Secure mode

AndroidViewClient has two possible back-ends:

• ViewServer
• UiAutomator

UiAutomator works on Android API 16 and higher, so if your device has a previous version your only alternative is ViewServer.

System ViewServer is started only when the device is not considered secure.

    private boolean isSystemSecure() {
        return "1".equals(SystemProperties.get(SYSTEM_SECURE, "1")) &&
                "0".equals(SystemProperties.get(SYSTEM_DEBUGGABLE, "0"));
    }

The properties involved to consider a device secure are

private static final String SYSTEM_SECURE = "ro.secure";
private static final String SYSTEM_DEBUGGABLE = "ro.debuggable";

This oneliner can be used to test these properties

$ (eval $(adb shell getprop | dos2unix | egrep '\[ro\.secure]|\[ro\.debuggable]' | sed 's/\./_/g; s/]: /=/g; s/[][]//g'); [[ 1 == $ro_secure && 0 == $ro_debuggable ]] && echo "System is secure: AVC won't work" || echo "System is not secure: AVC will work")

when run, this oneliner will tell you if AndroidViewClient could work on your device:

System is secure: AVC won't work

If you run it against any emulator (which is always not secure) it will return

System is not secure: AVC will work

Hierarchyviewer

hierarchyviewer is one of the standard Android tools (now deprecated in favor of tools/monitor) and it's described here.

For its operation hierarchyviewer uses the same ViewServer as AndroidViewClient so if you have doubts about it working on your device just try to run

$ hierarchyviewer

and if you receive a message like this

00:00:00 E/hierarchyviewer: Unable to debug device 0123456789

then neither AndroidViewClient or hierarchyviewer will work unless you follow (at your own risk) some of the instructions mentioned in Resources.

Resources

• patch the kernel image boot.img
• Enabling HierarchyViewer on Rooted Android Devices