Java tutorial
/******************************************************************************* * Copyright (c) 2010 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 *******************************************************************************/ package org.eclipse.wst.jsdt.debug.internal.ui.source; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.preference.PreferenceConverter; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.text.IDocument; import org.eclipse.jface.text.contentassist.IContentAssistant; import org.eclipse.jface.text.source.IOverviewRuler; import org.eclipse.jface.text.source.IVerticalRuler; import org.eclipse.jface.text.source.SourceViewer; import org.eclipse.jface.text.source.SourceViewerConfiguration; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.StyledText; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.RGB; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Display; import org.eclipse.ui.texteditor.AbstractTextEditor; import org.eclipse.wst.jsdt.debug.internal.ui.display.JavaScriptDebugViewerConfiguration; /** * A source viewer configured to display JavaScript source. This * viewer obeys the font and color preferences specified in * the JavaScript UI plugin. */ public class JavaScriptSourceViewer extends SourceViewer implements IPropertyChangeListener { private Font fFont; private Color fBackgroundColor; private Color fForegroundColor; private IPreferenceStore fStore; private JavaScriptDebugViewerConfiguration fConfiguration; /** * Constructor * @param parent * @param ruler * @param styles */ public JavaScriptSourceViewer(Composite parent, IVerticalRuler ruler, int styles) { this(parent, ruler, null, false, styles | SWT.LEFT_TO_RIGHT); } /** * Constructor * @param parent * @param ruler * @param overviewRuler * @param isOverviewRulerVisible * @param styles */ public JavaScriptSourceViewer(Composite parent, IVerticalRuler ruler, IOverviewRuler overviewRuler, boolean isOverviewRulerVisible, int styles) { super(parent, ruler, overviewRuler, isOverviewRulerVisible, styles | SWT.LEFT_TO_RIGHT); } /** * Updates the viewer's font to match the preferences. */ private void updateViewerFont() { IPreferenceStore store = getPreferenceStore(); if (store != null) { FontData data = null; if (store.contains(JFaceResources.TEXT_FONT) && !store.isDefault(JFaceResources.TEXT_FONT)) { data = PreferenceConverter.getFontData(store, JFaceResources.TEXT_FONT); } else { data = PreferenceConverter.getDefaultFontData(store, JFaceResources.TEXT_FONT); } if (data != null) { Font font = new Font(getTextWidget().getDisplay(), data); applyFont(font); if (getFont() != null) { getFont().dispose(); } setFont(font); return; } } // if all the preferences failed applyFont(JFaceResources.getTextFont()); } /** * Sets the current font. * * @param font the new font */ private void setFont(Font font) { fFont = font; } /** * Returns the current font. * * @return the current font */ private Font getFont() { return fFont; } /** * Sets the font for the given viewer sustaining selection and scroll position. * * @param font the font */ private void applyFont(Font font) { IDocument doc = getDocument(); if (doc != null && doc.getLength() > 0) { Point selection = getSelectedRange(); int topIndex = getTopIndex(); StyledText styledText = getTextWidget(); styledText.setRedraw(false); styledText.setFont(font); setSelectedRange(selection.x, selection.y); setTopIndex(topIndex); styledText.setRedraw(true); } else { getTextWidget().setFont(font); } } /** * Updates the given viewer's colors to match the preferences. */ public void updateViewerColors() { IPreferenceStore store = getPreferenceStore(); if (store != null) { StyledText styledText = getTextWidget(); Color color = store.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND_SYSTEM_DEFAULT) ? null : createColor(store, AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND, styledText.getDisplay()); styledText.setForeground(color); if (getForegroundColor() != null) { getForegroundColor().dispose(); } setForegroundColor(color); color = store.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT) ? null : createColor(store, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND, styledText.getDisplay()); styledText.setBackground(color); if (getBackgroundColor() != null) { getBackgroundColor().dispose(); } setBackgroundColor(color); } } /** * Creates a color from the information stored in the given preference store. * Returns <code>null</code> if there is no such information available. */ private Color createColor(IPreferenceStore store, String key, Display display) { RGB rgb = null; if (store.contains(key)) { if (store.isDefault(key)) { rgb = PreferenceConverter.getDefaultColor(store, key); } else { rgb = PreferenceConverter.getColor(store, key); } if (rgb != null) { return new Color(display, rgb); } } return null; } /** * Returns the current background color. * * @return the current background color */ protected Color getBackgroundColor() { return fBackgroundColor; } /** * Sets the current background color. * * @param backgroundColor the new background color */ protected void setBackgroundColor(Color backgroundColor) { fBackgroundColor = backgroundColor; } /** * Returns the current foreground color. * * @return the current foreground color */ protected Color getForegroundColor() { return fForegroundColor; } /** * Sets the current foreground color. * * @param foregroundColor the new foreground color */ protected void setForegroundColor(Color foregroundColor) { fForegroundColor = foregroundColor; } /* (non-Javadoc) * @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent) */ public void propertyChange(PropertyChangeEvent event) { String property = event.getProperty(); if (JFaceResources.TEXT_FONT.equals(property)) { updateViewerFont(); } if (AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND.equals(property) || AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND_SYSTEM_DEFAULT.equals(property) || AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND.equals(property) || AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT.equals(property)) { updateViewerColors(); } if (fConfiguration != null) { if (fConfiguration.affectsTextPresentation(event)) { fConfiguration.handlePropertyChangeEvent(event); invalidateTextPresentation(); } } } /** * Returns the current content assistant. * * @return the current content assistant */ public IContentAssistant getContentAssistant() { return fContentAssistant; } /** * Disposes the system resources currently in use by this viewer. */ public void dispose() { if (getFont() != null) { getFont().dispose(); setFont(null); } if (getBackgroundColor() != null) { getBackgroundColor().dispose(); setBackgroundColor(null); } if (getForegroundColor() != null) { getForegroundColor().dispose(); setForegroundColor(null); } if (fStore != null) { fStore.removePropertyChangeListener(this); fStore = null; } } /* (non-Javadoc) * @see org.eclipse.jface.text.source.SourceViewer#configure(org.eclipse.jface.text.source.SourceViewerConfiguration) */ public void configure(SourceViewerConfiguration configuration) { super.configure(configuration); if (fStore != null) { fStore.removePropertyChangeListener(this); fStore = null; } if (configuration instanceof JavaScriptDebugViewerConfiguration) { fConfiguration = (JavaScriptDebugViewerConfiguration) configuration; fStore = fConfiguration.getTextPreferenceStore(); fStore.addPropertyChangeListener(this); } updateViewerFont(); updateViewerColors(); } /** * Returns the preference store used to configure this source viewer or * <code>null</code> if none; */ private IPreferenceStore getPreferenceStore() { return fStore; } }