1 files changed, 313 insertions, 0 deletions
diff --git a/systemtap/org.eclipse.linuxtools.systemtap.ui.ide/src/org/eclipse/linuxtools/internal/systemtap/ui/ide/actions/ToggleCommentHandler.java b/systemtap/org.eclipse.linuxtools.systemtap.ui.ide/src/org/eclipse/linuxtools/internal/systemtap/ui/ide/actions/ToggleCommentHandler.java
new file mode 100644
index 0000000000..395a5b4f6b
--- /dev/null
+++ b/systemtap/org.eclipse.linuxtools.systemtap.ui.ide/src/org/eclipse/linuxtools/internal/systemtap/ui/ide/actions/ToggleCommentHandler.java
@@ -0,0 +1,313 @@
+/*******************************************************************************
+ * Copyright (c) 2013 Red Hat Inc.
+ * 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:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.linuxtools.internal.systemtap.ui.ide.actions;
+
+import org.eclipse.core.commands.AbstractHandler;
+import org.eclipse.core.commands.ExecutionEvent;
+import org.eclipse.jface.dialogs.MessageDialog;
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IDocumentExtension3;
+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.TextViewer;
+import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.linuxtools.internal.systemtap.ui.ide.Localization;
+import org.eclipse.linuxtools.systemtap.graphingapi.ui.widgets.ExceptionErrorDialog;
+import org.eclipse.swt.custom.BusyIndicator;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.ui.handlers.HandlerUtil;
+import org.eclipse.ui.texteditor.ITextEditor;
+
+/**
+ * Handler for command in charge of toggling comment prefixes. Based on
+ * org.eclipse.cdt.internal.ui.actions.ToggleCommentAction.
+ */
+public class ToggleCommentHandler extends AbstractHandler {
+
+	/** The text operation target */
+	private ITextOperationTarget operationTarget;
+
+	/**
+	 * Checks if the selected lines are all commented or not and
+	 * uncomments/comments them respectively.
+	 */
+	@Override
+	public Object execute(ExecutionEvent event) {
+		ITextEditor editor = (ITextEditor) HandlerUtil.getActiveEditor(event);
+		if (editor == null || !editor.isEditable()) {
+			return null;
+		}
+
+		updateOpTarget(editor);
+		if (operationTarget == null) {
+			return null;
+		}
+
+		ISelection selection = editor.getSelectionProvider().getSelection();
+		IDocument document = editor.getDocumentProvider().getDocument(
+				editor.getEditorInput());
+
+		final int operationCode;
+		if (isSelectionCommented(selection, document)) {
+			operationCode = ITextOperationTarget.STRIP_PREFIX;
+		} else {
+			operationCode = ITextOperationTarget.PREFIX;
+		}
+
+		Shell shell = editor.getSite().getShell();
+		if (!operationTarget.canDoOperation(operationCode)) {
+			if (shell != null) {
+				MessageDialog.openError(shell,
+						Localization.getString("ToggleComment_error_title"), //$NON-NLS-1$
+						Localization.getString("ToggleComment_error_message")); //$NON-NLS-1$
+			}
+			return null;
+		}
+
+		Display display = null;
+		if (shell != null && !shell.isDisposed())
+			display = shell.getDisplay();
+
+		BusyIndicator.showWhile(display, new Runnable() {
+			@Override
+			public void run() {
+				operationTarget.doOperation(operationCode);
+			}
+		});
+
+		return null;
+	}
+
+	/**
+	 * Creates a region describing the text block (something that starts at the
+	 * beginning of a line) completely containing the current selection.
+	 *
+	 * Note, the implementation has to match {@link TextViewer}
+	 * .getTextBlockFromSelection().
+	 *
+	 * @param selection The selection to use
+	 * @param document The document
+	 * @return the region describing the text block comprising the given
+	 *         selection
+	 * @throws BadLocationException
+	 */
+	public IRegion getTextBlockFromSelection(ITextSelection selection,
+			IDocument document) throws BadLocationException {
+		int start = document.getLineOffset(selection.getStartLine());
+		int end;
+		int endLine = selection.getEndLine();
+		if (document.getNumberOfLines() > endLine + 1) {
+			end = document.getLineOffset(endLine + 1);
+		} else {
+			end = document.getLength();
+		}
+		return new Region(start, end - start);
+	}
+
+	/**
+	 * Is the given selection on the specified document single-line commented?
+	 *
+	 * @param selection Selection to check
+	 * @param document The document
+	 * @return <code>true</code> iff all selected lines are commented
+	 */
+	public boolean isSelectionCommented(ISelection selection,
+			IDocument document) {
+
+		if (!(selection instanceof ITextSelection)) {
+			return false;
+		}
+
+		ITextSelection textSelection = (ITextSelection) selection;
+		if (textSelection.getStartLine() < 0 || textSelection.getEndLine() < 0) {
+			return false;
+		}
+
+		try {
+			IRegion block = getTextBlockFromSelection(textSelection, document);
+			ITypedRegion[] regions = TextUtilities.computePartitioning(
+					document, IDocumentExtension3.DEFAULT_PARTITIONING,
+					block.getOffset(), block.getLength(), false);
+
+			int[] lines = new int[regions.length * 2]; // [startline, endline,
+														// startline, endline,
+														// ...]
