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You can't remove an element from a virtual TableViewer. You can't even clear the whole content. The remove method seems to be a no-op. import org.eclipse.jface.viewers.TableViewer; import org.eclipse.swt.SWT; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class Test { public static void main(String[] args) { Shell shell=new Shell(Display.getCurrent()); shell.setLayout(new FillLayout()); TableViewer table=new TableViewer(shell,SWT.VIRTUAL); Object item="item"; table.add(item); table.remove(item); shell.setVisible(true); while(!shell.isDisposed()) { shell.getDisplay().readAndDispatch(); } } }
The problem starts in VirtualManager#addTableListener(). The code has the "problem" that the table's content is modified before it is shown to the user. So the table-listener is not notified about the "SWT.SetData" and no connection between the tableitem and our model object is known. So it could not be removed. The attached source behaves appropriate: Shell shell=new Shell(Display.getCurrent()); shell.setLayout(new FillLayout()); final TableViewer table=new TableViewer(shell,SWT.VIRTUAL); final Object item="item"; table.add(item); Button b = new Button(shell,SWT.PUSH); b.addSelectionListener(new SelectionListener() { public void widgetDefaultSelected(SelectionEvent arg0) { } public void widgetSelected(SelectionEvent arg0) { table.remove(item); } }); shell.setVisible(true); while(!shell.isDisposed()) { shell.getDisplay().readAndDispatch(); } I'm not sure what could be done to prevent the user from this situation at least is should be documented. (In reply to comment #0) > You can't remove an element from a virtual TableViewer. You can't even clear > the whole content. The remove method seems to be a no-op. > > import org.eclipse.jface.viewers.TableViewer; > import org.eclipse.swt.SWT; > import org.eclipse.swt.layout.FillLayout; > import org.eclipse.swt.widgets.Display; > import org.eclipse.swt.widgets.Shell; > > public class Test > { > public static void main(String[] args) > { > Shell shell=new Shell(Display.getCurrent()); > shell.setLayout(new FillLayout()); > > TableViewer table=new TableViewer(shell,SWT.VIRTUAL); > > Object item="item"; > > table.add(item); > table.remove(item); > > shell.setVisible(true); > > while(!shell.isDisposed()) > { > shell.getDisplay().readAndDispatch(); > } > } > } >
Sorry, I don't understand what this bug is about. Your TableViewer instance is not set up properly (you need a content provider and an input, and a label provider). There is a bug in TableViewer.remove for the virtual case, see bug 97786.
After a couple of hours struggling against my full software to manage to isolate the problem, here is a quick code demonstrating the problem I have with the element removal on VIRTUAL tables. The logic is as follows: Initially the table is empty, it contains no element. Then, some external trigger occurs (here a button), and three items are added into the table. Then, some new external trigger occurs (here the button again), and the three previously added elements are removed. Finally, a last trigger occurs (still my lovely button), and the three items get readded. Well actually they don't, because I get an AOOBE instead. Note that removing the VIRTUAL attribute solves the problem. I'm not quite sure this is a duplicate of bug 97786, but if it is, well... do you plan to fix it someday? :) import org.eclipse.jface.viewers.IStructuredContentProvider; import org.eclipse.jface.viewers.TableViewer; import org.eclipse.jface.viewers.Viewer; import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.layout.RowLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class Test { private static class MyContentProvider implements IStructuredContentProvider { private TableViewer _viewer; private int _step=0; private Object[] _items=new Object[] {"one","two","three"}; public Object[] getElements(Object arg0) { switch(_step) { case 0: return new Object[0]; case 1: return _items; case 2: return new Object[0]; case 3: return _items; } return new Object[0]; } public void dispose() { } public void inputChanged(Viewer arg0,Object arg1,Object arg2) { _viewer=(TableViewer)arg0; } public void nextStep() { _step++; switch(_step) { case 1: _viewer.add(_items); break; case 2: _viewer.remove(_items); break; case 3: _viewer.add(_items); break; } } } public static void main(String[] args) { Shell shell=new Shell(Display.getCurrent()); shell.setLayout(new RowLayout()); final TableViewer table=new TableViewer(shell,SWT.VIRTUAL); final MyContentProvider provider=new MyContentProvider(); table.setContentProvider(provider); table.setInput("input"); Button b1=new Button(shell,SWT.PUSH); b1.addSelectionListener(new SelectionListener() { public void widgetSelected(SelectionEvent arg0) { provider.nextStep(); } public void widgetDefaultSelected(SelectionEvent arg0) { }}); shell.setVisible(true); while(!shell.isDisposed()) { shell.getDisplay().readAndDispatch(); } } }
Thanks for the snippet! This does not look like a duplicate of bug 97786. As a workaround, does calling refresh() work?
