--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package net.sourceforge.phpdt.internal.ui.text;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+import org.eclipse.text.edits.MalformedTreeException;
+import org.eclipse.text.edits.TextEdit;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.custom.VerifyKeyListener;
+import org.eclipse.swt.events.VerifyEvent;
+import org.eclipse.swt.graphics.Point;
+
+import org.eclipse.jface.text.Assert;
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.ITextViewerExtension;
+import org.eclipse.jface.text.TextViewer;
+
+import net.sourceforge.phpdt.internal.ui.text.TypingRun.ChangeType;
+
+
+
+/**
+ * Installs as a verify key listener on a viewer and overwrites the behaviour
+ * of the backspace key. Clients may register undo specifications for certain
+ * offsets in a document. The <code>SmartBackspaceManager</code> will manage the
+ * specfications and execute the contained <code>TextEdit</code>s when backspace
+ * is pressed at the given offset and the specification is still valid.
+ * <p>
+ * Undo specifications are removed after a number of typing runs.
+ * </p>
+ *
+ * @since 3.0
+ */
+public class SmartBackspaceManager {
+ /* independent of JDT - may be moved to jface.text */
+
+ /**
+ * An undo specification describes the change that should be executed if
+ * backspace is pressed at its trigger offset.
+ *
+ * @since 3.0
+ */
+ public static final class UndoSpec {
+ private final int triggerOffset;
+ private final IRegion selection;
+ private final TextEdit[] undoEdits;
+ private final UndoSpec child;
+ int lives;
+
+ /**
+ * Creates a new spec. A specification consists of a number of
+ * <code>TextEdit</code> s that will be executed when backspace is
+ * pressed at <code>triggerOffset</code>. The spec will be removed
+ * when it is executed, or if more than <code>lives</code>
+ * <code>TypingRun</code>s have ended after registering the spec.
+ * <p>
+ * Optionally, a child specification can be registered. After executing
+ * the spec, the child spec will be registered with the manager. This allows
+ * to create chains of <code>UndoSpec</code>s that will be executed upon
+ * repeated pressing of backspace.
+ * </p>
+ *
+ * @param triggerOffset the offset where this spec is active
+ * @param selection the selection after executing the undo spec
+ * @param edits the <code>TextEdit</code> s to perform when executing
+ * the spec
+ * @param lives the number of <code>TypingRun</code> s before removing
+ * the spec
+ * @param child a child specification that will be registered after
+ * executing this spec, or <code>null</code>
+ */
+ public UndoSpec(int triggerOffset, IRegion selection, TextEdit[] edits, int lives, UndoSpec child) {
+ Assert.isLegal(triggerOffset >= 0);
+ Assert.isLegal(selection != null);
+ Assert.isLegal(lives >= 0);
+ Assert.isLegal(edits != null);
+ Assert.isLegal(edits.length > 0);
+ for (int i= 0; i < edits.length; i++) {
+ Assert.isLegal(edits[i] != null);
+ }
+
+ this.triggerOffset= triggerOffset;
+ this.selection= selection;
+ this.undoEdits= edits;
+ this.lives= lives;
+ this.child= child;
+ }
+ }
+
+
+ private class BackspaceListener implements VerifyKeyListener {
+
+ /*
+ * @see org.eclipse.swt.custom.VerifyKeyListener#verifyKey(org.eclipse.swt.events.VerifyEvent)
+ */
+ public void verifyKey(VerifyEvent event) {
+ if (fViewer != null && isBackspace(event)) {
+ int offset= getCaretOffset();
+ UndoSpec spec= removeEdit(offset);
+ if (spec != null) {
+ try {
+ beginChange();
+ for (int i= 0; i < spec.undoEdits.length; i++) {
+ spec.undoEdits[i].apply(getDocument(), TextEdit.UPDATE_REGIONS);
+ }
+ fViewer.setSelectedRange(spec.selection.getOffset(), spec.selection.getLength());
+ if (spec.child != null)
+ register(spec.child);
+ } catch (MalformedTreeException e) {
+ // fall back to standard bs
+ return;
+ } catch (BadLocationException e) {
+ // fall back to standard bs
+ return;
+ } finally {
+ endChange();
+ }
+ event.doit= false;
+ }
+
+ }
+ }
+
+ private void beginChange() {
+ ITextViewer viewer= fViewer;
+ if (viewer instanceof TextViewer) {
+ TextViewer v= (TextViewer) viewer;
+ v.getRewriteTarget().beginCompoundChange();
+ v.setRedraw(false);
+ }
+ }
+
+ private void endChange() {
+ ITextViewer viewer= fViewer;
+ if (viewer instanceof TextViewer) {
+ TextViewer v= (TextViewer) viewer;
+ v.getRewriteTarget().endCompoundChange();
+ v.setRedraw(true);
+ }
+ }
+
+ private boolean isBackspace(VerifyEvent event) {
+ return event.doit == true && event.character == SWT.BS && event.stateMask == 0;
+ }
+
+ private int getCaretOffset() {
+ ITextViewer viewer= fViewer;
+ Point point= viewer.getSelectedRange();
+ return point.x;
+ }
+
+ }
+
+ private ITextViewer fViewer;
+ private BackspaceListener fBackspaceListener;
+ private Map fSpecs;
+ private TypingRunDetector fRunDetector;
+ private ITypingRunListener fRunListener;
+
+ /**
+ * Registers an undo specification with this manager.
