/**

     * * Retrieves the pixels of width available for provided browser content.

     * */

    public int getAvailableWidth(BrowserContent browserField) {

       // Field has full screen.

       return Graphics.getScreenWidth();

       }

   

    /**

     * * Retrieves the history position for provided browser content.

     * */

    public int getHistoryPosition(BrowserContent browserField) {

       // No history support.

       return 0;

       }

    /**

     * * Retrieves cookies associated with a provided URL.

     * */

    public String getHTTPCookie(String url) {

       // No cookie support.

       return null;

       }

   

    /**

     * * Retrieves the specified resource.

     * */

    public HttpConnection getResource( RequestedResource resource, BrowserContent referrer)

    {

       if (resource == null) {

           return null;

           }

       // Check if this is cache-only request.

       if (resource.isCacheOnly()) {

           // No cache support.

           return null;

           }

       String url = resource.getUrl();

       if (url == null) {

           return null;

           }

      

       // If referrer is null, return the connection.

       if (referrer == null) {

           HttpConnection conn;

           try {

              return (HttpConnection) Connector.open(resource.getUrl());

              }

           catch (IOException e) {

              return null;

              }

           }

       else {

           // If referrer is provided, set up the connection on a

           // separate thread.

           Application.getApplication().invokeLater(

                  new RetrieveThread(resource, referrer));

           }

       return null;

       }

    /**

     * * Invokes the provided runnable object.

     * */

    public void invokeRunnable(Runnable runnable) {

(new Thread(runnable)).run();

}

}

class RenderingThread implements Runnable {

    BrowserContent _browserField;

    RenderingThread(BrowserContent field) {

       _browserField = field;

       }

    public void run() {

       try {

           browserField.finishLoading();

           }

       catch (RenderingException e) {

          

       }

    }

    }

 

class RetrieveThread implements Runnable {

    BrowserContent _browserField;

    RequestedResource _resource;

    RetrieveThread(RequestedResource resource, BrowserContent referrer) {

       _browserField = referrer;

       _resource = resource;

       }

    public void run() {

       HttpConnection conn;

       try {

           conn = (HttpConnection) Connector.open(_resource.getUrl());

           }

       catch (IOException e) {

           return;

       }

       _resource.setHttpConnection(conn);

       _browserField.resourceReady(_resource);

       }

}

---

支持附加MIME类型

浏览器页面API在net.rim.device.api.browser.plugin包中,它允许第三方应用程序向描绘库将它们自己注册为BlackBerry浏览器不支持的MIME类型的描绘提供者.
注: 如果你试着注册一个BlackBerry浏览器已经支持的MIME类型，BrowserFieldProviderRegistry.register()方法会抛出一个异常.为得到支持的MIME类型列表,调用RenderingSession.getSupportedMimeType().

注册一个MIME类型的呈现提供者

为支持附加的MIME类型,需要扩展BrowserContentProvider抽象类.为了指定显示特性,例如没有滚动条显示或全屏显示,需要实现BrowserPageContext接口.

呈现的类库调用BrowserContentProvider.getAccept()和BrowserContentProvider.getSupportedMimeTypes()标志提供者呈现的MIME类型.

 

列出接受的MIME类型

getAccept()和getSupportedMimeTypes()的实现列出了提供者接受的MIME类型,它们给定了一组呈现的选项. getAccept()方法考虑到已经设置的呈现选项.这个例子假设没有设置呈现选项.为得到更多信息.参看API参考的RenderingOptions

public String[] getAccept(RenderingOptions context) {     // Return subset of getSupportedMimeTypes() if accept depends on rendering     // options. For example, HTML can be turned off in the rendering options.     // This would cause HTMLConverter to remove HTML MIME types.     return ACCEPT;     }   public String[] getSupportedMimeTypes() {     return ACCEPT;     }

指定显示特征

BrowserPageContext接口的实现指定了显示的特征.如果没有实现此接口,将使用缺省的值.

