Intermittent update issues when scrolling up and down on 9810 + Blackberry
I'm having a weird scrolling issue on my 9810 device and simulator. I have a full order screen that is displayed when the user's order is confirmed.
At the top is the Vertical Field Manager, which contains another VerticalFieldManager (containing label fields and buttons) and a FlowFieldManager (containing images). Now the problem I am running into is that whenever I scan the screen up and down, a lot of gray lines appear on the screen. The device seems to be having a screen refresh issue. I tested the previous OS version (4.5, 4.5 4.7 5.0) everything works fine. The problem occurs in OS versions higher than 6.0.
For now, the correct screen should look like
As you can see, these gray lines appear when you scroll up and down the screen. Any ideas how to fix this issue?
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In the first image, it looks like you are trying to add a shadow effect at the top of the screen. The vertical margin manager uses some graphics optimization to improve scrolling performance. Instead of redrawing everything, it picks up pixels on the screen in the layout area and moves them around. This works as long as the entire coloring code does not match the virtual extent.
A certain UI effect, like the shadow effect, refers to the screen rather than the virtual scale, so this optimization takes those effects and copies them elsewhere, which looks bad. It also tends to look the same as your first image.
There are two ways to fix this:
Disable optimization. Override isScrollCopyable to return false. Your visual problems should go away, but scrolling performance will suffer.
Don't add UI effects on top of the scrollable area.
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