help request: wx, tk, qt backend leave event

I recently added support for a figure/axes enter/leave event. The
figure enter and axes enter/leave are easy to do with nothing new in
the backends, just using the native mpl events. The figure leave
event is harder, because when a user leaves a figure and activates
another window, mpl gets no events.

To correct this, I added a leave_notify_event method to
backend_bases.FigureCanvasBase (note this is not an mpl Event) but
when called it will trigger a callback to those registered to the
figure_leave_event with the last event that occurred in the window.

I added support for this in gtk by connecting the the gtk signal
'leave_notify_event' to the mpl backend method leave_notify_event. If
you know something about tk, wx or qt event handling, could you add a
similar method to the appropriate backend? You can follow the example
in backend_gtk.

You can test with examples/event_handling/figure_axes_enter_leave.py

Thanks,
JDH

I can have a look at the qt backends, maybe this weekend.

···

On Wed, Nov 26, 2008 at 2:05 PM, John Hunter <jdh2358@…149…> wrote:

I recently added support for a figure/axes enter/leave event. The

figure enter and axes enter/leave are easy to do with nothing new in

the backends, just using the native mpl events. The figure leave

event is harder, because when a user leaves a figure and activates

another window, mpl gets no events.

To correct this, I added a leave_notify_event method to

backend_bases.FigureCanvasBase (note this is not an mpl Event) but

when called it will trigger a callback to those registered to the

figure_leave_event with the last event that occurred in the window.

I added support for this in gtk by connecting the the gtk signal

‘leave_notify_event’ to the mpl backend method leave_notify_event. If

you know something about tk, wx or qt event handling, could you add a

similar method to the appropriate backend? You can follow the example

in backend_gtk.

You can test with examples/event_handling/figure_axes_enter_leave.py

Thanks,

JDH


This SF.Net email is sponsored by the Moblin Your Move Developer’s challenge

Build the coolest Linux based applications with Moblin SDK & win great prizes

Grand prize is a trip for two to an Open Source event anywhere in the world

http://moblin-contest.org/redirect.php?banner_id=100&url=/


Matplotlib-devel mailing list

Matplotlib-devel@lists.sourceforge.net

https://lists.sourceforge.net/lists/listinfo/matplotlib-devel

I implemented this in backend_qt4.

Darren

···

On Wed, Nov 26, 2008 at 2:05 PM, John Hunter <jdh2358@…149…> wrote:

I recently added support for a figure/axes enter/leave event. The

figure enter and axes enter/leave are easy to do with nothing new in

the backends, just using the native mpl events. The figure leave

event is harder, because when a user leaves a figure and activates

another window, mpl gets no events.

To correct this, I added a leave_notify_event method to

backend_bases.FigureCanvasBase (note this is not an mpl Event) but

when called it will trigger a callback to those registered to the

figure_leave_event with the last event that occurred in the window.

I added support for this in gtk by connecting the the gtk signal

‘leave_notify_event’ to the mpl backend method leave_notify_event. If

you know something about tk, wx or qt event handling, could you add a

similar method to the appropriate backend? You can follow the example

in backend_gtk.

You can test with examples/event_handling/figure_axes_enter_leave.py

John Hunter schrieb:

I recently added support for a figure/axes enter/leave event. The
figure enter and axes enter/leave are easy to do with nothing new in
the backends, just using the native mpl events. The figure leave
event is harder, because when a user leaves a figure and activates
another window, mpl gets no events.

To correct this, I added a leave_notify_event method to
backend_bases.FigureCanvasBase (note this is not an mpl Event) but
when called it will trigger a callback to those registered to the
figure_leave_event with the last event that occurred in the window.

I added support for this in gtk by connecting the the gtk signal
'leave_notify_event' to the mpl backend method leave_notify_event. If
you know something about tk, wx or qt event handling, could you add a
similar method to the appropriate backend? You can follow the example
in backend_gtk.

You can test with examples/event_handling/figure_axes_enter_leave.py

Thanks,
JDH

I attached a patch for the wx backend. Nearly everything has already been implemented. Instead of the new 'leave_notify_event' leaving the figure triggered a fake motion_event. I changed this.

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?

Gregor

leave.diff (630 Bytes)

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)?

Any takers out their to add support to tk?
Thanks,
JDH

···

On Tue, Dec 2, 2008 at 8:34 AM, Gregor Thalhammer <gregor.thalhammer@...149...> 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?

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.

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?

Finally, off topic, I committed the improved version checking in mpl.init, using subprocess instead of popen*, which were deprecated in python-2.6. This has been tested on two separate windows machines, hopefully there are no lurking issues. But its something to keep in mind when we cut the next release for windows.

Darren

···

On Tue, Dec 2, 2008 at 10:41 AM, John Hunter <jdh2358@…149…> wrote:

On Tue, Dec 2, 2008 at 8:34 AM, Gregor Thalhammer > > <gregor.thalhammer@…149…> 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)?

Can you update, repatch wx to use it (and Darren qt)?

I attached a patch that emits a enter_notify_event if the mouse enters the figure. Now the example behaves correctly.

Gregor

enter.diff (901 Bytes)

2008/12/2 Darren Dale <dsdale24@…149…>

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?

With all backends (Wx, GTK, Qt) I manage to leave the figure, without leaving an axis. Either I move very fast, or I stack the figures on screen so that I can leave an axis without touching the space around. We could emit axes_leave_events (to all axes of the figure, or do we keep record which axes has been entered recently?) before emitting a figure_leave_event, or leave this to the users implementation of the figure_leave_event callback. The first solution might lead to a lot of undesired redraws of the figure when leaving the figure if several axes are contained in the figure and each leave_axes callback issues a redraw, like in the example.

Gregor

···

On Tue, Dec 2, 2008 at 10:41 AM, John Hunter <jdh2358@…149…> wrote:

On Tue, Dec 2, 2008 at 8:34 AM, Gregor Thalhammer > > > > <gregor.thalhammer@…149…> wrote:

Yes, this is the behavior I see.

···

On Wed, Dec 3, 2008 at 9:26 AM, Gregor Thalhammer <gregor.thalhammer@…149…> wrote:

2008/12/2 Darren Dale <dsdale24@…149…>

On Tue, Dec 2, 2008 at 10:41 AM, John Hunter <jdh2358@…149…> wrote:

On Tue, Dec 2, 2008 at 8:34 AM, Gregor Thalhammer > > > > > > <gregor.thalhammer@…149…> 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?

Thanks Gregor -- just committed this. I don't have any other feedback
on the other points you and Darren are discussing yet....

JDH

···

On Wed, Dec 3, 2008 at 6:43 AM, Gregor Thalhammer <gregor.thalhammer@...149...> wrote:

Can you update, repatch wx to use it (and Darren qt)?

I attached a patch that emits a enter_notify_event if the mouse enters the
figure. Now the example behaves correctly.