Home » Eclipse Projects » Standard Widget Toolkit (SWT) » How to give a user feedback during a Tracker drag(Tracker uses its own event loop apparently. How can I shows users feedback?)
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| Re: How to give a user feedback during a Tracker drag [message #514660 is a reply to message #514572] |
Tue, 16 February 2010 09:12   |
Vijay Raj
Messages: 608
Registered: July 2009 |
Senior Member |
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Can you modify the below snippet for printing it on console...
*
* Drag and Drop example snippet: define a default operation (in this example, Copy)
*
* For a list of all SWT example snippets see
* http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
*/
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DragSource;
import org.eclipse.swt.dnd.DragSourceAdapter;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.DropTargetAdapter;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class Snippet84
{
public static void main(String[] args)
{
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new GridLayout(2, false));
final Label label = new Label(shell, SWT.BORDER);
label.setText("Drag Source");
DragSource source = new DragSource(label, DND.DROP_COPY | DND.DROP_MOVE | DND.DROP_LINK);
source.setTransfer(new Transfer[] { TextTransfer.getInstance() });
source.addDragListener(new DragSourceAdapter()
{
@Override
public void dragSetData(DragSourceEvent event)
{
event.data = "Text Transferred";
}
@Override
public void dragFinished(DragSourceEvent event)
{
if (event.doit)
{
String operation = null;
switch (event.detail)
{
case DND.DROP_MOVE:
operation = "moved";
break;
case DND.DROP_COPY:
operation = "copied";
break;
case DND.DROP_LINK:
operation = "linked";
break;
case DND.DROP_NONE:
operation = "disallowed";
break;
default:
operation = "unknown";
break;
}
label.setText("Drag Source (data " + operation + ")");
}
else
{
label.setText("Drag Source (drag cancelled)");
}
}
});
final Text text = new Text(shell, SWT.BORDER | SWT.MULTI);
text.setText("Drop Target");
DropTarget target = new DropTarget(text, DND.DROP_DEFAULT | DND.DROP_COPY | DND.DROP_MOVE
| DND.DROP_LINK);
target.setTransfer(new Transfer[] { TextTransfer.getInstance() });
target.addDropListener(new DropTargetAdapter()
{
@Override
public void dragEnter(DropTargetEvent event)
{
if (event.detail == DND.DROP_DEFAULT) event.detail = DND.DROP_COPY;
}
@Override
public void dragOperationChanged(DropTargetEvent event)
{
if (event.detail == DND.DROP_DEFAULT) event.detail = DND.DROP_COPY;
}
@Override
public void drop(DropTargetEvent event)
{
String operation = null;
switch (event.detail)
{
case DND.DROP_MOVE:
operation = "moved";
break;
case DND.DROP_COPY:
operation = "copied";
break;
case DND.DROP_LINK:
operation = "linked";
break;
case DND.DROP_NONE:
operation = "disallowed";
break;
default:
operation = "unknown";
break;
}
text.append("\n" + operation + (String) event.data);
}
});
shell.setSize(400, 400);
final Label label1 = new Label(shell, SWT.BORDER);
label1.setText("TEST");
shell.addMouseMoveListener(new MouseMoveListener()
{
@Override
public void mouseMove(MouseEvent e)
{
label1.setText(e.x + " " + e.y);
System.out.println(e.x + " " + e.y);
}
});
shell.open();
while (!shell.isDisposed())
{
if (!display.readAndDispatch()) display.sleep();
}
display.dispose();
}
}
---------------------
why, mr. Anderson, why, why do you persist?
Because I Choose To.
Regards,
Vijay
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| Re: How to give a user feedback during a Tracker drag [message #514782 is a reply to message #514572] |
Tue, 16 February 2010 15:55 |
 Grant Gayed
Messages: 2150
Registered: July 2009 |
Senior Member |
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Hi Mark,
You should not have to do anything special here, I think you're seeing a
bug. The snippet below updates a Label and a TableItem with the Tracker's x
value. On win32 and OSX both of these controls update successfully, but on
GTK only the Label updates, the TableItem does not. I assume you're using
Linux or Solaris?
I've logged https://bugs.eclipse.org/bugs/show_bug.cgi?id=302961 . In the
meantime, maybe you could work around this by using a Control like Label
that stays responsive while the Tracker is open?
public static void main (String [] args) {
Display display = new Display ();
final Shell shell = new Shell (display);
final Label label = new Label(shell, SWT.NONE);
label.setBounds(10,10,100,30);
label.setText("label");
Table table = new Table(shell, SWT.NONE);
table.setBounds(10,50,100,50);
final TableItem item = new TableItem(table, SWT.NONE);
shell.open ();
shell.addListener (SWT.MouseDown, new Listener () {
public void handleEvent (Event e) {
Tracker tracker = new Tracker (shell, SWT.NONE);
tracker.setRectangles (new Rectangle [] {
new Rectangle (e.x, e.y, 100, 100),
});
tracker.addListener(SWT.Move, new Listener() {
public void handleEvent(Event event) {
System.out.println(event.x);
String string = String.valueOf(event.x);
label.setText(string);
item.setText(string);
}
});
tracker.open ();
}
});
while (!shell.isDisposed()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}
Grant
"Mark" <Mark.Fenbers@noaa.gov> wrote in message
news:hlc7vj$gn1$1@build.eclipse.org...
> My program uses the "Tracker" widget to let users drag a box around the
window. The software lacks a means of providing feedback to the user as to
the exact location of the box they are dragging. In the Tracker's
ControlMoved handler/listener, I can write out these coordinates to the
console, but when I try to update the GUI, say through a ToolTip or through
a table cell, the update is blocked until the user releases the mouse button
(i.e., "drops" the Tracker).
>
> I tried putting the Tracker object in a new Runnable using "syncExec()",
but that provided no improvement over the problem. What must I do to have
GUI elements update on-the-fly while a Tracker widget is being dragged by
the user?
>
> Mark
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| Re: How to give a user feedback during a Tracker drag [message #514902 is a reply to message #514782] |
Wed, 17 February 2010 05:47 |
Vijay Raj
Messages: 608
Registered: July 2009 |
Senior Member |
|
|
But Grant...
With drag and drop operation the problem does happen...
Lets suppose user performs a drag and drop operation and tracker mechanism is used to show that drag operation...
In that case the GUI update does freez...
---------------------
why, mr. Anderson, why, why do you persist?
Because I Choose To.
Regards,
Vijay
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