archive/net.sourceforge.phpeclipse.css.ui/src/net/sourceforge/phpeclipse/css/ui/internal/preferences/SyntaxPreviewer.java

   1 /*
   2  * Copyright (c) 2003-2004 Christopher Lenz and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     Christopher Lenz - initial API and implementation
  10  *
  11  * $Id: SyntaxPreviewer.java,v 1.1 2004-09-02 18:11:50 jsurfer Exp $
  12  */
  13
  14 package net.sourceforge.phpeclipse.css.ui.internal.preferences;
  15
  16 import java.io.BufferedReader;
  17 import java.io.IOException;
  18 import java.io.InputStreamReader;
  19
  20 import net.sourceforge.phpeclipse.css.ui.CssUI;
  21 import net.sourceforge.phpeclipse.css.ui.internal.CssUIPreferences;
  22 import net.sourceforge.phpeclipse.css.ui.internal.text.CssSourceViewerConfiguration;
  23 import net.sourceforge.phpeclipse.css.ui.text.CssTextTools;
  24
  25 import org.eclipse.jface.preference.IPreferenceStore;
  26 import org.eclipse.jface.preference.PreferenceConverter;
  27 import org.eclipse.jface.resource.JFaceResources;
  28 import org.eclipse.jface.text.Document;
  29 import org.eclipse.jface.text.IDocument;
  30 import org.eclipse.jface.text.source.SourceViewer;
  31 import org.eclipse.jface.util.IPropertyChangeListener;
  32 import org.eclipse.jface.util.PropertyChangeEvent;
  33 import org.eclipse.swt.SWT;
  34 import org.eclipse.swt.custom.StyledText;
  35 import org.eclipse.swt.graphics.Color;
  36 import org.eclipse.swt.graphics.RGB;
  37 import org.eclipse.swt.widgets.Composite;
  38 import org.eclipse.swt.widgets.Display;
  39
  40 /**
  41  * A previewer for the syntax styling preferences, used to give real time
  42  * feedback on changes to the preferences.
  43  */
  44 public class SyntaxPreviewer extends SourceViewer {
  45
  46         // Constants ---------------------------------------------------------------
  47
  48         /**
  49          * Alias for the preference constant <code>EDITOR_BACKGROUND_COLOR</code>.
  50          */
  51         private static final String BACKGROUND_COLOR =
  52                 CssUIPreferences.EDITOR_BACKGROUND_COLOR;
  53
  54         /**
  55          * Alias for the preference constant
  56          * <code>EDITOR_BACKGROUND_DEFAULT_COLOR</code>.
  57          */
  58         private static final String BACKGROUND_DEFAULT_COLOR =
  59                 CssUIPreferences.EDITOR_BACKGROUND_DEFAULT_COLOR;
  60
  61         // Instance Variables ------------------------------------------------------
  62
  63         /**
  64          * The preference store used for loading the style settings.
  65          */
  66         private IPreferenceStore fStore;
  67
  68         /**
  69          * Listener that handles changes to the preference store.
  70          */
  71         private IPropertyChangeListener fPropertyChangeListener =
  72                 new IPropertyChangeListener() {
  73                         public void propertyChange(PropertyChangeEvent event) {
  74                                 if (affectsPresentation(event)) {
  75                                         updateColors();
  76                                 }
  77                                 invalidateTextPresentation();
  78                         }
  79                 };
  80
  81         private CssTextTools fTextTools;
  82
  83         /**
  84          * The cached background color of the previewer.
  85          */
  86         private Color fBackgroundColor;
  87
  88         // Constructors ------------------------------------------------------------
  89
  90         /**
  91          * Constructor.
