Dectects text change in an EditText. Concept prototype for Android functional testing.

textwatcher.py

################################################################################
#
# Requirements:
# * pexpect (http://www.noah.org/wiki/Pexpect)
# * Java SDK is on the PATH
#
# Steps:
# 1. Start target activity on a device or emulator
# 2. Start DDMS, click on the package name of the started activity from the
# devices & processes window on the left, the rightmost column should now
# say "86XX / 8700" in a default setup
# 3. Run this script
# 4. When it says ready, enter text in any EditTexts in the target activity
# 5. The script should print out relevent info
#
################################################################################

import re
import pexpect

_JDB_PROMPT = '\n> '
_JDB_BREAKPOINT_PROMPT = '\n<\d> '

def _get_expr_val(child, expr):
    child.sendline('print %s' % expr)
    child.expect(_JDB_BREAKPOINT_PROMPT)
    pat = re.compile('%s = (.+)' % re.escape(expr))
    val = pat.findall(child.before.strip())
    assert val and len(val) > 0
    return val[0]

def main():
    cmd = 'jdb -attach localhost:8700'
    child = pexpect.spawn(cmd)
    child.expect(_JDB_PROMPT)
    child.sendline('stop in android.widget.TextView.onTextChanged'),
    print 'ready'
    while True:
        ret = child.expect([_JDB_PROMPT, _JDB_BREAKPOINT_PROMPT], timeout=None)
        if ret != 1:
            continue
        cls = _get_expr_val(child, 'this.getClass().getName()')
        if cls == '"android.widget.EditText"':
            vid = int(_get_expr_val(child, 'this.getId()'))
            text = _get_expr_val(child, 'text')
            print 'text in EditText', vid, 'changed to', text
        child.sendline('cont')

if __name__ == '__main__':
    main()