[trunk] R4778 navigator

• Sep 13, 2011 - 14:01
S4 - Minor

The navigator can get into a state where it will continuously redraw the images (or not at all). The only way I can reproduce this is with a multi-page score (say about 5 or 6) and slowly change the navigator size until it is switching between having a scroll bar and no scroll bar.

Navigator just before a resize

Navigator after a resize down to force the scrollbar to appear

If I resize the navigator a bit more then the images will redraw properly again, and there will be a scroll bar, a bit smaller and it will also redraw properly without a scroll bar. There is a small "window' where it can't redraw properly.


Rolling the mouse over the nav window at this point, esp over the top line of the navigator so the adjustment cursor appears, will force the window to switch between no scrollbar and a scrollbar, and still show no images. Sometimes it will switch back'n forth on its own.

There is a feedback loop. As a workaround i tried to always show a scrollbar in the page preview. I did not see this effect in the navigator.
Rev. 4785 has a slightly different algorithm. Please check again. The bug may be qt version and operating system dependent.

Status (old) fixed active

Close, but there is still a very small "window" where it is a continuous redraw mode. If you have a multi-page score, edge the nav window size up (or down) _very_ slowly until the scroll bar either appears or is about to disappear. Sometimes MS will crash as it redraws but usually it just sits there trying to draw the nav pages, and eating up CPU (about 50-60%).