org.eclipse.swt.widgets.Widget Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH 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:
* Innoopract Informationssysteme GmbH - initial API and implementation
* EclipseSource - ongoing development
******************************************************************************/
package org.eclipse.swt.widgets;
import static org.eclipse.rap.rwt.internal.scripting.ClientListenerUtil.clientListenerAdded;
import static org.eclipse.rap.rwt.internal.scripting.ClientListenerUtil.clientListenerRemoved;
import org.eclipse.rap.rwt.Adaptable;
import org.eclipse.rap.rwt.RWT;
import org.eclipse.rap.rwt.internal.application.ApplicationContextImpl;
import org.eclipse.rap.rwt.internal.lifecycle.CurrentPhase;
import org.eclipse.rap.rwt.internal.lifecycle.PhaseId;
import org.eclipse.rap.rwt.internal.lifecycle.RemoteAdapter;
import org.eclipse.rap.rwt.internal.lifecycle.WidgetDataUtil;
import org.eclipse.rap.rwt.internal.lifecycle.WidgetLCAUtil;
import org.eclipse.rap.rwt.internal.theme.ThemeAdapter;
import org.eclipse.rap.rwt.internal.theme.ThemeManager;
import org.eclipse.rap.rwt.scripting.ClientListener;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.internal.SWTEventListener;
import org.eclipse.swt.internal.SerializableCompatibility;
import org.eclipse.swt.internal.events.EventList;
import org.eclipse.swt.internal.events.EventUtil;
import org.eclipse.swt.internal.widgets.IDisplayAdapter;
import org.eclipse.swt.internal.widgets.IWidgetGraphicsAdapter;
import org.eclipse.swt.internal.widgets.IdGenerator;
import org.eclipse.swt.internal.widgets.ParentHolderRemoteAdapter;
import org.eclipse.swt.internal.widgets.WidgetGraphicsAdapter;
import org.eclipse.swt.internal.widgets.WidgetRemoteAdapter;
/**
* This class is the abstract superclass of all user interface objects.
* Widgets are created, disposed and issue notification to listeners
* when events occur which affect them.
*
* - Styles:
* - (none)
* - Events:
* - Dispose
*
*
* IMPORTANT: This class is intended to be subclassed only
* within the SWT implementation. However, it has not been marked
* final to allow those outside of the SWT development team to implement
* patched versions of the class in order to get around specific
* limitations in advance of when those limitations can be addressed
* by the team. Any class built using subclassing to access the internals
* of this class will likely fail to compile or run between releases and
* may be strongly platform specific. Subclassing should not be attempted
* without an intimate and detailed understanding of the workings of the
* hierarchy. No support is provided for user-written classes which are
* implemented as subclasses of this class.
*
* Even though this class implements Adaptable this interface
* is not part of the RWT public API. It is only meant to be shared
* within the packages provided by RWT and should never be accessed from
* application code.
*
*
* @see #checkSubclass
* @since 1.0
*/
@SuppressWarnings( "deprecation" )
public abstract class Widget implements Adaptable, SerializableCompatibility {
private static final Listener[] EMPTY_LISTENERS = new Listener[ 0 ];
/* Default size for widgets */
static final int DEFAULT_WIDTH = 64;
static final int DEFAULT_HEIGHT = 64;
/* Global state flags */
static final int DISPOSED = 1 << 0;
// static final int CANVAS = 1 << 1;
static final int KEYED_DATA = 1 << 2;
static final int DISABLED = 1 << 3;
static final int HIDDEN = 1 << 4;
/* A layout was requested on this widget */
static final int LAYOUT_NEEDED = 1 << 5;
/* The preferred size of a child has changed */
static final int LAYOUT_CHANGED = 1 << 6;
/* A layout was requested in this widget hierarchy */
static final int LAYOUT_CHILD = 1 << 7;
/* Background flags */
static final int THEME_BACKGROUND = 1 << 8;
static final int PARENT_BACKGROUND = 1 << 10;
/* Dispose and release flags */
static final int RELEASED = 1 << 11;
static final int DISPOSE_SENT = 1 << 12;
/* Notify of the opportunity to skin this widget */
static final int SKIN_NEEDED = 1 << 21;
int style;
private int state;
Display display;
private Object data;
private EventTable eventTable;
private RemoteAdapter remoteAdapter;
private IWidgetGraphicsAdapter widgetGraphicsAdapter;
Widget() {
// prevent instantiation from outside this package
}
/**
* Constructs a new instance of this class given its parent
* and a style value describing its behavior and appearance.
