Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2005 IBM Corporation 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: * IBM Corporation - initial API and implementation * Vlad Dumitrescu *******************************************************************************/ package org.erlide.ui.editors.erl.outline; import java.util.ArrayList; import org.eclipse.core.runtime.ListenerList; import org.eclipse.core.runtime.SafeRunner; import org.eclipse.jface.util.SafeRunnable; import org.eclipse.jface.viewers.IColorProvider; import org.eclipse.jface.viewers.ILabelDecorator; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.ILabelProviderListener; import org.eclipse.jface.viewers.LabelProviderChangedEvent; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Image; import org.erlide.core.model.root.IErlElement; public class ErlangLabelProvider implements ILabelProvider, IColorProvider { private static final int LABEL_LENGTH_LIMIT = 200; protected ListenerList fListeners = new ListenerList(1); protected ErlangElementImageProvider fImageLabelProvider; private ArrayList<ILabelDecorator> fLabelDecorators; private int fImageFlags; private long fTextFlags; /** * Creates a new label provider with default flags. */ public ErlangLabelProvider() { this(0, ErlangElementImageProvider.OVERLAY_ICONS); } /** * @param textFlags * Flags defined in <code>ErlangElementLabels</code>. * @param imageFlags * Flags defined in <code>ErlangElementImageProvider</code>. */ public ErlangLabelProvider(final long textFlags, final int imageFlags) { fImageLabelProvider = new ErlangElementImageProvider(); fLabelDecorators = null; fImageFlags = imageFlags; fTextFlags = textFlags; } /** * Adds a decorator to the label provider */ public void addLabelDecorator(final ILabelDecorator decorator) { if (fLabelDecorators == null) { fLabelDecorators = new ArrayList<ILabelDecorator>(2); } fLabelDecorators.add(decorator); } /** * Sets the textFlags. * * @param textFlags * The textFlags to set */ public final void setTextFlags(final long textFlags) { fTextFlags = textFlags; } /** * Sets the imageFlags * * @param imageFlags * The imageFlags to set */ public final void setImageFlags(final int imageFlags) { fImageFlags = imageFlags; } /** * Gets the image flags. Can be overwriten by super classes. * * @return Returns a int */ public final int getImageFlags() { return fImageFlags; } /** * Gets the text flags. * * @return Returns a int */ public final long getTextFlags() { return fTextFlags; } /** * Evaluates the image flags for a element. Can be overwriten by super * classes. * * @return Returns a int */ protected int evaluateImageFlags(final Object element) { return getImageFlags(); } /** * Evaluates the text flags for a element. Can be overwriten by super * classes. * * @return Returns a int */ protected long evaluateTextFlags(final Object element) { return getTextFlags(); } protected Image decorateImage(Image image, final Object element) { if (fLabelDecorators != null && image != null) { for (int i = 0; i < fLabelDecorators.size(); i++) { final ILabelDecorator decorator = fLabelDecorators.get(i); image = decorator.decorateImage(image, element); } } return image; } @Override public Image getImage(final Object element) { final Image result = fImageLabelProvider.getImageLabel(element, evaluateImageFlags(element)); return decorateImage(result, element); } protected String decorateText(String text, final Object element) { if (fLabelDecorators != null && text.length() > 0) { for (int i = 0; i < fLabelDecorators.size(); i++) { final ILabelDecorator decorator = fLabelDecorators.get(i); text = decorator.decorateText(text, element); } } return text; } @Override public String getText(final Object element) { final String label = getLabelString(element); return decorateText(label, element); } public static String getLabelString(final Object element) { String label; if (element instanceof IErlElement) { final IErlElement el = (IErlElement) element; label = el.getLabelString(); } else { label = element.toString(); } if (label.length() > LABEL_LENGTH_LIMIT) { int i = label.indexOf(',', LABEL_LENGTH_LIMIT); if (i == -1) { i = LABEL_LENGTH_LIMIT; } label = label.substring(0, i) + "..."; } return label; } @Override public void dispose() { if (fLabelDecorators != null) { for (int i = 0; i < fLabelDecorators.size(); i++) { final ILabelDecorator decorator = fLabelDecorators.get(i); decorator.dispose(); } fLabelDecorators = null; } fImageLabelProvider.dispose(); } @Override public void addListener(final ILabelProviderListener listener) { if (fLabelDecorators != null) { for (int i = 0; i < fLabelDecorators.size(); i++) { final ILabelDecorator decorator = fLabelDecorators.get(i); decorator.addListener(listener); } } fListeners.add(listener); } @Override public boolean isLabelProperty(final Object element, final String property) { return true; } @Override public void removeListener(final ILabelProviderListener listener) { if (fLabelDecorators != null) { for (int i = 0; i < fLabelDecorators.size(); i++) { final ILabelDecorator decorator = fLabelDecorators.get(i); decorator.removeListener(listener); } } fListeners.remove(listener); } public static ILabelDecorator[] getDecorators(final boolean errortick, final ILabelDecorator extra) { if (errortick) { if (extra == null) { return new ILabelDecorator[] {}; } return new ILabelDecorator[] { extra }; } if (extra != null) { return new ILabelDecorator[] { extra }; } return null; } @Override public Color getForeground(final Object element) { return null; } @Override public Color getBackground(final Object element) { return null; } /** * Fires a label provider changed event to all registered listeners Only * listeners registered at the time this method is called are notified. * * @param event * a label provider changed event * * @see ILabelProviderListener#labelProviderChanged */ protected void fireLabelProviderChanged(final LabelProviderChangedEvent event) { final Object[] listeners = fListeners.getListeners(); for (final Object element : listeners) { final ILabelProviderListener l = (ILabelProviderListener) element; SafeRunner.run(new SafeRunnable() { @Override public void run() { l.labelProviderChanged(event); } }); } } }