Duong Nguyen has posted a response to my
query on the swt mailing list that should at least partially work for me.
The others on this email thread might want to take a look at it and see if it
will satisfy some of their requirements as well.
Duong’s Post for Posterity:
You should be able to send a DragDetect event any time you want. All
you
have to do is create an event and notify your listeners of a DragDetect
event.
Event event = new Event();
event.button = e.button;
event.x = e.x;
event.y = e.y;
canvas.notifyListeners(SWT.DragDetect, event);
The only problem that I can see in your case is that once the real
drag-and-drop is started, you can't terminate it prematurely (and revert
back to your fake drag-move). Personally, I think your canvas should
always perform the drag-and-drop even when you're moving the painted
"objects" within your canvas area. Then, you don't have this problem.
Below is an (unrealistic) example that demonstrates how you can send a
DragDetect event.
Good luck!
package swt.examples.dnd;
/*******************************************************************************
* Copyright (c) 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
*******************************************************************************/
/*
* Drag and Drop example : drag text between two text widgets using
DragDetect.
*/
import org.eclipse.swt.*;
import org.eclipse.swt.dnd.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
public class DragDetectExample {
public static void main (String [] args) {
Display display = new Display ();
final Shell shell = new Shell (display);
shell.setLayout(new FillLayout());
Transfer[] types = new Transfer[] {TextTransfer.getInstance()};
int operations = DND.DROP_MOVE | DND.DROP_COPY | DND.DROP_LINK;
final Text text1 = new Text (shell, SWT.BORDER);
text1.setText ("SOURCE");
DragSource source = new DragSource (text1, operations);
source.setTransfer(types);
source.addDragListener (new DragSourceListener () {
public void dragStart(DragSourceEvent event) {
event.doit = (text1.getText ().length () != 0);
}
public void dragSetData (DragSourceEvent event) {
event.data = "" ();
}
public void dragFinished(DragSourceEvent event) {
}
});
final Label label = new Label (shell, SWT.BORDER);
label.setText("Press here to start drag");
label.addMouseListener(new MouseListener() {
public void mouseDoubleClick(MouseEvent e) {
}
public void mouseDown(MouseEvent e) {
Event event = new Event();
event.button = e.button;
event.x = e.x;
event.y = e.y;
text1.notifyListeners(SWT.DragDetect, event);
}
public void mouseUp(MouseEvent e) {
}
});
final Text text2 = new Text (shell, SWT.BORDER);
text2.setText ("DESTINATION");
DropTarget target = new DropTarget(text2, operations);
target.setTransfer(types);
target.addDropListener (new DropTargetAdapter() {
public void drop(DropTargetEvent event) {
if (event.data == null) {
event.detail = DND.DROP_NONE;
return;
}
text2.setText((String) event.data);
}
});
shell.setSize (400, 50);
shell.open ();
while (!shell.isDisposed ()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}
public static void setDragDrop (final Text text) {
}
}
Trip Gilman
Eclipse Voice Tools Project Lead
OpenMethods
4741 Central Street | Suite 285 | Kansas City, MO | 64112-1533
o| +1.816.283.VXML (8965) x102 c| +1.816.729.0672 f| +1.816.817.0643
trip@xxxxxxxxxxxxxxx | www.openmethods.com
This message (including any attachments) contains confidential
information intended for a specific individual and purpose, and is protected by
law. If you are not the intended recipient, you should delete this
message and are hereby notified that any disclosure, copying, or distribution
of this message, or the taking of any action based on it, is strictly
prohibited.
From: platform-swt-dev-bounces@xxxxxxxxxxx
[mailto:platform-swt-dev-bounces@xxxxxxxxxxx] On
Behalf Of Trip Gilman
Sent: Thursday, April 05, 2007
12:18 PM
To: Eclipse Platform SWT component
developers list.
Subject: RE: [platform-swt-dev]
RE: Making a composite to listen to bothDroplistener and Mouse listener for
drop support andmovementrepectively.
Hi,
This sounds very similar to the situation
I described in my post yesterday. I’ve dug through the event system
and found the proper event to post into the event queue, but I haven’t
found a way to post this “fake” drag detect event into the queue without
modifying the SWT source and forking it into my own custom build which is
definitely not an option for the voice tools project. I’m not sure
if we have described the desired behavior very
well, so if you have any questions please
do not hesitate to ask.
Trip Gilman
Eclipse Voice Tools Project Lead
OpenMethods
4741 Central Street | Suite 285 | Kansas City, MO | 64112-1533
o| +1.816.283.VXML (8965) x102 c| +1.816.729.0672 f| +1.816.817.0643
trip@xxxxxxxxxxxxxxx | www.openmethods.com
This message (including any attachments) contains confidential
information intended for a specific individual and purpose, and is protected by
law. If you are not the intended recipient, you should delete this
message and are hereby notified that any disclosure, copying, or distribution
of this message, or the taking of any action based on it, is strictly
prohibited.
From:
platform-swt-dev-bounces@xxxxxxxxxxx
[mailto:platform-swt-dev-bounces@xxxxxxxxxxx] On
Behalf Of Kumar, Saurav
Sent: Thursday, April 05, 2007
10:20 AM
To: platform-swt-dev@xxxxxxxxxxx
Subject: [platform-swt-dev] RE:
Making a composite to listen to both Droplistener and Mouse listener for drop
support and movementrepectively.
We want move the children inside parent
freely as well as allowing child to drop something inside child.
Problem is only one listener is working at
time.
How to deal with such situation
From: Lakhanpal,
Srikant
Sent: Thursday, April 05, 2007
8:38 PM
To: 'platform-swt-dev@xxxxxxxxxxx'
Subject: Making a composite to
listen to both Drop listener and Mouse listener for drop support and movement
repectively.
I have problem regarding the DND support and mouse listener.
We have a situation that we need to make a composite (which
is the child of another parent composite) a drop target and also
allow it movement (using mouse listener mechanism ) within
the parent composite.
I have to make that child composite (which behave like Drop
target) setEnabled(true)... to listen to Drop event.
But at the same time to make it moveable we have to
setEnabled(false) for the respective child.
So, is there any suggession available for get out of the
problem.
plzzzz reply soon it's very urgent!!!!!!!!!!!!
Thanks
n Regards,
Srikant
Lakhanpal
Software Development Engineer
Barco | Control Rooms
A-5, Sector-5
Noida, India
Tel +91
120 4020000
Dir +91
120 4020266
Fax
+91 120 4020100
mailto: srikant.lakhanpal@xxxxxxxxx
http://www.barcocontrolrooms.com
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