This is the source code for a Stack Overflow question I posted.
This is an implementation of the sliding fragments DevByte. As this fragment slides in, it draws a shadow over the underlying content. This is implemented by rendering the fragment at twice the screen width.
There's an intermittent problem where this shadow is drawn properly as the fragment slides in, but not as the fragment slides back out. A more detailed description is in the question on Stack Overflow.
Note: A solution is now provided in the "solution" branch.
At the time of writing, I don't have access to my physical test devices. I'll update my observations as those come into grasp. Note that the sample size on each of the below isn't very large (one or two tries each), so I'm not sure whether the problem is consistent per device or somehow varies across installs. I've been unable to automate the observation, so it's tedious going to compile this list.
| Asus Nexus 7, 1st gen, Android 4.3 | exhibits the problem |
| Emulator, Nexus S, 4.0.3 system image, ARM w/ Host GPU | works as intended |
| Emulator, Nexus S, 4.0.3 system image, ARM w/o Host GPU | works as intended |
| Emulator, Galaxy Nexus, fresh 4.1.2 system image, ARM w/ Host GPU | exhibits the problem |
| Emulator, Galaxy Nexus, fresh 4.1.2 system image, ARM w/o Host GPU | works as intended |
| Emulator, Galaxy Nexus, fresh 4.2.2 system image, ARM w/ Host GPU | exhibits the problem |
| Emulator, Galaxy Nexus, fresh 4.2.2 system image, ARM w/o Host GPU | works as intended |
| Emulator, Galaxy Nexus, fresh 4.3 system image, ARM w/ Host GPU | exhibits the problem |
| Emulator, Galaxy Nexus, fresh 4.3 system image, ARM w/o Host GPU | works as intended |
| Emulator, Galaxy Nexus, fresh 4.3 system image, x86 w/ Intel HAXM | works as intended |
| Emulator, Nexus 4, fresh 4.4 system image, ARM w/ Host GPU | exhibits the problem |
| Emulator, Nexus 4, fresh 4.4 system image, ARM w/o Host GPU | works as intended |
| Samsung Galaxy SIII, Android 4.1.2 | exhibits the problem |
| Samsung Galaxy Tab 3 10.1", Android 4.2.2 | exhibits the problem |
| HTC One-X, Android 4.0.4 | works as intended |
It's clear that the Host GPU acceleration surfaces the problem on the emulators running Jelly Bean or newer. I'd leave it at that if my Nexus 7 were showing the animation as intended, but alas, it's not. It looks like I'm tripping over an optimization in Project Butter.