CameraImpl.java

package com.eclipsesource.tabris.internal;

import static com.eclipsesource.tabris.internal.Clauses.whenNull;
import static com.eclipsesource.tabris.internal.Constants.EVENT_IMAGE_SELECTION;
import static com.eclipsesource.tabris.internal.Constants.EVENT_IMAGE_SELECTION_CANCEL;
import static com.eclipsesource.tabris.internal.Constants.EVENT_IMAGE_SELECTION_ERROR;
import static com.eclipsesource.tabris.internal.Constants.METHOD_OPEN;
import static com.eclipsesource.tabris.internal.Constants.PROPERTY_COMPRESSON_QUALITY;
import static com.eclipsesource.tabris.internal.Constants.PROPERTY_IMAGE;
import static com.eclipsesource.tabris.internal.Constants.PROPERTY_RESOLUTION;
import static com.eclipsesource.tabris.internal.Constants.PROPERTY_SAVE_TO_ALBUM;
import static com.eclipsesource.tabris.internal.Constants.TYPE_CAMERA;

import java.io.ByteArrayInputStream;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.rap.json.JsonArray;
import org.eclipse.rap.json.JsonObject;
import org.eclipse.rap.rwt.RWT;
import org.eclipse.rap.rwt.internal.remote.ConnectionImpl;
import org.eclipse.rap.rwt.remote.AbstractOperationHandler;
import org.eclipse.rap.rwt.remote.RemoteObject;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Display;

import com.eclipsesource.tabris.camera.Camera;
import com.eclipsesource.tabris.camera.CameraListener;
import com.eclipsesource.tabris.camera.CameraOptions;


@SuppressWarnings("restriction")
public class CameraImpl extends AbstractOperationHandler implements Camera {

  private final RemoteObject remoteObject;
  private final List<CameraListener> cameraListeners;

  public CameraImpl() {
    cameraListeners = new ArrayList<CameraListener>();
    remoteObject = ( ( ConnectionImpl )RWT.getUISession().getConnection() ).createServiceObject( TYPE_CAMERA );
    remoteObject.setHandler( this );
  }

  private Image decodeImage( String encodedImage ) {
    byte[] bytes = Base64.decode( encodedImage );
    ByteArrayInputStream stream = new ByteArrayInputStream( bytes );
    return new Image( Display.getCurrent(), stream );
  }

  @Override
  public void addCameraListener( CameraListener listener ) {
    whenNull( listener ).throwIllegalArgument( "Listener must not be null" );
    cameraListeners.add( listener );
  }

  @Override
  public void removeCameraListener( CameraListener listener ) {
    whenNull( listener ).throwIllegalArgument( "Listener must not be null" );
    cameraListeners.remove( listener );
  }

  @Override
  public void takePicture( CameraOptions options ) {
    whenNull( options ).throwIllegalArgument( "Options must not be null" );
    JsonObject properties = createProperties( options );
    remoteObject.call( METHOD_OPEN, properties );
  }

  private JsonObject createProperties( CameraOptions options ) {
    JsonObject properties = new JsonObject();
    addResolution( properties, options );
    addSaveToAlbum( properties, options );
    addCompressionQuality( properties, options );
    return properties;
  }

  private void addResolution( JsonObject properties, CameraOptions options ) {
    Point resolution = options.getResolution();
    if( resolution != null ) {
      JsonArray jsonArray = new JsonArray();
      jsonArray.add( resolution.x );
      jsonArray.add( resolution.y );
      properties.add( PROPERTY_RESOLUTION, jsonArray );
    }
  }

  private void addSaveToAlbum( JsonObject properties, CameraOptions options ) {
    if( options.savesToAlbum() ) {
      properties.add( PROPERTY_SAVE_TO_ALBUM, true );
    }
  }

  private void addCompressionQuality( JsonObject properties, CameraOptions options ) {
    properties.add( PROPERTY_COMPRESSON_QUALITY, options.getCompressionQuality() );
  }

  @Override
  public void handleNotify( String event, JsonObject properties ) {
    if( EVENT_IMAGE_SELECTION.equals( event ) ) {
      Image image = decodeImage( properties.get( PROPERTY_IMAGE ).asString() );
      notifyListenersWithImage( image );
    } else if( EVENT_IMAGE_SELECTION_ERROR.equals( event ) || EVENT_IMAGE_SELECTION_CANCEL.equals( event ) ) {
      notifyListenersWithoutPicture();
    }
  }

  private void notifyListenersWithImage( Image image ) {
    List<CameraListener> listeners = new ArrayList<CameraListener>( cameraListeners );
    for( CameraListener listener : listeners ) {
      listener.receivedPicture( image );
    }
  }

  private void notifyListenersWithoutPicture() {
    List<CameraListener> listeners = new ArrayList<CameraListener>( cameraListeners );
    for( CameraListener listener : listeners ) {
      listener.receivedPicture( null );
    }
  }

  RemoteObject getRemoteObject() {
    return remoteObject;
  }

}