*
* The style value is either one of the style constants defined in
* class SWT which is applicable to instances of this
* class, or must be built by bitwise OR'ing together
* (that is, using the int "|" operator) two or more
* of those SWT style constants. The class description
* lists the style constants that are applicable to the class.
* Style bits are also inherited from superclasses.
*
*
* @param parent a widget 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
* - ERROR_INVALID_ARGUMENT - if the parent is disposed
*
* @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 SWT
* @see #checkSubclass
* @see #getStyle
*/
public Widget( Widget parent, int style ) {
checkSubclass();
if( parent == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
this.style = style;
display = parent.display;
reskinWidget();
remoteAdapter = new ParentHolderRemoteAdapter( parent );
}
/**
* Implementation of the Adaptable interface.
* IMPORTANT: This method is not part of the RWT
* public API. It is marked public only so that it can be shared
* within the packages provided by RWT. It should never be accessed
* from application code.
*
* @noreference This method is not intended to be referenced by clients.
*/
@Override
@SuppressWarnings("unchecked")
public T getAdapter( Class adapter ) {
// The adapters returned here are buffered for performance reasons. Don't change this without
// good reason
if( adapter == RemoteAdapter.class ) {
return (T) ensureRemoteAdapter();
}
if( adapter == ThemeAdapter.class ) {
ThemeManager themeManager = getApplicationContext().getThemeManager();
return (T) themeManager.getThemeAdapterManager().getThemeAdapter( this );
}
if( adapter == IWidgetGraphicsAdapter.class ) {
if( widgetGraphicsAdapter == null ) {
widgetGraphicsAdapter = new WidgetGraphicsAdapter();
}
return (T) widgetGraphicsAdapter;
}
return null;
}
/**
* Returns the application defined widget data associated
* with the receiver, or null if it has not been set. The
* widget data is a single, unnamed field that is
* stored with every widget.
*
* Applications may put arbitrary objects in this field. If
* the object stored in the widget data needs to be notified
* when the widget is disposed of, it is the application's
* responsibility to hook the Dispose event on the widget and
* do so.
*
*
* @return the widget data
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - when the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - when called from the wrong thread
*
*
* @see #setData(Object)
*/
public Object getData() {
checkWidget();
return hasState( KEYED_DATA ) ? ( ( Object[] )data )[ 0 ] : data;
}
/**
* Sets the application defined widget data associated
* with the receiver to be the argument. The widget
* data is a single, unnamed field that is stored
* with every widget.
*
* Applications may put arbitrary objects in this field. If
* the object stored in the widget data needs to be notified
* when the widget is disposed of, it is the application's
* responsibility to hook the Dispose event on the widget and
* do so.
*
*
* @param data the widget data
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - when the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - when called from the wrong thread
*
*
* @see #getData()
*/
public void setData( Object data ) {
checkWidget();
if( hasState( KEYED_DATA ) ) {
( ( Object[] )this.data )[ 0 ] = data;
} else {
this.data = data;
}
}
/**
* Returns the application defined property of the receiver
* with the specified name, or null if it has not been set.
*
* Applications may have associated arbitrary objects with the
* receiver in this fashion. If the objects stored in the
* properties need to be notified when the widget is disposed
* of, it is the application's responsibility to hook the
* Dispose event on the widget and do so.
