SimpleApp - To demonstrate sluggish portrait mode UI response in Android Things Dev Preview 6.1

This app demonstrates sluggish UI response, on portrait mode, with Android Things Dev Preview 6.1 running on i.MX7 (PICO-PI-IMX7-STARTKIT).

The bug was reported here: https://issuetracker.google.com/issues/70974565 and I commented on that bug ticket to indicate that I was seeing the same problem. This app is another example to illustrate the issue.

The environment

Hardware is the TechNexion PICO-PI-IMX7 starter kit: https://shop.technexion.com/pico-pi-imx7-startkit.html with the 5 inch display connected, WiFi enabled, no camera attached.

The IMX7 is flashed with Anrdroid Things Dev Preview 6.1

The problem

Sluggish UI response when switching activities (takes over 3 seconds to switch activities); response of all views is sluggish - buttons, seek bars, checkboxes, etc... The original reporter of this bug (no...@gmail.com) tracked the problem down to portriat mode; this example is another confirmation of this analysis.

The code

SimpleApp contains two activities, each with some dummy Buttons, SeekBars, Checkboxes and TextViews. Both activites are set to portrait mode in the app's manifest:

<activity android:name=".MainActivity"
          ...
          android:screenOrientation="portrait">

and

<activity android:name=".AnotherActivity"
            ...
            android:screenOrientation="portrait">
            

The app starts in MainActivity, then after 5 sec runs AnotherActivity.

Statements in AnotherActivity:onCreate(..) log the execution time of setContentView(R.layout.activity_another)

Run the app to observe the problem in Portrait mode

1. Execute the app
2. Observe that MainActivity is in portrait mode.
3. After 5 sec the app switches to AnotherActivity, note that this activity is also in portrait mode.
4. Note the log statement that indicates the execution time of setContentView(...). This illustrates the problem that the call to setContentView(...) is taking about 4 sec. Ex:
   I/AnotherActivity: =========== onCreate call to setContentView took: 4.125 sec ========
5. Move the SeekBars, press the Buttons and Checkbox; note the sluggish response

Run the app to observe the problem does not exist in Landscape mode

1. In the app's mainfest change to landscape mode:

<activity android:name=".MainActivity"
          ...
          android:screenOrientation="landscape">

and

<activity android:name=".AnotherActivity"
            ...
            android:screenOrientation="landscape">
            

2. Observe that MainActivity is in landscape mode.
3. After 5 sec the app switches to AnotherActivity, note that this activity is also in landscape mode.
4. Note the log statement that indicates the execution time of setContentView(...). Compare this time with the above execution time in portrait mode.
   Ex:
   I/AnotherActivity: =========== onCreate call to setContentView took: 0.341 sec ========
5. Move the SeekBars, press the Buttons and Checkbox; note the response is as expected.

My results (from the log)

Portrait Mode:

02/20 10:49:09: Launching app
$ adb install-multiple -r -t -p d.htp.simpleapp C:\AT\exApps\SimpleApp\app\build\intermediates\split-apk\debug\slices\slice_9.apk 
Split APKs installed
$ adb shell am start -n "d.htp.simpleapp/d.htp.simpleapp.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Client not ready yet..Waiting for process to come online
Connected to process 3675 on device google-iot_imx7d_pico-000000749f839b02
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
I/InstantRun: starting instant run server: is main process
I/MainActivity: Switching to AnotherActivity in 5 sec.
D/vndksupport: Loading /vendor/lib/hw/android.hardware.graphics.mapper@2.0-impl.so from current namespace instead of sphal namespace.
D/vndksupport: Loading /vendor/lib/hw/gralloc.imx7d.so from current namespace instead of sphal namespace.
I/display: IonManager used
D/OpenGLRenderer: HWUI GL Pipeline
I/zygote: Background concurrent copying GC freed 1834(288KB) AllocSpace objects, 0(0B) LOS objects, 27% free, 1330KB/1842KB, paused 136us total 118.235ms
W/zygote: Verification of java.lang.Object d.htp.simpleapp.AnotherActivity.access$super(d.htp.simpleapp.AnotherActivity, java.lang.String, java.lang.Object[]) took 178.975ms
I/AnotherActivity: =========== onCreate call to setContentView took: 3.314 sec ========
I/Choreographer: Skipped 209 frames!  The application may be doing too much work on its main thread.
I/Choreographer: Skipped 44 frames!  The application may be doing too much work on its main thread.
I/zygote: Do partial code cache collection, code=25KB, data=29KB
I/zygote: After code cache collection, code=25KB, data=29KB
I/zygote: Increasing code cache capacity to 128KB
I/zygote: Background concurrent copying GC freed 1920(157KB) AllocSpace objects, 0(0B) LOS objects, 24% free, 1607KB/2MB, paused 129us total 216.716ms

Landscape Mode:

02/20 10:51:38: Launching app
$ adb install-multiple -r -t -p d.htp.simpleapp C:\AT\exApps\SimpleApp\app\build\outputs\apk\debug\app-debug.apk 
Split APKs installed
$ adb shell am start -n "d.htp.simpleapp/d.htp.simpleapp.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Client not ready yet..Waiting for process to come online
Connected to process 3834 on device google-iot_imx7d_pico-000000749f839b02
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
I/InstantRun: starting instant run server: is main process
I/MainActivity: Switching to AnotherActivity in 5 sec.
D/vndksupport: Loading /vendor/lib/hw/android.hardware.graphics.mapper@2.0-impl.so from current namespace instead of sphal namespace.
D/vndksupport: Loading /vendor/lib/hw/gralloc.imx7d.so from current namespace instead of sphal namespace.
I/display: IonManager used
D/OpenGLRenderer: HWUI GL Pipeline
I/AnotherActivity: =========== onCreate call to setContentView took: 0.324 sec ========
I/zygote: Do partial code cache collection, code=26KB, data=30KB
I/zygote: After code cache collection, code=26KB, data=30KB
I/zygote: Increasing code cache capacity to 128KB

Summary

Switching activites in portrait mode took 3.314 sec and the UI response to touches was very slow. After changing the activites to landscape and rerunning the app; switching activities took 0.324 sec and the UI response was as expected.
The time it takes to switch activities varies quite a bit, occasionally times of over 5 sec were observed.