/*******************************************************************************
* Copyright (c) 2005, 2006 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
* Jens Lukowski/Innoopract - initial renaming/restructuring
*******************************************************************************/
package org.eclipse.jst.jsp.ui.internal.autoedit;
import org.eclipse.core.runtime.Preferences;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.ConfigurableLineTracker;
import org.eclipse.jface.text.DocumentCommand;
import org.eclipse.jface.text.IAutoEditStrategy;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ILineTracker;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.TextUtilities;
import org.eclipse.jst.jsp.ui.internal.Logger;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.texteditor.ITextEditor;
import org.eclipse.ui.texteditor.ITextEditorExtension3;
import org.eclipse.wst.html.core.internal.HTMLCorePlugin;
import org.eclipse.wst.html.core.internal.preferences.HTMLCorePreferenceNames;
/**
* AutoEditStrategy to handle characters inserted when Tab key is pressed
*/
public class AutoEditStrategyForTabs implements IAutoEditStrategy {
private final String TAB_CHARACTER = "\t"; //$NON-NLS-1$
public void customizeDocumentCommand(IDocument document, DocumentCommand command) {
// if not in smart insert mode just ignore
if (!isSmartInsertMode())
return;
// spaces for tab character
if (command.length == 0 && command.text != null && command.text.length() > 0 && command.text.indexOf(TAB_CHARACTER) != -1)
smartInsertForTab(command, document);
}
/**
* Insert spaces for tabs
*
* @param command
*/
private void smartInsertForTab(DocumentCommand command, IDocument document) {
// tab key was pressed. now check preferences to see if need to insert
// spaces instead of tab
int indentationWidth = getIndentationWidth();
if (indentationWidth > -1) {
String originalText = command.text;
StringBuffer newText = new StringBuffer(originalText);
// determine where in line this command begins
int lineOffset = -1;
try {
IRegion lineInfo = document.getLineInformationOfOffset(command.offset);
lineOffset = command.offset - lineInfo.getOffset();
} catch (BadLocationException e) {
Logger.log(Logger.WARNING_DEBUG, e.getMessage(), e);
}
ILineTracker lineTracker = getLineTracker(document, originalText);
int startIndex = 0;
int index = newText.indexOf(TAB_CHARACTER);
while (index != -1) {
String indent = getIndentString(indentationWidth, lineOffset, lineTracker, index);
// replace \t character with spaces
newText.replace(index, index + 1, indent);
if (lineTracker != null) {
try {
lineTracker.replace(index, 1, indent);
} catch (BadLocationException e) {
// if something goes wrong with replacing text, just
// reset to current string
lineTracker.set(newText.toString());
Logger.log(Logger.WARNING_DEBUG, e.getMessage(), e);
}
}
startIndex = index + indent.length();
index = newText.indexOf(TAB_CHARACTER, startIndex);
}
command.text = newText.toString();
}
}
/**
* Calculate number of spaces for next tab stop
*/
private String getIndentString(int indentationWidth, int lineOffset, ILineTracker lineTracker, int index) {
int indentSize = indentationWidth;
int offsetInLine = -1;
if (lineTracker != null) {
try {
IRegion lineInfo = lineTracker.getLineInformationOfOffset(index);
if (lineInfo.getOffset() == 0 && lineOffset > -1)
offsetInLine = lineOffset + index;
else
offsetInLine = index - lineInfo.getOffset();
} catch (BadLocationException e) {
Logger.log(Logger.WARNING_DEBUG, e.getMessage(), e);
}
} else {
if (lineOffset > -1) {
offsetInLine = lineOffset + index;
}
}
if (offsetInLine > -1 && indentationWidth > 0) {
int remainder = offsetInLine % indentationWidth;
indentSize = indentationWidth - remainder;
}
StringBuffer indent = new StringBuffer();
for (int i = 0; i < indentSize; i++)
indent.append(' ');
return indent.toString();
}
/**
* Set up a line tracker for text within command if text is multi-line
*/
private ILineTracker getLineTracker(IDocument document, String originalText) {
ConfigurableLineTracker lineTracker = null;
int[] delims = TextUtilities.indexOf(document.getLegalLineDelimiters(), originalText, 0);
if (delims[0] != -1 || delims[1] != -1) {
lineTracker = new ConfigurableLineTracker(document.getLegalLineDelimiters());
lineTracker.set(originalText);
}
return lineTracker;
}
/**
* Return true if active editor is in smart insert mode, false otherwise
*
* @return
*/
private boolean isSmartInsertMode() {
boolean isSmartInsertMode = false;
ITextEditor textEditor = null;
IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
if (window != null) {
IWorkbenchPage page = window.getActivePage();
if (page != null) {
IEditorPart editor = page.getActiveEditor();
if (editor != null) {
if (editor instanceof ITextEditor)
textEditor = (ITextEditor) editor;
else
textEditor = (ITextEditor) editor.getAdapter(ITextEditor.class);
}
}
}
// check if smart insert mode
if (textEditor instanceof ITextEditorExtension3 && ((ITextEditorExtension3) textEditor).getInsertMode() == ITextEditorExtension3.SMART_INSERT)
isSmartInsertMode = true;
return isSmartInsertMode;
}
/**
* Returns indentation width if using spaces for indentation, -1 otherwise
*
* @return
*/
private int getIndentationWidth() {
int width = -1;
Preferences preferences = HTMLCorePlugin.getDefault().getPluginPreferences();
if (HTMLCorePreferenceNames.SPACE.equals(preferences.getString(HTMLCorePreferenceNames.INDENTATION_CHAR)))
width = preferences.getInt(HTMLCorePreferenceNames.INDENTATION_SIZE);
return width;
}
}