*
*
* @param key the name of the property
* @return the value of the property or null if it has not been set
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the key is null
*
* @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
*
*
* @see #setData(String, Object)
*/
public Object getData( String key ) {
checkWidget();
if( key == null ) {
error( SWT.ERROR_NULL_ARGUMENT );
}
Object result = null;
if( hasState( KEYED_DATA ) ) {
Object[] table = ( Object[] )data;
for( int i = 1; result == null && i < table.length; i += 2 ) {
if( key.equals( table[ i ] ) ) {
result = table[ i + 1 ];
}
}
}
return result;
}
/**
* Sets the application defined property of the receiver
* with the specified name to the given value.
*
* Applications may associate arbitrary objects with the
* receiver in this fashion. If the objects stored in the
* properties need to be notified when the widget is disposed
* of, it is the application's responsibility to hook the
* Dispose event on the widget and do so.
*
*
* @param key the name of the property
* @param value the new value for the property
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the key is null
*
* @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
*
*
* @see #getData(String)
*/
public void setData( String key, Object value ) {
checkWidget();
if( key == null ) {
error( SWT.ERROR_NULL_ARGUMENT );
}
if( RWT.CUSTOM_VARIANT.equals( key ) ) {
if( value != null ) {
checkCustomVariant( value );
}
WidgetLCAUtil.preserveCustomVariant( this );
}
if( WidgetDataUtil.getDataKeys().contains( key ) ) {
WidgetLCAUtil.preserveData( this );
}
int index = 1;
Object[] table = null;
if( hasState( KEYED_DATA ) ) {
table = ( Object[] )data;
while( index < table.length ) {
if( key.equals( table[ index ] ) ) {
break;
}
index += 2;
}
}
if( value != null ) {
if( hasState( KEYED_DATA ) ) {
if( index == table.length ) {
Object[] newTable = new Object[ table.length + 2 ];
System.arraycopy( table, 0, newTable, 0, table.length );
data = table = newTable;
}
} else {
table = new Object[ 3 ];
table[ 0 ] = data;
data = table;
addState( KEYED_DATA );
}
table[ index ] = key;
table[ index + 1 ] = value;
} else {
if( hasState( KEYED_DATA ) ) {
if( index != table.length ) {
int length = table.length - 2;
if( length == 1 ) {
data = table[ 0 ];
removeState( KEYED_DATA );
} else {
Object[] newTable = new Object[ length ];
System.arraycopy( table, 0, newTable, 0, index );
System.arraycopy( table, index + 2, newTable, index, length - index );
data = newTable;
}
}
}
}
if( key.equals( SWT.SKIN_CLASS ) || key.equals( SWT.SKIN_ID ) ) {
reskin( SWT.ALL );
}
}
///////////////////////////////////////////
// Methods to get/set single and keyed data
/**
* Returns the Display that is associated with
* the receiver.
*
* A widget's display is either provided when it is created
* (for example, top level Shells) or is the
* same as its parent's display.
*
*
* @return the receiver's display
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
*
*/
public Display getDisplay() {
if( hasState( DISPOSED ) ) {
error( SWT.ERROR_WIDGET_DISPOSED );
}
return display;
}
/**
* Returns the receiver's style information.
*
* Note that the value which is returned by this method may
* not match the value which was provided to the constructor
* when the receiver was created. This can occur when the underlying
* operating system does not support a particular combination of
* requested styles. For example, if the platform widget used to
* implement a particular SWT widget always has scroll bars, the
* result of calling this method would always have the
* SWT.H_SCROLL and SWT.V_SCROLL bits set.
*
*
* @return the style bits
*
* @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 getStyle() {
checkWidget();
return style;
}
///////////////////////////////////////////////
// Registration and deregistration of listeners
/**
* Adds the listener to the collection of listeners who will
* be notified when the widget is disposed. When the widget is
* disposed, the listener is notified by sending it the
* widgetDisposed() message.
*
* @param listener the listener which should be notified when the receiver is disposed
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the listener is null
*
* @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
*
*
* @see DisposeListener
* @see #removeDisposeListener
*/
public void addDisposeListener( DisposeListener listener ) {
checkWidget();
if( listener == null ) {
error( SWT.ERROR_NULL_ARGUMENT );
}
TypedListener typedListener = new TypedListener( listener );
addListener( SWT.Dispose, typedListener );
}
/**
* Removes the listener from the collection of listeners who will
* be notified when the widget is disposed.
