org.eclipse.rap.rwt.widgets.DropDown Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2013, 2018 EclipseSource 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:
* EclipseSource - initial API and implementation
******************************************************************************/
package org.eclipse.rap.rwt.widgets;
import static org.eclipse.rap.rwt.internal.lifecycle.WidgetLCAUtil.getStyles;
import static org.eclipse.rap.rwt.internal.protocol.JsonUtil.createJsonArray;
import java.util.ArrayList;
import java.util.Arrays;
import org.eclipse.rap.json.JsonObject;
import org.eclipse.rap.json.JsonValue;
import org.eclipse.rap.rwt.RWT;
import org.eclipse.rap.rwt.internal.lifecycle.RemoteAdapter;
import org.eclipse.rap.rwt.internal.lifecycle.WidgetDataUtil;
import org.eclipse.rap.rwt.internal.protocol.JsonUtil;
import org.eclipse.rap.rwt.internal.scripting.ClientListenerUtil;
import org.eclipse.rap.rwt.remote.AbstractOperationHandler;
import org.eclipse.rap.rwt.remote.RemoteObject;
import org.eclipse.rap.rwt.scripting.ClientListener;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.internal.events.EventLCAUtil;
import org.eclipse.swt.internal.widgets.WidgetRemoteAdapter;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.Widget;
/**
* Instances of this class represent a list of items that are attached to a control (parent).
* If made visible (setVisibility(true)), the list
* appears attached to the control. The user can select an item from the list
* using the arrows keys and Enter, or the mouse.
*
* The list disappears automatically if the control looses focus, if an item is clicked,
* or if the escape key is pressed.
*
* This class supports the {@link RWT#MARKUP_ENABLED} property the same way Table and Tree do.
*
*
*
* - Events:
* - DefaultSelection, Selection
*
*
*
* IMPORTANT: This class is not intended to be subclassed.
*
* @since 2.3
*
*/
@SuppressWarnings( "deprecation" )
public class DropDown extends Widget {
private static final String COLUMNS = "columns";
private static final String REMOTE_TYPE = "rwt.widgets.DropDown";
private static final String SELECTION = "Selection";
private static final String DEFAULT_SELECTION = "DefaultSelection";
private static final String[] ALLOWED_STYLES = {
"V_SCROLL", "H_SCROLL"
};
private final java.util.List items;
private RemoteObject remoteObject;
private Object widgetAdapter;
private final Control parent;
private final Listener disposeListener;
private boolean visibility = false;
private int selectionIndex = -1;
private int visibleItemCount = 5;
/**
* Constructs a new instance of this class given its parent
* and a style value describing its behavior.
*
* @param parent a control, usually Text,
* which will be the parent of the new instance (cannot be null)
* @param style the style of widget to construct
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the parent is null
*
* @exception SWTException
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
* - ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
*
*
* @see Text
* @see Widget#checkSubclass
*
* @since 3.2
*/
public DropDown( Control parent, int style ) {
super( parent, checkStyle( style ) );
this.parent = parent;
items = new ArrayList<>();
getRemoteObject().set( "parent", WidgetUtil.getId( parent ) );
getRemoteObject().set( "style", createJsonArray( getStyles( this, ALLOWED_STYLES ) ) );
getRemoteObject().setHandler( new InternalOperationHandler() );
disposeListener = new Listener() {
@Override
public void handleEvent( Event event ) {
DropDown.this.dispose();
}
};
parent.addListener( SWT.Dispose, disposeListener );
}
/**
* Constructs a new instance of this class given its parent.
*
* @param parent a control, usually Text,
* which will be the parent of the new instance (cannot be null)
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the parent is null
*
* @exception SWTException
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
* - ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
*
*
* @see Text
* @see Widget#checkSubclass
*/
public DropDown( Control parent ) {
this( parent, SWT.V_SCROLL );
}
/**
* Sets the receiver's items to be the given array of items.
*
* @param items the array of items
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the items array is null
* - ERROR_INVALID_ARGUMENT - if an item in the items array is null
*
*/
public void setItems( String[] items ) {
checkWidget();
if( items == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
for( int i = 0; i < items.length; i++ ) {
if( items[ i ] == null ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
}
this.items.clear();
this.items.addAll( Arrays.asList( items ) );
remoteObject.set( "items", createJsonArray( items ) );
setSelectionIndexImpl( -1 );
}
/**
* Returns a (possibly empty) array of Strings which
* are the items in the receiver.
*
* Note: This is not the actual structure used by the receiver
* to maintain its list of items, so modifying the array will
* not affect the receiver.
*
*
* @return the items in the receiver's list
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public String[] getItems() {
checkWidget();
return items.toArray( new String[ items.size() ] );
}
/**
* Selects the item at the given zero-relative index in the receiver.
* If the item at the index was already selected, it remains selected.
* Indices that are out of range are ignored.
*
* @param selection the index of the item to select
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setSelectionIndex( int selection ) {
checkWidget();
if( selectionIndex != selection && selection >= -1 && selection < items.size() ) {
setSelectionIndexImpl( selection );
remoteObject.set( "selectionIndex", selection );
}
}
/**
* Returns the zero-relative index of the item which is currently
* selected in the receiver, or -1 if no item is selected.
*
* @return the index of the selected item or -1
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public int getSelectionIndex() {
checkWidget();
return selectionIndex;
}
/**
* Sets the maximum number of items that are visible in the receiver's list.
*
* @param itemCount the new number of items to be visible (default is 5)
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setVisibleItemCount( int itemCount ) {
checkWidget();
if( visibleItemCount != itemCount ) {
visibleItemCount = itemCount;
remoteObject.set( "visibleItemCount", itemCount );
}
}
/**
* Gets the number of items that are visible in the receiver's list.
