Backend for Pyside

Gerald_Storer1 · March 17, 2011, 3:21am

Please forgive me if I’m raising a heretical question with this
since I
understand the topic of competing Qt bindings for Python gets a
little
touchy in and of itself. Nonetheless, the elephant is in the
room. I
searched the archives and found only a few comments on the
subject:
"
target=“_new”>>
Has there been any additional discussion among the developers
about
creating a formal backend for Pyside?
Its actually a fairly easy to get the PyQt backend working with
PySide. It would have been laughably easy if not for a couple of
bugs in PySide that took awhile to track down.
To get it working PySide working you need to:
It might also be a good idea to convert all the signals/slots into
the new style but it seems to work just fine with only the above
changes.
Regards,
Gerald.

···

matplotlib-users@lists.sourceforge.net/msg18652.htmlhttp://www.mail-archive.com/matplotlib-users@lists.sourceforge.net/msg18652.html

Obviously replace the reference to PyQt with PySide
```
    Remove the reference to PyQt/Pyside.Qt and Qt.qApp by
```
replacing it with QtGui.qApp (I think this is already done in
the most recent Git version)
Replace the toolbar message signal with a new style signal by:

      adding 'message = QtCore.Signal(str)' to the

NavigationToolbar2QT class definition

      replacing: QtCore.QObject.connect(self.toolbar,

QtCore.SIGNAL(“message”),

self.window.statusBar().showMessage)

      with:self.toolbar.message.connect(self.window.statusBar().showMessage)

replacing: self.emit(QtCore.SIGNAL(“message”), s)
```
      with: self.message.emit(s)
```
```
    Work around the PySide bug with QImage and convert the string
```
passed from the Agg backend into a python buffer with
buffer(stringBuffer) or wait for PySide to fix bug 489.
```
    Work around a PySide bug (738) by creating functions to
```
perform the slider.setMaxiumum/setMinimum tasks or ignore the
runtime errors for now and wait for a bug fix.

    I haven't bothered with the figure options editor at this

point - I just commented out the references to it.

Gerald_Storer1 · March 17, 2011, 9:00am

It turns out that it was also trivial to get the figure options
editor working with PySide.

All that needed to be done was (in formlayout.py):

Replace the references to PyQt with PySide

    Change: from PyQt.QtCore import (Qt, SIGNAL, SLOT, QSize,

QString,

                              pyqtSignature, pyqtProperty)

#QString,

                              #pyqtSignature, pyqtProperty)

                               Slot as pyqtSignature, Property as

pyqtProperty)

Add the following after the import statements:

    # Hacks to emulate PyQt

    QString = str

    class QColorDialog(QColorDialog):

        @staticmethod

        def getRgba(color,parent):

            result =

QColorDialog.getColor(QColor.fromRgba(color),parent,’’)

            return result.rgba(),result.isValid()

Formlayout could probably be updated so it doesn’t need the hacks
but I wanted to keep changes to a minimum.

Gerald.

···

matplotlib-users@lists.sourceforge.net/msg18652.htmlhttp://www.mail-archive.com/matplotlib-users@lists.sourceforge.net/msg18652.html

Obviously replace the reference to PyQt with PySide
```
      Remove the reference to PyQt/Pyside.Qt and Qt.qApp by
```
replacing it with QtGui.qApp (I think this is already done in
the most recent Git version)

      Replace the toolbar message signal with a new style signal

by:

        adding 'message = QtCore.Signal(str)' to the

NavigationToolbar2QT class definition

```
        replacing: QtCore.QObject.connect(self.toolbar,
```
QtCore.SIGNAL(“message”),

self.window.statusBar().showMessage)

with:self.toolbar.message.connect(self.window.statusBar().showMessage)
replacing: self.emit(QtCore.SIGNAL(“message”), s)
```
        with: self.message.emit(s)
```
```
      Work around the PySide bug with QImage and convert the
```
string passed from the Agg backend into a python buffer with
buffer(stringBuffer) or wait for PySide to fix bug 489.
```
      Work around a PySide bug (738) by creating functions to
```
perform the slider.setMaxiumum/setMinimum tasks or ignore the
runtime errors for now and wait for a bug fix.

      I haven't bothered with the figure options editor at this

point - I just commented out the references to it.

Gerald_Storer1 · March 23, 2011, 7:33am

I’ve just noticed that its possible to use an external package as a
back end so I moved my changes into their own package. This is
sufficient for my own use but I’m guessing others may find is useful
as well (and it might speed official support).

Attached is the package.

Regards,

Gerald.

pysidempl.zip (17.9 KB)

···

On 17/03/2011 5:00 PM, Gerald Storer wrote:

  It turns out that it was also trivial to get the figure options

editor working with PySide.

  ...



  Gerald.