在本例中,所有属性都是整型.一个带有Boolean,String,和Object属性的应用程序将实现对应的方法.

public boolean getPropertyWithBooleanValue(int id, boolean defaultValue) {     // TODO Implement.     return false;     }   public int getPropertyWithIntValue(int id, int defaultValue) {     if (id == BrowserPageContext.DISPLAY_STYLE) {        // Turn off the scroll bar.        return BrowserPageContext.STYLE_NO_VERTICAL_SCROLLBAR;        }     return 0; }   public Object getPropertyWithObjectValue(int id, Object defaultValue) {     // TODO Implement.     return null;     }   public String getPropertyWithStringValue(int id, String defaultValue) {     // TODO Implement.     return null; }

 

获取一个域呈现内容

实现getBrowserContent(BrowserContentProviderContext)方法.

public BrowserContent getBrowserContent( BrowserContentProviderContext context)                 throws RenderingException {     if (context == null) {        throw new RenderingException("No Context is passed into Provider");        }     BrowserContentBaseImpl browserContentBaseImpl = new     BrowserContentBaseImpl(context.getHttpConnection().getURL(), null,            context.getRenderingApplication(),            context.getRenderingSession().getRenderingOptions(), context.getFlags());     VerticalFieldManager vfm = new VerticalFieldManager(Manager.VERTICAL_SCROLL);     vfm.add(new LabelField("Mime type: ") );     vfm.add(new LabelField(ACCEPT[0]));     vfm.add(new SeparatorField());     vfm.add(new LabelField("Content of the resource file: \n"));     vfm.add(new SeparatorField());     try {        HttpConnection conn = context.getHttpConnection();        InputStream in = conn.openInputStream();        byte[] data = IOUtilities.streamToBytes(in);        vfm.add(new LabelField(new String(data)));        }     catch (IOException e) {        // TODO Implement.        e.printStackTrace();        }         browserContentBaseImpl.setContent(vfm);     browserContentBaseImpl.setTitle(ACCEPT[0]);     // Set browser page context, this will tell the browser how to display this     // field.     browserContentBaseImpl.setBrowserPageContext(this);     return browserContentBaseImpl;     }

 

在BlackBerry启动时注册

创建一个类库工程,将它的属性设置为启动时自动运行.在libMain()里,调用BrowserFieldProviderRegistry.getInstance()方法,然后再调用invoke register().

public static void libMain( String[] args ) {     BrowserContentProviderRegistry converterRegistry =        BrowserContentProviderRegistry.getInstance();     if (converterRegistry != null) {        converterRegistry.register(new BrowserPlugin());        }     }

代码实例

下面的例子包含2个文件, LoaderApp.java和BrowserPlugin.java.当BlackBerry设备启动时LoaderApp.java增加一个新支持的MIME类型. BrowserPlugin.java包含了一个扩展了BrowserContentProvider的类.

例: BrowserPlugin.java和LoaderApp.java

/**

* LoaderApp.java

* Copyright (C) 2004-2005 Research In Motion Limited.

*/

package com.rim.samples.docs.browser;

import net.rim.device.api.browser.plugin.BrowserContentProviderRegistry;

 

final class LoaderApp {

    public static void libMain( String[] args ) {

       BrowserContentProviderRegistry converterRegistry =

           BrowserContentProviderRegistry.getInstance();

       if (converterRegistry != null) {

           converterRegistry.register(new BrowserPlugin());

           }

       }

    }

 

/**

* BrowserPlugin.java

* Copyright (C) 2004-2005 Research In Motion Limited.

*/

package com.rim.samples.docs.browser;

import java.io.IOException;

import java.io.InputStream;

import javax.microedition.io.HttpConnection;

import net.rim.device.api.browser.field.*;

import net.rim.device.api.browser.plugin.*;

import net.rim.device.api.ui.Manager;

import net.rim.device.api.ui.component.LabelField;

import net.rim.device.api.ui.component.SeparatorField;

import net.rim.device.api.ui.container.VerticalFieldManager;

/**

* Create a file with xxtest extension and associate that type with

* application/x-vnd.rim.xxxtest mime type on any server.

*/

public final class BrowserPlugin extends BrowserContentProvider

                        implements BrowserPageContext {

    private static final String[] ACCEPT = {"application/x-vnd.rim.xxxtest"};

    /**

     * Retrieves list of mime types this provider can accept given a set of rendering options.

     *  * @param context Rendering options in place this provider should consider.

     *  * @return Array of mime types this provider will accept, given the provided rendering

     *