+
+			// For each partition in the text selection, figure out the
+			// startline and endline.
+			// Count the number of lines that are selected.
+			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--;
+				}
+
+				// If there is no startline for this region (startline = -1),
+				// then there is no endline,
+				// otherwise, get the line number of the endline and store it in
+				// the array.
+				lines[j + 1] = (lines[j] == -1 ? -1 : document
+						.getLineOfOffset(offset));
+
+				// We could count the number of lines that are selected in this
+				// region
+				// lineCount += lines[j + 1] - lines[j] + 1;
+
+				assert i < regions.length;
+				assert j < regions.length * 2;
+			}
+
+			// Perform the check
+			boolean hasComment = false;
+			for (int i = 0, j = 0; i < regions.length; i++, j += 2) {
+				String prefix = "//"; //$NON-NLS-1$
+				if (lines[j] >= 0 && lines[j + 1] >= 0) {
+					if (isBlockCommented(lines[j], lines[j + 1], prefix,
+							document)) {
+						hasComment = true;
+					} else if (!isBlockEmpty(lines[j], lines[j + 1], document)) {
+						return false;
+					}
+				}
+			}
+			return hasComment;
+		} catch (BadLocationException e) {
+			ExceptionErrorDialog.openError(e.getLocalizedMessage(), e);
+		}
+
+		return false;
+	}
+
+	/**
+	 * 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
+	 */
+	public int getFirstCompleteLineOfRegion(IRegion region, IDocument document) {
+		try {
+			int startLine = document.getLineOfOffset(region.getOffset());
+
+			int offset = document.getLineOffset(startLine);
+			if (offset >= region.getOffset()) {
+				return startLine;
+			}
+
+			offset = document.getLineOffset(startLine + 1);
+			return (offset > region.getOffset() + region.getLength() ? -1
+				: startLine + 1);
+		} catch (BadLocationException e) {
+			ExceptionErrorDialog.openError(e.getLocalizedMessage(), e);
+		}
+
+		return -1;
+	}
+
+	/**
+	 * Determines whether each line is empty
+	 *
+	 * @param startLine Start line in document
+	 * @param endLine End line in document
+	 * @param document The document
+	 * @return <code>true</code> if each line from <code>startLine</code> to and
+	 *         including <code>endLine</code> is empty
+	 */
+	public boolean isBlockEmpty(int startLine, int endLine, IDocument document) {
+		try {
+			for (int i = startLine; i <= endLine; i++) {
+				IRegion line = document.getLineInformation(i);
+				String text = document.get(line.getOffset(), line.getLength());
+
+				boolean isEmptyLine = text.trim().length() == 0;
+				if (!isEmptyLine) {
+					return false;
+				}
+			}
+			return true;
+		} catch (BadLocationException e) {
+			ExceptionErrorDialog.openError(e.getLocalizedMessage(), e);
+		}
+
+		return false;
+	}
+
+	/**
+	 * Determines whether each line is prefixed by one of the prefixes.
+	 *
+	 * @param startLine Start line in document
+	 * @param endLine End line in document
+	 * @param prefix Comment prefix
+	 * @param document The document
+	 * @return <code>true</code> iff each line from <code>startLine</code> to
+	 *         and including <code>endLine</code> is prepended by the
+	 *         <code>prefix</code>, ignoring whitespace at the begin of line
+	 */
+	public boolean isBlockCommented(int startLine, int endLine, String prefix,
+			IDocument document) {
+		try {
+			// Check for occurrences of prefixes in the given lines
+			boolean hasComment = false;
+			for (int i = startLine; i <= endLine; i++) {
+				IRegion line = document.getLineInformation(i);
+				String text = document.get(line.getOffset(), line.getLength());
+
+				boolean isEmptyLine = text.trim().length() == 0;
+				if (isEmptyLine) {
+					continue;
+				}
+
+				int prefixIndex = text.indexOf(prefix, 0);
+
+				if (prefixIndex == -1) {
+					// Found a line which is not commented
+					return false;
+				}
+				String s = document.get(line.getOffset(), prefixIndex);
+				s = s.trim();
+				if (s.length() != 0) {
+					// Found a line which is not commented
+					return false;
+				}
+				hasComment = true;
+			}
+			return hasComment;
+		} catch (BadLocationException e) {
+			ExceptionErrorDialog.openError(e.getLocalizedMessage(), e);
+		}
+
+		return false;
+	}
+
+	/**
+	 * Update text operation target based on the specified text editor.
+	 *
+	 * @param editor ITextEditor editor to associate operation target to.
+	 */
+	public void updateOpTarget(ITextEditor editor) {
+		if (editor != null) {
+			operationTarget = (ITextOperationTarget) editor
+					.getAdapter(ITextOperationTarget.class);
+		}
+	}
+}