/*******************************************************************************
* Copyright (c) 2000, 2011 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 melnorme.lang.ide.ui.editor.actions;
import java.util.HashMap;
import java.util.Map;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextOperationTarget;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.TextUtilities;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.SourceViewerConfiguration;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.texteditor.ITextEditor;
import melnorme.lang.ide.core.LangCore;
import melnorme.lang.ide.ui.editor.AbstractLangEditor;
import melnorme.lang.ide.ui.editor.LangEditorMessages;
import melnorme.lang.ide.ui.utils.operations.BasicEditorOperation;
import melnorme.utilbox.core.CommonException;
/**
* An action which toggles comment prefixes on the selected lines.
*
* @since 3.0
*/
public class ToggleCommentAction extends TextEditorAction_Adapter {
/** The text operation target */
private ITextOperationTarget fOperationTarget;
/** The document partitioning */
private String fDocumentPartitioning;
/** The comment prefixes */
private Map<String, String[]> fPrefixesMap;
public ToggleCommentAction(IWorkbenchPage page) {
super(page);
}
protected String getOperationName() {
return LangEditorMessages.ToggleComment_error_title;
}
@Override
public boolean isEnabled() {
return super.isEnabled() && canModifyEditor() && isTargetOperationEnabled();
}
protected boolean isTargetOperationEnabled() {
ITextEditor editor = getTextEditor();
if(editor != null) {
fOperationTarget = (ITextOperationTarget) editor.getAdapter(ITextOperationTarget.class);
}
return fOperationTarget != null &&
fOperationTarget.canDoOperation(ITextOperationTarget.PREFIX) &&
fOperationTarget.canDoOperation(ITextOperationTarget.STRIP_PREFIX);
}
public void configure(ISourceViewer sourceViewer, SourceViewerConfiguration configuration) {
fPrefixesMap= null;
String[] types= configuration.getConfiguredContentTypes(sourceViewer);
Map<String, String[]> prefixesMap= new HashMap<String, String[]>(types.length);
for (int i= 0; i < types.length; i++) {
String type= types[i];
String[] prefixes= configuration.getDefaultPrefixes(sourceViewer, type);
if (prefixes != null && prefixes.length > 0) {
int emptyPrefixes= 0;
for (int j= 0; j < prefixes.length; j++)
if (prefixes[j].length() == 0)
emptyPrefixes++;
if (emptyPrefixes > 0) {
String[] nonemptyPrefixes= new String[prefixes.length - emptyPrefixes];
for (int j= 0, k= 0; j < prefixes.length; j++) {
String prefix= prefixes[j];
if (prefix.length() != 0) {
nonemptyPrefixes[k]= prefix;
k++;
}
}
prefixes= nonemptyPrefixes;
}
prefixesMap.put(type, prefixes);
}
}
fDocumentPartitioning= configuration.getConfiguredDocumentPartitioning(sourceViewer);
fPrefixesMap= prefixesMap;
}
@Override
protected BasicEditorOperation createOperation(ITextEditor editor) {
return new BasicEditorOperation(getOperationName(), editor) {
@Override
protected void doRunWithEditor(AbstractLangEditor editor) throws CommonException {
configure(editor.getSourceViewer_(), editor.getSourceViewerConfiguration_asLang());
if (fOperationTarget == null || fDocumentPartitioning == null || fPrefixesMap == null) {
throw new CommonException("Partitioning parameters not set");
}
if (!validateEditorInputState())
return;
if(!isTargetOperationEnabled()) {
throw new CommonException(LangEditorMessages.ToggleComment_error_message);
}
final int operationCode;
if (isSelectionCommented(editor.getSelectionProvider().getSelection())) {
operationCode= ITextOperationTarget.STRIP_PREFIX;
} else {
operationCode= ITextOperationTarget.PREFIX;
}
Display display = getShell().getDisplay();
BusyIndicator.showWhile(display, new Runnable() {
@Override
public void run() {
fOperationTarget.doOperation(operationCode);
}
});
}
};
}
/**
* Is the given selection single-line commented?
