Pinch to Zoom with mouse wheel.
You can test it.
download libinput.so here.
$adb remount
$adb push libinput.so /system/lib/
$adb shell sync
$adb shell reboot
settings -> Developer options -> Show touches(check)
1077 void CursorButtonAccumulator::process(const RawEvent* rawEvent) {
1078 if (rawEvent->type == EV_KEY) {
1079 switch (rawEvent->scanCode) {
1080 case BTN_LEFT:
1081 mBtnLeft = rawEvent->value;
1082 break;
1083 case BTN_RIGHT:
1084 //codewalker
1085 //mBtnRight = rawEvent->value;
1086 mBtnBack = rawEvent->value;