  92          *
  93          * @param parent The parent composite
  94          * @param store The preference store to use for loading the style settings
  95          */
  96         public SyntaxPreviewer(Composite parent, IPreferenceStore store) {
  97                 super(parent, null, SWT.V_SCROLL | SWT.H_SCROLL | SWT.BORDER);
  98                 this.fStore = store;
  99                 this.fTextTools = new CssTextTools(this.fStore);
 100
 101                 configure(new CssSourceViewerConfiguration(
 102                         this.fTextTools, this.fStore));
 103                 setEditable(false);
 104                 getTextWidget().setFont(JFaceResources.getTextFont());
 105
 106                 IDocument document = new Document(
 107                         loadTextFromResource("preview.css")); //$NON-NLS-1$
 108                 this.fTextTools.setupDocument(document);
 109                 setDocument(document);
 110
 111                 this.fStore.addPropertyChangeListener(this.fPropertyChangeListener);
 112         }
 113
 114         // SourceViewer Implementation ---------------------------------------------
 115
 116         /**
 117          * @see org.eclipse.jface.text.TextViewer#handleDispose()
 118          */
 119         protected void handleDispose() {
 120                 if (this.fStore != null) {
 121                         if (this.fPropertyChangeListener != null) {
 122                                 this.fStore.removePropertyChangeListener(
 123                                         this.fPropertyChangeListener);
 124                                 this.fPropertyChangeListener = null;
 125                         }
 126                         this.fStore = null;
 127                 }
 128                 if (this.fTextTools != null) {
 129                         this.fTextTools.dispose();
 130                         this.fTextTools = null;
 131                 }
 132                 if ((this.fBackgroundColor != null)
 133                  && !this.fBackgroundColor.isDisposed()) {
 134                         this.fBackgroundColor.dispose();
 135                 }
 136                 super.handleDispose();
 137         }
 138
 139         // Private Methods ---------------------------------------------------------
 140
 141         private boolean affectsPresentation(PropertyChangeEvent event) {
 142                 String p = event.getProperty();
 143                 if (BACKGROUND_COLOR.equals(p)
 144                  || BACKGROUND_DEFAULT_COLOR.equals(p)) {
 145                         return true;
 146                 }
 147                 return false;
 148         }
 149
 150         /**
 151          * Creates a color from the information stored in the given preference
 152          * store.
 153          *
 154          * @param key The preference key under which the color is stored
 155          * @param display The display
 156          * @return The color found, or <code>null</code> if no corresponding
 157          *         preference is available
 158          */
 159         private Color createColor(String key, Display display) {
 160                 Color color = null;
 161                 if (this.fStore.contains(key)) {
 162                         RGB rgb = null;
 163                         if (this.fStore.isDefault(key)) {
 164                                 rgb = PreferenceConverter.getDefaultColor(this.fStore, key);
 165                         } else {
 166                                 rgb = PreferenceConverter.getColor(this.fStore, key);
 167                         }
 168                         if (rgb != null) {
 169                                 color = new Color(display, rgb);
 170                         }
 171                 }
 172                 return color;
 173         }
 174
 175         /**
 176          * Loads and returns the text stored in the specified resource.
 177          *
 178          * @param name The resource name
 179          * @return The text loaded from the resource, or an empty string if there
 180          *         was an error reading the resource contents
 181          */
 182         private String loadTextFromResource(String name) {
 183                 String line;
 184                 String separator = System.getProperty("line.separator"); //$NON-NLS-1$
 185                 StringBuffer buffer = new StringBuffer(512);
 186                 BufferedReader reader = null;
 187                 try {
 188                         reader = new BufferedReader(new InputStreamReader(
 189                                 getClass().getResourceAsStream(name)));
 190                         while ((line = reader.readLine()) != null) {
 191                                 buffer.append(line);
 192                                 buffer.append(separator);
 193                         }
 194                 } catch (IOException io) {
 195                         CssUI.log(io);
 196                 } finally {
 197                         if (reader != null) {
 198                                 try {
 199                                         reader.close();
 200                                 } catch (IOException e) {
 201                                         // ignore
 202                                 }
 203                         }
 204                 }
 205                 return buffer.toString();
 206         }
 207
 208         /**
 209          * Updates the previewer colors.
 210          */
 211         private void updateColors() {
 212                 if (this.fStore != null) {
 213                         StyledText styledText = getTextWidget();
 214                         Color color = null;
 215                         if (!this.fStore.getBoolean(BACKGROUND_DEFAULT_COLOR)) {
 216                                 color = createColor(BACKGROUND_COLOR,
 217                                         styledText.getDisplay());
 218                         }
 219                         styledText.setBackground(color);
 220                         if (this.fBackgroundColor != null) {
 221                                 this.fBackgroundColor.dispose();
 222                         }
 223                         this.fBackgroundColor = color;
 224                 }
 225         }
 226
 227 }