Following ag/19119857, this existing piece of documentation is updated.
Note that most of the class names and links in the document were
incorrect, probably due to drift between refactors that renamed stuff
(like `StatusBar.java`) and this document.
Where it was possible and sensical, I updated the document. Where it
wasn't, I removed specifics related to class/method names or line
numbers. The general gist of how the double-click on the power button
ends up launching the camera is still correct.
Bug: b/235403546
Test: N/A
Change-Id: I017c2f83ce70545b9044e11ade7e5c15e8ca8a53
Using an implicit intent at the moment of picture-taking
usually goes unnoticed. But immediately after installing a
new camera, this behavior becomes incredibly frustrating to
users as they are presented with a puzzling resolver dialog
(or in the case of the secure camera, the authenticator).
And if, at this moment, the user chooses to make one of the
options a default, it's almost impossible to figure out how
to change this setting.
As a result, many OEMs simply hardcode the camera gesture to
launch a specific preinstalled camera, but this is poorly
supported by AOSP, leading to duplicate implementations and
bugs. This patch routes all camera intents in System UI
through a single utility class, creating a convenient spot
to insert a resource that contains the OEM's default
preinstalled camera app.
Note that this does not affect implicit intent resolution in
any way; any app may create a chooser for, e.g.,
MediaStore.INTENT_ACTION_STILL_IMAGE_CAMERA and allow the
user to pick from the available cameras.
Bugreport/dumpsys output to look for:
$ adb shell dumpsys activity service com.android.systemui | grep -C3 'Camera gesture' | tail -3
Camera gesture intents:
Insecure camera: Intent { act=android.media.action.STILL_IMAGE_CAMERA }
Secure camera: Intent { act=android.media.action.STILL_IMAGE_CAMERA_SECURE flg=0x800000 }
Override package: null
Bug: 171807357
Fixes: 154218868
Test: atest SystemUITests
Change-Id: I2c0033e52c8a3963768d29f2e76e555d405aaa7e
