/*******************************************************************************
* 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.ui.internal.texteditor.quickdiff;
import org.eclipse.jface.viewers.IPostSelectionProvider;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.text.IRewriteTarget;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.text.source.IAnnotationModel;
import org.eclipse.jface.text.source.IAnnotationModelExtension;
import org.eclipse.jface.text.source.IChangeRulerColumn;
import org.eclipse.jface.text.source.ILineDiffer;
import org.eclipse.jface.text.source.IVerticalRulerInfo;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.texteditor.IDocumentProvider;
import org.eclipse.ui.texteditor.IEditorStatusLine;
import org.eclipse.ui.texteditor.ITextEditor;
import org.eclipse.ui.texteditor.TextEditorAction;
/**
* Abstract superclass of actions that restore / revert parts of a document displayed in the action's
* editor to the state described by the {@link ILineDiffer ILineDiffer} associated with the document's
* {@link IAnnotationModel IAnnotationModel}.
*
* @since 3.0
*/
public abstract class QuickDiffRestoreAction extends TextEditorAction implements ISelectionChangedListener {
private int fLastLine= -1;
private final boolean fIsRulerAction;
/**
* Creates a new instance.
*
* @param prefix a prefix to be prepended to the various resource keys
* @param editor the editor this action belongs to
* @param isRulerAction <code>true</code> if this is a ruler action
*/
QuickDiffRestoreAction(String prefix, ITextEditor editor, boolean isRulerAction) {
super(QuickDiffMessages.getBundleForConstructedKeys(), prefix, editor);
fIsRulerAction= isRulerAction;
ISelectionProvider selectionProvider= editor.getSelectionProvider();
if (selectionProvider instanceof IPostSelectionProvider)
((IPostSelectionProvider)selectionProvider).addPostSelectionChangedListener(this);
}
/**
* Called by this action's run method inside a pair of calls to <code>IRewriteTarget.beginCompoundChange</code>
* and <code>IRewriteTarget.endCompoundChange</code>().
*
* @see IRewriteTarget
*/
protected abstract void runCompoundChange();
/*
* @see org.eclipse.jface.action.IAction#run()
*/
public void run() {
ITextEditor editor= getTextEditor();
if (editor == null || !validateEditorInputState())
return;
IRewriteTarget target= (IRewriteTarget)editor.getAdapter(IRewriteTarget.class);
if (target != null)
target.beginCompoundChange();
runCompoundChange();
if (target != null)
target.endCompoundChange();
}
/*
* @see org.eclipse.ui.texteditor.IUpdate#update()
*/
public void update() {
/*
* Update only works if we're updated from the ruler action
* (see AbstractDecoratedTextEditor.rulerContextMenuAboutToShow).
*/
super.update();
setEnabled(computeEnablement());
}
/*
* @see org.eclipse.jface.viewers.ISelectionChangedListener#selectionChanged(org.eclipse.jface.viewers.SelectionChangedEvent)
* @since 3.3
*/
public void selectionChanged(SelectionChangedEvent event) {
update();
}
/**
* Computes, caches and returns the internal state, including enablement.
*
* @return <code>true</code> if the action is enabled, <code>false</code>
* if it is not
*/
protected boolean computeEnablement() {
if (!super.isEnabled())
return false;
if (!canModifyEditor())
return false;
fLastLine= computeLine(fIsRulerAction);
return true;
}
/**
* Returns the selection of the editor this action belongs to.
*
* @return the editor's selection, or <code>null</code>
*/
protected ITextSelection getSelection() {
if (getTextEditor() == null)
return null;
ISelectionProvider sp= getTextEditor().getSelectionProvider();
if (sp == null)
return null;
ISelection s= sp.getSelection();
if (s instanceof ITextSelection)
return (ITextSelection)s;
return null;
}
/**
* Returns the current line of activity
*
* @return the currently active line
* @since 3.1
*/
protected int getLastLine() {
return fLastLine;
}
/**
* Returns the active line.
*
* @param useRulerInfo <code>true</code> if ruler info should be used
* @return the line of interest.
* @since 3.1
*/
private int computeLine(boolean useRulerInfo) {
int lastLine;
if (useRulerInfo) {
IVerticalRulerInfo ruler= getRuler();
if (ruler == null)
lastLine= -1;
else
lastLine= ruler.getLineOfLastMouseButtonActivity();
} else {
ITextSelection selection= getSelection();
if (selection == null)
lastLine= -1;
else
lastLine= selection.getEndLine();
}
return lastLine;
}
/**
* Returns the annotation model of the document displayed in this action's editor, if it
* implements the {@link IAnnotationModelExtension IAnnotationModelExtension} interface.
*
* @return the displayed document's annotation model if it is an <code>IAnnotationModelExtension</code>, or <code>null</code>
*/
private IAnnotationModelExtension getModel() {
if (getTextEditor() == null)
return null;
IDocumentProvider provider= getTextEditor().getDocumentProvider();
IEditorInput editorInput= getTextEditor().getEditorInput();
IAnnotationModel m= provider.getAnnotationModel(editorInput);
if (m instanceof IAnnotationModelExtension)
return (IAnnotationModelExtension)m;
return null;
}
/**
* Returns the diff model associated with the annotation model of the document currently displayed
* in this action's editor, if any.
*
* @return the diff model associated with the displayed document, or <code>null</code>
*/
protected ILineDiffer getDiffer() {
IAnnotationModelExtension extension= getModel();
if (extension != null)
return (ILineDiffer)extension.getAnnotationModel(IChangeRulerColumn.QUICK_DIFF_MODEL_ID);
return null;
}
/**
* Returns a <code>IVerticalRulerInfo</code> if this action's editor adapts to one.
*
* @return the <code>IVerticalRulerInfo</code> for the editor's vertical ruler, or <code>null</code>
*/
protected IVerticalRulerInfo getRuler() {
if (getTextEditor() != null)
return (IVerticalRulerInfo)getTextEditor().getAdapter(IVerticalRulerInfo.class);
return null;
}
/**
* Sets the status line error message to <code>string</code>.
*
* @param string the message to be displayed as error.
*/
protected void setStatus(String string) {
if (getTextEditor() != null) {
IEditorStatusLine statusLine= (IEditorStatusLine) getTextEditor().getAdapter(IEditorStatusLine.class);
if (statusLine != null) {
statusLine.setMessage(true, string, null);
}
}
}
}