Re: [matplotlib-devel] wrote a selection bar widget (attached)

[Egor Z. <ez...@gm...>]

Hi John,

John Hunter wrote:
> On Wed, Nov 26, 2008 at 11:57 AM, Egor Zindy <ez...@gm...> wrote:
>
>   
>> thank you, I'll have to check out the repository to see how I can use the
>> changes.
>>
>> Just a thought: a figure_leave / figure_enter event could be triggered by
>> comparing the currently held axis with event.inaxes (that's what Slider and
>> my bar widget do in _update() ).
>>     
>
> That's exactly how its done.  The problem I referred to above (which
> will not affect your use case since you are leaving the axes) occurs
> when you want to connect to a figure leave event and move your mouse
> to a non-mpl window.  Then we get no events to compare to the prior.
>
> JDH
>   

The new version attached that fixes a few of the things I was unhappy about:
* radius for clicking the bar now in pixels
* case when mouse pointer is outside the graph now handled correctly.
* commented the methods a bit more (still working on that)

Both these rely on the following two functions:

    #convert from x to xdata
    print self.ax.transData.inverted().transform_point((event.x, event.y))

    #convert from xdata to x
    print self.ax.transData.transform_point((event.xdata, event.ydata))

event.x always returns a value, so I used that to "fix" xdata when the 
cursor is outside the graph

Things I have struggled with (this time):
* there is a toobar.set_cursor() but no toolbar.get_cursor() which would 
be interesting to have to set the cursor back to what it should be 
(rather than arbitrary POINTER type).
* more cursor types would be nice (could do with size_ver and size_hor 
in 
http://wiki.openusability.org/guidelines/index.php/Design_and_Layout:Visual_Design:Cursors).
* took a long time to check out matplotlib from SVN, have yet to check 
the new events out.
* a nice name? (been struggling with that a lot lately!) Is "Bar" OK? or 
maybe "SelectionBar"?

Regards,
Egor