bug#21813: 24.5; python.el & Qt (PySide) - widgets remain hidden

bug#21813: 24.5; python.el & Qt (PySide) - widgets remain hidden

[Angus Melville]

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The following lines should make a QT widget appear on the screen, and will
do if run direcly from IDLE or from iPython notebook:

import sys
from PySide import QtGui

app = QtGui.QApplication.instance()
if not app:
    app = QtGui.QApplication(sys.argv)

class Widget(QtGui.QDialog):
    def __init__(self):
        super().__init__()

widget = Widget()
widget.show()

sys.exit(app.exec_())

However if run from EMACS using the default python.el mode, no widget
will pop up on the screen.  This means that many Pyside programs, such
as example programs found at
https://github.com/nicoddemus/PySide-Examples/tree/master/examples when
run from EMACS will produce no response.

If we modify the program to embed a second widget within our main widget,
as below, the widget does pop up on the screen:

import sys
from PySide import QtGui

app = QtGui.QApplication.instance()
if not app:
    app = QtGui.QApplication(sys.argv)

class Widget1(QtGui.QDialog):
    def __init__(self):
        super().__init__()
        widget2 = Widget2()
        widget2.show()
        layout = QtGui.QVBoxLayout()
        layout.addWidget(widget2)
        self.setLayout(layout)

class Widget2(QtGui.QDialog):
    def __init__(self):
        super().__init__()

widget = Widget1()
widget.show()

sys.exit(app.exec_())


This suggests that perhaps in the first example the widget immediately goes
out of scope.

Thanks for any help

Angus M


In GNU Emacs 24.5.1 (i686-pc-mingw32)
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bug#21813: 24.5; python.el & Qt (PySide) - widgets remain hidden

[Lars Ingebrigtsen]

Angus Melville <anguscmelville@gmail.com> writes:

> The following lines should make a QT widget appear on the screen, and will do if
> run direcly from IDLE or from iPython notebook:
>
> import sys
> from PySide import QtGui

[...]

> However if run from EMACS using the default python.el mode, no widget
> will pop up on the screen.

(This bug report unfortunately got no response at the time.)

I tried reproducing this in Emacs 28, but I apparently do not have the
correct libraries installed, and after "apt install" on everything that
seemed likely, I still get

ImportError: No module named PySide

Anybody know what I should be installing?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#21813: 24.5; python.el & Qt (PySide) - widgets remain hidden

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> I tried reproducing this in Emacs 28, but I apparently do not have the
> correct libraries installed, and after "apt install" on everything that
> seemed likely, I still get
>
> ImportError: No module named PySide
>
> Anybody know what I should be installing?

There was no response here, so it seems unlikely that there'll be
further progress in this bug report, and I'm closing it.  If progress
can be made, please respond to the debbugs address and we'll reopen.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no