Android example source code file (WebChromeClient.java)

This example Android source code file (WebChromeClient.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, bitmap, customviewcallback, deprecated, jspromptresult, jsresult, message, net, network, os, string, ui, view, webchromeclient

The WebChromeClient.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * 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 android.webkit;

import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Message;
import android.view.View;

public class WebChromeClient {

    /**
     * Tell the host application the current progress of loading a page.
     * @param view The WebView that initiated the callback.
     * @param newProgress Current page loading progress, represented by
     *                    an integer between 0 and 100.
     */
    public void onProgressChanged(WebView view, int newProgress) {}

    /**
     * Notify the host application of a change in the document title.
     * @param view The WebView that initiated the callback.
     * @param title A String containing the new title of the document.
     */
    public void onReceivedTitle(WebView view, String title) {}

    /**
     * Notify the host application of a new favicon for the current page.
     * @param view The WebView that initiated the callback.
     * @param icon A Bitmap containing the favicon for the current page.
     */
    public void onReceivedIcon(WebView view, Bitmap icon) {}

    /**
     * Notify the host application of the url for an apple-touch-icon.
     * @param view The WebView that initiated the callback.
     * @param url The icon url.
     * @param precomposed True if the url is for a precomposed touch icon.
     */
    public void onReceivedTouchIconUrl(WebView view, String url,
            boolean precomposed) {}

    /**
     * A callback interface used by the host application to notify
     * the current page that its custom view has been dismissed.
     */
    public interface CustomViewCallback {
        /**
         * Invoked when the host application dismisses the
         * custom view.
         */
        public void onCustomViewHidden();
    }

    /**
     * Notify the host application that the current page would
     * like to show a custom View.
     * @param view is the View object to be shown.
     * @param callback is the callback to be invoked if and when the view
     * is dismissed.
     */
    public void onShowCustomView(View view, CustomViewCallback callback) {};

    /**
     * Notify the host application that the current page would
     * like to hide its custom view.
     */
    public void onHideCustomView() {}

    /**
     * Request the host application to create a new Webview. The host
     * application should handle placement of the new WebView in the view
     * system. The default behavior returns null.
     * @param view The WebView that initiated the callback.
     * @param dialog True if the new window is meant to be a small dialog
     *               window.
     * @param userGesture True if the request was initiated by a user gesture
     *                    such as clicking a link.
     * @param resultMsg The message to send when done creating a new WebView.
     *                  Set the new WebView through resultMsg.obj which is 
     *                  WebView.WebViewTransport() and then call
     *                  resultMsg.sendToTarget();
     * @return Similar to javscript dialogs, this method should return true if
     *         the client is going to handle creating a new WebView. Note that
     *         the WebView will halt processing if this method returns true so
     *         make sure to call resultMsg.sendToTarget(). It is undefined
     *         behavior to call resultMsg.sendToTarget() after returning false
     *         from this method.
     */
    public boolean onCreateWindow(WebView view, boolean dialog,
            boolean userGesture, Message resultMsg) {
        return false;
    }

    /**
     * Request display and focus for this WebView. This may happen due to
     * another WebView opening a link in this WebView and requesting that this
     * WebView be displayed.
     * @param view The WebView that needs to be focused.
     */
    public void onRequestFocus(WebView view) {}

    /**
     * Notify the host application to close the given WebView and remove it
     * from the view system if necessary. At this point, WebCore has stopped
     * any loading in this window and has removed any cross-scripting ability
     * in javascript.
     * @param window The WebView that needs to be closed.
     */
    public void onCloseWindow(WebView window) {}

    /**
     * Tell the client to display a javascript alert dialog.  If the client
     * returns true, WebView will assume that the client will handle the
     * dialog.  If the client returns false, it will continue execution.
     * @param view The WebView that initiated the callback.
     * @param url The url of the page requesting the dialog.
     * @param message Message to be displayed in the window.
     * @param result A JsResult to confirm that the user hit enter.
     * @return boolean Whether the client will handle the alert dialog.
     */
    public boolean onJsAlert(WebView view, String url, String message,
            JsResult result) {
        return false;
    }

    /**
     * Tell the client to display a confirm dialog to the user. If the client
     * returns true, WebView will assume that the client will handle the
     * confirm dialog and call the appropriate JsResult method. If the
     * client returns false, a default value of false will be returned to
     * javascript. The default behavior is to return false.
     * @param view The WebView that initiated the callback.
     * @param url The url of the page requesting the dialog.
     * @param message Message to be displayed in the window.
     * @param result A JsResult used to send the user's response to
     *               javascript.
     * @return boolean Whether the client will handle the confirm dialog.
     */
    public boolean onJsConfirm(WebView view, String url, String message,
            JsResult result) {
        return false;
    }

    /**
     * Tell the client to display a prompt dialog to the user. If the client
     * returns true, WebView will assume that the client will handle the
     * prompt dialog and call the appropriate JsPromptResult method. If the
     * client returns false, a default value of false will be returned to to
     * javascript. The default behavior is to return false.
     * @param view The WebView that initiated the callback.
     * @param url The url of the page requesting the dialog.
     * @param message Message to be displayed in the window.
     * @param defaultValue The default value displayed in the prompt dialog.
     * @param result A JsPromptResult used to send the user's reponse to
     *               javascript.
     * @return boolean Whether the client will handle the prompt dialog.
     */
    public boolean onJsPrompt(WebView view, String url, String message,
            String defaultValue, JsPromptResult result) {
        return false;
    }

