Re: [JPP-Devel] Pan and Zoom shortcut keys problem

[Larry B. <bec...@gm...>]

If no one really needs the pan and zoom shortcut keys, we could just disable
InstallKeyPanPlugIn in the default-plugins.xml file.  Those who really need
it and are willing to accept the side effects can add it to their
workbench-properties.xml file.  Comments?

regards,
Larry

On Thu, Jan 29, 2009 at 1:49 PM, Larry Becker <bec...@gm...>wrote:

> I now have a pretty complete understanding of the "Pan and Zoom shortcut
> keys problem".  I have attempted to fix it, but nothing seems to work.  To
> reiterate the problem, when the arrow and page up/page down keys are used to
> move the cursor while editing layer names, they continue to pan and zoom the
> layer view.   This unexpected behavior also occurs during other arrow key
> uses like menu selection.  I consider this a "must fix" problem because is
> makes the UI unpredictable.  Here is what I've found out so far:
>
> 1) Pan and Zoom key shortcuts are implemented in a separate plugin written
> by Ugo.
> 2) It uses the WorkBenchFrame#addKeyboardShortcut method (I'm doing this
> from memory so don't quote me on the exact name).
> 3) It implements no checks to determine the context before executing the
> shortcut commands.
> 4) It is possible to add an EnableCheck when the keyboard shortcut is
> defined.
> 5)  I have tried several EnableCheck versions, but so far have not found a
> way to restrict the pan and zoom behavior to only the layer view.  This
> seems trivial, but isn't because the methods are called multiple times with
> different panels "active".
> 6) The LayerNamePanel and the LayerViewPanel are implemented as JSplitPane
> panels under the TaskFrame.
> 7) Here is the real problem: There doesn't seem to be a definition in Java
> of "front most" component in a split pane, so both panels get all of the key
> events.
> 8) In order to fix the problem it is necessary to restrict the scope of the
> pan and zoom keyboard shortcuts.
> 9) I could not find a way to ensure that the LayerViewPanel is "not active"
> when the task window active.  I'm not even sure if this would be a good
> idea.
> 10) Unless someone can see a way out of this trap, it doesn't look like the
> problem has a code solution.
>
> The floor is open for alternative solutions.  We could, for instance, check
> for less often used key combinations like control-arrow which might minimize
> the conflicts.
>
> regards,
> Larry
> --
> http://amusingprogrammer.blogspot.com/
>



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