*
* @param listener the listener which should no longer be notified when the receiver is disposed
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the listener is null
*
* @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
*
*
* @see DisposeListener
* @see #addDisposeListener
*/
public void removeDisposeListener( DisposeListener listener ) {
checkWidget();
if( listener == null ) {
error( SWT.ERROR_NULL_ARGUMENT );
}
preserveListeners();
if( eventTable != null ) {
eventTable.unhook( SWT.Dispose, listener );
}
}
////////////////////////////////////////
// Methods for untyped listener handling
/**
* Adds the listener to the collection of listeners who will be notified when
* an event of the given type occurs. When the event does occur in the widget,
* the listener is notified by sending it the handleEvent()
* message. The event type is one of the event constants defined in class
* SWT.
*
* @param eventType the type of event to listen for
* @param listener the listener which should be notified when the event occurs
* @exception IllegalArgumentException
*
* - ERROR_NULL_ARGUMENT - if the listener is null
*
* @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
*
* @see Listener
* @see SWT
* @see #removeListener
* @see #notifyListeners
*/
public void addListener( int eventType, Listener listener ) {
checkWidget();
if( listener == null ) {
error( SWT.ERROR_NULL_ARGUMENT );
}
ensureEventTable();
preserveListeners();
eventTable.hook( eventType, listener );
if( listener instanceof ClientListener ) {
clientListenerAdded( this, eventType, ( ClientListener )listener );
}
}
/**
* Removes the listener from the collection of listeners who will be notified
* when an event of the given type occurs. The event type is one of the event
* constants defined in class SWT.
*
* @param eventType the type of event to listen for
* @param listener the listener which should no longer be notified when the
* event occurs
* @exception IllegalArgumentException
*
* - ERROR_NULL_ARGUMENT - if the listener is null
*
* @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
*
* @see Listener
* @see SWT
* @see #addListener
* @see #notifyListeners
*/
public void removeListener( int eventType, Listener listener ) {
checkWidget();
if( listener == null ) {
error( SWT.ERROR_NULL_ARGUMENT );
}
preserveListeners();
if( eventTable != null ) {
eventTable.unhook( eventType, listener );
}
if( listener instanceof ClientListener ) {
clientListenerRemoved( this, eventType, ( ClientListener )listener );
}
}
/**
* Notifies all of the receiver's listeners for events
* of the given type that one such event has occurred by
* invoking their handleEvent() method. The
* event type is one of the event constants defined in class
* SWT.
*
* @param eventType the type of event which has occurred
* @param event the event data
*
* @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
*
*
* @see SWT
* @see #addListener
* @see #getListeners(int)
* @see #removeListener(int, Listener)
* @since 1.2
*/
public void notifyListeners( int eventType, Event event ) {
checkWidget();
Event newEvent = event == null ? new Event() : event;
newEvent.widget = this;
newEvent.type = eventType;
newEvent.display = display;
if( newEvent.time == 0 ) {
newEvent.time = EventUtil.getLastEventTime();
}
sendEvent( newEvent );
}
/**
* Returns true if there are any listeners
* for the specified event type associated with the receiver,
* and false otherwise. The event type is one of
* the event constants defined in class SWT.
*
* @param eventType the type of event
* @return true if the event is hooked
*
* @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
*
*
* @see SWT
* @since 1.3
*/
public boolean isListening( int eventType ) {
checkWidget();
return eventTable == null ? false : eventTable.hooks( eventType );
}
/**
* Returns an array of listeners who will be notified when an event
* of the given type occurs. The event type is one of the event constants
* defined in class SWT.
*
* @param eventType the type of event to listen for
* @return an array of listeners that will be notified when the event occurs
*
* @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
*
*
* @see Listener
* @see SWT
* @see #addListener(int, Listener)
* @see #removeListener(int, Listener)
* @see #notifyListeners
*
* @since 1.3
*/
public Listener[] getListeners( int eventType ) {
checkWidget();
return eventTable == null ? EMPTY_LISTENERS : eventTable.getListeners( eventType );
}
/**
* Removes the listener from the collection of listeners who will
* be notified when an event of the given type occurs.
