Repairing pywin32 example (#224)

examples/pywin32.py

@@ -0,0 +1,123 @@
+# Example of embedding CEF browser using the PyWin32 extension.
+# Tested with pywin32 version 219.
+
+from cefpython3 import cefpython as cef
+
+import distutils.sysconfig
+import math
+import os
+import platform
+import sys
+
+import win32api
+import win32con
+import win32gui
+
+WindowUtils = cef.WindowUtils()
+
+# Platforms (Windows only)
+assert(platform.system() == "Windows")
+
+def main(multi_threaded_message_loop):
+
+    check_versions()
+    sys.excepthook = cef.ExceptHook  # To shutdown all CEF processes on error
+
+    settings = {"multi_threaded_message_loop": 1 if multi_threaded_message_loop else 0,
+                "remote_debugging_port": 2020}
+    cef.Initialize(settings)
+
+    wndproc = {
+        win32con.WM_CLOSE: CloseWindow,
+        win32con.WM_DESTROY: QuitApplication,
+        win32con.WM_SIZE: WindowUtils.OnSize,
+        win32con.WM_SETFOCUS: WindowUtils.OnSetFocus,
+        win32con.WM_ERASEBKGND: WindowUtils.OnEraseBackground
+    }
+    windowHandle = CreateWindow(title="pywin32 example", className="cefpython3_example", width=1024, height=768, windowProc=wndproc)
+
+    windowInfo = cef.WindowInfo()
+    windowInfo.SetAsChild(windowHandle)
+
+    if(multi_threaded_message_loop):
+        # when using multi-threaded message loop, CEF's UI thread is no more application's main thread
+        cef.PostTask(cef.TID_UI, _createBrowserInUiThread, windowInfo, {}, "https://www.google.com/")
+        win32gui.PumpMessages()
+
+    else:
+        browser = _createBrowserInUiThread(windowInfo, {}, "https://www.google.com/")
+        cef.MessageLoop()
+
+    cef.Shutdown()
+
+
+def check_versions():
+    print("[pywin32.py] CEF Python {ver}".format(ver=cef.__version__))
+    print("[pywin32.py] Python {ver} {arch}".format(ver=platform.python_version(), arch=platform.architecture()[0]))
+    print("[pywin32.py] pywin32 {ver}".format(ver=GetPywin32Version()))
+    assert cef.__version__ >= "55.3", "CEF Python v55.3+ required to run this"
+
+
+def _createBrowserInUiThread(windowInfo, settings, url):
+
+    assert(cef.IsThread(cef.TID_UI))
+    browser = cef.CreateBrowserSync(windowInfo, settings, url)
+
+
+def CloseWindow(windowHandle, message, wparam, lparam):
+    browser = cef.GetBrowserByWindowHandle(windowHandle)
+    browser.CloseBrowser()
+    return win32gui.DefWindowProc(windowHandle, message, wparam, lparam)
+
+
+def QuitApplication(windowHandle, message, wparam, lparam):
+    win32gui.PostQuitMessage(0)
+    return 0
+
+
+def CreateWindow(title, className, width, height, windowProc):
+
+    wndclass = win32gui.WNDCLASS()
+    wndclass.hInstance = win32api.GetModuleHandle(None)
+    wndclass.lpszClassName = className
+    wndclass.style = win32con.CS_VREDRAW | win32con.CS_HREDRAW
+    # win32con.CS_GLOBALCLASS
+    wndclass.hbrBackground = win32con.COLOR_WINDOW
+    wndclass.hCursor = win32gui.LoadCursor(0, win32con.IDC_ARROW)
+    wndclass.lpfnWndProc = windowProc
+    atomClass = win32gui.RegisterClass(wndclass)
+    assert(atomClass != 0)
+
+    # Center window on the screen.
+    screenx = win32api.GetSystemMetrics(win32con.SM_CXSCREEN)
+    screeny = win32api.GetSystemMetrics(win32con.SM_CYSCREEN)
+    xpos = int(math.floor((screenx - width) / 2))
+    ypos = int(math.floor((screeny - height) / 2))
+    if xpos < 0: xpos = 0
+    if ypos < 0: ypos = 0
+
+    windowHandle = win32gui.CreateWindow(className, title, 
+                                         win32con.WS_OVERLAPPEDWINDOW | win32con.WS_CLIPCHILDREN | win32con.WS_VISIBLE,
+                                         xpos, ypos, width, height, # xpos, ypos, width, height
+                                         0, 0, wndclass.hInstance, None)
+
+    assert(windowHandle != 0)
+    return windowHandle
+
+
+def GetPywin32Version():
+    pth = distutils.sysconfig.get_python_lib(plat_specific=1)
+    ver = open(os.path.join(pth, "pywin32.version.txt")).read().strip()
+    return ver
+
+
+if __name__ == '__main__':
+
+    if "--multi_threaded_message_loop" in sys.argv:
+        print("[pywin32.py] Message loop mode: CEF multi-threaded (best performance)")
+        multi_threaded_message_loop = True
+    else:
+        print("[pywin32.py] Message loop mode: CEF single-threaded")
+        multi_threaded_message_loop = False
+
+    main(multi_threaded_message_loop)