Multi-Row Drag and Drop strange behavior

Hi Guys,

I am experiencing some strange behaviour with a table drag and drop. I have it configured for the table to drop multi-rows onto other rows.

The issue is, if a row is selected and you drag on another row (that is not selected) a drag will begin with the unselected row. My understanding is that if the DragMode is set to MULTIROW I should not be able to start a drag by dragging unselected items.

Test Code to reproduce:

public class TableMultiSelectApplication extends Application {
	@Override
	public void init() {
		Window mainWindow = new Window("Table Application");
		Table t = new Table("Table");
		t.addContainerProperty("Id", String.class, null);
		t.addItem(new Object[]{"1"}, new Integer(1));
		t.addItem(new Object[]{"2"}, new Integer(2));
		t.addItem(new Object[]{"3"}, new Integer(3));
		t.addItem(new Object[]{"4"}, new Integer(4));
		t.addItem(new Object[]{"5"}, new Integer(5));
		t.addItem(new Object[]{"6"}, new Integer(6));
		t.setSizeFull();
		t.setSelectable(true);
		t.setMultiSelect(true);
		t.setDragMode(TableDragMode.MULTIROW);
		mainWindow.addComponent(t);
		setMainWindow(mainWindow);
	}
}

So in this example, if you select items 3 & 4, and then drag item 1, a new drag will initiate with record #1. Running Vaadin 6.7.9.

Let me know if I have something setup wrong.

Cheers,
~Ben

PS: I also noted that if I shift-select 3 items and drag them, the drag overlay only shows 1 record. When you command-select 3 items it shows all 3. This is purely a graphical issue though, where as the first issue I can't work around.

Can anyone else verify this behavior?

Is nobody else having this issue? This bug basically makes table drag and drop unusable.

Ben Lewis: The issue is, if a row is selected and you drag on another row (that is not selected) a drag will begin with the unselected row. My understanding is that if the DragMode is set to MULTIROW I should not be able to start a drag by dragging unselected items.

The behavior of Vaadin matches that of e.g. Windows Explorer and Nautilus on Linux - if you start a drag from an unselected item, only that item is dragged.

Hi Henri,

Oh wow you are right. I have never noticed this - to me that seems bizarre - surely the dragged row should become selected - anyway so its not a bug. Has the documentation been updated on this, I can't seem to find the reference to drags not starting if other rows are selected. PS: this drag behavior is the same on Mac OS X as well.

Thanks for your help!

~Ben