*
* IMPORTANT: This method is not part of the SWT
* public API. It is marked public only so that it can be shared
* within the packages provided by SWT. It should never be
* referenced from application code.
*
*
* @param eventType the type of event to listen for
* @param listener the listener which should no longer be notified
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the listener is null
*
* @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
*
*
* @see Listener
* @see #addListener
*
* @noreference This method is not intended to be referenced by clients.
* @since 2.0
*/
protected void removeListener( int eventType, SWTEventListener listener ) {
checkWidget();
if( listener == null ) {
error( SWT.ERROR_NULL_ARGUMENT );
}
preserveListeners();
if( eventTable != null ) {
eventTable.unhook( eventType, listener );
}
}
private void sendEvent( Event event ) {
if( isEventProcessingPhase() ) {
event.display.filterEvent( event );
if( eventTable != null ) {
eventTable.sendEvent( event );
}
} else {
EventList.getInstance().add( event );
}
}
private static boolean isEventProcessingPhase() {
PhaseId currentPhase = CurrentPhase.get();
return PhaseId.PREPARE_UI_ROOT.equals( currentPhase )
|| PhaseId.PROCESS_ACTION.equals( currentPhase );
}
private void ensureEventTable() {
if( eventTable == null ) {
eventTable = new EventTable();
}
}
///////////////////
// Skinning support
/**
* Marks the widget to be skinned.
*
* The skin event is sent to the receiver's display when appropriate (usually before the next event
* is handled). Widgets are automatically marked for skinning upon creation as well as when its skin
* id or class changes. The skin id and/or class can be changed by calling Display.setData(String, Object)
* with the keys SWT.SKIN_ID and/or SWT.SKIN_CLASS. Once the skin event is sent to a widget, it
* will not be sent again unless reskin(int) is called on the widget or on an ancestor
* while specifying the SWT.ALL flag.
*
*
* The parameter flags may be either:
*
* - SWT.ALL
* - all children in the receiver's widget tree should be skinned
* - SWT.NONE
* - only the receiver should be skinned
*
*
* @param flags the flags specifying how to reskin
*
* @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
*
* @since 1.3
*/
public void reskin( int flags ) {
checkWidget();
reskinWidget();
if( ( flags & SWT.ALL ) != 0 ) {
reskinChildren( flags );
}
}
@SuppressWarnings( "unused" )
void reskinChildren( int flags ) {
}
void reskinWidget() {
if( !hasState( SKIN_NEEDED ) ) {
addState( SKIN_NEEDED );
display.addSkinnableWidget( this );
}
}
///////////////////////
// toString and helpers
/**
* Returns a string containing a concise, human-readable
* description of the receiver.
*
* @return a string representation of the receiver
*/
@Override
public String toString() {
String string = "*Disposed*";
if( !isDisposed() ) {
string = "*Wrong Thread*";
if( isValidThread() ) {
string = getNameText();
}
}
return getName() + " {" + string + "}";
}
/**
* Returns the name of the widget. This is the name of
* the class without the package name.
*
* @return the name of the widget
*/
String getName() {
String string = getClass().getName();
int index = string.lastIndexOf( '.' );
if( index != -1 ) {
string = string.substring( index + 1, string.length() );
}
return string;
}
/*
* Returns a short printable representation for the contents
* of a widget. For example, a button may answer the label
* text. This is used by toString to provide a
* more meaningful description of the widget.
*
* @return the contents string for the widget
*
* @see #toString
*/
String getNameText() {
return "";
}
///////////////////////////////////
// Methods to dispose of the widget
/**
* Disposes of the operating system resources associated with
* the receiver and all its descendents. After this method has
* been invoked, the receiver and all descendents will answer
* true when sent the message isDisposed().
* Any internal connections between the widgets in the tree will
* have been removed to facilitate garbage collection.
