content: /*******************************************************************************
   * Copyright (c) 2000, 2008 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.internal.ui.javaeditor;
  
  
  
  import org.eclipse.jface.action.IAction;
  import org.eclipse.jface.preference.IPreferenceStore;
  import org.eclipse.jface.text.IRegion;
  import org.eclipse.jface.util.IPropertyChangeListener;
  import org.eclipse.jface.util.PropertyChangeEvent;
  import org.eclipse.ui.IEditorInput;
  import org.eclipse.ui.PlatformUI;
  import org.eclipse.ui.texteditor.ITextEditor;
  import org.eclipse.ui.texteditor.TextEditorAction;
  import org.eclipse.wst.jsdt.core.IClassFile;
  import org.eclipse.wst.jsdt.internal.ui.IJavaHelpContextIds;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  import org.eclipse.wst.jsdt.internal.ui.JavaPluginImages;
  import org.eclipse.wst.jsdt.ui.IWorkingCopyManager;
  import org.eclipse.wst.jsdt.ui.PreferenceConstants;
  
  
  /**
   * A tool bar action which toggles the presentation model of the
   * connected text editor. The editor shows either the highlight range
   * only or always the whole document.
   */
  public class TogglePresentationAction extends TextEditorAction implements IPropertyChangeListener {
  
  	private IPreferenceStore fStore;
  
  	/**
  	 * Constructs and updates the action.
  	 */
  	public TogglePresentationAction() {
  		super(JavaEditorMessages.getBundleForConstructedKeys(), "TogglePresentation.", null, IAction.AS_CHECK_BOX); //$NON-NLS-1$
  		JavaPluginImages.setToolImageDescriptors(this, "segment_edit.gif"); //$NON-NLS-1$
  		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IJavaHelpContextIds.TOGGLE_PRESENTATION_ACTION);
  		update();
  	}
  
  	/*
  	 * @see IAction#actionPerformed
  	 */
  	public void run() {
  
  		ITextEditor editor= getTextEditor();
  		if (editor == null)
  			return;
  
  		IRegion remembered= editor.getHighlightRange();
  		editor.resetHighlightRange();
  
  		boolean showAll= !editor.showsHighlightRangeOnly();
  		setChecked(showAll);
  
  		editor.showHighlightRangeOnly(showAll);
  		if (remembered != null)
  			editor.setHighlightRange(remembered.getOffset(), remembered.getLength(), true);
  
  		fStore.removePropertyChangeListener(this);
  		fStore.setValue(PreferenceConstants.EDITOR_SHOW_SEGMENTS, showAll);
  		fStore.addPropertyChangeListener(this);
  	}
  
  	/*
  	 * @see TextEditorAction#update
  	 */
  	public void update() {
  		ITextEditor editor= getTextEditor();
  		boolean checked= (editor != null && editor.showsHighlightRangeOnly());
  		setChecked(checked);
  		if (editor instanceof CompilationUnitEditor) {
  			IWorkingCopyManager manager= JavaScriptPlugin.getDefault().getWorkingCopyManager();
  			setEnabled(manager.getWorkingCopy(editor.getEditorInput()) != null);
  		} else if (editor instanceof ClassFileEditor) {
  			IEditorInput input= editor.getEditorInput();
  			IClassFile cf= null;
  			if (input instanceof IClassFileEditorInput) {
  				IClassFileEditorInput cfi= (IClassFileEditorInput)input;
  				cf= cfi.getClassFile();
  			}
  			setEnabled(cf != null && cf.exists());
  		} else
  			setEnabled(editor != null);
  	}
  
  	/*
  	 * @see TextEditorAction#setEditor(ITextEditor)
  	 */
  	public void setEditor(ITextEditor editor) {
  
  		super.setEditor(editor);
  
  		if (editor != null) {
  
  			if (fStore == null) {
  				fStore= JavaScriptPlugin.getDefault().getPreferenceStore();
  				fStore.addPropertyChangeListener(this);
  			}
  			synchronizeWithPreference(editor);
  
  		} else if (fStore != null) {
  			fStore.removePropertyChangeListener(this);
  			fStore= null;
  		}
  
  		update();
  	}
  
  	/**
  	 * Synchronizes the appearance of the editor with what the preference store tells him.
  	 *
  	 * @param editor the text editor
  	 */
  	private void synchronizeWithPreference(ITextEditor editor) {
  
  		if (editor == null)
  			return;
  
  		boolean showSegments= fStore.getBoolean(PreferenceConstants.EDITOR_SHOW_SEGMENTS);
  		setChecked(showSegments);
  
  		if (editor.showsHighlightRangeOnly() != showSegments) {
  			IRegion remembered= editor.getHighlightRange();
  			editor.resetHighlightRange();
  			editor.showHighlightRangeOnly(showSegments);
  			if (remembered != null)
  				editor.setHighlightRange(remembered.getOffset(), remembered.getLength(), true);
  		}
  	}
  
  	/*
  	 * @see IPropertyChangeListener#propertyChange(PropertyChangeEvent)
  	 */
  	public void propertyChange(PropertyChangeEvent event) {
  		if (event.getProperty().equals(PreferenceConstants.EDITOR_SHOW_SEGMENTS))
  			synchronizeWithPreference(getTextEditor());
  	}
  }
  