/*******************************************************************************
* Copyright (c) 2006, 2007 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.fieldassist;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.IHandler;
import org.eclipse.jface.fieldassist.ContentProposalAdapter;
import org.eclipse.jface.fieldassist.ControlDecoration;
import org.eclipse.jface.fieldassist.FieldDecoration;
import org.eclipse.jface.fieldassist.FieldDecorationRegistry;
import org.eclipse.jface.fieldassist.IContentProposalProvider;
import org.eclipse.jface.fieldassist.IControlContentAdapter;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
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.Control;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.handlers.IHandlerActivation;
import org.eclipse.ui.handlers.IHandlerService;
import org.eclipse.ui.internal.WorkbenchMessages;
import org.eclipse.ui.keys.IBindingService;
/**
* ContentAssistCommandAdapter extends {@link ContentProposalAdapter} to invoke
* content proposals using a specified {@link org.eclipse.ui.commands.ICommand}.
* The ability to specify a {@link org.eclipse.jface.bindings.keys.KeyStroke}
* that explicitly invokes content proposals is hidden by this class, and
* instead the String id of a command is used. If no command id is specified by
* the client, then the default workbench content assist command is used.
* <p>
* As of 3.3, ContentAssistCommandAdapter can be optionally configured to
* install the content assist decoration on its control.
* <p>
* This class is not intended to be subclassed.
*
* @since 3.2
*/
public class ContentAssistCommandAdapter extends ContentProposalAdapter {
private static final String CONTENT_ASSIST_DECORATION_ID = "org.eclipse.ui.fieldAssist.ContentAssistField"; //$NON-NLS-1$
private String commandId;
/**
* The command id used for content assist. (value
* <code>"org.eclipse.ui.edit.text.contentAssist.proposals"</code>)
*/
public static final String CONTENT_PROPOSAL_COMMAND = "org.eclipse.ui.edit.text.contentAssist.proposals"; //$NON-NLS-1$
// Default autoactivation delay in milliseconds
// TODO: This should eventually be controlled by
// a platform UI preference.
private static final int DEFAULT_AUTO_ACTIVATION_DELAY = 500;
private IHandlerService handlerService;
private IHandlerActivation activeHandler;
private IHandler proposalHandler = new AbstractHandler() {
public Object execute(ExecutionEvent event) {
openProposalPopup();
return null;
}
};
private ControlDecoration decoration;
/**
* Construct a content proposal adapter that can assist the user with
* choosing content for the field. No visual indicator of content assist is
* shown.
*
* @param control
* the control for which the adapter is providing content assist.
* May not be <code>null</code>.
* @param controlContentAdapter
* the <code>IControlContentAdapter</code> used to obtain and
* update the control's contents as proposals are accepted. May
* not be <code>null</code>.
* @param proposalProvider
* the <code>IContentProposalProvider</code> used to obtain
* content proposals for this control, or <code>null</code> if
* no content proposal is available.
* @param commandId
* the String id of the command that will invoke the content
* assistant. If not supplied, the default value will be
* "org.eclipse.ui.edit.text.contentAssist.proposals".
* @param autoActivationCharacters
* An array of characters that trigger auto-activation of content
* proposal. If specified, these characters will trigger
* auto-activation of the proposal popup, regardless of the
* specified command id.
*/
public ContentAssistCommandAdapter(Control control,
IControlContentAdapter controlContentAdapter,
IContentProposalProvider proposalProvider, String commandId,
char[] autoActivationCharacters) {
this(control, controlContentAdapter, proposalProvider, commandId,
autoActivationCharacters, false);
}
/**
* Construct a content proposal adapter that can assist the user with
* choosing content for the field.
*
* @param control
* the control for which the adapter is providing content assist.
* May not be <code>null</code>.
* @param controlContentAdapter
* the <code>IControlContentAdapter</code> used to obtain and
* update the control's contents as proposals are accepted. May
* not be <code>null</code>.
* @param proposalProvider
* the <code>IContentProposalProvider</code> used to obtain
* content proposals for this control, or <code>null</code> if
* no content proposal is available.
* @param commandId
* the String id of the command that will invoke the content
* assistant. If not supplied, the default value will be
* "org.eclipse.ui.edit.text.contentAssist.proposals".
* @param autoActivationCharacters
* An array of characters that trigger auto-activation of content
* proposal. If specified, these characters will trigger
* auto-activation of the proposal popup, regardless of the
* specified command id.
