Property with a list as possible values for custom widget?

Panoss

I 'm making a custom widget.
I 'm trying to make a property that will have a list of values.
And, in Qt Designer, I 'll be able to choose whichever I want from the list.
So, my question is how do I make such a property?
(that has a list, a combo box)
Like e.g QLabel has the frameShape, or the frameShadow property.

mrjj

Hi
I think those are just Qt enums and it should work automatically.
Did not try it though.
Try code from sample and see what you get.

http://doc.qt.io/qt-5/properties.html

class MyClass : public QObject
{
    Q_OBJECT
    Q_PROPERTY(Priority priority READ priority WRITE setPriority NOTIFY priorityChanged)
    Q_ENUMS(Priority)

public:
    MyClass(QObject *parent = 0);
    ~MyClass();

    enum Priority { High, Low, VeryHigh, VeryLow };

    void setPriority(Priority priority)
    {
        m_priority = priority;
        emit priorityChanged(priority);
    }
    Priority priority() const
    { return m_priority; }

signals:
    void priorityChanged(Priority);

private:
    Priority m_priority;
};

VRonin

I agree with @mrjj , the only remark is that Q_ENUMS is now deprecated, Q_ENUM should now be used (see https://woboq.com/blog/q_enum.html for further details)

Panoss

And If I want to change the content of the list dynamically?
The list will contain the names of the widgets that are in the same container as my custom widget.
Let's say I add (in Qt Designer) a new widget in the container.
Can I add the name of this widget in the list?

mrjj

@Panoss
Hi ahh yes. That type of list.
Well you can just use a QList or QStringList
Make sure to define both Read and Write

Q_PROPERTY(QList<int> points READ getpoints WRITE putpoints )
(list of ints)

Panoss

I forgot to mention I 'm working in python, so I'm trying to 'translate' your code in python.
I 'll call my property 'ContainersWidgets'.
So, a 'translation' of the above code by mrJJ would be something like:

ContainersWidgets = QtCore.pyqtProperty(QList, getContainersWidgets , setContainersWidgets )

Where should '(list of ints)' go?

mrjj

@Panoss
Im 110% python noob but it seems yes.
https://wiki.qt.io/Using_Qt_Properties_in_PySide

from PySide.QtCore import QObject, Property
 
class MyObject(QObject):
 def ''init''(self,startval=42):
 QObject.''init''(self)
 self.ppval = startval
 
def readPP(self):
 return self.ppval
 
def setPP(self,val):
 self.ppval = val
 
pp = Property(int, readPP, setPP)
 
obj = MyObject()
obj.pp = 47
print (obj.pp)

Panoss

I use QtGui.QListWidget (the Qt Designer 's QListWidget )

ContainersWidgets = QtCore.pyqtProperty(QtGui.QListWidget, getContainersWidgets, setContainersWidgets)

But how do I set the value?

@QtCore.pyqtSlot(int)
    def setContainersWidgets(self, value):
        self._containers_widgets = value

So the variable self._containers_widgets will get the value.
How shall I put this value as selected item from the list?

First of all, how shall I refer to the list?(I mean the widget, the QtGui.QListWidget)
list=??

mrjj

@Panoss

Hi
Sadly I dont know enough python to know.

http://pyqt.sourceforge.net/Docs/PyQt4/qstringlist.html#details

Panoss

Don't worry my friend, 'll find out the way, sooner or later.
I 'm not sure it is correct that I 'm using Qt Designer 's QListWidget in the place of 'QList<int>' you wrote above.
Or maybe I should use QStringList?
The QList you 're referring to, is a widget?

I think I should use QStringList in place of your QList.

mrjj

@Panoss

Hi
QListWidget is a widget ( listbox) so that is not well for properties.

I think I should use QStringList in place of your QList.
I agree since QList is template based it might be missing as QList.
But QStringList is
class QStringList : public QList<QString>
So very alike.

Maybe this can be used
http://www.programcreek.com/python/example/63681/PyQt4.QtCore.QStringList

Panoss

Even though referred in the examples you posted, PyQt4.QtCore.QStringList doesn't exist!!

mrjj

@Panoss
And you have something like
from PyQt4.QtCore import QStringList
or similar import ?

Panoss

I find nothing similar to QStringList in PyQt4.QtCore.
That's quite strange, either it has been moved...or I have no idea! :)

Panoss

From here:

From PyQt4 4.6+ in Python3 QString doesn't exist and you are supposed to use ordinary Python3 unicode objects (string literals). To do this so that your code will work in both Python 2.x AND Python 3.x you can do following:

try:
    from PyQt4.QtCore import QString
except ImportError:
    # we are using Python3 so QString is not defined
    QString = type("")

Ok, this for QString.

From here:
The QList class is a template class that provides lists. available in C++ only. But in python, it have python list data-type ready to used. If you want to use behavior like list you can use python list similar QList

So how will I do it? QList = []?

(with '[]' we define a list in python)

Panoss

I tried this:

QList = []

ContainersWidgets = QtCore.pyqtProperty(QList, getContainersWidgets, setContainersWidgets)

But I get an error:
"ContainersWidgets = QtCore.pyqtProperty(QList, getContainersWidgets, setContainersWidgets)
TypeError: bytes or ASCII string expected not 'list'"

It doesn't accept a List, only bytes or ASCII.

mrjj

I think you need a python head for this :)
Are you using
https://pypi.python.org/pypi/PyQt5

or what version ?

Panoss

The previous version, PyQt4.

mrjj

@Panoss said in Property with a list as possible values for custom widget?:

PyQt4

ok it really should have the qstringlist

http://pyqt.sourceforge.net/Docs/PyQt4/qstringlist.html

Panoss

Yes it should, but it doesn't :) !!!