protected void checkSubclass() {
String name = getClass().getName();
String validName = DragSource.class.getName();
if (!validName.equals(name)) {
DND.error(SWT.ERROR_INVALID_SUBCLASS);
}
}
/**
* Adds the listener to the collection of listeners who will be notified when a drag and drop
* operation is in progress, by sending it one of the messages defined in the <code>
* DragSourceListener</code> interface.
*
* <p>
*
* <ul>
* <li><code>dragStart</code> is called when the user has begun the actions required to drag the
* widget. This event gives the application the chance to decide if a drag should be
* started.
* <li><code>dragSetData</code> is called when the data is required from the drag source.
* <li><code>dragFinished</code> is called when the drop has successfully completed (mouse up
* over a valid target) or has been terminated (such as hitting the ESC key). Perform
* cleanup such as removing data from the source side on a successful move operation.
* </ul>
*
* @param listener the listener which should be notified
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null
* </ul>
*
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
* </ul>
*
* @see DragSourceListener
* @see #getDragListeners
* @see #removeDragListener
* @see DragSourceEvent
*/
public void addDragListener(DragSourceListener listener) {
if (listener == null) DND.error(SWT.ERROR_NULL_ARGUMENT);
DNDListener typedListener = new DNDListener(listener);
typedListener.dndWidget = this;
addListener(DND.DragStart, typedListener);
addListener(DND.DragSetData, typedListener);
addListener(DND.DragEnd, typedListener);
}
/**
* Creates a new <code>DragSource</code> to handle dragging from the specified <code>Control
* </code>. Creating an instance of a DragSource may cause system resources to be allocated
* depending on the platform. It is therefore mandatory that the DragSource instance be disposed
* when no longer required.
*
* @param control the <code>Control</code> that the user clicks on to initiate the drag
* @param style the bitwise OR'ing of allowed operations; this may be a combination of any of
* DND.DROP_NONE, DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK
* @exception SWTException
* <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
* </ul>
*
* @exception SWTError
* <ul>
* <li>ERROR_CANNOT_INIT_DRAG - unable to initiate drag source; this will occur if more than
* one drag source is created for a control or if the operating system will not allow
* the creation of the drag source
* </ul>
* <p>NOTE: ERROR_CANNOT_INIT_DRAG should be an SWTException, since it is a recoverable error,
* but can not be changed due to backward compatibility.
* @see Widget#dispose
* @see DragSource#checkSubclass
* @see DND#DROP_NONE
* @see DND#DROP_COPY
* @see DND#DROP_MOVE
* @see DND#DROP_LINK
*/
public DragSource(Control control, int style) {
super(control, checkStyle(style));
this.control = control;
if (control.getData(DND.DRAG_SOURCE_KEY) != null) {
DND.error(DND.ERROR_CANNOT_INIT_DRAG);
}
control.setData(DND.DRAG_SOURCE_KEY, this);
createCOMInterfaces();
this.AddRef();
controlListener =
new Listener() {
public void handleEvent(Event event) {
if (event.type == SWT.Dispose) {
if (!DragSource.this.isDisposed()) {
DragSource.this.dispose();
}
}
if (event.type == SWT.DragDetect) {
if (!DragSource.this.isDisposed()) {
DragSource.this.drag(event);
}
}
}
};
control.addListener(SWT.Dispose, controlListener);
control.addListener(SWT.DragDetect, controlListener);
this.addListener(
SWT.Dispose,
new Listener() {
public void handleEvent(Event e) {
DragSource.this.onDispose();
}
});
Object effect = control.getData(DEFAULT_DRAG_SOURCE_EFFECT);
if (effect instanceof DragSourceEffect) {
dragEffect = (DragSourceEffect) effect;
} else if (control instanceof Tree) {
dragEffect = new TreeDragSourceEffect((Tree) control);
} else if (control instanceof Table) {
dragEffect = new TableDragSourceEffect((Table) control);
}
}
/**
* This implementation of <code>javaToNative</code> converts an ImageData object represented by
* java <code>ImageData</code> to a platform specific representation.
*
* @param object a java <code>ImageData</code> containing the ImageData to be converted
* @param transferData an empty <code>TransferData</code> object that will be filled in on return
* with the platform specific format of the data
* @see Transfer#nativeToJava
*/
public void javaToNative(Object object, TransferData transferData) {
if (!checkImage(object) || !isSupportedType(transferData)) {
DND.error(DND.ERROR_INVALID_DATA);
}
if (OS.GTK_VERSION < OS.VERSION(2, 4, 0)) return;
ImageData imgData = (ImageData) object;
if (imgData == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
Image image = new Image(Display.getCurrent(), imgData);
long /*int*/ pixbuf = ImageList.createPixbuf(image);
if (pixbuf != 0) {
String typeStr = "";
if (transferData.type == JPEG_ID) typeStr = "jpeg";
else if (transferData.type == PNG_ID) typeStr = "png";
else if (transferData.type == BMP_ID) typeStr = "bmp";
else if (transferData.type == EPS_ID) typeStr = "eps";
else if (transferData.type == PCX_ID) typeStr = "pcx";
else if (transferData.type == PPM_ID) typeStr = "ppm";
else if (transferData.type == RGB_ID) typeStr = "rgb";
else if (transferData.type == TGA_ID) typeStr = "tga";
else if (transferData.type == XBM_ID) typeStr = "xbm";
else if (transferData.type == XPM_ID) typeStr = "xpm";
else if (transferData.type == XV_ID) typeStr = "xv";
byte[] type = Converter.wcsToMbcs(null, typeStr, true);
long /*int*/[] buffer = new long /*int*/[1];
long /*int*/[] len = new long /*int*/[1];
if (type == null) return;
OS.gdk_pixbuf_save_to_bufferv(pixbuf, buffer, len, type, null, null, null);
OS.g_object_unref(pixbuf);
transferData.pValue = buffer[0];
transferData.length = (int) (len[0] + 3) / 4 * 4;
transferData.result = 1;
transferData.format = 32;
}
image.dispose();
}
/**
* Removes the listener from the collection of listeners who will be notified when a drag and drop
* operation is in progress.
*
* @param listener the listener which should no longer be notified
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null
* </ul>
*
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
* </ul>
*
* @see DragSourceListener
* @see #addDragListener
* @see #getDragListeners
*/
public void removeDragListener(DragSourceListener listener) {
if (listener == null) DND.error(SWT.ERROR_NULL_ARGUMENT);
removeListener(DND.DragStart, listener);
removeListener(DND.DragSetData, listener);
removeListener(DND.DragEnd, listener);
}