[news.eclipse.platform.swt] Re: Windows fires SelectionEvent on tree.set

["Grant Gayed" <grant_gayed@xxxxxxxxxx>]

Hi,

I've logged swt bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=229171 .
As I said there, I think that what's making your case fail on win32 is the
disposing of the previously-focused/selected item before changing the
selection.  So somehow not doing this (eg.- changing the order of some
steps, etc.) should allow you to work around this.  Another workaround would
be to unhook and re-hook the Selection listener as you've tried, but to put
the re-hook in a display.asyncExec(...) so that it runs a bit later.

Grant


"Fabian Zeindl" <fabian@xxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:fv222m$5pd$1@xxxxxxxxxxxxxxxxxxxx
> Here you are...
>
> fabian
>
> Tom Schindl schrieb:
> > Hi,
> >
> > Well you could try. If you need immediate help you can use IRC
> > (#eclipse-dev at irc.freenode.net, nick: tomsontom), I'm online today in
> > the late afternoon. So if you ping have snippet post it to this thread
> > and then ping me on IRC.
> >
> > Greetings from the western part of Austria :-)
> >
> > Tom
> >
> > Fabian Zeindl schrieb:
> >> Tom Schindl schrieb:
> >>> Looks like a timing issue or are do doing something with
> >>> Display#asyncExec()? From what you say I construct the following.
> >>>
> >>> You've got a TextWidget and TreeWidget and when entry text you are
> >>> updating the selection in your Tree and the other way round, right?
> >>
> >> true.
> >>
> >>> I guess we need some code to reproduce this. You should try to write
> >>> a small snippet you can paste here and we can run.
> >>
> >> ok I'll do that. Will you be online again at some time this weekend?
> >> Unfortunately my solution is due on monday :-/.
> >>
> >> greetings / Grüße
> >> fabian
> >>
> >>> Tom
> >>>
> >>> Fabian Zeindl schrieb:
> >>>> Another strange problem: When I remove the SelectionListener right
> >>>> before the setSelection and add it afterwards it still gets called
> >>>> when calling setSelection. Why is that?
> >>>> I don't know whether this helps, but the SelectionListener gets
> >>>> called _after_ the method which calls setSelection finished. The
> >>>> method itself is a ModifyListener.
> >>>>
> >>>> fabian
> >>>>
> >>>> Tom Schindl schrieb:
> >>>>> It is a bug if SWT fires a SelectionEvent when setting a selection
> >>>>> programmatically!
> >>>>>
> >>>>> Tom
> >>>>>
> >>>>> Fabian Zeindl schrieb:
> >>>>>> Hi,
> >>>>>>  for some unknown reason Win32 fires a SelectionEvent when I do
> >>>>>> tree.setSelection(TreeItem item) where gnu/linux doesn't fire one.
> >>>>>> Is there a reason for this behaviour? Funnily enough, when I
> >>>>>> change the code to be simpler, Windows doesn't fire an event on
> >>>>>> setSelection.
> >>>>>> Is this an SWT-Bug?
> >>>>>>
> >>>>>> thanks in advance
> >>>>>> fabian
> >>>>>
> >>>>>
> >>>
> >>>
> >
> >
>
>


----------------------------------------------------------------------------
----


