samples/showcase/src/com/google/gwt/sample/showcase/client/ContentWidget.java - gwt - Git at Google

 /*
  * Copyright 2008 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.google.gwt.sample.showcase.client;

 import com.google.gwt.core.client.GWT;
 import com.google.gwt.event.logical.shared.SelectionEvent;
 import com.google.gwt.event.logical.shared.SelectionHandler;
 import com.google.gwt.http.client.Request;
 import com.google.gwt.http.client.RequestBuilder;
 import com.google.gwt.http.client.RequestCallback;
 import com.google.gwt.http.client.RequestException;
 import com.google.gwt.http.client.Response;
 import com.google.gwt.i18n.client.Constants;
 import com.google.gwt.i18n.client.HasDirection;
 import com.google.gwt.i18n.client.LocaleInfo;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.ui.DeckPanel;
 import com.google.gwt.user.client.ui.HTML;
 import com.google.gwt.user.client.ui.LazyPanel;
 import com.google.gwt.user.client.ui.TabBar;
 import com.google.gwt.user.client.ui.VerticalPanel;
 import com.google.gwt.user.client.ui.Widget;

 import java.util.HashMap;
 import java.util.Map;

 /**
  * <p>
  * A widget used to show GWT examples in the ContentPanel. It includes a tab bar
  * with options to view the example, view the source, or view the css style
  * rules.
  * </p>
  * <p>
  * This {@link Widget} extends {@link LazyPanel} so that the content is not
  * rendered until the widget first becomes visible. The data in the source and
  * css tabs are loaded using an RPC call to the server.
  * </p>
  * <h3>CSS Style Rules</h3>
  * <ul class="css">
  * <li>.sc-ContentWidget { Applied to the entire widget }</li>
  * <li>.sc-ContentWidget-tabBar { Applied to the TabBar }</li>
  * <li>.sc-ContentWidget-deckPanel { Applied to the DeckPanel }</li>
  * <li>.sc-ContentWidget-name { Applied to the name }</li>
  * <li>.sc-ContentWidget-description { Applied to the description }</li>
  * </ul>
  */
 public abstract class ContentWidget extends LazyPanel implements
     SelectionHandler<Integer> {
   /**
    * The constants used in this Content Widget.
    */
   public static interface CwConstants extends Constants {
     String contentWidgetExample();

     String contentWidgetSource();

     String contentWidgetStyle();
   }

   /**
    * The default style name.
    */
   private static final String DEFAULT_STYLE_NAME = "sc-ContentWidget";

   /**
    * The static loading image displayed when loading CSS or source code.
    */
   private static String loadingImage;

   /**
    * An instance of the constants.
    */
   private final CwConstants constants;

   /**
    * The deck panel with the contents.
    */
   private DeckPanel deckPanel = null;

   /**
    * A boolean indicating whether or not the RPC request for the source code has
    * been sent.
    */
   private boolean sourceLoaded = false;

   /**
    * The widget used to display source code.
    */
   private HTML sourceWidget = null;

   /**
    * A mapping of themes to style definitions.
    */
   private Map<String, String> styleDefs = null;

   /**
    * The widget used to display css style.
    */
   private HTML styleWidget = null;

   /**
    * The tab bar of options.
    */
   private TabBar tabBar = null;

   /**
    * Constructor.
    *
    * @param constants the constants
    */
   public ContentWidget(CwConstants constants) {
     this.constants = constants;
     tabBar = new TabBar();
   }

   /**
    * Add an item to this content widget. Should not be called before
    * {@link #onInitializeComplete} has been called.
    *
    * @param w the widget to add
    * @param tabText the text to display in the tab
    */
   public void add(Widget w, String tabText) {
     tabBar.addTab(tabText);
     deckPanel.add(w);
   }

   /**
    * Get the description of this example.
    *
    * @return a description for this example
    */
   public abstract String getDescription();

   /**
    * Get the name of this example to use as a title.
    *
    * @return a name for this example
    */
   public abstract String getName();

   /**
    * @return the tab bar
    */
   public TabBar getTabBar() {
     return tabBar;
   }

   /**
    * Returns true if this widget has a source section.
    *
    * @return true if source tab available
    */
   public boolean hasSource() {
     return true;
   }

   /**
    * Returns true if this widget has a style section.
    *
    * @return true if style tab available
    */
   public boolean hasStyle() {
     return true;
   }

   /**
    * When the widget is first initialized, this method is called. If it returns
    * a Widget, the widget will be added as the first tab. Return null to disable
    * the first tab.
    *
    * @return the widget to add to the first tab
    */
   public abstract Widget onInitialize();

   /**
    * Called when initialization has completed and the widget has been added to
    * the page.
    */
   public void onInitializeComplete() {
   }

   public void onSelection(SelectionEvent<Integer> event) {
     // Show the associated widget in the deck panel
     int tabIndex = event.getSelectedItem().intValue();
     deckPanel.showWidget(tabIndex);

