/*******************************************************************************
* Copyright (c) 2003, 2015 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
* Fair Issac Corp - bug 287103 - NCSLabelProvider does not properly handle overrides
*******************************************************************************/
package org.eclipse.ui.internal.navigator;
import java.util.Collection;
import java.util.Iterator;
import org.eclipse.core.commands.common.EventManager;
import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.jface.util.SafeRunnable;
import org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider.IStyledLabelProvider;
import org.eclipse.jface.viewers.IColorProvider;
import org.eclipse.jface.viewers.IFontProvider;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.jface.viewers.ITableLabelProvider;
import org.eclipse.jface.viewers.ITreePathLabelProvider;
import org.eclipse.jface.viewers.LabelProviderChangedEvent;
import org.eclipse.jface.viewers.StyledString;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.jface.viewers.ViewerLabel;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
import org.eclipse.ui.internal.navigator.extensions.NavigatorContentExtension;
import org.eclipse.ui.navigator.CommonViewer;
import org.eclipse.ui.navigator.ICommonLabelProvider;
import org.eclipse.ui.navigator.INavigatorContentService;
/**
* <p>
* Provides relevant labels based on the associated
* {@link INavigatorContentService}for the contents of a
* TreeViewer .
* <p>
*
* <p>
* Except for the dependency on
* {@link INavigatorContentService}, this class has no
* dependencies on the rest of the Common Navigator framework. Tree viewers that would like to use
* the extensions defined by the Common Navigator, without using the actual view part or other
* pieces of functionality (filters, sorting, etc) may choose to use this class, in effect using an
* extensible label provider.
* </p>
* <p>
*
* @since 3.2
*
* @see org.eclipse.ui.internal.navigator.NavigatorContentService
* @see org.eclipse.ui.internal.navigator.NavigatorContentServiceContentProvider
*/
public class NavigatorContentServiceLabelProvider extends EventManager
implements ILabelProvider, IColorProvider, IFontProvider, ITreePathLabelProvider, ITableLabelProvider, ILabelProviderListener, IStyledLabelProvider {
private final NavigatorContentService contentService;
private final boolean isContentServiceSelfManaged;
private final ReusableViewerLabel reusableLabel = new ReusableViewerLabel();
/**
* <p>
* Uses the supplied content service to acquire the available extensions.
* </p>
*
* @param aContentService
* The associated NavigatorContentService that should be used to acquire information.
*/
public NavigatorContentServiceLabelProvider(NavigatorContentService aContentService) {
contentService = aContentService;
isContentServiceSelfManaged = false;
}
/**
* <p>
* Return the appropriate image for anElement. The image will be used as the icon for anElement
* when displayed in the tree viewer. This method uses information from its contentService to
* know what extensions to use to supply the correct label.
* </p>
* {@inheritDoc}
*
* @param anElement
* An element from the Tree Viewer
* @return The Image that will be used as the icon when anElement is displayed in the viewer.
* @see org.eclipse.jface.viewers.ILabelProvider#getImage(java.lang.Object)
*/
@Override
public Image getImage(Object anElement) {
return getColumnImage(anElement, -1);
}
@Override
public Image getColumnImage(Object element, int columnIndex) {
Collection contentExtensions = contentService.findPossibleLabelExtensions(element);
Image image = null;
for (Iterator itr = contentExtensions.iterator(); itr.hasNext() && image == null; ) {
image = findImage((NavigatorContentExtension) itr.next(), element, columnIndex);
}
return image;
}
/**
* <p>
* Return a String representation of anElement to be used as the display name in the tree
* viewer.
* </p>
*
* @param anElement
* An element from the Tree Viewer
* @return The String label to display for the object when represented in the viewer.
* @see org.eclipse.jface.viewers.ILabelProvider#getText(java.lang.Object)
*/
@Override
public String getText(Object anElement) {
return getColumnText(anElement, -1);
}
@Override
public String getColumnText(Object anElement, int aColumn) {
ILabelProvider[] labelProviders = contentService.findRelevantLabelProviders(anElement);
if (labelProviders.length == 0)
return NLS.bind(CommonNavigatorMessages.NavigatorContentServiceLabelProvider_Error_no_label_provider_for_0_, makeSmallString(anElement));
String text = null;
for (ILabelProvider labelProvider : labelProviders) {
if (labelProvider instanceof ITableLabelProvider && aColumn != -1)
text = ((ITableLabelProvider)labelProvider).getColumnText(anElement, aColumn);
else
text = labelProvider.getText(anElement);
if (text != null && text.length() > 0)
return text;
}
return text;
}
@Override
public StyledString getStyledText(Object anElement) {
Collection extensions = contentService.findPossibleLabelExtensions(anElement);
if (extensions.size() == 0)
return new StyledString(NLS.bind(CommonNavigatorMessages.NavigatorContentServiceLabelProvider_Error_no_label_provider_for_0_, makeSmallString(anElement)));
StyledString text = null;
for (Iterator itr = extensions.iterator(); itr.hasNext() && text == null; ) {
text = findStyledText((NavigatorContentExtension) itr.next(), anElement);
}
return text != null ? text : new StyledString();
}
/**
* Search for a styled text label and take overrides into account.
* Uses only simple ITreeContentProvider.getParent() style semantics.