*
* @param selection Selection to check
* @return <code>true</code> iff all selected lines are commented
*/
private boolean isSelectionCommented(ISelection selection) {
if (!(selection instanceof ITextSelection))
return false;
ITextSelection textSelection= (ITextSelection) selection;
if (textSelection.getStartLine() < 0 || textSelection.getEndLine() < 0)
return false;
IDocument document= getTextEditor().getDocumentProvider().getDocument(getTextEditor().getEditorInput());
try {
IRegion block= getTextBlockFromSelection(textSelection, document);
ITypedRegion[] regions= TextUtilities.computePartitioning(document, fDocumentPartitioning,
block.getOffset(), block.getLength(), false);
int[] lines= new int[regions.length * 2]; // [startline, endline, startline, endline, ...]
for (int i= 0, j= 0; i < regions.length; i++, j+= 2) {
// start line of region
lines[j]= getFirstCompleteLineOfRegion(regions[i], document);
// end line of region
int length= regions[i].getLength();
int offset= regions[i].getOffset() + length;
if (length > 0)
offset--;
lines[j + 1]= (lines[j] == -1 ? -1 : document.getLineOfOffset(offset));
}
// Perform the check
for (int i= 0, j= 0; i < regions.length; i++, j += 2) {
String[] prefixes= fPrefixesMap.get(regions[i].getType());
if (prefixes != null && prefixes.length > 0 && lines[j] >= 0 && lines[j + 1] >= 0)
if (!isBlockCommented(lines[j], lines[j + 1], prefixes, document))
return false;
}
return true;
} catch (BadLocationException x) {
// should not happen
LangCore.logError("Unexpected error.", x);
}
return false;
}
/**
* Creates a region describing the text block (something that starts at
* the beginning of a line) completely containing the current selection.
*
* @param selection The selection to use
* @param document The document
* @return the region describing the text block comprising the given selection
*/
protected static IRegion getTextBlockFromSelection(ITextSelection selection, IDocument document) {
try {
IRegion line= document.getLineInformationOfOffset(selection.getOffset());
int length= selection.getLength() == 0 ?
line.getLength() :
selection.getLength() + (selection.getOffset() - line.getOffset());
return new Region(line.getOffset(), length);
} catch (BadLocationException x) {
// should not happen
LangCore.logError("Unexpected error.", x);
}
return null;
}
/**
* Returns the index of the first line whose start offset is in the given text range.
*
* @param region the text range in characters where to find the line
* @param document The document
* @return the first line whose start index is in the given range, -1 if there is no such line
*/
protected static int getFirstCompleteLineOfRegion(IRegion region, IDocument document) {
try {
final int startLine= document.getLineOfOffset(region.getOffset());
int offset= document.getLineOffset(startLine);
if (offset >= region.getOffset())
return startLine;
final int nextLine= startLine + 1;
if (nextLine == document.getNumberOfLines())
return -1;
offset= document.getLineOffset(nextLine);
return (offset > region.getOffset() + region.getLength() ? -1 : nextLine);
} catch (BadLocationException x) {
// should not happen
LangCore.logError("Unexpected error.", x);
}
return -1;
}
/**
* Determines whether each line is prefixed by one of the prefixes.
*
* @param startLine Start line in document
* @param endLine End line in document
* @param prefixes Possible comment prefixes
* @param document The document
* @return <code>true</code> iff each line from <code>startLine</code>
* to and including <code>endLine</code> is prepended by one
* of the <code>prefixes</code>, ignoring whitespace at the
* begin of line
*/
protected boolean isBlockCommented(int startLine, int endLine, String[] prefixes, IDocument document) {
try {
// check for occurrences of prefixes in the given lines
for (int i= startLine; i <= endLine; i++) {
IRegion line= document.getLineInformation(i);
String text= document.get(line.getOffset(), line.getLength());
int[] found= TextUtilities.indexOf(prefixes, text, 0);
if (found[0] == -1)
// found a line which is not commented
return false;
String s= document.get(line.getOffset(), found[0]);
s= s.trim();
if (s.length() != 0)
// found a line which is not commented
return false;
}
return true;
} catch (BadLocationException x) {
// should not happen
LangCore.logError("Unexpected error.", x);
}
return false;
}
}