Java tutorial
/******************************************************************************* * Copyright (c) 2007, 2009 David Green and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * David Green - initial API and implementation *******************************************************************************/ package org.eclipse.mylyn.internal.wikitext.ui.viewer; import java.io.BufferedInputStream; import java.io.InputStream; import java.net.MalformedURLException; import java.net.URL; import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import java.util.concurrent.atomic.AtomicInteger; import org.eclipse.core.runtime.IStatus; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.text.BadLocationException; import org.eclipse.jface.text.DocumentEvent; import org.eclipse.jface.text.IDocument; import org.eclipse.jface.text.IDocumentListener; import org.eclipse.jface.text.ITextInputListener; import org.eclipse.jface.text.Position; import org.eclipse.jface.text.TextPresentation; import org.eclipse.jface.text.hyperlink.IHyperlink; import org.eclipse.jface.text.source.Annotation; import org.eclipse.jface.text.source.AnnotationModel; import org.eclipse.jface.text.source.AnnotationPainter; import org.eclipse.jface.viewers.ISelectionChangedListener; import org.eclipse.jface.viewers.SelectionChangedEvent; import org.eclipse.mylyn.internal.wikitext.ui.WikiTextUiPlugin; import org.eclipse.mylyn.internal.wikitext.ui.util.ImageCache; import org.eclipse.mylyn.internal.wikitext.ui.viewer.annotation.ImageAnnotation; import org.eclipse.mylyn.internal.wikitext.ui.viewer.annotation.ImageDrawingStrategy; import org.eclipse.mylyn.wikitext.ui.viewer.HtmlViewer; import org.eclipse.osgi.util.NLS; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.custom.StyleRange; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.MouseEvent; import org.eclipse.swt.events.MouseListener; import org.eclipse.swt.events.MouseMoveListener; import org.eclipse.swt.events.PaintEvent; import org.eclipse.swt.graphics.Cursor; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; /** * Manages all aspects of image download/display in an {@link HtmlViewer}. Manages the download of images for viewing in * an {@link HtmlViewer}, and creates appropriate space for their display. Downloads image data in a background thread, * instantiates the corresopnding images, and ensures that enough vertical space exists in the viewer to display the * images. * * @see ImageAnnotation * @see ImageDrawingStrategy * @see ImageCache * @see HtmlViewer * @author David Green */ public class ImageManager implements ITextInputListener, DisposeListener, IDocumentListener, ISelectionChangedListener { private class HyperlinkMouseListener implements MouseMoveListener, MouseListener { @SuppressWarnings("unused") public void mouseEnter(MouseEvent e) { // ignore } @SuppressWarnings("unused") public void mouseExit(MouseEvent e) { disarm(); } public void mouseMove(MouseEvent e) { adjust(e); } public void mouseDoubleClick(MouseEvent e) { // ignore } public void mouseDown(MouseEvent e) { // ignore } public void mouseUp(MouseEvent e) { clicked(e); } } private final HtmlViewer viewer; private final Display display; private final ImageCache imageCache; private final Set<ImageAnnotation> annotations = new HashSet<>(); private ImageResolver imageResolver; private boolean computingChanges; private final AnnotationPainter painter; private boolean armed = false; private Cursor cursor; private Cursor previousCursor; public ImageManager(HtmlViewer viewer, ImageCache imageCache, AnnotationPainter painter) { this.viewer = viewer; this.painter = painter; display = viewer.getTextWidget().getDisplay(); this.imageCache = imageCache; inspect(); viewer.getTextWidget().addDisposeListener(this); viewer.addTextInputListener(this); if (viewer.getDocument() != null) { viewer.getDocument().addDocumentListener(this); } viewer.addSelectionChangedListener(this); viewer.addPostSelectionChangedListener(this); // bug 257868 support image hyperlinks HyperlinkMouseListener mouseListener = new HyperlinkMouseListener(); viewer.getTextWidget().addMouseMoveListener(mouseListener); viewer.getTextWidget().addMouseListener(mouseListener); } private IHyperlink getHyperlink(MouseEvent e) { // bug 257868 support image hyperlinks if (annotations.isEmpty()) { return null; } Point point = new Point(e.x, e.y); for (ImageAnnotation annotation : annotations) { if (annotation.getHyperlnkAnnotation() == null) { continue; } Rectangle region = getRegion(annotation); if (region != null) { if (region.contains(point)) { AnnotationHyperlinkDetector detector = (AnnotationHyperlinkDetector) viewer.getTextWidget() .getData(AnnotationHyperlinkDetector.class.getName()); if (detector != null) { IHyperlink hyperlink = detector.createHyperlink(viewer, viewer.getAnnotationModel(), annotation.getHyperlnkAnnotation()); return hyperlink; } } } } return null; } public void clicked(MouseEvent e) { IHyperlink hyperlink = getHyperlink(e); if (hyperlink != null) { disarm(); hyperlink.open(); } } /** * get the widget-relative region of the given annotation * * @return the region, or null if it is unknown */ private Rectangle getRegion(ImageAnnotation annotation) { if (annotation.getImage() == null) { return null; } Position position = viewer.getAnnotationModel().getPosition(annotation); Point locationAtOffset = viewer.getTextWidget().getLocationAtOffset(position.offset); Rectangle bounds = annotation.getImage().getBounds(); Rectangle rectange = new Rectangle(locationAtOffset.x, locationAtOffset.y, bounds.width, bounds.height); return rectange; } void adjust(MouseEvent e) { IHyperlink hyperlink = getHyperlink(e); if (hyperlink == null) { disarm(); } else { // always arm here even if already armed, otherwise the cursor // setting interacts poorly with other things that set the cursor. armed = true; Cursor currentCursor = viewer.getTextWidget().getCursor(); if (cursor == null || currentCursor != cursor) { previousCursor = currentCursor; if (cursor == null) { cursor = new Cursor(viewer.getTextWidget().getDisplay(), SWT.CURSOR_HAND); } viewer.getTextWidget().setCursor(cursor); } } } void disarm() { if (armed) { if (previousCursor != null) { viewer.getTextWidget().setCursor(previousCursor); } armed = false; } } public void inputDocumentAboutToBeChanged(IDocument oldInput, IDocument newInput) { stop(); } public void inputDocumentChanged(IDocument oldInput, IDocument newInput) { if (oldInput != null) { oldInput.removeDocumentListener(this); } if (newInput != null) { newInput.addDocumentListener(this); } inspect(); } @SuppressWarnings("unchecked") private void inspect() { synchronized (this) { annotations.clear(); if (viewer.getAnnotationModel() != null) { Iterator<Annotation> iterator = viewer.getAnnotationModel().getAnnotationIterator(); while (iterator.hasNext()) { Annotation annotation = iterator.next(); if (annotation instanceof ImageAnnotation) { annotations.add((ImageAnnotation) annotation); } } } } if (!annotations.isEmpty()) { ImageResolver resolver; synchronized (this) { resolver = imageResolver; } if (resolver != null) { try { resolver.join(); } catch (InterruptedException e) { return; } } imageResolver = new ImageResolver(); imageResolver.start(); } } private synchronized void stop() { ImageResolver resolver = imageResolver; if (resolver != null) { resolver.interrupt(); } } public void widgetDisposed(DisposeEvent e) { if (cursor != null) { cursor.dispose(); cursor = null; } stop(); } @SuppressWarnings("unchecked") private void updateImage(String imgSrc, ImageData imageData) { if (display.isDisposed() || viewer.getTextWidget().isDisposed()) { return; } Image image = imageData == null ? imageCache.getMissingImage() : ImageDescriptor.createFromImageData(imageData).createImage(); imageCache.putImage(imgSrc, image); Set<ImageAnnotation> modifiedAnnotations = new HashSet<>(); AnnotationModel annotationModel = (AnnotationModel) viewer.getAnnotationModel(); Object annotationLockObject = annotationModel.getLockObject(); if (annotationLockObject == null) { annotationLockObject = annotationModel; } synchronized (annotationLockObject) { Iterator<Annotation> iterator = annotationModel.getAnnotationIterator(); while (iterator.hasNext()) { Annotation annotation = iterator.next(); if (annotation instanceof ImageAnnotation) { ImageAnnotation imageAnnotation = (ImageAnnotation) annotation; if (imgSrc.equals(imageAnnotation.getUrl())) { imageAnnotation.setImage(image); modifiedAnnotations.add(imageAnnotation); } } } } if (!modifiedAnnotations.isEmpty()) { computingChanges = true; try { boolean rangesAdjusted = false; List<StyleRange> ranges = new ArrayList<>(); Iterator<?