* @param installDecoration
* A boolean that specifies whether a content assist control
* decoration should be installed. The client is responsible for
* ensuring that adequate space is reserved for the decoration.
* Clients that want more fine-grained control of the
* decoration's location or appearance should use
* <code>false</code> for this parameter, creating their own
* {@link ControlDecoration} and managing it directly.
* @since 3.3
*/
public ContentAssistCommandAdapter(Control control,
IControlContentAdapter controlContentAdapter,
IContentProposalProvider proposalProvider, String commandId,
char[] autoActivationCharacters, boolean installDecoration) {
super(control, controlContentAdapter, proposalProvider, null,
autoActivationCharacters);
this.commandId = commandId;
if (commandId == null) {
this.commandId = CONTENT_PROPOSAL_COMMAND;
}
// If no autoactivation characters were specified, set them to the empty
// array so that we don't get the alphanumeric auto-trigger of our
// superclass.
if (autoActivationCharacters == null) {
this.setAutoActivationCharacters(new char[] {});
}
// Set a default autoactivation delay.
setAutoActivationDelay(DEFAULT_AUTO_ACTIVATION_DELAY);
// Add listeners to the control to manage activation of the handler
addListeners(control);
// Cache the handler service so we don't have to retrieve it each time
this.handlerService = (IHandlerService) PlatformUI.getWorkbench()
.getService(IHandlerService.class);
if (installDecoration) {
// Note top left is used for compatibility with 3.2, although
// this may change to center alignment in the future.
decoration = new ControlDecoration(control, SWT.TOP | SWT.LEFT);
decoration.setShowOnlyOnFocus(true);
FieldDecoration dec = getContentAssistFieldDecoration();
decoration.setImage(dec.getImage());
decoration.setDescriptionText(dec.getDescription());
}
}
/*
* Add the listeners needed in order to activate the content assist command
* on the control.
*/
private void addListeners(Control control) {
control.addFocusListener(new FocusListener() {
public void focusLost(FocusEvent e) {
if (activeHandler != null) {
handlerService.deactivateHandler(activeHandler);
activeHandler = null;
}
}
public void focusGained(FocusEvent e) {
if (isEnabled()) {
if (activeHandler == null) {
activeHandler = handlerService.activateHandler(
commandId, proposalHandler);
}
} else {
if (activeHandler != null) {
handlerService.deactivateHandler(activeHandler);
}
activeHandler = null;
}
}
});
control.addDisposeListener(new DisposeListener() {
public void widgetDisposed(DisposeEvent e) {
if (activeHandler != null) {
handlerService.deactivateHandler(activeHandler);
activeHandler = null;
}
}
});
}
/**
* Return the string command ID of the command used to invoke content
* assist.
*
* @return the command ID of the command that invokes content assist.
*/
public String getCommandId() {
return commandId;
}
/*
* Return the field decoration that should be used to indicate that content
* assist is available for a field. Ensure that the decoration text includes
* the correct key binding.
*
* @return the {@link FieldDecoration} that should be used to show content
* assist.
*
* @since 3.3
*/
private FieldDecoration getContentAssistFieldDecoration() {
FieldDecorationRegistry registry = FieldDecorationRegistry.getDefault();
// Look for a decoration installed for this particular command id.
String decId = CONTENT_ASSIST_DECORATION_ID + getCommandId();
FieldDecoration dec = registry.getFieldDecoration(decId);
// If there is not one, base ours on the standard JFace one.
if (dec == null) {
FieldDecoration originalDec = registry
.getFieldDecoration(FieldDecorationRegistry.DEC_CONTENT_PROPOSAL);
registry.registerFieldDecoration(decId, null, originalDec
.getImage());
dec = registry.getFieldDecoration(decId);
}
// Always update the decoration text since the key binding may
// have changed since it was last retrieved.
IBindingService bindingService = (IBindingService) PlatformUI
.getWorkbench().getService(IBindingService.class);
dec
.setDescription(NLS
.bind(
WorkbenchMessages.ContentAssist_Cue_Description_Key,
bindingService
.getBestActiveBindingFormattedFor(getCommandId())));
// Now return the field decoration
return dec;
}
/*
* (non-Javadoc)
*
* Overridden to hide and show the content assist decoration
*
* @see org.eclipse.jface.fieldassist.ContentProposalAdapter#setEnabled(boolean)
* @since 3.3
*/
public void setEnabled(boolean enabled) {
super.setEnabled(enabled);
if (decoration == null) {
return;
}
if (enabled) {
decoration.show();
} else {
decoration.hide();
}
}
}