Introduction
Python wrapper around the Java Access Bridge / Windows Access Bridge.
Requirements
Enable the Java Access Bridge in windows
C:\path\to\java\bin\jabswitch -enable
Install
pip install java-access-bridge-wrapper
How to use
Import the Java Access Bridge (JAB) wrapper and optionally the context tree
from JABWrapper.jab_wrapper import JavaAccessBridgeWrapper
from JABWrapper.context_tree import ContextNode, ContextTree, SearchElement
The JAB creates an virtual GUI window when it is opened. For the JAB to operate and receive events from the GUI, the calling code needs to implement the windows
message pump and call it in a loop. The JABWrapper object needs to be in the same thread.
This can be achieved for example by starting the message pump in a separate thread, where the JAB object is also initialized.
GetMessage = ctypes.windll.user32.GetMessageW
TranslateMessage = ctypes.windll.user32.TranslateMessage
DispatchMessage = ctypes.windll.user32.DispatchMessageW
def pump_background(pipe: queue.Queue):
try:
jab_wrapper = JavaAccessBridgeWrapper()
pipe.put(jab_wrapper)
message = byref(wintypes.MSG())
while GetMessage(message, 0, 0, 0) > 0:
TranslateMessage(message)
logging.debug("Dispatching msg={}".format(repr(message)))
DispatchMessage(message)
except Exception as err:
pipe.put(None)
def main():
pipe = queue.Queue()
thread = threading.Thread(target=pump_background, daemon=True, args=[pipe])
thread.start()
jab_wrapper = pipe.get()
if not jab_wrapper:
raise Exception("Failed to initialize Java Access Bridge Wrapper")
time.sleep(0.1) # Wait until the initial messages are parsed, before accessing frames
if __name__ == "__main__":
main()
Once the JABWrapper object is initialized, attach to some frame and optionally create the context tree to get the element tree of the application.
jab_wrapper.switch_window_by_title("Frame title")
context_tree = ContextTree(jab_wrapper)
Development
Prerequisites
- Install Invoke, Poetry and the other required dependencies in order to be able to develop and package the library:
pip install -Ur requirements.txt
.
- If you want to isolate these from the other projects and not rely on the OS
Python, enable a (pyenv) virtual environment first by following these
instructions.
- Now you're ready to set-up Poetry for the first time with
inv setup
.
- Check with
-h
on how to pass credentials for ensuring that both your production PyPI and CI DevPI are
configured. You'll find these in our Robocorp > Shared 1Password by searching for keywords like "pypi"
(where we recommend a personal token instead) and "devpi".
- Run
inv update
so the library gets ready for development.
Testing
Run test script against a simple Swing application.
Set environment variable
set RC_JAVA_ACCESS_BRIDGE_DLL="C:\path\to\Java\bin\WindowsAccessBridge-64.dll"
Update requirements and install the library in development mode
inv update
Run tests
inv test # runs all the tests in all scenarios
inv test -s -t test_jab_wrapper.py # runs all the tests from a file in one simple common scenario
inv test -s -c -t test_jab_wrapper.py::test_depth # as above, but specific test and captures output
Packaging
Check linting
inv lint # apply with '-a'
Building and publishing
inv publish # '-c' for DevPI
TODO:
- Support for 32-bit Java Access Bridge version
- Implement rest of the utility functions to the JABWrapper