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/*******************************************************************************
* Copyright (c) 2008, 2015 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
* Robin Stocker - Bug 236006 - [Viewers] Add tooltip support for DelegatingStyledCellLabelProvider
*******************************************************************************/
package org.eclipse.jface.viewers;
import java.util.Arrays;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
/**
* A {@link DelegatingStyledCellLabelProvider} is a
* {@link StyledCellLabelProvider} that delegates requests for the styled string
* and the image to a
* {@link DelegatingStyledCellLabelProvider.IStyledLabelProvider}.
*
*
* Existing label providers can be enhanced by implementing
* {@link DelegatingStyledCellLabelProvider.IStyledLabelProvider} so they can be
* used in viewers with styled labels.
*
*
*
* The {@link DelegatingStyledCellLabelProvider.IStyledLabelProvider} can
* optionally implement {@link IColorProvider} and {@link IFontProvider} to
* provide foreground and background color and a default font.
*
*
*
* Since 3.10, {@link DelegatingStyledCellLabelProvider.IStyledLabelProvider}
* can optionally implement {@link IToolTipProvider} to provide tooltip
* support.
*
*
* @since 3.4
*/
public class DelegatingStyledCellLabelProvider extends StyledCellLabelProvider {
/**
* Interface marking a label provider that provides styled text labels and
* images.
*
* The {@link DelegatingStyledCellLabelProvider.IStyledLabelProvider} can
* optionally implement {@link IColorProvider} and {@link IFontProvider} to
* provide foreground and background color and a default font.
*
*/
public static interface IStyledLabelProvider extends IBaseLabelProvider {
/**
* Returns the styled text label for the given element
*
* @param element
* the element to evaluate the styled string for
*
* @return the styled string.
*/
public StyledString getStyledText(Object element);
/**
* Returns the image for the label of the given element. The image is
* owned by the label provider and must not be disposed directly.
* Instead, dispose the label provider when no longer needed.
*
* @param element
* the element for which to provide the label image
* @return the image used to label the element, or null
* if there is no image for the given object
*/
public Image getImage(Object element);
}
private IStyledLabelProvider styledLabelProvider;
/**
* Creates a {@link DelegatingStyledCellLabelProvider} that delegates the
* requests for the styled labels and the images to a
* {@link IStyledLabelProvider}.
*
* @param labelProvider
* the label provider that provides the styled labels and the
* images
*/
public DelegatingStyledCellLabelProvider(IStyledLabelProvider labelProvider) {
if (labelProvider == null)
throw new IllegalArgumentException(
"Label provider must not be null"); //$NON-NLS-1$
this.styledLabelProvider = labelProvider;
}
@Override
public void update(ViewerCell cell) {
Object element = cell.getElement();
StyledString styledString = getStyledText(element);
String newText= styledString.toString();
StyleRange[] oldStyleRanges= cell.getStyleRanges();
StyleRange[] newStyleRanges= isOwnerDrawEnabled() ? styledString.getStyleRanges() : null;
if (!Arrays.equals(oldStyleRanges, newStyleRanges)) {
cell.setStyleRanges(newStyleRanges);
if (cell.getText().equals(newText)) {
// make sure there will be a refresh from a change
cell.setText(""); //$NON-NLS-1$
}
}
cell.setText(newText);
cell.setImage(getImage(element));
cell.setFont(getFont(element));
cell.setForeground(getForeground(element));
cell.setBackground(getBackground(element));
// no super call required. changes on item will trigger the refresh.
}
/**
* Provides a foreground color for the given element.
*
* @param element
* the element
* @return the foreground color for the element, or null to
* use the default foreground color
*/
public Color getForeground(Object element) {
if (this.styledLabelProvider instanceof IColorProvider) {
return ((IColorProvider) this.styledLabelProvider)
.getForeground(element);
}
return null;
}
/**
* Provides a background color for the given element.
*
* @param element
* the element
* @return the background color for the element, or null to
* use the default background color
*/
public Color getBackground(Object element) {
if (this.styledLabelProvider instanceof IColorProvider) {
return ((IColorProvider) this.styledLabelProvider)
.getBackground(element);
}
return null;
}
/**
* Provides a font for the given element.
*
* @param element
* the element
* @return the font for the element, or null to use the
* default font
*/
public Font getFont(Object element) {
if (this.styledLabelProvider instanceof IFontProvider) {
return ((IFontProvider) this.styledLabelProvider).getFont(element);
}
return null;
}
@Override
public String getToolTipText(Object element) {
if (styledLabelProvider instanceof IToolTipProvider) {
return ((IToolTipProvider) this.styledLabelProvider).getToolTipText(element);
}
return super.getToolTipText(element);
}
/**
* Returns the image for the label of the given element. The image is owned
* by the label provider and must not be disposed directly. Instead, dispose
* the label provider when no longer needed.
*
* @param element
* the element for which to provide the label image
* @return the image used to label the element, or null if
* there is no image for the given object
*/
public Image getImage(Object element) {
return this.styledLabelProvider.getImage(element);
}
/**
* Returns the styled text for the label of the given element.
*
* @param element
* the element for which to provide the styled label text
* @return the styled text string used to label the element
*/
protected StyledString getStyledText(Object element) {
return this.styledLabelProvider.getStyledText(element);
}
/**
* Returns the styled string provider.
*
* @return the wrapped label provider
*/
public IStyledLabelProvider getStyledStringProvider() {
return this.styledLabelProvider;
}
@Override
public void addListener(ILabelProviderListener listener) {
super.addListener(listener);
this.styledLabelProvider.addListener(listener);
}
@Override
public void removeListener(ILabelProviderListener listener) {
super.removeListener(listener);
this.styledLabelProvider.removeListener(listener);
}
@Override
public boolean isLabelProperty(Object element, String property) {
return this.styledLabelProvider.isLabelProperty(element, property);
}
@Override
public void dispose() {
super.dispose();
this.styledLabelProvider.dispose();
}
}