/*=============================================================================#
# Copyright (c) 2000-2016 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
# Stephan Wahlbrink
#=============================================================================*/
// ORG: org.eclipse.jdt.internal.ui.preferences.JavaSourcePreviewerUpdater
package de.walware.ecommons.text.ui;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Font;
import de.walware.ecommons.ui.util.UIAccess;
/**
* Handles editor font and properties changes for source viewers.
* <p>
* It disposes itself automatically.</p>
*/
public class TextViewerJFaceUpdater {
protected final ISourceViewer fViewer;
protected final IPreferenceStore fPreferenceStore;
private IPropertyChangeListener fFontChangeListener;
private final String fSymbolicFontName;
/**
* Creates a source preview updater for the given viewer and preference store.
*
* @param viewer the viewer
* @param preferenceStore the preference store
*/
public TextViewerJFaceUpdater(final ISourceViewer viewer, final IPreferenceStore preferenceStore) {
this(viewer, preferenceStore, JFaceResources.TEXT_FONT);
}
public TextViewerJFaceUpdater(final ISourceViewer viewer, final IPreferenceStore preferenceStore,
final String symbolicFontName) {
assert (viewer != null);
assert (preferenceStore != null);
assert (symbolicFontName != null);
fViewer = viewer;
fPreferenceStore = preferenceStore;
fSymbolicFontName = symbolicFontName;
viewer.getTextWidget().addDisposeListener(new DisposeListener() {
@Override
public void widgetDisposed(final DisposeEvent e) {
dispose();
}
});
fFontChangeListener = new IPropertyChangeListener() {
@Override
public void propertyChange(final PropertyChangeEvent event) {
if (fSymbolicFontName.equals(event.getProperty())) {
updateFont();
}
}
};
JFaceResources.getFontRegistry().addListener(fFontChangeListener);
updateFont();
}
protected void updateFont() {
final Font font = JFaceResources.getFont(fSymbolicFontName);
final StyledText styledText = fViewer.getTextWidget();
if (UIAccess.isOkToUse(styledText) && font != null) {
fViewer.getTextWidget().setFont(font);
}
}
public final void dispose() {
if (fFontChangeListener != null) {
JFaceResources.getFontRegistry().removeListener(fFontChangeListener);
}
fFontChangeListener = null;
}
}