+ *
+ * @param spec the specification to register
+ * @throws IllegalStateException if the manager is not installed
+ */
+ public void register(UndoSpec spec) {
+ if (fViewer == null)
+ throw new IllegalStateException();
+
+ ensureListenerInstalled();
+ addEdit(spec);
+ }
+
+ private void addEdit(UndoSpec spec) {
+ Integer i= new Integer(spec.triggerOffset);
+ fSpecs.put(i, spec);
+ }
+
+ private UndoSpec removeEdit(int offset) {
+ Integer i= new Integer(offset);
+ UndoSpec spec= (UndoSpec) fSpecs.remove(i);
+ return spec;
+ }
+
+ private void ensureListenerInstalled() {
+ if (fBackspaceListener == null) {
+ fBackspaceListener= new BackspaceListener();
+ ITextViewer viewer= fViewer;
+ if (viewer instanceof ITextViewerExtension)
+ ((ITextViewerExtension) viewer).prependVerifyKeyListener(fBackspaceListener);
+ else
+ viewer.getTextWidget().addVerifyKeyListener(fBackspaceListener);
+ }
+ }
+
+ private void ensureListenerRemoved() {
+ if (fBackspaceListener != null) {
+ ITextViewer viewer= fViewer;
+ if (viewer instanceof ITextViewerExtension)
+ ((ITextViewerExtension) viewer).removeVerifyKeyListener(fBackspaceListener);
+ else
+ viewer.getTextWidget().removeVerifyKeyListener(fBackspaceListener);
+ fBackspaceListener= null;
+ }
+ }
+
+ private IDocument getDocument() {
+ return fViewer.getDocument();
+ }
+
+ /**
+ * Installs the receiver on a text viewer.
+ *
+ * @param viewer
+ */
+ public void install(ITextViewer viewer) {
+ Assert.isLegal(viewer != null);
+
+ fViewer= viewer;
+ fSpecs= new HashMap();
+ fRunDetector= new TypingRunDetector();
+ fRunDetector.install(viewer);
+ fRunListener= new ITypingRunListener() {
+
+ /*
+ * @see org.eclipse.jface.text.TypingRunDetector.ITypingRunListener#typingRunStarted(org.eclipse.jface.text.TypingRunDetector.TypingRun)
+ */
+ public void typingRunStarted(TypingRun run) {
+ }
+
+ /*
+ * @see org.eclipse.jface.text.TypingRunDetector.ITypingRunListener#typingRunEnded(org.eclipse.jface.text.TypingRunDetector.TypingRun)
+ */
+ public void typingRunEnded(TypingRun run, ChangeType reason) {
+ if (reason == TypingRun.SELECTION)
+ fSpecs.clear();
+ else
+ prune();
+ }
+ };
+ fRunDetector.addTypingRunListener(fRunListener);
+ }
+
+ private void prune() {
+ for (Iterator it= fSpecs.values().iterator(); it.hasNext();) {
+ UndoSpec spec= (UndoSpec) it.next();
+ if (--spec.lives < 0)
+ it.remove();
+ }
+ }
+
+ /**
+ * Uninstalls the receiver. No undo specifications may be registered on an
+ * uninstalled manager.
+ */
+ public void uninstall() {
+ if (fViewer != null) {
+ fRunDetector.removeTypingRunListener(fRunListener);
+ fRunDetector.uninstall();
+ fRunDetector= null;
+ ensureListenerRemoved();
+ fViewer= null;
+ }
+ }
+}
git://secure.phpeclipse.com / phpeclipse.git / blobdiff