Alt key issues with wxPython

Scripting Issues
1

Hey all,

I know others have reported alt key issues in other threads but I’m not sure this is the same issue.

I have a Panda3D window as a child of a wx frame. I’m also trying to duplicate Maya style controls, so moving the editor camera is done by holding down alt with one of the mouse buttons. If I move focus to another panel of the frame then click back on the Panda panel, I get a click captured but no modifiers captured if I am also holding down alt.

I thought maybe I could beat this by storing the alt modifier separately instead of binding to the click and modifier at the same time like this:

self.accept( 'alt-mouse1', self.SetButton )

but even using

self.accept( 'alt', self.OnAltDown )
self.accept( 'alt-up', self.OnAltUp )

doesn’t seem to give reliable results - the alt key up doesn’t seem to fire all the time.

Does anyone know how I can beat this? Thanks in advance!

2

The alt key is particularly troublesome because the operating system often eats it before Panda even gets a chance to see it. This is certainly true on Linux and OSX. What operating system are you running on?

David

3

Running on win7 with latest stable release of Panda.

4

Does it behave correctly if you leave the window unattached to the wx frame? It might be an issue with the wxFrame eating the alt events as well.

David

5

I believe so. I suppose I could bind the alt key on the wx side to toggle a flag that Panda could read, so either loop could catch the event. Seems a bit dirty to do it that way however :frowning:

6

For anyone interested, I got around this issue by using this code:

def OnKey( evt, action='' ):
    
    """
    Bind this method to a wx.EVT_KEY_XXX event coming from a wx panel or
    other widget, and it will stop wx 'eating' the event and passing it to
    Panda's base class instead.
    """
    
    keyCode = evt.GetKeyCode()
    
    if keyCode == wx.WXK_SPACE:
        messenger.send( 'space' + action )
    elif keyCode == wx.WXK_DELETE:
        messenger.send( 'del' + action )
    elif keyCode == wx.WXK_BACK:
         messenger.send( 'backspace' + action )
    elif keyCode == wx.WXK_ALT:
        messenger.send( 'alt' + action )
    elif keyCode in range( 256 ):
        messenger.send( chr( keyCode ).lower() + action )

def OnKeyUp( evt ):
    OnKey( evt, '-up' )
    

def OnKeyDown( evt ):
    OnKey( evt )

and binding it to my wx.Frame (and any other panels that were catching events out of the box) like this:

self.Bind( wx.EVT_KEY_UP, OnKeyUp )
self.Bind( wx.EVT_KEY_DOWN, OnKeyDown )