*
* NOTE: This method is not called recursively on the descendents
* of the receiver. This means that, widget implementers can not
* detect when a widget is being disposed of by re-implementing
* this method, but should instead listen for the Dispose
* event.
*
*
* @exception SWTException
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*
* @see #addDisposeListener
* @see #removeDisposeListener
* @see #checkWidget
*/
// TODO [rh] ensure that this implementation aligns with SWT rules for
// disposing (see The Standard Widget Toolkit, p 13)
public void dispose() {
if( !isDisposed() ) {
if( !isValidThread() ) {
error( SWT.ERROR_THREAD_INVALID_ACCESS );
}
if( !hasState( DISPOSE_SENT ) ) {
addState( DISPOSE_SENT );
notifyListeners( SWT.Dispose, new Event() );
}
if( !hasState( DISPOSED ) ) {
releaseChildren();
}
if( !hasState( RELEASED ) ) {
addState( RELEASED );
releaseParent();
releaseWidget();
getAdapter( RemoteAdapter.class ).markDisposed( this );
}
}
}
/**
* Returns true if the widget has been disposed,
* and false otherwise.
*
* This method gets the dispose state for the widget.
* When a widget has been disposed, it is an error to
* invoke any other method using the widget.
*
*
* @return true when the widget is disposed and false otherwise
*/
public boolean isDisposed() {
return hasState( DISPOSED );
}
boolean isInDispose() {
return hasState( DISPOSE_SENT );
}
void releaseChildren() {
// do nothing - derived classes may override
}
void releaseParent() {
// do nothing - derived classes may override
}
void releaseWidget() {
eventTable = null;
addState( DISPOSED );
}
/**
* Checks that this class can be subclassed.
*
* The SWT class library is intended to be subclassed
* only at specific, controlled points (most notably,
* Composite and Canvas when
* implementing new widgets). This method enforces this
* rule unless it is overridden.
*
* IMPORTANT: By providing an implementation of this
* method that allows a subclass of a class which does not
* normally allow subclassing to be created, the implementer
* agrees to be fully responsible for the fact that any such
* subclass will likely fail between SWT releases and will be
* strongly platform specific. No support is provided for
* user-written classes which are implemented in this fashion.
*
* The ability to subclass outside of the allowed SWT classes
* is intended purely to enable those not on the SWT development
* team to implement patches in order to get around specific
* limitations in advance of when those limitations can be
* addressed by the team. Subclassing should not be attempted
* without an intimate and detailed understanding of the hierarchy.
*
*
* @exception SWTException
* - ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
*
*/
protected void checkSubclass() {
if( !isValidSubclass() ) {
error( SWT.ERROR_INVALID_SUBCLASS );
}
}
/*
* Returns true when subclassing is
* allowed and false otherwise
*
* @return true when subclassing is allowed and false otherwise
*/
boolean isValidSubclass() {
return Display.isValidClass( getClass() );
}
/**
* Throws an SWTException if the receiver can not
* be accessed by the caller. This may include both checks on
* the state of the receiver and more generally on the entire
* execution context. This method should be called by
* widget implementors to enforce the standard SWT invariants.
*
* Currently, it is an error to invoke any method (other than
* isDisposed()) on a widget that has had its
* dispose() method called. It is also an error
* to call widget methods from any thread that is different
* from the thread that created the widget.
*
* In future releases of SWT, there may be more or fewer error
* checks and exceptions may be thrown for different reasons.
*
*
* @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
*
*/
protected void checkWidget() {
if( !isValidThread() ) {
error( SWT.ERROR_THREAD_INVALID_ACCESS );
}
if( hasState( DISPOSED ) ) {
error( SWT.ERROR_WIDGET_DISPOSED );
}
}
/*
* Returns true when the current thread is
* the thread that created the widget and false
* otherwise.
