Filter columns in QAbstractItemModel

[Djab]

Hi all readers,

I've got a Model (a sub class of QAbstractTableModel) that work like a charm what ever the standard view I plug it in, that do not support the sort function.

But this model as 'too' many columns most of the time... (thinks of it as the result of select * from table).

So I build a simple model that filter columns, here is the code (in python) (btw I wanted to use QIdentityProxyModel but it does not exist in Qt 4.7...):

class ModelColumnFilter(QtGui.QSortFilterProxyModel):
    def __init__(self):
        QtGui.QSortFilterProxyModel.__init__(self)
        self.colMapFromSource = {} # col source -> col proxy
        self.colMapFromProxy = tuple() # col proxy -> col source
 
    def set_column_to_display(self, column_to_display):
        self.beginResetModel()
        self.colMapFromProxy = tuple(column_to_display)
        for i, x in enumerate(self.colMapFromProxy):
            self.colMapFromSource[x] = i
        self.endResetModel()
 
    def flags(self, index):
        return self.sourceModel().flags(self.mapToSource(index))
 
    def setSourceModel(self, sourceModel):
        QtGui.QSortFilterProxyModel.setSourceModel(self, sourceModel)
        # by default display all column with same order
        self.set_column_to_display(
            tuple(i for i in xrange(self.sourceModel().columnCount())))
 
    def columnCount(self, parent=QtCore.QModelIndex()):
        return len(self.colMapFromProxy)
 
    def mapFromSource(self, sourceIndex):
        if sourceIndex.isValid():
            if sourceIndex.column() in self.colMapFromSource:
                return self.createIndex(sourceIndex.row(),
                    self.colMapFromSource[sourceIndex.column()])
        return QtCore.QModelIndex()
 
    def mapToSource(self, proxyIndex):
        if proxyIndex.isValid():
            return self.sourceModel().index(proxyIndex.row(),
                    self.colMapFromProxy[proxyIndex.column()])
        return QtCore.QModelIndex()

class ModelColumnFilter(QtGui.QSortFilterProxyModel):
    def __init__(self):
        QtGui.QSortFilterProxyModel.__init__(self)
        self.colMapFromSource = {} # col source -> col proxy
        self.colMapFromProxy = tuple() # col proxy -> col source

    def set_column_to_display(self, column_to_display):
        self.beginResetModel()
        self.colMapFromProxy = tuple(column_to_display)
        for i, x in enumerate(self.colMapFromProxy):
            self.colMapFromSource[x] = i
        self.endResetModel()

    def flags(self, index):
        return self.sourceModel().flags(self.mapToSource(index))

    def setSourceModel(self, sourceModel):
        QtGui.QSortFilterProxyModel.setSourceModel(self, sourceModel)
        # by default display all column with same order
        self.set_column_to_display(
            tuple(i for i in xrange(self.sourceModel().columnCount())))

    def columnCount(self, parent=QtCore.QModelIndex()):
        return len(self.colMapFromProxy)

    def mapFromSource(self, sourceIndex):
        if sourceIndex.isValid():
            if sourceIndex.column() in self.colMapFromSource:
                return self.createIndex(sourceIndex.row(),
                    self.colMapFromSource[sourceIndex.column()])
        return QtCore.QModelIndex()

    def mapToSource(self, proxyIndex):
        if proxyIndex.isValid():
            return self.sourceModel().index(proxyIndex.row(),
                    self.colMapFromProxy[proxyIndex.column()])
        return QtCore.QModelIndex()

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So, whatever the number of view I'm using to display data in this model, they see only what I need (more over in the order I need).

This work great if I use it as is.

But if I want to sort columns, and use an other QSortFilterProxyModel like this:

mo = MyModel()
 
mf = ModelColumnFilter()
mf.setSourceModel(mo)
set_column_to_display([....])
 
mp = QtGui.QSortFilterProxyModel()
mp.setSourceModel(mf)
 
view1 = QtGui.QTreeView()
view1.setModel(mp)
view1.setSortingEnabled(True)
 
 
view2 = QtGui.QTreeView()
view2.setModel(mp)
view2.setSortingEnabled(True)

mo = MyModel()

mf = ModelColumnFilter()
mf.setSourceModel(mo)
set_column_to_display([....])

mp = QtGui.QSortFilterProxyModel()
mp.setSourceModel(mf)

view1 = QtGui.QTreeView()
view1.setModel(mp)
view1.setSortingEnabled(True)


view2 = QtGui.QTreeView()
view2.setModel(mp)
view2.setSortingEnabled(True)

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view2 cause the application to crash.
I suppose it's a problem in my model (an index not very well formed ??).

Tell me if I'm doing it wrong, or How can I change this to make it work.

Thanks

[StrikeByte]

Hi,

I think the problem is that you try to connect two views to only one QSortFilterProxyModel you can try to create two sepatate QSortFilterProxyModel's for each view one

[ecanela]

QSortFilterProxyModel only filter rows, if you need filter columns the easy way is rewrite the DB query to include ONLY the column you need.

BTW: QIdentityProxyModel cant sort or filter the data in the model. QIdentityProxyModel is more suitable for transform the data of the source model. transforms like change num of second in a format "mm:ss" convert all the string to upper.

[ecanela]

another option is hide the columns in the view. but still is preferable rewrite your querys.