*
* @returns the styled text or <code>null</code> if no extension has been found that provides a label
*/
private StyledString findStyledText(NavigatorContentExtension foundExtension, Object anElement) {
ICommonLabelProvider labelProvider= foundExtension.getLabelProvider();
if (labelProvider instanceof IStyledLabelProvider) {
StyledString styledText= ((IStyledLabelProvider) labelProvider).getStyledText(anElement);
// paranoia check for null, although null is not a valid return value for IStyledLabelProvider.getStyledText
if (styledText != null && styledText.length() > 0) {
return styledText;
}
} else {
String text= labelProvider.getText(anElement);
if (text != null && text.length() > 0) {
return new StyledString(text);
}
}
return null;
}
private String makeSmallString(Object obj) {
if (obj == null)
return "null"; //$NON-NLS-1$
String str = obj.toString();
int len = str.length();
return str.substring(0, len < 50 ? len : 49);
}
/**
* Search for image and take overrides into account.
* Uses only simple ITreeContentProvider.getParent() style semantics.
*/
private Image findImage(NavigatorContentExtension foundExtension, Object anElement, int aColumn) {
Image image = null;
ICommonLabelProvider provider = foundExtension.getLabelProvider();
if (provider instanceof ITableLabelProvider && aColumn >= 0)
image = ((ITableLabelProvider)provider).getColumnImage(anElement, aColumn);
else
image = provider.getImage(anElement);
return image;
}
@Override
public Font getFont(Object anElement) {
ILabelProvider[] labelProviders = contentService.findRelevantLabelProviders(anElement);
for (ILabelProvider provider : labelProviders) {
if (provider instanceof IFontProvider) {
IFontProvider fontProvider = (IFontProvider) provider;
Font font = fontProvider.getFont(anElement);
if (font != null) {
return font;
}
}
}
return null;
}
@Override
public Color getForeground(Object anElement) {
ILabelProvider[] labelProviders = contentService.findRelevantLabelProviders(anElement);
for (ILabelProvider provider : labelProviders) {
if (provider instanceof IColorProvider) {
IColorProvider colorProvider = (IColorProvider) provider;
Color color = colorProvider.getForeground(anElement);
if (color != null) {
return color;
}
}
}
return null;
}
@Override
public Color getBackground(Object anElement) {
ILabelProvider[] labelProviders = contentService.findRelevantLabelProviders(anElement);
for (ILabelProvider provider : labelProviders) {
if (provider instanceof IColorProvider) {
IColorProvider colorProvider = (IColorProvider) provider;
Color color = colorProvider.getBackground(anElement);
if (color != null) {
return color;
}
}
}
return null;
}
/**
* <p>
* Indicates whether anElelement has aProperty that affects the display of the label.
* </p>
* {@inheritDoc}
*
* @param anElement
* An element from the Tree Viewer
* @param aProperty
* A property of the given element that could be a label provider
* @return True if any of the extensions enabled on anElement consider aProperty a
* label-changing property.
* @see org.eclipse.jface.viewers.IBaseLabelProvider#isLabelProperty(java.lang.Object,
* java.lang.String)
*/
@Override
public boolean isLabelProperty(Object anElement, String aProperty) {
boolean result = false;
ILabelProvider[] labelProviders = contentService.findRelevantLabelProviders(anElement);
for (int i = 0; i < labelProviders.length && !result; i++) {
result = labelProviders[i].isLabelProperty(anElement, aProperty);
}
return result;
}
/**
* <p>
* Label provider listeners are currently supported.
* </p>
*
* {@inheritDoc}
* @see org.eclipse.jface.viewers.IBaseLabelProvider#addListener(org.eclipse.jface.viewers.ILabelProviderListener)
*/
@Override
public void addListener(ILabelProviderListener aListener) {
addListenerObject(aListener);
}
/**
* <p>
* Label provider listeners are currently supported.
* </p>
*
* {@inheritDoc}
* @see org.eclipse.jface.viewers.IBaseLabelProvider#removeListener(org.eclipse.jface.viewers.ILabelProviderListener)
*/
@Override
public void removeListener(ILabelProviderListener aListener) {
removeListenerObject(aListener);
}
/**
* <p>
* Dispose of the content service, if it was created and not supplied.
* </p>
* <p>
* <b>If a client uses this class outside of the framework of {@link CommonViewer}, this method
* must be called when finished. </b>
* </p>
*
* {@inheritDoc}
* @see org.eclipse.jface.viewers.IBaseLabelProvider#dispose()
*/
@Override
public void dispose() {
if (isContentServiceSelfManaged) {
contentService.dispose();
}
}
/**
* 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) {
for (Object listener : getListeners()) {
final ILabelProviderListener labelProviderListener = (ILabelProviderListener) listener;
SafeRunner.run(new SafeRunnable() {
@Override
public void run() {
labelProviderListener.labelProviderChanged(event);
}
});
}
}
@Override
public void updateLabel(ViewerLabel label, TreePath elementPath) {
Collection contentExtensions = contentService.findPossibleLabelExtensions(elementPath.getLastSegment());
reusableLabel.reset(label);
for (Iterator itr = contentExtensions.iterator(); itr.hasNext() && !(reusableLabel.isValid() && reusableLabel.hasChanged()); ) {
findUpdateLabel((NavigatorContentExtension)itr.next(), reusableLabel, elementPath);
}
reusableLabel.fill(label);
}
/**
* Search for text label and take overrides into account.
* Uses only simple ITreeContentProvider.getParent() style semantics.
*/
private void findUpdateLabel(NavigatorContentExtension foundExtension, ReusableViewerLabel label, TreePath elementPath) {
ILabelProvider labelProvider = foundExtension.getLabelProvider();
if (labelProvider instanceof ITreePathLabelProvider) {
ITreePathLabelProvider tplp = (ITreePathLabelProvider) labelProvider;
tplp.updateLabel(label, elementPath);
} else {
label.setImage(labelProvider.getImage(elementPath.getLastSegment()));
label.setText(labelProvider.getText(elementPath.getLastSegment()));
}
}
@Override
public void labelProviderChanged(LabelProviderChangedEvent event) {
fireLabelProviderChanged(event);
}
}