> allStyleRangeIterator = viewer.getTextPresentation().getAllStyleRangeIterator(); while (allStyleRangeIterator.hasNext()) { StyleRange range = (StyleRange) allStyleRangeIterator.next(); ranges.add((StyleRange) range.clone()); } GC gc = new GC(viewer.getTextWidget()); try { viewer.getTextWidget().setRedraw(false); TextPresentation textPresentation = viewer.getTextPresentation(); // textPresentation. for (ImageAnnotation annotation : modifiedAnnotations) { int height = annotation.getImage().getBounds().height; Position position = annotationModel.getPosition(annotation); String widgetText = viewer.getTextWidget().getText(); Font font = null; if (widgetText.length() > 0 && widgetText.length() > position.offset) { StyleRange styleRange = viewer.getTextWidget().getStyleRangeAtOffset(position.offset); if (styleRange != null) { font = styleRange.font; } } if (font == null) { font = viewer.getTextWidget().getFont(); } gc.setFont(font); Point extent = gc.textExtent("\n"); //$NON-NLS-1$ if (extent.y > 0) { int numNewlines = (int) Math.ceil(((double) height) / ((double) extent.y)); final int originalNewlines = numNewlines; IDocument document = viewer.getDocument(); try { for (int x = position.offset; x < document.getLength(); ++x) { if (document.getChar(x) == '\n') { if (x != position.offset && Util.annotationsIncludeOffset(viewer.getAnnotationModel(), x)) { break; } --numNewlines; } else { break; } } if (numNewlines > 0) { String newlines = ""; //$NON-NLS-1$ for (int x = 0; x < numNewlines; ++x) { newlines += "\n"; //$NON-NLS-1$ } document.replace(position.offset + 1, 0, newlines); } else if (numNewlines < 0) { document.replace(position.offset, -numNewlines, ""); //$NON-NLS-1$ } if (numNewlines != 0) { // no need to fixup other annotation positions, since the annotation model is hooked into the document. // fix up styles for (StyleRange range : ranges) { if (range.start > position.offset) { range.start += numNewlines; rangesAdjusted = true; } else if (range.start + range.length > position.offset) { range.length += numNewlines; rangesAdjusted = true; } } } // bug# 248643: update the annotation size to reflect the full size of the image // so that it gets repainted when some portion of the image is exposed // as a result of scrolling if (position.getLength() != originalNewlines) { annotationModel.modifyAnnotationPosition(annotation, new Position(position.offset, originalNewlines)); } } catch (BadLocationException e) { // ignore } } } if (rangesAdjusted) { TextPresentation presentation = new TextPresentation(); if (textPresentation.getDefaultStyleRange() != null) { StyleRange defaultStyleRange = (StyleRange) textPresentation.getDefaultStyleRange() .clone(); if (viewer.getDocument() != null) { if (defaultStyleRange.length < viewer.getDocument().getLength()) { defaultStyleRange.length = viewer.getDocument().getLength(); } } presentation.setDefaultStyleRange(defaultStyleRange); } for (StyleRange range : ranges) { presentation.addStyleRange(range); } viewer.setTextPresentation(presentation); viewer.invalidateTextPresentation(); } } finally { viewer.getTextWidget().setRedraw(true); gc.dispose(); } viewer.getTextWidget().redraw(); } finally { computingChanges = false; } } } private static final AtomicInteger resolverIdSeed = new AtomicInteger(1); private class ImageResolver extends Thread { public ImageResolver() { setName(ImageResolver.class.getSimpleName() + '-' + resolverIdSeed.getAndIncrement()); setDaemon(true); } @Override public void run() { try { final Map<String, ImageData> urlToImageData = new HashMap<>(); for (ImageAnnotation annotation : annotations) { final String imgSrc = annotation.getUrl(); if (imgSrc != null && !urlToImageData.containsKey(imgSrc)) { try { URL location = imageCache.getBase() == null ? new URL(imgSrc) : new URL(imageCache.getBase(), imgSrc); try { InputStream in = new BufferedInputStream(location.openStream()); try { urlToImageData.put(imgSrc, new ImageData(in)); } catch (SWTException e) { if (e.code != SWT.ERROR_INVALID_IMAGE) { throw e; } urlToImageData.put(imgSrc, null); } finally { in.close(); } } catch (Exception e) { if (WikiTextUiPlugin.getDefault() != null) { WikiTextUiPlugin.getDefault().log(IStatus.ERROR, NLS.bind(Messages.ImageManager_accessFailed, new Object[] { location }), e); } urlToImageData.put(imgSrc, null); } } catch (MalformedURLException e) { urlToImageData.put(imgSrc, null); } display.asyncExec(new Runnable() { public void run() { updateImage(imgSrc, urlToImageData.get(imgSrc)); } }); } if (Thread.currentThread().isInterrupted()) { break; } } } finally { imageResolver = null; } } } public void documentAboutToBeChanged(DocumentEvent event) { if (computingChanges) { return; } stop(); } public void documentChanged(DocumentEvent event) { if (computingChanges) { return; } inspect(); } public void selectionChanged(SelectionChangedEvent event) { GC gc = new GC(viewer.getTextWidget()); try { Event e = new Event(); e.gc = gc; e.widget = viewer.getTextWidget(); Rectangle bounds = viewer.getTextWidget().getBounds(); e.height = bounds.height; e.width = bounds.width; e.x = 0; e.y = 0; PaintEvent paintEvent = new PaintEvent(e); painter.paintControl(paintEvent); } finally { gc.dispose(); } } }