*
* @return true when the current thread is the thread that
* created the widget and false otherwise
*/
boolean isValidThread() {
return getDisplay().isValidThread();
}
static int checkBits( int style, int int0, int int1, int int2, int int3, int int4, int int5 ) {
int mask = int0 | int1 | int2 | int3 | int4 | int5;
int result = style;
if( ( result & mask ) == 0 ) {
result |= int0;
}
if( ( result & int0 ) != 0 ) {
result = ( result & ~mask ) | int0;
}
if( ( result & int1 ) != 0 ) {
result = ( result & ~mask ) | int1;
}
if( ( result & int2 ) != 0 ) {
result = ( result & ~mask ) | int2;
}
if( ( result & int3 ) != 0 ) {
result = ( result & ~mask ) | int3;
}
if( ( result & int4 ) != 0 ) {
result = ( result & ~mask ) | int4;
}
if( ( result & int5 ) != 0 ) {
result = ( result & ~mask ) | int5;
}
return result;
}
void checkOrientation( Widget parent ) {
style &= ~SWT.MIRRORED;
if( ( style & ( SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT ) ) == 0 ) {
if( parent != null ) {
if( ( parent.style & SWT.LEFT_TO_RIGHT ) != 0 ) {
style |= SWT.LEFT_TO_RIGHT;
}
if( ( parent.style & SWT.RIGHT_TO_LEFT ) != 0 ) {
style |= SWT.RIGHT_TO_LEFT;
}
}
}
style = checkBits( style, SWT.LEFT_TO_RIGHT, SWT.RIGHT_TO_LEFT, 0, 0, 0, 0 );
}
void error( int code ) {
SWT.error( code );
}
boolean hasState( int flag ) {
return ( state & flag ) != 0;
}
void addState( int flag ) {
state |= flag;
}
void removeState( int flag ) {
state &= ~flag;
}
private void preserveListeners() {
WidgetRemoteAdapter adapter = ( WidgetRemoteAdapter )ensureRemoteAdapter();
if( !( adapter ).hasPreservedListeners() ) {
WidgetLCAUtil.preserveListeners( this, eventTable != null ? eventTable.getEventList() : 0 );
}
}
private RemoteAdapter ensureRemoteAdapter() {
if( remoteAdapter == null ) {
remoteAdapter = createRemoteAdapter( null );
} else if( remoteAdapter instanceof ParentHolderRemoteAdapter ) {
remoteAdapter = createRemoteAdapter( remoteAdapter.getParent() );
}
return remoteAdapter;
}
private RemoteAdapter createRemoteAdapter( Widget parent ) {
String id = IdGenerator.getInstance( RWT.getUISession( display ) ).createId( this );
return createRemoteAdapter( parent, id );
}
RemoteAdapter createRemoteAdapter( Widget parent, String id ) {
WidgetRemoteAdapter remoteAdapter = new WidgetRemoteAdapter( id );
remoteAdapter.setParent( parent );
return remoteAdapter;
}
private ApplicationContextImpl getApplicationContext() {
IDisplayAdapter displayAdapter = display.getAdapter( IDisplayAdapter.class );
return ( ApplicationContextImpl )displayAdapter.getUISession().getApplicationContext();
}
private static void checkCustomVariant( Object value ) {
if( !( value instanceof String ) ) {
throw new IllegalArgumentException( "Custom variant is not a string" );
}
if( !validateVariantString( ( String )value ) ) {
throw new IllegalArgumentException( "Invalid custom variant: " + value );
}
}
private static boolean validateVariantString( String variant ) {
int start = 0;
int length = variant.length();
if( variant.startsWith( "-" ) ) {
start++ ;
}
if( length == 0 ) {
return false;
}
if( !isValidStart( variant.charAt( start ) ) ) {
return false;
}
for( int i = start + 1; i < length; i++ ) {
if( !isValidPart( variant.charAt( i ) ) ) {
return false;
}
}
return true;
}
private static boolean isValidStart( char ch ) {
return ch == '_'
|| ( ch >= 'a' && ch <= 'z' )
|| ( ch >= 'A' && ch <= 'Z' )
|| ( ch >= 128 && ch <= 255 );
}
private static boolean isValidPart( char ch ) {
return isValidStart( ch )
|| ( ch >= '0' && ch <= '9' )
|| ch == '-';
}
}
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