*
* @return the number of items that are visible
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public int getVisibleItemCount() {
checkWidget();
return visibleItemCount;
}
/**
* Marks the receiver as visible if the argument is true,
* and marks it invisible otherwise.
*
* @param visible the new visibility state
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setVisible( boolean visible ) {
checkWidget();
if( visibility != visible ) {
setVisibleImpl( visible );
remoteObject.set( "visible", visible );
}
}
/**
* Returns true if the receiver is visible, and
* false otherwise.
*
* The initial value is false.
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*
* @return the receiver's visibility state
*
*/
public boolean getVisible() {
checkWidget();
return visibility;
}
/**
* Returns the receiver's parent, which must be a Control.
*
* @return the receiver's parent
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public Control getParent() {
checkWidget();
return parent;
}
@Override
public void dispose() {
if( !isDisposed() ) {
super.dispose();
parent.removeListener( SWT.Dispose, disposeListener );
remoteObject.destroy();
}
}
@Override
public void setData( String key, Object value ) {
super.setData( key, value );
renderData( key, value );
if( RWT.MARKUP_ENABLED.equals( key ) && value instanceof Boolean ) {
remoteObject.set( "markupEnabled", ( ( Boolean )value ).booleanValue() );
} else if( COLUMNS.equals( key ) ) {
if( value instanceof int[] ) {
int arr[] = ( int[] )value;
remoteObject.set( COLUMNS, createJsonArray( arr ) );
} else {
remoteObject.set( COLUMNS, JsonValue.NULL );
}
}
}
@Override
public void addListener( int eventType, Listener listener ) {
boolean wasListening = EventLCAUtil.isListening( this, eventType );
super.addListener( eventType, listener );
boolean isListening = EventLCAUtil.isListening( this, eventType );
String remoteType = eventTypeToString( eventType );
if( listener instanceof ClientListener ) {
JsonObject parameters = new JsonObject()
.add( "eventType", ClientListenerUtil.getEventType( eventType ) )
.add( "listenerId", ClientListenerUtil.getRemoteId( ( ClientListener )listener ) );
remoteObject.call( "addListener", parameters );
} else if( remoteType != null && !wasListening && isListening ) {
remoteObject.listen( remoteType, true );
}
}
@Override
public void removeListener( int eventType, Listener listener ) {
boolean wasListening = EventLCAUtil.isListening( this, eventType );
super.removeListener( eventType, listener );
boolean isListening = EventLCAUtil.isListening( this, eventType );
String remoteType = eventTypeToString( eventType );
if( listener instanceof ClientListener ) {
JsonObject parameters = new JsonObject()
.add( "eventType", ClientListenerUtil.getEventType( eventType ) )
.add( "listenerId", ClientListenerUtil.getRemoteId( ( ClientListener )listener ) );
remoteObject.call( "removeListener", parameters );
} else if( remoteType != null && wasListening && !isListening ) {
remoteObject.listen( remoteType, false );
}
}
//////////////
// overwritten
@Override
@SuppressWarnings( "unchecked" )
public T getAdapter( Class adapter ) {
T result;
if( adapter == RemoteAdapter.class ) {
// TODO [tb] : This way of getting the right id into the WidgetAdapter is obviously
// not ideal. Revise once Bug 397602 (Render operations in the order of their
// occurrence) is fixed.
if( widgetAdapter == null ) {
widgetAdapter = new WidgetRemoteAdapter( getProtocolId() );
}
result = ( T )widgetAdapter;
} else {
result = super.getAdapter( adapter );
}
return result;
}
//////////
// private
private class InternalOperationHandler extends AbstractOperationHandler {
@Override
public void handleSet( JsonObject properties ) {
if( properties.get( "visible" ) != null ) {
setVisibleImpl( properties.get( "visible" ).asBoolean() );
}
if( properties.get( "selectionIndex" ) != null ) {
setSelectionIndexImpl( properties.get( "selectionIndex" ).asInt() );
}
}
@Override
public void handleNotify( String type, JsonObject properties ) {
if( SELECTION.equals( type ) || DEFAULT_SELECTION.equals( type )) {
Event event = new Event();
event.index = properties.get( "index" ).asInt();
event.text = event.index >= 0 ? items.get( event.index ) : "";
notifyListeners( stringToEventType( type ), event );
}
}
}
private void setVisibleImpl( boolean value ) {
visibility = value;
}
private void setSelectionIndexImpl( int value ) {
selectionIndex = value;
}
private String getProtocolId() {
return getRemoteObject().getId();
}
private RemoteObject getRemoteObject() {
if( remoteObject == null ) {
remoteObject = RWT.getUISession().getConnection().createRemoteObject( REMOTE_TYPE );
}
return remoteObject;
}
private void renderData( String key, Object value ) {
// TODO [tb] : could be optimized using a PhaseListener
// This implementation assumes the client merges the new values with the existing
// ones, which is the case in the WebClient
if( WidgetDataUtil.getDataKeys().contains( key ) ) {
JsonObject data = new JsonObject().add( key, JsonUtil.createJsonValue( value ) );
remoteObject.set( "data", data );
}
}
private static String eventTypeToString( int type ) {
String result;
switch( type ) {
case SWT.Selection:
result = SELECTION;
break;
case SWT.DefaultSelection:
result = DEFAULT_SELECTION;
break;
default:
result = null;
break;
}
return result;
}
private static int stringToEventType( String str ) {
int result = -1;
if( SELECTION.equals( str ) ) {
result = SWT.Selection;
} else if( DEFAULT_SELECTION.equals( str ) ) {
result = SWT.DefaultSelection;
}
return result;
}
private static int checkStyle( int style ) {
return style | SWT.V_SCROLL;
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy