/*******************************************************************************
* Copyright (c) 2000, 2008 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 org.eclipse.ui.contentassist;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Text;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.commands.IHandler;
import org.eclipse.jface.bindings.TriggerSequence;
import org.eclipse.jface.contentassist.AbstractControlContentAssistSubjectAdapter;
import org.eclipse.jface.contentassist.ComboContentAssistSubjectAdapter;
import org.eclipse.jface.contentassist.SubjectControlContentAssistant;
import org.eclipse.jface.contentassist.TextContentAssistSubjectAdapter;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.handlers.IHandlerActivation;
import org.eclipse.ui.handlers.IHandlerService;
import org.eclipse.ui.internal.texteditor.NLSUtility;
import org.eclipse.ui.keys.IBindingService;
import org.eclipse.ui.texteditor.ITextEditorActionDefinitionIds;
/**
* A content assistant handler which handles the key binding and
* the cue for a {@link org.eclipse.jface.text.contentassist.ContentAssistant}
* and its subject adapter.
*
* @since 3.0
* @deprecated As of 3.2, replaced by JFace field assist support
*/
public class ContentAssistHandler {
/**
* The target control.
*/
private Control fControl;
/**
* The content assist subject adapter.
*/
private AbstractControlContentAssistSubjectAdapter fContentAssistSubjectAdapter;
/**
* The content assistant.
*/
private SubjectControlContentAssistant fContentAssistant;
/**
* The currently installed FocusListener, or <code>null</code> iff none installed.
* This is also used as flag to tell whether content assist is enabled
*/
private FocusListener fFocusListener;
/**
* The currently installed IHandlerActivation, or <code>null</code> iff none installed.
*/
private IHandlerActivation fHandlerActivation;
/**
* Creates a new {@link ContentAssistHandler} for the given {@link Combo}.
* Only a single {@link ContentAssistHandler} may be installed on a {@link Combo} instance.
* Content Assist is enabled by default.
*
* @param combo target combo
* @param contentAssistant a configured content assistant
* @return a new {@link ContentAssistHandler}
*/
public static ContentAssistHandler createHandlerForCombo(Combo combo, SubjectControlContentAssistant contentAssistant) {
return new ContentAssistHandler(combo, new ComboContentAssistSubjectAdapter(combo), contentAssistant);
}
/**
* Creates a new {@link ContentAssistHandler} for the given {@link Text}.
* Only a single {@link ContentAssistHandler} may be installed on a {@link Text} instance.
* Content Assist is enabled by default.
*
* @param text target text
* @param contentAssistant a configured content assistant
* @return a new {@link ContentAssistHandler}
*/
public static ContentAssistHandler createHandlerForText(Text text, SubjectControlContentAssistant contentAssistant) {
return new ContentAssistHandler(text, new TextContentAssistSubjectAdapter(text), contentAssistant);
}
/**
* Internal constructor.
*
* @param control target control
* @param subjectAdapter content assist subject adapter
* @param contentAssistant content assistant
*/
private ContentAssistHandler(
Control control,
AbstractControlContentAssistSubjectAdapter subjectAdapter,
SubjectControlContentAssistant contentAssistant) {
fControl= control;
fContentAssistant= contentAssistant;
fContentAssistSubjectAdapter= subjectAdapter;
setEnabled(true);
fControl.addDisposeListener(new DisposeListener() {
public void widgetDisposed(DisposeEvent e) {
setEnabled(false);
}
});
}
/**
* @return <code>true</code> iff content assist is enabled
*/
public boolean isEnabled() {
return fFocusListener != null;
}
/**
* Controls enablement of content assist.
* When enabled, a cue is shown next to the focused field
* and the affordance hover shows the shortcut.
*
* @param enable enable content assist iff true
*/
public void setEnabled(boolean enable) {
if (enable == isEnabled())
return;
if (enable)
enable();
else
disable();
}
/**
* Enable content assist.
*/
private void enable() {
if (! fControl.isDisposed()) {
fContentAssistant.install(fContentAssistSubjectAdapter);
installCueLabelProvider();
installFocusListener();
if (fControl.isFocusControl())
activateHandler();
}
}
/**
* Disable content assist.
*/
private void disable() {
if (! fControl.isDisposed()) {
fContentAssistant.uninstall();
fContentAssistSubjectAdapter.setContentAssistCueProvider(null);
fControl.removeFocusListener(fFocusListener);
fFocusListener= null;
if (fHandlerActivation != null)
deactivateHandler();
}
}
/**
* Create and install the {@link LabelProvider} for fContentAssistSubjectAdapter.
*/
private void installCueLabelProvider() {
ILabelProvider labelProvider= new LabelProvider() {
/*
* @see org.eclipse.jface.viewers.ILabelProvider#getText(java.lang.Object)
*/
public String getText(Object element) {
IBindingService bindingService= (IBindingService) PlatformUI.getWorkbench().getAdapter(IBindingService.class);
TriggerSequence[] activeBindings= bindingService.getActiveBindingsFor(ITextEditorActionDefinitionIds.CONTENT_ASSIST_PROPOSALS);
if (activeBindings.length == 0)
return ContentAssistMessages.ContentAssistHandler_contentAssistAvailable;
return NLSUtility.format(ContentAssistMessages.ContentAssistHandler_contentAssistAvailableWithKeyBinding, activeBindings[0].format());
}
};
fContentAssistSubjectAdapter.setContentAssistCueProvider(labelProvider);
}
/**
* Create fFocusListener and install it on fControl.
*/
private void installFocusListener() {
fFocusListener= new FocusListener() {
public void focusGained(final FocusEvent e) {
if (fHandlerActivation == null)
activateHandler();
}
public void focusLost(FocusEvent e) {
if (fHandlerActivation != null)
deactivateHandler();
}
};
fControl.addFocusListener(fFocusListener);
}
/**
* Create and register fHandlerSubmission.
*/
private void activateHandler() {
IHandlerService handlerService= (IHandlerService)PlatformUI.getWorkbench().getAdapter(IHandlerService.class);
if (handlerService == null)
return;
IHandler handler= new AbstractHandler() {
public Object execute(ExecutionEvent event) throws ExecutionException {
if (ContentAssistHandler.this.isEnabled()) // don't call AbstractHandler#isEnabled()!
fContentAssistant.showPossibleCompletions();
return null;
}
};
fHandlerActivation= handlerService.activateHandler(ITextEditorActionDefinitionIds.CONTENT_ASSIST_PROPOSALS, handler);
}
/**
* Unregister the {@link IHandlerActivation} from the shell.
*/
private void deactivateHandler() {
IHandlerService handlerService= (IHandlerService)PlatformUI.getWorkbench().getAdapter(IHandlerService.class);
if (handlerService != null)
handlerService.deactivateHandler(fHandlerActivation);
fHandlerActivation= null;
}
}