SvgViewerFactory.java

package org.freeplane.plugin.svg;

import java.awt.Dimension;
import java.net.URI;

import javax.swing.JComponent;

import org.apache.batik.swing.JSVGCanvas;
import org.apache.batik.swing.gvt.GVTTreeRendererAdapter;
import org.apache.batik.swing.gvt.GVTTreeRendererEvent;
import org.apache.batik.util.SVGConstants;
import org.freeplane.core.resources.ResourceController;
import org.freeplane.core.util.TextUtils;
import org.freeplane.view.swing.features.filepreview.ExternalResource;
import org.freeplane.view.swing.features.filepreview.IViewerFactory;
import org.freeplane.view.swing.features.filepreview.ViewerLayoutManager;
import org.w3c.dom.svg.SVGDocument;
import org.w3c.dom.svg.SVGLength;
import org.w3c.dom.svg.SVGSVGElement;

public class SvgViewerFactory implements IViewerFactory {
	private final class ViewerComponent extends JSVGCanvas {
		/**
		 * 
		 */
		private static final long serialVersionUID = 1L;
		private Dimension originalSize = null;

		protected Dimension getOriginalSize() {
			return new Dimension(originalSize);
		}

		public ViewerComponent(final URI uri) {
			super(null, false, false);
			setDocumentState(ALWAYS_STATIC);
			setSize(1, 1);
			addGVTTreeRendererListener(new GVTTreeRendererAdapter() {
				@Override
				public void gvtRenderingStarted(final GVTTreeRendererEvent e) {
					super.gvtRenderingStarted(e);
					final SVGDocument document = getSVGDocument();
					final SVGSVGElement rootElement = document.getRootElement();
					final SVGLength width = rootElement.getWidth().getBaseVal();
					final SVGLength height = rootElement.getHeight().getBaseVal();
					float defaultWidth = (float) Math.ceil(width.getValue());
					float defaultHeigth = (float) Math.ceil(height.getValue());
					if (defaultWidth == 1f && defaultHeigth == 1f) {
						defaultWidth = ResourceController.getResourceController().getIntProperty(
						    "default_external_component_width", 200);
						defaultHeigth = ResourceController.getResourceController().getIntProperty(
						    "default_external_component_height", 200);
					}
					originalSize = new Dimension((int) defaultWidth, (int) defaultHeigth);
					if ("".equals(rootElement.getAttributeNS(null, SVGConstants.SVG_VIEW_BOX_ATTRIBUTE))) {
						rootElement.setAttributeNS(null, SVGConstants.SVG_VIEW_BOX_ATTRIBUTE, "0 0 " + defaultWidth
						        + " " + defaultHeigth);
					}
					setSize(originalSize);
					removeGVTTreeRendererListener(this);
				}
			});
			setURI(uri.toString());
		}

		@Override
		public Dimension getPreferredSize() {
			if (originalSize == null) {
				return new Dimension(1, 1);
			}
			return super.getPreferredSize();
		}
	}

	public boolean accept(final URI uri) {
		return uri.getRawPath().endsWith(".svg");
	}

	public String getDescription() {
		return TextUtils.getText("svg");
	};

	public JComponent createViewer(final ExternalResource resource, final URI uri, final int maximumWidth) {
		final ViewerComponent canvas = new ViewerComponent(uri);
		canvas.addGVTTreeRendererListener(new GVTTreeRendererAdapter() {
			@Override
			public void gvtRenderingCompleted(final GVTTreeRendererEvent e) {
				final Dimension preferredSize = canvas.getOriginalSize();
				float r = resource.getZoom();
				final int originalWidth = preferredSize.width;
				if(r == -1){
					r = resource.setZoom(originalWidth, maximumWidth);
				}
				preferredSize.width = (int) (Math.rint(originalWidth * r));
				preferredSize.height = (int) (Math.rint(preferredSize.height * r));
				canvas.setPreferredSize(preferredSize);
				canvas.setLayout(new ViewerLayoutManager(1f));
				canvas.revalidate();
				canvas.removeGVTTreeRendererListener(this);
			}

		});
		return canvas;
	}

	public JComponent createViewer(final URI uri, final Dimension preferredSize) {
		final ViewerComponent canvas = new ViewerComponent(uri);
		canvas.setPreferredSize(preferredSize);
		canvas.setSize(preferredSize);
		canvas.addGVTTreeRendererListener(new GVTTreeRendererAdapter() {
			@Override
			public void gvtRenderingCompleted(final GVTTreeRendererEvent e) {
				canvas.setMySize(preferredSize);
				canvas.setSize(preferredSize);
				canvas.revalidate();
				canvas.removeGVTTreeRendererListener(this);
			}
		});
		return canvas;
	}

	public Dimension getOriginalSize(final JComponent viewer) {
		final ViewerComponent canvas = (ViewerComponent) viewer;
		return canvas.getOriginalSize();
	}

	public void setFinalViewerSize(final JComponent viewer, final Dimension size) {
		final JSVGCanvas canvas = (JSVGCanvas) viewer;
		canvas.setMySize(size);
	}

	public void setDraftViewerSize(JComponent viewer, Dimension size) {
		setFinalViewerSize(viewer, size);
	}
}