     // Load the source code
     String tabHTML = getTabBar().getTabHTML(tabIndex);
     if (!sourceLoaded && tabHTML.equals(constants.contentWidgetSource())) {
       sourceLoaded = true;
       String className = this.getClass().getName();
       className = className.substring(className.lastIndexOf(".") + 1);
       requestSourceContents(ShowcaseConstants.DST_SOURCE_EXAMPLE + className
           + ".html", sourceWidget, null);
     }

     // Load the style definitions
     if (hasStyle() && tabHTML.equals(constants.contentWidgetStyle())) {
       final String theme = Showcase.CUR_THEME;
       if (styleDefs.containsKey(theme)) {
         styleWidget.setHTML(styleDefs.get(theme));
       } else {
         styleDefs.put(theme, "");
         RequestCallback callback = new RequestCallback() {
           public void onError(Request request, Throwable exception) {
             styleDefs.put(theme, "Style not available.");
           }

           public void onResponseReceived(Request request, Response response) {
             styleDefs.put(theme, response.getText());
           }
         };

         String srcPath = ShowcaseConstants.DST_SOURCE_STYLE + theme;
         if (LocaleInfo.getCurrentLocale().isRTL()) {
           srcPath += "_rtl";
         }
         String className = this.getClass().getName();
         className = className.substring(className.lastIndexOf(".") + 1);
         requestSourceContents(srcPath + "/" + className + ".html", styleWidget,
             callback);
       }
     }
   }

   /**
    * Select a tab.
    *
    * @param index the tab index
    */
   public void selectTab(int index) {
     tabBar.selectTab(index);
   }

   /**
    * Initialize this widget by creating the elements that should be added to the
    * page.
    */
   protected final Widget createWidget() {
     deckPanel = new DeckPanel();

     setStyleName(DEFAULT_STYLE_NAME);

     // Add a tab handler
     tabBar.addSelectionHandler(this);

     // Create a container for the main example
     final VerticalPanel vPanel = new VerticalPanel();
     add(vPanel, constants.contentWidgetExample());

     // Add the name
     HTML nameWidget = new HTML(getName());
     nameWidget.setStyleName(DEFAULT_STYLE_NAME + "-name");
     vPanel.add(nameWidget);

     // Add the description
     HTML descWidget = new HTML(getDescription());
     descWidget.setStyleName(DEFAULT_STYLE_NAME + "-description");
     vPanel.add(descWidget);

     // Add source code tab
     if (hasSource()) {
       sourceWidget = new HTML();
       add(sourceWidget, constants.contentWidgetSource());
     } else {
       sourceLoaded = true;
     }

     // Add style tab
     if (hasStyle()) {
       styleDefs = new HashMap<String, String>();
       styleWidget = new HTML();
       add(styleWidget, constants.contentWidgetStyle());
     }

     // Initialize the showcase widget (if any) and add it to the page
     Widget widget = onInitialize();
     if (widget != null) {
       vPanel.add(widget);
     }
     onInitializeComplete();

     return deckPanel;
   }

   @Override
   protected void onLoad() {
     ensureWidget();

     // Select the first tab
     if (getTabBar().getTabCount() > 0) {
       tabBar.selectTab(0);
     }
   }

   /**
    * Load the contents of a remote file into the specified widget.
    *
    * @param url a partial path relative to the module base URL
    * @param target the target Widget to place the contents
    * @param callback the callback when the call completes
    */
   protected void requestSourceContents(String url, final HTML target,
       final RequestCallback callback) {
     // Show the loading image
     if (loadingImage == null) {
       loadingImage = "<img src=\"" + GWT.getModuleBaseURL()
           + "images/loading.gif\">";
     }
     target.setDirection(HasDirection.Direction.LTR);
     DOM.setStyleAttribute(target.getElement(), "textAlign", "left");
     target.setHTML("&nbsp;&nbsp;" + loadingImage);

     // Request the contents of the file
     RequestBuilder builder = new RequestBuilder(RequestBuilder.GET,
         GWT.getModuleBaseURL() + url);
     RequestCallback realCallback = new RequestCallback() {
       public void onError(Request request, Throwable exception) {
         target.setHTML("Cannot find resource");
         if (callback != null) {
           callback.onError(request, exception);
         }
       }

       public void onResponseReceived(Request request, Response response) {
         target.setHTML(response.getText());
         if (callback != null) {
           callback.onResponseReceived(request, response);
         }
       }
     };
     builder.setCallback(realCallback);

