Re: [matplotlib-devel] help request: wx, tk, qt backend leave event

[Darren D. <dsd...@gm...>]

On Wed, Dec 3, 2008 at 9:26 AM, Gregor Thalhammer <
gre...@gm...> wrote:

>
>
> 2008/12/2 Darren Dale <dsd...@gm...>
>
>>
>>
>> On Tue, Dec 2, 2008 at 10:41 AM, John Hunter <jd...@gm...> wrote:
>>
>>> On Tue, Dec 2, 2008 at 8:34 AM, Gregor Thalhammer
>>> <gre...@gm...> wrote:
>>>
>>> > If a mouse button is pressed while leaving the figure the behaviour is
>>> > somewhat strange. First, a figure_leave_event is emitted. Then, further
>>> > moving the mouse outside the figure a new figure_enter_event is
>>> created.
>>> > This is the case since all mouse events, also movements outside the
>>> window,
>>> > are captured as long as a mouse button is pressed. This is a very
>>> convenient
>>> > behaviour for panning/zooming. However, when finally releasing the
>>> mouse
>>> > button no figure_leave_event is triggered. With the GTK backend such an
>>> > event is created.
>>> > So what should be the desired behaviour?
>>>
>>> Ahh, I hadn't considered this problem.  It arises because I am using
>>> mpl location events to trigger the figure enter event.  The solution
>>> is to use the gui event for the figure enter event too -- basically
>>> the gui needs to call the canvas.enter_notify_event.  I added your
>>> patch and modified gtk to handle the enter_notify_event in svn r6468.
>>> Can you update, repatch wx to use it (and Darren qt)?
>>
>>
>> This is done for qt and qt4. In qt, if you hold the  button, leave the
>> figure, enter the second figure, and release the button, the old  figure
>> receives the leave event, but the new figure does not receive the enter
>> event. This seems like an issue with qt3, the new figure does receive the
>> enter event with qt4.
>>
>
> with the patched wx backend I observe the same behaviour. The second figure
> does not recieve an enter event. This might be because the wx backend
> captures the mouse if a button is pressed, i.e., all mouse events are
> redirected to the first figure.
>
> > I noticed that if one moves the cursor rapidly through the figure and
> axes, some events are not captured. For example, the cursor is in an axes
> but the last event the axes received was a leave event. I'm not sure how
> that could be improved, do you see it as well?
>
> Exactly this behaviour I can't see with the wx backend. Did I understood
> correctly: You manage to place the mouse within an axis, without having
> received a enter event?
>

Yes, this is the behavior I see.