// Copyright (c) 2014 The Chromium Embedded Framework Authors. All rights
// reserved. Use of this source code is governed by a BSD-style license that
// can be found in the LICENSE file.

package tests.simple;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.KeyboardFocusManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JFrame;
import javax.swing.JTextField;

import org.cef.CefApp;
import org.cef.CefApp.CefAppState;
import org.cef.CefClient;
import org.cef.CefSettings;
import org.cef.OS;
import org.cef.browser.CefBrowser;
import org.cef.browser.CefFrame;
import org.cef.handler.CefAppHandlerAdapter;
import org.cef.handler.CefDisplayHandlerAdapter;
import org.cef.handler.CefFocusHandlerAdapter;

/**
 * This is a simple example application using JCEF.
 * It displays a JFrame with a JTextField at its top and a CefBrowser in its
 * center. The JTextField is used to enter and assign an URL to the browser UI.
 * No additional handlers or callbacks are used in this example.
 *
 * The number of used JCEF classes is reduced (nearly) to its minimum and should
 * assist you to get familiar with JCEF.
 *
 * For a more feature complete example have also a look onto the example code
 * within the package "tests.detailed".
 */
public class MainFrame extends JFrame {
 private static final long serialVersionUID = -5570653778104813836L;
 private final JTextField address_;
 private final CefApp cefApp_;
 private final CefClient client_;
 private final CefBrowser browser_;
 private final Component browerUI_;
 private boolean browserFocus_ = true;

 /**
 * To display a simple browser window, it suffices completely to create an
 * instance of the class CefBrowser and to assign its UI component to your
 * application (e.g. to your content pane).
 * But to be more verbose, this CTOR keeps an instance of each object on the
 * way to the browser UI.
 */
 private MainFrame(String startURL, boolean useOSR, boolean isTransparent) {
 // (1) The entry point to JCEF is always the class CefApp. There is only one
 // instance per application and therefore you have to call the method
 // "getInstance()" instead of a CTOR.
 //
 // CefApp is responsible for the global CEF context. It loads all
 // required native libraries, initializes CEF accordingly, starts a
 // background task to handle CEF's message loop and takes care of
 // shutting down CEF after disposing it.
 CefApp.addAppHandler(new CefAppHandlerAdapter(null) {
 @Override
 public void stateHasChanged(org.cef.CefApp.CefAppState state) {
 // Shutdown the app if the native CEF part is terminated
 if (state == CefAppState.TERMINATED) System.exit(0);
 }
 });
 CefSettings settings = new CefSettings();
 settings.windowless_rendering_enabled = useOSR;
 cefApp_ = CefApp.getInstance(settings);

 // (2) JCEF can handle one to many browser instances simultaneous. These
 // browser instances are logically grouped together by an instance of
 // the class CefClient. In your application you can create one to many
 // instances of CefClient with one to many CefBrowser instances per
 // client. To get an instance of CefClient you have to use the method
 // "createClient()" of your CefApp instance. Calling an CTOR of
 // CefClient is not supported.
 //
 // CefClient is a connector to all possible events which come from the
 // CefBrowser instances. Those events could be simple things like the
 // change of the browser title or more complex ones like context menu
 // events. By assigning handlers to CefClient you can control the
 // behavior of the browser. See tests.detailed.MainFrame for an example
 // of how to use these handlers.
 client_ = cefApp_.createClient();

 // (3) One CefBrowser instance is responsible to control what you'll see on
 // the UI component of the instance. It can be displayed off-screen
 // rendered or windowed rendered. To get an instance of CefBrowser you
 // have to call the method "createBrowser()" of your CefClient
 // instances.
 //
 // CefBrowser has methods like "goBack()", "goForward()", "loadURL()",
 // and many more which are used to control the behavior of the displayed
 // content. The UI is held within a UI-Compontent which can be accessed
 // by calling the method "getUIComponent()" on the instance of CefBrowser.
 // The UI component is inherited from a java.awt.Component and therefore
 // it can be embedded into any AWT UI.
 browser_ = client_.createBrowser(startURL, useOSR, isTransparent);
 browerUI_ = browser_.getUIComponent();

 // (4) For this minimal browser, we need only a text field to enter an URL
 // we want to navigate to and a CefBrowser window to display the content
 // of the URL. To respond to the input of the user, we're registering an
 // anonymous ActionListener. This listener is performed each time the
 // user presses the "ENTER" key within the address field.
 // If this happens, the entered value is passed to the CefBrowser
 // instance to be loaded as URL.
 address_ = new JTextField(startURL, 100);
 address_.addActionListener(new ActionListener() {
 @Override
 public void actionPerformed(ActionEvent e) {
 browser_.loadURL(address_.getText());
 }
 });

 // Update the address field when the browser URL changes.
 client_.addDisplayHandler(new CefDisplayHandlerAdapter() {
 @Override
 public void onAddressChange(CefBrowser browser, CefFrame frame, String url) {
 address_.setText(url);
 }
 });

 // Clear focus from the browser when the address field gains focus.
 address_.addFocusListener(new FocusAdapter() {
 @Override
 public void focusGained(FocusEvent e) {
 if (!browserFocus_) return;
 browserFocus_ = false;
 KeyboardFocusManager.getCurrentKeyboardFocusManager().clearGlobalFocusOwner();
 address_.requestFocus();
 }
 });

 // Clear focus from the address field when the browser gains focus.
 client_.addFocusHandler(new CefFocusHandlerAdapter() {
 @Override
 public void onGotFocus(CefBrowser browser) {
 if (browserFocus_) return;
 browserFocus_ = true;
 KeyboardFocusManager.getCurrentKeyboardFocusManager().clearGlobalFocusOwner();
 browser.setFocus(true);
 }

 @Override
 public void onTakeFocus(CefBrowser browser, boolean next) {
 browserFocus_ = false;
 }
 });

 // (5) All UI components are assigned to the default content pane of this
 // JFrame and afterwards the frame is made visible to the user.
 getContentPane().add(address_, BorderLayout.NORTH);
 getContentPane().add(browerUI_, BorderLayout.CENTER);
 pack();
 setSize(800, 600);
 setVisible(true);

 // (6) To take care of shutting down CEF accordingly, it's important to call
 // the method "dispose()" of the CefApp instance if the Java
 // application will be closed. Otherwise you'll get asserts from CEF.
 addWindowListener(new WindowAdapter() {
 @Override
 public void windowClosing(WindowEvent e) {
 CefApp.getInstance().dispose();
 dispose();
 }
 });
 }

 public static void main(String[] args) {
 // Perform startup initialization on platforms that require it.
 if (!CefApp.startup()) {
 System.out.println("Startup initialization failed!");
 return;
 }

 // The simple example application is created as anonymous class and points
 // to Google as the very first loaded page. Windowed rendering mode is used by
 // default. If you want to test OSR mode set |useOsr| to true and recompile.
 boolean useOsr = false;
 new MainFrame("http://www.google.com", useOsr, false);
 }
}