org.eclipse.jface.viewers.DecoratingLabelProvider Maven / Gradle / Ivy
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/*******************************************************************************
* Copyright (c) 2000, 2016 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
* Alexander Kurtakov - Bug 459761
*******************************************************************************/
package org.eclipse.jface.viewers;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
/**
* A decorating label provider is a label provider which combines
* a nested label provider and an optional decorator.
* The decorator decorates the label text, image, font and colors provided by
* the nested label provider.
*/
public class DecoratingLabelProvider extends LabelProvider implements IViewerLabelProvider, IColorProvider,
IFontProvider, ITreePathLabelProvider {
private ILabelProvider provider;
private ILabelDecorator decorator;
// Need to keep our own list of listeners
private ListenerList listeners = new ListenerList<>();
private IDecorationContext decorationContext = DecorationContext.DEFAULT_CONTEXT;
/**
* Creates a decorating label provider which uses the given label decorator
* to decorate labels provided by the given label provider.
*
* @param provider the nested label provider
* @param decorator the label decorator, or null if no decorator is to be used initially
*/
public DecoratingLabelProvider(ILabelProvider provider,
ILabelDecorator decorator) {
Assert.isNotNull(provider);
this.provider = provider;
this.decorator = decorator;
}
/**
* The DecoratingLabelProvider implementation of this IBaseLabelProvider method
* adds the listener to both the nested label provider and the label decorator.
*
* @param listener a label provider listener
*/
@Override
public void addListener(ILabelProviderListener listener) {
super.addListener(listener);
provider.addListener(listener);
if (decorator != null) {
decorator.addListener(listener);
}
listeners.add(listener);
}
/**
* The DecoratingLabelProvider implementation of this IBaseLabelProvider method
* disposes both the nested label provider and the label decorator.
*/
@Override
public void dispose() {
provider.dispose();
if (decorator != null) {
decorator.dispose();
}
}
/**
* The DecoratingLabelProvider implementation of this
* ILabelProvider method returns the image provided
* by the nested label provider's getImage method,
* decorated with the decoration provided by the label decorator's
* decorateImage method.
*/
@Override
public Image getImage(Object element) {
Image image = provider.getImage(element);
if (decorator != null) {
if (decorator instanceof LabelDecorator) {
LabelDecorator ld2 = (LabelDecorator) decorator;
Image decorated = ld2.decorateImage(image, element, getDecorationContext());
if (decorated != null) {
return decorated;
}
} else {
Image decorated = decorator.decorateImage(image, element);
if (decorated != null) {
return decorated;
}
}
}
return image;
}
/**
* Returns the label decorator, or null if none has been set.
*
* @return the label decorator, or null if none has been set.
*/
public ILabelDecorator getLabelDecorator() {
return decorator;
}
/**
* Returns the nested label provider.
*
* @return the nested label provider
*/
public ILabelProvider getLabelProvider() {
return provider;
}
/**
* The DecoratingLabelProvider implementation of this
* ILabelProvider method returns the text label provided
* by the nested label provider's getText method,
* decorated with the decoration provided by the label decorator's
* decorateText method.
*/
@Override
public String getText(Object element) {
String text = provider.getText(element);
if (decorator != null) {
if (decorator instanceof LabelDecorator) {
LabelDecorator ld2 = (LabelDecorator) decorator;
String decorated = ld2.decorateText(text, element, getDecorationContext());
if (decorated != null) {
return decorated;
}
} else {
String decorated = decorator.decorateText(text, element);
if (decorated != null) {
return decorated;
}
}
}
return text;
}
/**
* The DecoratingLabelProvider implementation of this
* IBaseLabelProvider method returns true if the corresponding method
* on the nested label provider returns true or if the corresponding method on the
* decorator returns true.
*/
@Override
public boolean isLabelProperty(Object element, String property) {
if (provider.isLabelProperty(element, property)) {
return true;
}
if (decorator != null && decorator.isLabelProperty(element, property)) {
return true;
}
return false;
}
/**
* The DecoratingLabelProvider implementation of this IBaseLabelProvider method
* removes the listener from both the nested label provider and the label decorator.
*
* @param listener a label provider listener
*/
@Override
public void removeListener(ILabelProviderListener listener) {
super.removeListener(listener);
provider.removeListener(listener);
if (decorator != null) {
decorator.removeListener(listener);
}
listeners.remove(listener);
}
/**
* Sets the label decorator.
* Removes all known listeners from the old decorator, and adds all known listeners to the new decorator.
* The old decorator is not disposed.
* Fires a label provider changed event indicating that all labels should be updated.
* Has no effect if the given decorator is identical to the current one.
