QListWidget-based tabs may become invisible to the user

[ovl-1]

In the test version Stellarium 0.11.4dev4 (BZR r5453), another tab has been added to the configuration window. The consequence of this is that there is not enough horisontal space for all the tabs to be shown. After seeing through some languages several had this problem. For example, when the last tab is open the first tab is not visible at all. (Yes, the window can be dragged wider at the edge, but presumably most users will not think about doing this so it is really a big problem.)

Have earlier seen similar problem in a couple of other programs, and in those the problem was solved by adding clickable arrow buttons on the tab bar for moving forward and backwards. In this way the problem is solved once and for all even when adding more tabs later. Maybe a solution for Stellarium?

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[Alexander Wolf (alexwolf)]

This bug related with Qt 4.8.x - latest test build was compiled with Qt 4.8.1 for Win32 and Qt 4.8.2 for Win64.

[Bogdan Marinov (daggerstab)]

The reason for this is that the Configuration window and the View window don't use QTabWidget, but a combination of QListWidget for the tab bar and QStackedWidget for the "pages". QTabWidget shows indication when a tab goes out of the viewport, but a QList widget normally just add a scrollbar, something that has been disabled to make it look like a tab bar. (For the way a QListWidget and QStackedWidget are used normally in this way, see this Qt example: http://qt-project.org/doc/qt-4.8/dialogs-configdialog.html )

I've searched for a solution. Apparently, the only way to make a QListWidget to resize to its contents is to make a subclass of QListWidget with a custom (minimum)sizeHint() method using the undocumented protected function QListView::contentsSize(). (QListWidget is a subclass of QListView.)

And no, this is not related to bug #995107. That one affected things like buttons.

[Bogdan Marinov (daggerstab)]

I've committed a tentative fix that resizes the QListWidget (and therefore, the window) to make sure that all tab icons are visible:
http://bazaar.launchpad.net/~stellarium/stellarium/trunk/revision/5467

I'm not happy with it, though. There are a number of things that can be improved.