrl(); return true; } else if (itemId == R.id.print_dialog) { print(); return true; } else if (itemId == R.id.copyright_information) { showCopyrightInformation(); return true; } else if (itemId == R.id.open_source_licenses) { showOpenSourceLicenses(); return true; } else if (itemId == R.id.privacy_policy) { showPrivacyPolicy(); return true; } return super.onOptionsItemSelected(item); } @TargetApi(19) private void print() { // pick a name for the print job we will create final String title = getActivity().getActionBar().getTitle().toString(); final String jobName = getString(R.string.print_job_name, title); // ask the webview for a print adapter final PrintDocumentAdapter pda = mWebView.createPrintDocumentAdapter(); // ask the print manager to print the contents of the webview using the job name final PrintManager pm = (PrintManager) getActivity().getSystemService(Context.PRINT_SERVICE); pm.print(jobName, pda, new PrintAttributes.Builder().build()); } private void showAppUrl() { final Uri uri = Uri.parse(getString(R.string.app_url)); final Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent); } private void showCopyrightInformation() { new CopyrightDialogFragment().show(getFragmentManager(), "copyright"); } private void showOpenSourceLicenses() { final Context context = getActivity(); final Intent intent = new Intent(context, LicensesActivity.class); context.startActivity(intent); } private void showPrivacyPolicy() { final Uri uri = Uri.parse(getString(R.string.privacy_policy_uri)); final Intent i = new Intent(Intent.ACTION_VIEW, uri); startActivity(i); } public static class CopyrightDialogFragment extends DialogFragment { public CopyrightDialogFragment() { } @Override public Dialog onCreateDialog(Bundle savedInstanceState) { // generate and display a copyright statement resembling " Google 2014" final int year = Calendar.getInstance().get(Calendar.YEAR); final String copyright = getString(R.string.copyright, year); return new AlertDialog.Builder(getActivity()).setMessage(copyright) .setNegativeButton(R.string.cancel, null).create(); } } }