     // Send the request
     Request request = null;
     try {
       request = builder.send();
     } catch (RequestException e) {
       realCallback.onError(request, e);
     }
   }
 }
	/*
	* Copyright 2008 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.google.gwt.sample.showcase.client;

	import com.google.gwt.core.client.GWT;
	import com.google.gwt.event.logical.shared.SelectionEvent;
	import com.google.gwt.event.logical.shared.SelectionHandler;
	import com.google.gwt.http.client.Request;
	import com.google.gwt.http.client.RequestBuilder;
	import com.google.gwt.http.client.RequestCallback;
	import com.google.gwt.http.client.RequestException;
	import com.google.gwt.http.client.Response;
	import com.google.gwt.i18n.client.Constants;
	import com.google.gwt.i18n.client.HasDirection;
	import com.google.gwt.i18n.client.LocaleInfo;
	import com.google.gwt.user.client.DOM;
	import com.google.gwt.user.client.ui.DeckPanel;
	import com.google.gwt.user.client.ui.HTML;
	import com.google.gwt.user.client.ui.LazyPanel;
	import com.google.gwt.user.client.ui.TabBar;
	import com.google.gwt.user.client.ui.VerticalPanel;
	import com.google.gwt.user.client.ui.Widget;

	import java.util.HashMap;
	import java.util.Map;

	/**
	* <p>
	* A widget used to show GWT examples in the ContentPanel. It includes a tab bar
	* with options to view the example, view the source, or view the css style
	* rules.
	* </p>
	* <p>
	* This {@link Widget} extends {@link LazyPanel} so that the content is not
	* rendered until the widget first becomes visible. The data in the source and
	* css tabs are loaded using an RPC call to the server.
	* </p>
	* <h3>CSS Style Rules</h3>
	* <ul class="css">
	* <li>.sc-ContentWidget { Applied to the entire widget }</li>
	* <li>.sc-ContentWidget-tabBar { Applied to the TabBar }</li>
	* <li>.sc-ContentWidget-deckPanel { Applied to the DeckPanel }</li>
	* <li>.sc-ContentWidget-name { Applied to the name }</li>
	* <li>.sc-ContentWidget-description { Applied to the description }</li>
	* </ul>
	*/
	public abstract class ContentWidget extends LazyPanel implements
	SelectionHandler<Integer> {
	/**
	* The constants used in this Content Widget.
	*/
	public static interface CwConstants extends Constants {
	String contentWidgetExample();

	String contentWidgetSource();

	String contentWidgetStyle();
	}

	/**
	* The default style name.
	*/
	private static final String DEFAULT_STYLE_NAME = "sc-ContentWidget";

	/**
	* The static loading image displayed when loading CSS or source code.
	*/
	private static String loadingImage;

	/**
	* An instance of the constants.
	*/
	private final CwConstants constants;

	/**
	* The deck panel with the contents.
	*/
	private DeckPanel deckPanel = null;

	/**
	* A boolean indicating whether or not the RPC request for the source code has
	* been sent.
	*/
	private boolean sourceLoaded = false;

	/**
	* The widget used to display source code.
	*/
	private HTML sourceWidget = null;

	/**
	* A mapping of themes to style definitions.
	*/
	private Map<String, String> styleDefs = null;

	/**
	* The widget used to display css style.
	*/
	private HTML styleWidget = null;

	/**
	* The tab bar of options.
	*/
	private TabBar tabBar = null;

	/**
	* Constructor.
	*
	* @param constants the constants
	*/
	public ContentWidget(CwConstants constants) {
	this.constants = constants;
	tabBar = new TabBar();
	}

	/**
	* Add an item to this content widget. Should not be called before
	* {@link #onInitializeComplete} has been called.
	*
	* @param w the widget to add
	* @param tabText the text to display in the tab
	*/
	public void add(Widget w, String tabText) {
	tabBar.addTab(tabText);
	deckPanel.add(w);
	}

	/**
	* Get the description of this example.
	*
	* @return a description for this example
	*/
	public abstract String getDescription();

	/**
	* Get the name of this example to use as a title.
	*
	* @return a name for this example
	*/
	public abstract String getName();

	/**
	* @return the tab bar
	*/
	public TabBar getTabBar() {
	return tabBar;
	}

	/**
	* Returns true if this widget has a source section.
	*
	* @return true if source tab available
	*/
	public boolean hasSource() {
	return true;
	}

	/**
	* Returns true if this widget has a style section.
	*
	* @return true if style tab available
	*/
	public boolean hasStyle() {
	return true;
	}

	/**
	* When the widget is first initialized, this method is called. If it returns
	* a Widget, the widget will be added as the first tab. Return null to disable
	* the first tab.
	*
	* @return the widget to add to the first tab
	*/
	public abstract Widget onInitialize();

