archive/net.sourceforge.phpeclipse.css.ui/src/net/sourceforge/phpeclipse/css/ui/internal/editor/UncommentAction.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: UncommentAction.java,v 1.1 2004-09-02 18:11:50 jsurfer Exp $
  12  */
  13
  14 package net.sourceforge.phpeclipse.css.ui.internal.editor;
  15
  16 import java.util.ResourceBundle;
  17
  18 import net.sourceforge.phpeclipse.css.ui.internal.text.CssPartitionScanner;
  19
  20 import org.eclipse.jface.text.BadLocationException;
  21 import org.eclipse.jface.text.IDocument;
  22 import org.eclipse.jface.text.IRewriteTarget;
  23 import org.eclipse.jface.text.ITextSelection;
  24 import org.eclipse.jface.text.ITypedRegion;
  25 import org.eclipse.jface.viewers.ISelection;
  26 import org.eclipse.jface.viewers.ISelectionProvider;
  27 import org.eclipse.ui.IEditorInput;
  28 import org.eclipse.ui.texteditor.IDocumentProvider;
  29 import org.eclipse.ui.texteditor.ITextEditor;
  30 import org.eclipse.ui.texteditor.ITextEditorExtension2;
  31 import org.eclipse.ui.texteditor.TextEditorAction;
  32
  33 /**
  34  * (Heavily inspired by the RemoveBlockComment class in JDT-UI)
  35  */
  36 public class UncommentAction extends TextEditorAction {
  37
  38         // Constructors ------------------------------------------------------------
  39
  40         /**
  41          * Creates a new instance.
  42          *
  43          * @param bundle the resource bundle
  44          * @param prefix a prefix to be prepended to the various resource keys
  45          *        (described in <code>ResourceAction</code> constructor), or
  46          *        <code>null</code> if none
  47          * @param editor the text editor
  48          */
  49         public UncommentAction(ResourceBundle bundle, String prefix,
  50                 ITextEditor editor) {
  51                 super(bundle, prefix, editor);
  52         }
  53
  54         // TextEditorAction Implementation -----------------------------------------
  55
  56         /**
  57          * @see org.eclipse.jface.action.Action#run()
  58          */
  59         public void run() {
  60                 if (!isEnabled()) {
  61                         return;
  62                 }
  63                 ITextEditor editor = getTextEditor();
  64                 if ((editor == null) || !ensureEditable(editor)) {
  65                         return;
  66                 }
  67                 ITextSelection selection = getCurrentSelection();
  68                 if (!isValidSelection(selection)) {
  69                         return;
  70                 }
  71                 IDocumentProvider docProvider = editor.getDocumentProvider();
  72                 IEditorInput input = editor.getEditorInput();
  73                 if (docProvider == null || input == null) {
  74                         return;
  75                 }
  76                 IDocument document = docProvider.getDocument(input);
  77                 if (document == null) {
  78                         return;
  79                 }
  80                 IRewriteTarget target = (IRewriteTarget)
  81                         editor.getAdapter(IRewriteTarget.class);
  82                 if (target != null) {
  83                         target.beginCompoundChange();
  84                 }
  85                 try {
  86                         ITypedRegion region = getBlockCommentRegion(document, selection);
  87                         if (region != null) {
  88                                 int offset = region.getOffset();
  89                                 document.replace(offset, 2, ""); //$NON-NLS-1$
  90                                 document.replace(offset + region.getLength() - 4, 2,
  91                                         ""); //$NON-NLS-1$
  92                         }
  93                 } catch (BadLocationException e) {
  94                         // ignore
  95                 } finally {
  96                         if (target != null) {
  97                                 target.endCompoundChange();
  98                         }
  99                 }
 100         }
 101
 102         // Private Methods ---------------------------------------------------------
 103
 104         /**
 105          * Ensures that the editor is modifyable. If the editor is an instance of
 106          * <code>ITextEditorExtension2</code>, its
 107          * <code>validateEditorInputState</code> method is called, otherwise, the
 108          * result of <code>isEditable</code> is returned.
 109          *
 110          * @param editor the editor to be checked
 111          * @return <code>true</code> if the editor is editable, <code>false</code>
 112          *         otherwise
 113          */
 114         private boolean ensureEditable(ITextEditor editor) {
 115                 if (editor instanceof ITextEditorExtension2) {
 116                         ITextEditorExtension2 extension = (ITextEditorExtension2) editor;
 117                         return extension.validateEditorInputState();
 118                 }
 119                 return editor.isEditable();
 120         }
 121
 122         /**
 123          * Returns the block comment typed region enclosing the position at the end
 124          * of <code>selection</code> or <code>null</code> if there is no block
 125          * comment at this position.
 126          *
 127          * @param selection the caret position (the end of the selection is taken as
 128          *        the position)
 129          * @return the block comment region at the selection's end, or
 130          *         <code>null</code>
 131          */
 132         private ITypedRegion getBlockCommentRegion(IDocument document,
 133                 ITextSelection selection) {
 134                 try {
 135                         ITypedRegion region = document.getPartition(
 136                                 selection.getOffset() + selection.getLength());
 137                         if (CssPartitionScanner.CSS_COMMENT.equals(region.getType())) {
 138                                 return region;
 139                         }
 140                 } catch (BadLocationException e) {
 141                         // ignore
 142                 }
 143                 return null;
 144         }
 145
 146         /**
 147          * Returns the editor's selection, or <code>null</code> if no selection can
 148          * be obtained or the editor is <code>null</code>.
 149          *
 150          * @return the selection of the action's editor, or <code>null</code>
 151          */
 152         private ITextSelection getCurrentSelection() {
 153                 ITextEditor editor = getTextEditor();
 154                 if (editor != null) {
 155                         ISelectionProvider provider = editor.getSelectionProvider();
 156                         if (provider != null) {
 157                                 ISelection selection = provider.getSelection();
 158                                 if (selection instanceof ITextSelection) {
 159                                         return (ITextSelection) selection;
 160                                 }
 161                         }
 162                 }
 163                 return null;
 164         }
 165
 166         /**
 167          * Checks whether given selection is valid, i.e. neither <code>null</code>
 168          * or empty.
 169          *
 170          * @param selection the selection to check
 171          * @return <code>true</code> if the selection is valid, <code>false</code>
 172          *         otherwise
 173          */
 174         private boolean isValidSelection(ITextSelection selection) {
 175                 if (selection != null) {
 176                         return (!selection.isEmpty() && (selection.getLength() > 0));
 177                 }
 178                 return false;
 179         }
 180
 181 }