[Test Harness] Add custom ContextThemeWrapper to improve test harness behavior in previews #1414
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alexvanyo
commented
Nov 29, 2022
| * This is a modification of androidx.appcompat.view.ContextThemeWrapper to allow the | ||
| * TestHarness to work in previews. | ||
| */ | ||
| class ContextThemeWrapper extends ContextWrapper { |
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I kept this class in .java, to be closer to the appcompat ContextThemeWrapper. I could convert and simplify, if desired.
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If you are happy to maintain Java code, fine by me!
bentrengrove
approved these changes
Nov 30, 2022
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Adds a custom
ContextThemeWrapperto work around the issue that currently causesTestHarnessto fail in previews.The cause of the crash is that
Context.createConfigurationContextreturnsnullforBridgeContextin layoutlib: https://cs.android.com/android/platform/superproject/+/master:frameworks/layoutlib/bridge/src/com/android/layoutlib/bridge/android/BridgeContext.java;l=1380;drc=58bd418e161b5d4fdde39b46523d3e49269117e3ContextThemeWrapperuses thisContext.createConfigurationContextinternally and assumes it is not null, which causes the crash.The
androidx.appcompat.view.ContextThemeWrapperhas a fallback mechanism for older API versions using a deprecatedResourcesconstructor, so this PR adds a customContextThemeWrapperbased on the appcompat one that uses that fallback mechanism in caseContext.createConfigurationContextis null.This improves behavior, preventing the crash, but doesn't remove all of the limitations. In particular, alternate resources are not loaded (such as the string not translated in the below image), which is probably related to how layoutlib manages resources.