Pending release of 0.3

[Chris Colbert]

The plugin system makes it extremely easy to make any kind of display
plugin you want. You just have to provide at least two methods and
shake hands with the window manager.

your plugin must provide the following two functions:

imshow(img, *arg, **kwarge)

and

__app_show()


you must also "shake hands" with the window manager.  A common
occurance in the gui tookits is the windows opened from within
functions during an interactive python session will be garbage
collected after the function returns and they fall out of scope. Thus
the window manager maintains a reference to the window until it is
closed. Also, because the gui toolkits set PyOS_InputHook, we have to
make sure that only one gui kit gets imported in a session (some kits
will trample on other, but not vice-versa) so the window manager also
implements a "gui lock" that you must acquire before using it or your
gui kit:

from util import window_manager

window_manager.acquire('qt')  #or 'gtk' or 'mybadassplugin'

then evertime you create a window, register the main_window handle
with the manager.

window_manager.add_window(mynew_window)

Then, make sure that mynew_window's destroy event, whatever that may
be, makes a call to window_manager.remove_window(mynew_window)

The window manager also implements a callback that can be set, that
will be called when there are no more registered windows.
This was necessary for non-interactive sessions, so you can kill the
event loop. This is also the reason for __app_show():

You're plugin must also define an __app_show() method. When not
running interactively (i.e. from a script), calls to imshow() will
queue up windows, but without a gui mainloop running, they will never
display. When a user calls show(), this calls your plugins
__app_show() method, which should do two things:
1) register a callback with window_manager that will be called when
all windows are closed and will cause the event loop to exit (this may
not be required for some kits. i.e. PyQt4)
2) start the mainloop

for the pygtk plugin, it looks like this:

def __app_show():


On Wed, Nov 4, 2009 at 7:53 AM, SirVer <sirver at gmx.de> wrote:
>
> Hi Stefan,
>
> I do not know were I'm currently at. My gui branch is not merged to
> master, so I guess you are unhappy with it. There is other development
> based on the plugin architecture and we have now yet another image
> viewer in pyqt. Still I feel that a full featured gui module could
> lead to much more powerful image processing widgets than the plugin
> system could. So I am unsure if and if yes how I should advance with
> my gui & camcalib branch.
>
> Cheers,
> Holger
>
> On 3 Nov., 22:40, Stéfan van der Walt <ste... at sun.ac.za> wrote:
>> Hi all,
>>
>> I am planning to tag version 0.3 by the end of this week or early next
>> week.  Please let me know if there are any branches I should review
>> before then.
>>
>> Happy hacking!
>> Stéfan