Label justification bounces left/right and top/bottom during scroll-zoom when labels fit the matrix scale

[Robert Leach]

Label size and position changes behave correctly when the label port is active, but once zoomed into a level where the label sizes change dynamically, the justification jumps right to left & back. The end result is always correct, but the jumpiness is distracting. Tested this on the 6kx6k test matrix and using right/bottom justification.

Here is a screen recording demonstrating this behavior:

https://bitbucket.org/TreeView3Dev/treeview3/downloads/jumpy_justification_of_fitted_labels_during_scroll_zoom.mov

Watch the row labels during zoom out. They briefly jumpy to what appears to be left justified and then back to right justified.

[Robert Leach]

Issue #337 was marked as a duplicate of this issue.

[Robert Leach]

Removing milestone: Navigation (automated comment)

[Robert Leach]

This appears to occur when the font size changes. Once the font size is at the minimum when zooming out or at the maximum when zooming in, there's no jumpiness. When the font size changes though, that's when the jumping occurs. I recall that when the font size changes, the scroll is reset because we don't attempt to keep any existing partial scroll position. It's probably the reset that's doing it. The reset might also be changing the top/bottom or left/right alignment.

[Robert Leach]

Actually, I don't think that the top/bottom of left/right alignment is changing. I think that the new font size is being drawn initially at a position calculated using the previous font size - that's my guess.