QTreeWidget: how to limit the number of displayed rows?
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With the Designer, I have placed two QTreeWidget on a QVBoxLayout. I would like to force the upper one to display only 4 rows, giving more space to the lower one. I can obtain something of acceptable by limiting the maximum size with the designer, but I would like to be independent on the pixel and limits in term of rows, in particular to the number of used rows.
How can I do?
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As far as I know there is no easy way to achieve this. One has to account for the frame size of the scroll area, individual row heights (including font size, multi-line rows), header height, scroll bars and probably more in a platform independent way.
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Hi,
you should use QTreeView, and implement your custom model. So you can choose the number of "rowCount" for each parent node in the tree.
T.
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I suppose you could also insert a QSortFilterProxyModel-derived class and reimplement filterAcceptRows in order to reject all rows which have index.row() > 4.
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in designer on a upper QTreeWidget, Make minimumSize and maximumSize Height a same number as geometry height.
Add four rows and do a quick preview (ctrl + r). Come back and re-adjust that number based on how it previews. Once you are satisfied, you've your perfect locked-down state. If you resize the widget, this treewidget wouldn't resize.
Alternately, you could set the vertical sizepolicy as fixed.
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iunknwn: it is not a good solution. Rows can have different heights, in other OSes there can be another sizes in styles and so on.
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The proxy filter model solutions seems not to be what the user wants. The tree widget should have a height to show 4 rows simultaneously and provide a scroll bar if there are more than 4 rows to display.
Another solution might be to use a "QSplitter":http://doc.qt.nokia.com/4.7/qsplitter.html, let the user choose the ratio between the two widgets and save the splitter's state when closing the window or quitting the application.
See
"QSplitter::saveState()":http://doc.qt.nokia.com/4.7/qsplitter.html#saveState
"QSplitter::restoreState()":http://doc.qt.nokia.com/4.7/qsplitter.html#restoreState
"QSettings":http://doc.qt.nokia.com/4.7/qsettings.html
for details.