Fire a pinch in/out command to Android phone using adb

Question

So far I\'m able to tap, swipe, unlock, install/uninstall and launch app using adb commands but not able to find how to perform zoom in/out using adb command.

I have

Answer 1

A (kind of hacky) solution with adb shell input looks like

adb shell input tap 200 200 & PIDTAP=$!
sleep 0.1
adb shell input swipe 200 200 200 100 1000 & PIDSWIPE=$!
wait $PIDTAP
wait $PIDSWIPE

The idea is that we launch TAP command, then short sleep and then perform SWIPE. Such commands sequence is interpreted as tap + swipe hence zoom is performed. The example above would be a zoom out on a map.