> import org.eclipse.swt.*;
> import org.eclipse.swt.layout.*;
> import org.eclipse.swt.widgets.*;
> import org.eclipse.swt.graphics.*;
> import org.eclipse.swt.events.*;
> import java.util.*;
>
> public class Test
> {
> public static void main(String[] args)
> {
> new Test();
> }
>
> private Text text1, text2;
> private Tree tree;
> private TextModifyListener textlistener = new TextModifyListener();
> private TreeSelectionListener treelistener = new TreeSelectionListener();
> private ArrayList<TreeItem> lastCreatedItems = new ArrayList<TreeItem>();
>
> public Test()
> {
> Display display = new Display();
> Shell shell = new Shell();
> shell.setLayout( new GridLayout(2,false) );
>
> // Text 1
> text1 = new Text(shell, SWT.BORDER);
> text1.setLayoutData( new GridData(SWT.NONE,SWT.NONE,true,true) );
> text1.addModifyListener(textlistener);
>
> // Tree
> tree = new Tree(shell, SWT.BORDER);
> tree.setLayoutData( new GridData(SWT.FILL,SWT.FILL,true,true,1,2) );
> tree.addSelectionListener(treelistener);
>
> // Kinder erzeugen
> TreeItem item = new TreeItem(tree, SWT.NONE);
> item.setText("parent1");
> item = new TreeItem(item, SWT.NONE);
> item.setText("child1");
> item = new TreeItem(tree, SWT.NONE);
> item.setText("parent2");
> item = new TreeItem(item, SWT.NONE);
> item.setText("child2");
>
> // Text 2
> text2 = new Text(shell, SWT.BORDER);
> text2.setLayoutData( new GridData(SWT.NONE,SWT.NONE,true,true) );
> text2.addModifyListener(textlistener);
>
> shell.open();
> while (!shell.isDisposed())
> if (!display.readAndDispatch())
> display.sleep();
> }
>
> private void createTreeItems(ArrayList<String> category)
> {
> // run through list to find last non-empty entry
> int lastNonEmptyLevel = -1;
> for (int i = (category.size()-1); i >= 0; i--)
> {
> if (!category.get(i).matches("\\s*"))
> {
> lastNonEmptyLevel = i;
> break;
> }
> }
>
> // delete all manually created items
> for (TreeItem item : lastCreatedItems)
> item.dispose();
> lastCreatedItems.clear();
>
> // create TreeItems for category
> TreeItem parent = null;
> for (int i=0; i <= lastNonEmptyLevel; i++)
> {
> // Search for matching item and created
> TreeItem item = getMatchingChild(parent, category.get(i));
> if (item == null)
> {
> item = createChild(parent, category.get(i));
> lastCreatedItems.add( item );
> }
>
> // expand item
> if (parent != null)
> parent.setExpanded(true);
>
> parent = item;
> }
>
> // Removing the Listener doesn't work
> // this.tree.removeSelectionListener( this.treelistener );
>
> // comment out -> no SelectionEvents
> if (parent != null) {
> tree.setSelection(parent);
> }
>
> // this.tree.addSelectionListener( this.treelistener );
> }
>
> private class TextModifyListener implements ModifyListener
> {
> public void modifyText(ModifyEvent e)
> {
> System.out.println( "text: ModifyEvent!" );
>
> ArrayList<String> list = new ArrayList<String>();
> list.add(text1.getText());
> list.add(text2.getText());
> createTreeItems( list );
>
> System.out.println( "text: ModifyEvent dispatched!" );
> }
> }
>
> private class TreeSelectionListener extends SelectionAdapter
> {
> public void widgetSelected(SelectionEvent e)
> {
> System.out.println( "tree: SelectionEvent: " + e.hashCode() );
>
> if (tree.getSelectionCount() > 0)
> {
> TreeItem selectedItem = tree.getSelection()[0];
>
> // depth of selection
> int depth = 0;
> TreeItem parent = selectedItem;
> while ((parent = parent.getParentItem()) != null)
> depth ++;
>
> // fill TextFields
> switch (depth)
> {
> case 0:
> text1.setText( selectedItem.getText() );
> text2.setText("");
> break;
> case 1:
> text1.setText( selectedItem.getParentItem().getText() );
> text2.setText( selectedItem.getText() );
> break;
> }
> }
>
> System.out.println( "tree: SelectionEvent dispatched!" );
> }
> }
>
> private TreeItem getMatchingChild(TreeItem parent, String text)
> {
> TreeItem[] children = (parent != null ? parent.getItems() :
this.tree.getItems());
>
> for (TreeItem item : children)
> {
> if (item.getText().equals(text))
> {
> return item;
> }
> }
>
> return null;
> }
>
> private TreeItem createChild(TreeItem parent, String text)
> {
> TreeItem[] children = (parent != null ? parent.getItems() :
this.tree.getItems());
>
> int index=0;
> while (index < children.length &&
children[index].getText().compareTo(text) < 0)
> {
> index++;
> }
>
> TreeItem newItem = (parent != null ? new TreeItem(parent, SWT.NONE, index)
: new TreeItem(this.tree, SWT.NONE, index));
> newItem.setText(text);
>
> return newItem;
> }
> }
>