/*
* Copyright (c) 2012, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.eclipse.org/legal/epl-v10.html
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.dart.tools.ui.internal.text.correction.proposals;
import com.google.dart.tools.internal.corext.refactoring.util.Messages;
import com.google.dart.tools.ui.DartToolsPlugin;
import com.google.dart.tools.ui.internal.text.correction.CorrectionCommandHandler;
import com.google.dart.tools.ui.internal.text.correction.CorrectionMessages;
import com.google.dart.tools.ui.internal.text.correction.ICommandAccess;
import com.google.dart.tools.ui.internal.util.ExceptionHandler;
import com.google.dart.tools.ui.text.dart.IDartCompletionProposal;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRewriteTarget;
import org.eclipse.jface.text.contentassist.ICompletionProposalExtension5;
import org.eclipse.jface.text.contentassist.ICompletionProposalExtension6;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.link.LinkedModeModel;
import org.eclipse.jface.util.Util;
import org.eclipse.jface.viewers.StyledCellLabelProvider;
import org.eclipse.jface.viewers.StyledString;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.IUndoManager;
import org.eclipse.ltk.core.refactoring.NullChange;
import org.eclipse.ltk.core.refactoring.RefactoringCore;
import org.eclipse.ltk.core.refactoring.RefactoringStatus;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.TraverseEvent;
import org.eclipse.swt.events.TraverseListener;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.IEditorPart;
/**
* Implementation of a Java completion proposal to be used for quick fix and quick assist proposals
* that invoke a {@link Change}. The proposal offers a proposal information but no context
* information.
*
* @coverage dart.editor.ui.correction
*/
public class ChangeCorrectionProposal implements IDartCompletionProposal, ICommandAccess,
ICompletionProposalExtension5, ICompletionProposalExtension6 {
private static final NullChange COMPUTING_CHANGE = new NullChange(
"ChangeCorrectionProposal computing..."); //$NON-NLS-1$
private Change fChange;
private String fName;
private int fRelevance;
private Image fImage;
private String fCommandId;
/**
* Constructs a change correction proposal.
*
* @param name The name that is displayed in the proposal selection dialog.
* @param change The change that is executed when the proposal is applied or <code>null</code> if
* the change will be created by implementors of {@link #createChange()}.
* @param relevance The relevance of this proposal.
* @param image The image that is displayed for this proposal or <code>null</code> if no image is
* desired.
*/
public ChangeCorrectionProposal(String name, Change change, int relevance, Image image) {
if (name == null) {
throw new IllegalArgumentException("Name must not be null"); //$NON-NLS-1$
}
fName = name;
fChange = change;
fRelevance = relevance;
fImage = image;
fCommandId = null;
}
/*
* @see ICompletionProposal#apply(IDocument)
*/
@Override
public void apply(IDocument document) {
try {
performChange(DartToolsPlugin.getActivePage().getActiveEditor(), document);
} catch (CoreException e) {
ExceptionHandler.handle(
e,
CorrectionMessages.ChangeCorrectionProposal_error_title,
CorrectionMessages.ChangeCorrectionProposal_error_message);
}
}
/*
* @see ICompletionProposal#getAdditionalProposalInfo()
*/
@Override
public String getAdditionalProposalInfo() {
Object info = getAdditionalProposalInfo(new NullProgressMonitor());
return info == null ? null : info.toString();
}
@Override
public Object getAdditionalProposalInfo(IProgressMonitor monitor) {
StringBuffer buf = new StringBuffer();
buf.append("<p>"); //$NON-NLS-1$
try {
Change change = getChange();
if (change != null) {
String name = change.getName();
if (name.length() == 0) {
return null;
}
buf.append(name);
} else {
return null;
}
} catch (CoreException e) {
buf.append("Unexpected error when accessing this proposal:<p><pre>"); //$NON-NLS-1$
buf.append(e.getLocalizedMessage());
buf.append("</pre>"); //$NON-NLS-1$
}
buf.append("</p>"); //$NON-NLS-1$
return buf.toString();
}
/**
* Returns the change that will be executed when the proposal is applied.
*
* @return returns the change for this proposal.
* @throws CoreException thrown when the change could not be created
*/
public final Change getChange() throws CoreException {
if (Util.isGtk()) {
// workaround for https://bugs.eclipse.org/bugs/show_bug.cgi?id=293995 :
// [Widgets] Deadlock while UI thread displaying/computing a change proposal and non-UI thread creating image
// Solution is to create the change outside a 'synchronized' block.
// Synchronization is achieved by polling fChange, using "fChange == COMPUTING_CHANGE" as barrier.
// Timeout of 10s for safety reasons (should not be reached).
long end = System.currentTimeMillis() + 10000;
do {
boolean computing;
synchronized (this) {
computing = fChange == COMPUTING_CHANGE;
}
if (computing) {
try {
Display display = Display.getCurrent();
if (display != null) {
while (!display.isDisposed() && display.readAndDispatch()) {
}
display.sleep();
} else {
Thread.sleep(100);
}
} catch (InterruptedException e) {
//continue
}
} else {
synchronized (this) {
if (fChange == COMPUTING_CHANGE) {
continue;
} else if (fChange != null) {
return fChange;
} else {
fChange = COMPUTING_CHANGE;
}
}
Change change = createChange();
synchronized (this) {
fChange = change;
}
return change;
}
} while (System.currentTimeMillis() < end);
synchronized (this) {
if (fChange == COMPUTING_CHANGE) {
return null; //failed
}
}
} else {
synchronized (this) {
if (fChange == null) {
fChange = createChange();
}
}
}
return fChange;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jdt.internal.ui.text.correction.IShortcutProposal#getProposalId()
*/
@Override
public String getCommandId() {
return fCommandId;
}
/*
* @see ICompletionProposal#getContextInformation()
*/
@Override
public IContextInformation getContextInformation() {
return null;
}
/*
* @see ICompletionProposal#getDisplayString()
*/
@Override
public String getDisplayString() {
String shortCutString = CorrectionCommandHandler.getShortCutString(getCommandId());
if (shortCutString != null) {
return Messages.format(
CorrectionMessages.ChangeCorrectionProposal_name_with_shortcut,
new String[] {getName(), shortCutString});
}
return getName();
}
/*
* @see ICompletionProposal#getImage()
*/
@Override
public Image getImage() {
return fImage;
}
/**
* Returns the name of the proposal.
