/*=============================================================================#
# Copyright (c) 2011-2016 Stephan Wahlbrink (WalWare.de) 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:
# Stephan Wahlbrink - initial API and implementation
#=============================================================================*/
package de.walware.ecommons.ltk.ui.sourceediting.actions;
import java.util.IdentityHashMap;
import java.util.Map;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.commands.IHandler2;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.ui.IWorkbenchPart;
import de.walware.ecommons.text.core.sections.IDocContentSections;
import de.walware.ecommons.workbench.ui.WorkbenchUIUtil;
import de.walware.ecommons.ltk.ui.sourceediting.ISourceEditor;
/**
* Command handler supporting separate implementation for each document content section type.
*
* Implement {@link #createHandler(String)} for lazy initialization of the command handlers
* of the section types.
*
* @see IDocContentSections
*/
public class MultiContentSectionHandler extends AbstractHandler {
private static final Object NULL= new Object();
private final IDocContentSections sections;
private final Map<String, Object> handlers= new IdentityHashMap<>(8);
private ISourceEditor expliciteEditor;
public MultiContentSectionHandler(final IDocContentSections sections) {
if (sections == null) {
throw new NullPointerException("sections"); //$NON-NLS-1$
}
this.sections= sections;
}
public MultiContentSectionHandler(final IDocContentSections sections,
final String sectionType1, final IHandler2 handler1) {
this(sections, sectionType1, handler1, null, null);
}
public MultiContentSectionHandler(final IDocContentSections sections,
final String sectionType1, final IHandler2 handler1,
final String sectionType2, final IHandler2 handler2) {
this(sections);
if (sectionType1 != null) {
registerHandler(sectionType1, handler1);
}
if (sectionType2 != null) {
registerHandler(sectionType2, handler2);
}
}
protected void setEditor(final ISourceEditor editor) {
this.expliciteEditor= editor;
}
protected final IDocContentSections getSections() {
return this.sections;
}
@Override
public void dispose() {
super.dispose();
for (final Object handler : this.handlers.values()) {
if (handler != NULL) {
((IHandler2) handler).dispose();
}
}
this.handlers.clear();
}
protected ISourceEditor getEditor(final Object applicationContext) {
if (this.expliciteEditor != null) {
return this.expliciteEditor;
}
final IWorkbenchPart activePart= WorkbenchUIUtil.getActivePart(applicationContext);
if (activePart instanceof ISourceEditor) {
return (ISourceEditor) activePart;
}
return (ISourceEditor) activePart.getAdapter(ISourceEditor.class);
}
public void registerHandler(final String sectionType, final IHandler2 handler) {
if (sectionType == null) {
throw new NullPointerException("sectionType");
}
this.handlers.put(sectionType, handler);
}
protected final IHandler2 getHandler(final String sectionType) {
if (sectionType == IDocContentSections.ERROR) {
return null;
}
Object handler= this.handlers.get(sectionType);
if (handler == null) {
handler= NULL;
try {
final IHandler2 newHandler= createHandler(sectionType);
if (newHandler != null) {
handler= newHandler;
}
}
finally {
this.handlers.put(sectionType, handler);
}
}
return (handler != NULL) ? (IHandler2) handler : null;
}
protected IHandler2 createHandler(final String sectionType) {
return null;
}
@Override
public Object execute(final ExecutionEvent event) throws ExecutionException {
final ISourceEditor editor= getEditor(event.getApplicationContext());
if (editor == null) {
return null;
}
final SourceViewer viewer= editor.getViewer();
if (viewer == null) {
return null;
}
final IHandler2 handler= getHandler(
this.sections.getType(viewer.getDocument(), viewer.getSelectedRange().x) );
if (handler != null) {
return handler.execute(event);
}
return null;
}
}