java-access-bridge-wrapper 0.9.0

Python wrapper for the Windows Java Access Bridge

Introduction

Python wrapper around the Java Access Bridge / Windows Access Bridge.

Prerequisites

• 64-bit Windows
• Java >= 8 (https://docs.aws.amazon.com/corretto/latest/corretto-8-ug/downloads-list.html)
• Python >= 3.7 (https://www.python.org/downloads/release/python-375/)

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

Development prerequisites

• Install poetry: https://python-poetry.org/docs/

Test

Run test script against simple Swing application

set environment variable

set RC_JAVA_ACCESS_BRIDGE_DLL="C:\path\to\Java\bin\WindowsAccessBridge-64.dll"

Run test with poetry

poetry run python tests\test.py

Packaging

poetry build
poetry publish

TODO:

• Support for 32-bit Java Access Bridge version
• Implement rest of the utility functions to the JABWrapper