*
* @return return the name of the proposal
*/
public String getName() {
return fName;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jdt.ui.text.java.IJavaCompletionProposal#getRelevance()
*/
@Override
public int getRelevance() {
return fRelevance;
}
/*
* @see ICompletionProposal#getSelection(IDocument)
*/
@Override
public Point getSelection(IDocument document) {
return null;
}
/*
* (non-Javadoc)
*
* @see
* org.eclipse.jface.text.contentassist.ICompletionProposalExtension6#getStyledDisplayString()
*/
@Override
public StyledString getStyledDisplayString() {
StyledString str = new StyledString(getName());
String shortCutString = CorrectionCommandHandler.getShortCutString(getCommandId());
if (shortCutString != null) {
String decorated = Messages.format(
CorrectionMessages.ChangeCorrectionProposal_name_with_shortcut,
new String[] {getName(), shortCutString});
return StyledCellLabelProvider.styleDecoratedString(
decorated,
StyledString.QUALIFIER_STYLER,
str);
}
return str;
}
/**
* Set the proposal id to allow assigning a shortcut to the correction proposal.
*
* @param commandId The proposal id for this proposal or <code>null</code> if no command should be
* assigned to this proposal.
*/
public void setCommandId(String commandId) {
fCommandId = commandId;
}
/**
* Sets the display name.
*
* @param name the name to set
*/
public void setDisplayName(String name) {
if (name == null) {
throw new IllegalArgumentException("Name must not be null"); //$NON-NLS-1$
}
fName = name;
}
/**
* Sets the proposal's image or <code>null</code> if no image is desired.
*
* @param image the desired image.
*/
public void setImage(Image image) {
fImage = image;
}
/**
* Sets the relevance.
*
* @param relevance the relevance to set
*/
public void setRelevance(int relevance) {
fRelevance = relevance;
}
/**
* Creates the text change for this proposal. This method is only called once and only when no
* text change has been passed in {@link #ChangeCorrectionProposal(String, Change, int, Image)}.
*
* @return returns the created change.
* @throws CoreException thrown if the creation of the change failed.
*/
protected Change createChange() throws CoreException {
return new NullChange();
}
/**
* Performs the change associated with this proposal.
*
* @param activeEditor The editor currently active or <code>null</code> if no editor is active.
* @param document The document of the editor currently active or <code>null</code> if no editor
* is visible.
* @throws CoreException Thrown when the invocation of the change failed.
*/
protected void performChange(IEditorPart activeEditor, IDocument document) throws CoreException {
StyledText disabledStyledText = null;
TraverseListener traverseBlocker = null;
Change change = null;
IRewriteTarget rewriteTarget = null;
try {
change = getChange();
if (change != null) {
if (document != null) {
LinkedModeModel.closeAllModels(document);
}
if (activeEditor != null) {
rewriteTarget = (IRewriteTarget) activeEditor.getAdapter(IRewriteTarget.class);
if (rewriteTarget != null) {
rewriteTarget.beginCompoundChange();
}
/*
* Workaround for https://bugs.eclipse.org/bugs/show_bug.cgi?id=195834#c7 : During change
* execution, an EventLoopProgressMonitor can process the event queue while the text
* widget has focus. When that happens and the user e.g. pressed a key, the event is
* prematurely delivered to the text widget and screws up the document. Change execution
* fails or performs wrong changes.
*
* The fix is to temporarily disable the text widget.
*/
Object control = activeEditor.getAdapter(Control.class);
if (control instanceof StyledText) {
disabledStyledText = (StyledText) control;
if (disabledStyledText.getEditable()) {
disabledStyledText.setEditable(false);
traverseBlocker = new TraverseListener() {
@Override
public void keyTraversed(TraverseEvent e) {
e.doit = true;
e.detail = SWT.TRAVERSE_NONE;
}
};
disabledStyledText.addTraverseListener(traverseBlocker);
} else {
disabledStyledText = null;
}
}
}
change.initializeValidationData(new NullProgressMonitor());
RefactoringStatus valid = change.isValid(new NullProgressMonitor());
if (valid.hasFatalError()) {
IStatus status = new Status(
IStatus.ERROR,
DartToolsPlugin.getPluginId(),
IStatus.ERROR,
valid.getMessageMatchingSeverity(RefactoringStatus.FATAL),
null);
throw new CoreException(status);
} else {
IUndoManager manager = RefactoringCore.getUndoManager();
Change undoChange;
boolean successful = false;
try {
manager.aboutToPerformChange(change);
undoChange = change.perform(new NullProgressMonitor());
successful = true;
} finally {
manager.changePerformed(change, successful);
}
if (undoChange != null) {
undoChange.initializeValidationData(new NullProgressMonitor());
manager.addUndo(getName(), undoChange);
}
}
}
} finally {
if (disabledStyledText != null) {
disabledStyledText.setEditable(true);
disabledStyledText.removeTraverseListener(traverseBlocker);
}
if (rewriteTarget != null) {
rewriteTarget.endCompoundChange();
}
if (change != null) {
change.dispose();
}
}
}
}