BrowserFieldCustomErrorHandler.java

/*
* Copyright 2010-2011 Research In Motion Limited.
*
* 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 blackberry.web.widget.bf;

import javax.microedition.io.InputConnection;

import net.rim.device.api.browser.field2.BrowserField;
import net.rim.device.api.browser.field2.BrowserFieldErrorHandler;
import net.rim.device.api.browser.field2.BrowserFieldRequest;
import net.rim.device.api.io.transport.TransportInfo;
import net.rim.device.api.system.Application;
import net.rim.device.api.system.ApplicationManager;
import net.rim.device.api.system.EventLogger;
import net.rim.device.api.web.WidgetConfig;

import blackberry.web.widget.Widget;
import blackberry.web.widget.exception.MediaHandledException;
import blackberry.web.widget.impl.WidgetConfigImpl;
import blackberry.web.widget.impl.WidgetError;
import blackberry.web.widget.impl.WidgetException;

/**
 * Custom error handler class for WebWorks.
 */
public class BrowserFieldCustomErrorHandler extends BrowserFieldErrorHandler {
    private WidgetConfig _config;

    /* Constructor */
    BrowserFieldCustomErrorHandler( BrowserField browserField, WidgetConfig widgetConfig ) {
        super( browserField );
        _config = widgetConfig;
    }

    /* Override */public void displayContentError( String url, InputConnection connection, Throwable t ) {
        if( url == null ) {
            invokeError( t, null );
        } else {
            invokeError( t, url );
        }
    }

    /* Override */public void requestContentError( BrowserFieldRequest request, Throwable t ) {
        invokeError( t, request.getURL() );
    }

    /* Override */public void navigationRequestError( BrowserFieldRequest request, Throwable t ) {

        // Do not display an error message if our custom exception is found.
        if( t instanceof MediaHandledException ) {
            return;
        }
        invokeError( t, request.getURL() );
    }

    private void invokeError( Throwable t, String url ) {

        WidgetConfigImpl cfg = (WidgetConfigImpl) _config;

        if( cfg.getForegroundSource().length() == 0 && cfg.getBackgroundSource() != null
                || ApplicationManager.getApplicationManager().inStartup() ) {
            EventLogger.logEvent( Widget.WIDGET_GUID, t.getMessage().getBytes() );
            return;
        }

        WidgetError we = null;
        try {
            canConnect( url );
            we = new WidgetError( t, url );
        } catch( Exception e ) {
            we = new WidgetError( e, url );
        }
        Application.getApplication().invokeAndWait( we );

    }

    /**
     * This method checks for some more specific errors than BF2 - radio off, out of coverage which allows for a better detailed
     * message.
     * 
     * @param url
     *            The URL that was being retrieved when the error occured.
     */
    private void canConnect( String url ) throws Exception {
        // Null urls not checked.
        if( url == null ) {
            return;
        }

        // If this is a 'local' resource, then no need to check radio/data coverage.
        url = url.trim().toLowerCase();
        if( url.startsWith( "file:" ) || url.startsWith( "cod:" ) || url.startsWith( "local:" ) ) {
            return;
        }

        // Use network API to determine availability.
        boolean isAvailable = false;
        int[] transports = ( (WidgetConfigImpl) _config ).getPreferredTransports();
        if( transports == null ) {
            transports = BrowserFieldScreen.PREFERRED_TRANSPORTS;
        }
        int numTransports = transports.length;
        int transport;
        for( int i = 0; i < numTransports; i++ ) {
            transport = transports[ i ];
            if( TransportInfo.isTransportTypeAvailable( transport ) ) {
                isAvailable = true;
                break;
            }
        }
        if( !isAvailable ) {
            throw new WidgetException( WidgetException.ERROR_NETWORK_NOT_AVAILABLE, url );
        }

        // Use network API to determine coverage.
        boolean hasCoverage = false;
        for( int i = 0; i < numTransports; i++ ) {
            transport = transports[ i ];
            if( TransportInfo.hasSufficientCoverage( transport ) ) {
                hasCoverage = true;
                break;
            }
        }
        if( !hasCoverage ) {
            throw new WidgetException( WidgetException.ERROR_INSUFFICIENT_COVERAGE, url );
        }
    }
}