*
* @param decorator the label decorator, or null if no decorations are to be applied
*/
public void setLabelDecorator(ILabelDecorator decorator) {
ILabelDecorator oldDecorator = this.decorator;
if (oldDecorator != decorator) {
if (oldDecorator != null) {
for (ILabelProviderListener l : listeners) {
oldDecorator.removeListener(l);
}
}
this.decorator = decorator;
if (decorator != null) {
for (ILabelProviderListener l : listeners) {
decorator.addListener(l);
}
}
fireLabelProviderChanged(new LabelProviderChangedEvent(this));
}
}
@Override
public void updateLabel(ViewerLabel settings, Object element) {
ILabelDecorator currentDecorator = getLabelDecorator();
String oldText = settings.getText();
boolean decorationReady = true;
if (currentDecorator instanceof IDelayedLabelDecorator) {
IDelayedLabelDecorator delayedDecorator = (IDelayedLabelDecorator) currentDecorator;
if (!delayedDecorator.prepareDecoration(element, oldText)) {
// The decoration is not ready but has been queued for processing
decorationReady = false;
}
}
// update icon and label
if (decorationReady || oldText == null
|| settings.getText().isEmpty()) {
settings.setText(getText(element));
}
Image oldImage = settings.getImage();
if (decorationReady || oldImage == null) {
settings.setImage(getImage(element));
}
if(decorationReady) {
updateForDecorationReady(settings,element);
}
}
/**
* Decoration is ready. Update anything else for the settings.
* @param settings The object collecting the settings.
* @param element The Object being decorated.
* @since 3.1
*/
protected void updateForDecorationReady(ViewerLabel settings, Object element) {
if(decorator instanceof IColorDecorator){
IColorDecorator colorDecorator = (IColorDecorator) decorator;
settings.setBackground(colorDecorator.decorateBackground(element));
settings.setForeground(colorDecorator.decorateForeground(element));
}
if(decorator instanceof IFontDecorator) {
settings.setFont(((IFontDecorator) decorator).decorateFont(element));
}
}
@Override
public Color getBackground(Object element) {
if(provider instanceof IColorProvider) {
return ((IColorProvider) provider).getBackground(element);
}
return null;
}
@Override
public Font getFont(Object element) {
if(provider instanceof IFontProvider) {
return ((IFontProvider) provider).getFont(element);
}
return null;
}
@Override
public Color getForeground(Object element) {
if(provider instanceof IColorProvider) {
return ((IColorProvider) provider).getForeground(element);
}
return null;
}
/**
* Return the decoration context associated with this label provider.
* It will be passed to the decorator if the decorator is an
* instance of {@link LabelDecorator}.
* @return the decoration context associated with this label provider
*
* @since 3.2
*/
public IDecorationContext getDecorationContext() {
return decorationContext;
}
/**
* Set the decoration context that will be based to the decorator
* for this label provider if that decorator implements {@link LabelDecorator}.
* @param decorationContext the decoration context.
*
* @since 3.2
*/
public void setDecorationContext(IDecorationContext decorationContext) {
Assert.isNotNull(decorationContext);
this.decorationContext = decorationContext;
}
@Override
public void updateLabel(ViewerLabel settings, TreePath elementPath) {
ILabelDecorator currentDecorator = getLabelDecorator();
String oldText = settings.getText();
Object element = elementPath.getLastSegment();
boolean decorationReady = true;
if (currentDecorator instanceof LabelDecorator) {
LabelDecorator labelDecorator = (LabelDecorator) currentDecorator;
if (!labelDecorator.prepareDecoration(element, oldText, getDecorationContext())) {
// The decoration is not ready but has been queued for processing
decorationReady = false;
}
} else if (currentDecorator instanceof IDelayedLabelDecorator) {
IDelayedLabelDecorator delayedDecorator = (IDelayedLabelDecorator) currentDecorator;
if (!delayedDecorator.prepareDecoration(element, oldText)) {
// The decoration is not ready but has been queued for processing
decorationReady = false;
}
}
settings.setHasPendingDecorations(!decorationReady);
// update icon and label
if (provider instanceof ITreePathLabelProvider) {
ITreePathLabelProvider pprov = (ITreePathLabelProvider) provider;
if (decorationReady || oldText == null
|| settings.getText().isEmpty()) {
pprov.updateLabel(settings, elementPath);
decorateSettings(settings, elementPath);
}
} else {
if (decorationReady || oldText == null
|| settings.getText().isEmpty()) {
settings.setText(getText(element));
}
Image oldImage = settings.getImage();
if (decorationReady || oldImage == null) {
settings.setImage(getImage(element));
}
if(decorationReady) {
updateForDecorationReady(settings,element);
}
}
}
/**
* Decorate the settings
* @param settings the settings obtained from the label provider
* @param elementPath the element path being decorated
*/
private void decorateSettings(ViewerLabel settings, TreePath elementPath) {
Object element = elementPath.getLastSegment();
if (decorator != null) {
if (decorator instanceof LabelDecorator) {
LabelDecorator labelDecorator = (LabelDecorator) decorator;
String text = labelDecorator.decorateText(settings.getText(), element, getDecorationContext());
if (text != null && text.length() > 0)
settings.setText(text);
Image image = labelDecorator.decorateImage(settings.getImage(), element, getDecorationContext());
if (image != null)
settings.setImage(image);
} else {
String text = decorator.decorateText(settings.getText(), element);
if (text != null && text.length() > 0)
settings.setText(text);
Image image = decorator.decorateImage(settings.getImage(), element);
if (image != null)
settings.setImage(image);
}
if(decorator instanceof IColorDecorator){
IColorDecorator colorDecorator = (IColorDecorator) decorator;
Color background = colorDecorator.decorateBackground(element);
if (background != null)
settings.setBackground(background);
Color foreground = colorDecorator.decorateForeground(element);
if (foreground != null)
settings.setForeground(foreground);
}
if(decorator instanceof IFontDecorator) {
Font font = ((IFontDecorator) decorator).decorateFont(element);
if (font != null)
settings.setFont(font);
}
}
}
}