Boris as you may see from the code I added the problem is that the "SWT.SetData" event only occurs if you have opened the shell and because the tableItem#setData(modelobject) only happens if this table event is triggered the removal of elements using tableViewer#remove(modelobject) is NOT working until you have opened the main shell! As far as I can see this has nothing todo with content-providers, ... (In reply to comment #2) > Sorry, I don't understand what this bug is about. Your TableViewer instance is > not set up properly (you need a content provider and an input, and a label > provider). > > There is a bug in TableViewer.remove for the virtual case, see bug 97786. >
(In reply to comment #3) > After a couple of hours struggling against my full software to manage to > isolate the problem, here is a quick code demonstrating the problem I have with > the element removal on VIRTUAL tables. > > The logic is as follows: > Initially the table is empty, it contains no element. > Then, some external trigger occurs (here a button), and three items are added > into the table. > Then, some new external trigger occurs (here the button again), and the three > previously added elements are removed. > Finally, a last trigger occurs (still my lovely button), and the three items > get readded. Well actually they don't, because I get an AOOBE instead. > > Note that removing the VIRTUAL attribute solves the problem. I've tried this bug with the fix given in bug #144406 and its working as expected: 1st Button press: 3 items are added 2nd Buttun press: 3 items are removed 3rd Button press: 3 items are added So it seems this fixes your main problem what stays unfixed is the problem demonstrated in your first snippet where the structure changes are not propagated because they happen before the main shell is opened.
Boris if you are not planning to address this for 3.2.1 you should remove the tag. The release candidates start next week.
I will attach a patch to bug 154755 but leave this one open to track the particular issue reported here. Unfortunately, there are just too many changes required to fix the problems with VIRTUAL TableViewer so we have to move this to 3.3.
I hope we can get to this in 3.4. In 3.3, I ended up spending so much time on the virtual tree (which is used by Debug) that I never got to look at virtual tables.
Mass update - removing 3.4 target. This was one of the bugs I marked for investigation (and potential fixing) in 3.4 but I ran out of time. Please ping on the bug if fixing it would be really important for 3.4, and does not require API changes or feature work.
Any known workaround?
(In reply to comment #11) > Any known workaround? To which exact problem? Could you file a new bug with a snippet for me to look at?
I used to have this code: remove_the_object_from_my_content_provider(); viewer.remove(deletedObject); but doesn't work well due to this bug. So, I have tried now this logic for removing an object: remove_the_object_from_my_content_provider(); viewer.setItemCount(viewer.getTable().getItemCount()-1); viewer.refresh(); but it doesn't refresh well my data. What do you recommend me to do?
My problem is this: I have a table viewer which manages a table with the virtual style, and a content provider that implements ILazyContentProvider. When I delete a single object, first I delete from my content provider and then I invoke tableViewer.remove(deletedItem). Sometimes, the item count of the table isn't decreased, and the deleted item is showed twice. I could spend some time getting a simple snippet showing the problem, but I think I don't need to invest this time, as this is an already known problem. Example: I have these items in my table viewer: A B and I delete the A item (the selected index). The viewer then shows this: B B
Hitesh is now responsible for watching bugs in the [Viewers] component area.
It's incredible such an old and basic bug isn't yet solved. Probably because few people use virtual tables.
Mike, something for you?
This bug hasn't had any activity in quite some time. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet. As such, we're closing this bug. If you have further information on the current state of the bug, please add it and reopen this bug. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant. -- The automated Eclipse Genie.