    /**
     * Tell the client to display a dialog to confirm navigation away from the
     * current page. This is the result of the onbeforeunload javascript event.
     * If the client returns true, WebView will assume that the client will
     * handle the confirm dialog and call the appropriate JsResult method. If
     * the client returns false, a default value of true will be returned to
     * javascript to accept navigation away from the current page. The default
     * behavior is to return false. Setting the JsResult to true will navigate
     * away from the current page, false will cancel the navigation.
     * @param view The WebView that initiated the callback.
     * @param url The url of the page requesting the dialog.
     * @param message Message to be displayed in the window.
     * @param result A JsResult used to send the user's response to
     *               javascript.
     * @return boolean Whether the client will handle the confirm dialog.
     */
    public boolean onJsBeforeUnload(WebView view, String url, String message,
            JsResult result) {
        return false;
    }

   /**
    * Tell the client that the database quota for the origin has been exceeded.
    * @param url The URL that triggered the notification
    * @param databaseIdentifier The identifier of the database that caused the
    *     quota overflow.
    * @param currentQuota The current quota for the origin.
    * @param estimatedSize The estimated size of the database.
    * @param totalUsedQuota is the sum of all origins' quota.
    * @param quotaUpdater A callback to inform the WebCore thread that a new
    *     quota is available. This callback must always be executed at some
    *     point to ensure that the sleeping WebCore thread is woken up.
    */
    public void onExceededDatabaseQuota(String url, String databaseIdentifier,
        long currentQuota, long estimatedSize, long totalUsedQuota,
        WebStorage.QuotaUpdater quotaUpdater) {
        // This default implementation passes the current quota back to WebCore.
        // WebCore will interpret this that new quota was declined.
        quotaUpdater.updateQuota(currentQuota);
    }

   /**
    * Tell the client that the Application Cache has exceeded its max size.
    * @param spaceNeeded is the amount of disk space that would be needed
    * in order for the last appcache operation to succeed.
    * @param totalUsedQuota is the sum of all origins' quota.
    * @param quotaUpdater A callback to inform the WebCore thread that a new
    * app cache size is available. This callback must always be executed at
    * some point to ensure that the sleeping WebCore thread is woken up.
    */
    public void onReachedMaxAppCacheSize(long spaceNeeded, long totalUsedQuota,
            WebStorage.QuotaUpdater quotaUpdater) {
        quotaUpdater.updateQuota(0);
    }

    /**
     * Instructs the client to show a prompt to ask the user to set the
     * Geolocation permission state for the specified origin.
     */
    public void onGeolocationPermissionsShowPrompt(String origin,
            GeolocationPermissions.Callback callback) {}

    /**
     * Instructs the client to hide the Geolocation permissions prompt.
     */
    public void onGeolocationPermissionsHidePrompt() {}

    /**
     * Tell the client that a JavaScript execution timeout has occured. And the
     * client may decide whether or not to interrupt the execution. If the
     * client returns true, the JavaScript will be interrupted. If the client
     * returns false, the execution will continue. Note that in the case of
     * continuing execution, the timeout counter will be reset, and the callback
     * will continue to occur if the script does not finish at the next check
     * point.
     * @return boolean Whether the JavaScript execution should be interrupted.
     */
    public boolean onJsTimeout() {
        return true;
    }

    /**
     * Report a JavaScript error message to the host application. The ChromeClient
     * should override this to process the log message as they see fit.
     * @param message The error message to report.
     * @param lineNumber The line number of the error.
     * @param sourceID The name of the source file that caused the error.
     * @deprecated Use {@link #onConsoleMessage(ConsoleMessage) onConsoleMessage(ConsoleMessage)}
     *      instead.
     */
    @Deprecated
    public void onConsoleMessage(String message, int lineNumber, String sourceID) { }

    /**
     * Report a JavaScript console message to the host application. The ChromeClient
     * should override this to process the log message as they see fit.
     * @param consoleMessage Object containing details of the console message.
     * @return true if the message is handled by the client.
     */
    public boolean onConsoleMessage(ConsoleMessage consoleMessage) {
        // Call the old version of this function for backwards compatability.
        onConsoleMessage(consoleMessage.message(), consoleMessage.lineNumber(),
                consoleMessage.sourceId());
        return false;
    }

    /**
     * When not playing, video elements are represented by a 'poster' image. The
     * image to use can be specified by the poster attribute of the video tag in
     * HTML. If the attribute is absent, then a default poster will be used. This
     * method allows the ChromeClient to provide that default image.
     *
     * @return Bitmap The image to use as a default poster, or null if no such image is
     * available.
     */
    public Bitmap getDefaultVideoPoster() {
        return null;
    }

    /**
     * When the user starts to playback a video element, it may take time for enough
     * data to be buffered before the first frames can be rendered. While this buffering
     * is taking place, the ChromeClient can use this function to provide a View to be
     * displayed. For example, the ChromeClient could show a spinner animation.
     *
     * @return View The View to be displayed whilst the video is loading.
     */
    public View getVideoLoadingProgressView() {
        return null;
    }

    /** Obtains a list of all visited history items, used for link coloring
     */
    public void getVisitedHistory(ValueCallback<String[]> callback) {
    }

    /**
     * Tell the client to open a file chooser.
     * @param uploadFile A ValueCallback to set the URI of the file to upload.
     *      onReceiveValue must be called to wake up the thread.
     * @hide
     */
    public void openFileChooser(ValueCallback<Uri> uploadFile) {
        uploadFile.onReceiveValue(null);
    }
}