EDIT

/**

* Copyright (C) 2007 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.taxeditor.ui.element;

import java.io.IOException;

import java.io.InputStream;

import java.net.URI;

import org.apache.http.HttpException;

import org.eclipse.core.runtime.IProgressMonitor;

import org.eclipse.core.runtime.IStatus;

import org.eclipse.core.runtime.Status;

import org.eclipse.core.runtime.jobs.Job;

import org.eclipse.jface.operation.IRunnableWithProgress;

import org.eclipse.swt.events.PaintEvent;

import org.eclipse.swt.events.PaintListener;

import org.eclipse.swt.graphics.GC;

import org.eclipse.swt.graphics.Image;

import org.eclipse.swt.graphics.Rectangle;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Control;

import org.eclipse.swt.widgets.Display;

import org.eclipse.swt.widgets.Event;

import org.eclipse.ui.forms.widgets.TableWrapData;

import eu.etaxonomy.cdm.common.UriUtils;

import eu.etaxonomy.taxeditor.model.AbstractUtility;

import eu.etaxonomy.taxeditor.model.MessagingUtils;

/**

 * @author n.hoffmann

 * @created Sep 24, 2010

 * @version 1.0

 */

public class ImageElement extends AbstractCdmFormElement implements PaintListener{

	private URI imageUri;

	private Image image;

	private Composite container;

	private final Runnable postRunnable = new Runnable(){

        @Override

        public void run() {

            AbstractUtility.reflowDetailsViewer();

            AbstractUtility.reflowSupplementalViewer();

        }

    };

	protected ImageElement(CdmFormFactory formFactory, ICdmFormElement parentElement, URI imageUri, int style) {

		super(formFactory, parentElement);

		container = new Composite(getLayoutComposite(), style);

		container.setLayoutData(LayoutConstants.FILL(2, 1));

		container.addPaintListener(this);

	}

	public void initImageUri(URI uri) throws IOException, HttpException {

		this.imageUri = uri;

		InputStream imageStream = UriUtils.getInputStream(imageUri);

		image = new Image(Display.getCurrent(), imageStream);

	}

	public URI getImageUri() {

		return imageUri;

	}

	public void loadImage(){

		if(getImageUri() != null){

			Job job = new Job("Loading image") {

				@Override

				protected IStatus run(IProgressMonitor monitor) {

					IRunnableWithProgress runnable = getLoadImageRunnable(postRunnable);

					try {

						runnable.run(monitor);

					} catch (Exception e) {

						MessagingUtils.messageDialog("Could not load image", getClass(), e.getMessage()  + ": " +  getImageUri(), e);

					}

					return Status.OK_STATUS;

				}

			};

			job.schedule();

		}

	}

	public void unloadImage() {

		Job job = new Job("Unloading image") {

			@Override

			protected IStatus run(IProgressMonitor monitor) {

				IRunnableWithProgress runnable = getLoadImageRunnable(postRunnable);

				try {

					runnable.run(monitor);

				} catch (Exception e) {

					MessagingUtils.messageDialog("Could not unload image", getClass(), e.getMessage()  + ": " +  getImageUri(), e);

				}

				return Status.OK_STATUS;

			}

		};

		job.schedule();

	}

	public IRunnableWithProgress getLoadImageRunnable(final Runnable postRunnable){

		final Display display = getLayoutComposite().getDisplay();

		IRunnableWithProgress runnable = new IRunnableWithProgress(){

			@Override

			public void run(IProgressMonitor monitor) {

				monitor.beginTask("Loading: " + getImageUri(), IProgressMonitor.UNKNOWN);

				// redraw the image container

				display.asyncExec(new Runnable(){

					@Override

					public void run() {

						if(! getLayoutComposite().isDisposed() && container!=null){

							Event untypedEvent = new Event();

							untypedEvent.widget = container;

							PaintEvent event = new PaintEvent(untypedEvent);

							event.gc = new GC(container);

							paintControl(event);

							getLayoutComposite().layout();

						}

					}

				});

				// execute the external runnable

				if(postRunnable != null){

					display.asyncExec(postRunnable);

				}

				monitor.done();

			}

		};

		return runnable;

	}

	private Rectangle calculateImageBounds(Image image, Control control){

		Rectangle imageBounds = image.getBounds();

		Rectangle containerBounds = control.getBounds();

		Integer imgWidth = imageBounds.width;

		Integer imgHeight = imageBounds.height;

		Float ratio = imgHeight.floatValue()/imgWidth.floatValue();

		Integer width = containerBounds.width;

		Integer height = ((Float) (width * ratio)).intValue();

		return new Rectangle(containerBounds.x, containerBounds.y, width, height);

	}

	public void dispose(){

	    if(image!=null){

	        image.dispose();

	        image = null;

	    }

	    imageUri = null;

	    if(container!=null){

	        container.dispose();

	        container = null;

	    }

	}

	/** {@inheritDoc} */

	@Override

	public void paintControl(PaintEvent e) {

		TableWrapData layoutData = LayoutConstants.FILL(2, 1);

		Control control = (Control) e.widget;

		if(image != null){

			Rectangle imageMaxBounds = calculateImageBounds(image, control);

			layoutData.heightHint = imageMaxBounds.height;

			e.gc.drawImage(image, 0, 0, image.getBounds().width, image.getBounds().height, 0, 0, imageMaxBounds.width, imageMaxBounds.height);

		}else{

			layoutData.heightHint = 10;

			e.gc.drawRectangle(0, 0, 0, 10);

		}

		control.setLayoutData(layoutData);

		e.gc.dispose();

	}

}