	/**
	* Called when initialization has completed and the widget has been added to
	* the page.
	*/
	public void onInitializeComplete() {
	}

	public void onSelection(SelectionEvent<Integer> event) {
	// Show the associated widget in the deck panel
	int tabIndex = event.getSelectedItem().intValue();
	deckPanel.showWidget(tabIndex);

	// Load the source code
	String tabHTML = getTabBar().getTabHTML(tabIndex);
	if (!sourceLoaded && tabHTML.equals(constants.contentWidgetSource())) {
	sourceLoaded = true;
	String className = this.getClass().getName();
	className = className.substring(className.lastIndexOf(".") + 1);
	requestSourceContents(ShowcaseConstants.DST_SOURCE_EXAMPLE + className
	+ ".html", sourceWidget, null);
	}

	// Load the style definitions
	if (hasStyle() && tabHTML.equals(constants.contentWidgetStyle())) {
	final String theme = Showcase.CUR_THEME;
	if (styleDefs.containsKey(theme)) {
	styleWidget.setHTML(styleDefs.get(theme));
	} else {
	styleDefs.put(theme, "");
	RequestCallback callback = new RequestCallback() {
	public void onError(Request request, Throwable exception) {
	styleDefs.put(theme, "Style not available.");
	}

	public void onResponseReceived(Request request, Response response) {
	styleDefs.put(theme, response.getText());
	}
	};

	String srcPath = ShowcaseConstants.DST_SOURCE_STYLE + theme;
	if (LocaleInfo.getCurrentLocale().isRTL()) {
	srcPath += "_rtl";
	}
	String className = this.getClass().getName();
	className = className.substring(className.lastIndexOf(".") + 1);
	requestSourceContents(srcPath + "/" + className + ".html", styleWidget,
	callback);
	}
	}
	}

	/**
	* Select a tab.
	*
	* @param index the tab index
	*/
	public void selectTab(int index) {
	tabBar.selectTab(index);
	}

	/**
	* Initialize this widget by creating the elements that should be added to the
	* page.
	*/
	protected final Widget createWidget() {
	deckPanel = new DeckPanel();

	setStyleName(DEFAULT_STYLE_NAME);

	// Add a tab handler
	tabBar.addSelectionHandler(this);

	// Create a container for the main example
	final VerticalPanel vPanel = new VerticalPanel();
	add(vPanel, constants.contentWidgetExample());

	// Add the name
	HTML nameWidget = new HTML(getName());
	nameWidget.setStyleName(DEFAULT_STYLE_NAME + "-name");
	vPanel.add(nameWidget);

	// Add the description
	HTML descWidget = new HTML(getDescription());
	descWidget.setStyleName(DEFAULT_STYLE_NAME + "-description");
	vPanel.add(descWidget);

	// Add source code tab
	if (hasSource()) {
	sourceWidget = new HTML();
	add(sourceWidget, constants.contentWidgetSource());
	} else {
	sourceLoaded = true;
	}

	// Add style tab
	if (hasStyle()) {
	styleDefs = new HashMap<String, String>();
	styleWidget = new HTML();
	add(styleWidget, constants.contentWidgetStyle());
	}

	// Initialize the showcase widget (if any) and add it to the page
	Widget widget = onInitialize();
	if (widget != null) {
	vPanel.add(widget);
	}
	onInitializeComplete();

	return deckPanel;
	}

	@Override
	protected void onLoad() {
	ensureWidget();

	// Select the first tab
	if (getTabBar().getTabCount() > 0) {
	tabBar.selectTab(0);
	}
	}

	/**
	* Load the contents of a remote file into the specified widget.
	*
	* @param url a partial path relative to the module base URL
	* @param target the target Widget to place the contents
	* @param callback the callback when the call completes
	*/
	protected void requestSourceContents(String url, final HTML target,
	final RequestCallback callback) {
	// Show the loading image
	if (loadingImage == null) {
	loadingImage = "<img src=\"" + GWT.getModuleBaseURL()
	+ "images/loading.gif\">";
	}
	target.setDirection(HasDirection.Direction.LTR);
	DOM.setStyleAttribute(target.getElement(), "textAlign", "left");
	target.setHTML("  " + loadingImage);

	// Request the contents of the file
	RequestBuilder builder = new RequestBuilder(RequestBuilder.GET,
	GWT.getModuleBaseURL() + url);
	RequestCallback realCallback = new RequestCallback() {
	public void onError(Request request, Throwable exception) {
	target.setHTML("Cannot find resource");
	if (callback != null) {
	callback.onError(request, exception);
	}
	}

	public void onResponseReceived(Request request, Response response) {
	target.setHTML(response.getText());
	if (callback != null) {
	callback.onResponseReceived(request, response);
	}
	}
	};
	builder.setCallback(realCallback);

	// Send the request
	Request request = null;
	try {
	request = builder.send();
	} catch (RequestException e) {
	realCallback.onError(request, e);
	}
	}
	}