Fix window resize issues (cztomczak#464). Expose Browser.SetBounds method,

update examples and documentation.

Fix event handling in qt.py example. Parent methods need to be called
when overriding events.

Fix screenshot.py example. Sometimes OnLoadingStateChange was called
before OnPaint resulting in error.

Author: cztomczak

api/Browser.md

@@ -814,7 +814,12 @@ Description from upstream CEF:
 | height | int |
 | __Return__ | void |
 
-Linux-only. Set window bounds.
+Set browser internal window bounds. This method should be called during
+size events of parent window in which CEF browser is embedded.
+
+On Windows the x and y parameters are ignored.
+
+On Mac this function does nothing.
 
 
 ### SendKeyEvent

api/WindowUtils.md

@@ -46,7 +46,11 @@ Windows-only. This method processes WM_SETFOCUS message which is sent to a windo
 | lparam | long |
 | __Return__ | void |
 
-Windows-only. This method processes WM_SIZE message which is sent to a window after its size has changed.
+Windows-only. This method should be called during WM_SIZE message which
+is sent to a window after its size has changed. Most examples should call
+the `Browser`.[SetBounds](Browser.md#setbounds) method during size events.
+The `pywin32.py` example is an exception and it needs to use the
+`WindowUtils.OnSize` method.
 
 
 ### OnEraseBackground (Win)

docs/Migration-guide.md

@@ -51,7 +51,7 @@ Table of contents:
 * [v66+ RequestHandler.GetCookieManager not getting called in some cases](#v66-requesthandlergetcookiemanager-not-getting-called-in-some-cases)
 * [v66+ Changes to Mac apps that integrate into existing message loop (Qt, wxPython)](#v66-changes-to-mac-apps-that-integrate-into-existing-message-loop-qt-wxpython)
 * [v66.1+ Navigation urls passed to CreateBrowserSync or LoadUrl methods need to be encoded by app code](#v661-navigation-urls-passed-to-createbrowsersync-or-loadurl-methods-need-to-be-encoded-by-app-code)
-* [v67+ Do not call the 'WindowUtils.OnSize' function](#v67-do-not-call-the-windowutilsonsize-function)
+* [v66.1+ Do not call 'WindowUtils.OnSize', use `Browser.SetBounds` instead.](#v661-do-not-call-windowutilsonsize-use-browsersetbounds-instead)
 
 
 ## v49+ Distribution packages
@@ -499,10 +499,10 @@ Python 2 (`urllib.request.pathname2url` in Python 3) depending on your case.
 The `cef.GetNavigateUrl` function was removed from the cefpython3 module.
 
 
-## v67+ Do not call the 'WindowUtils.OnSize' function
+## v66.1+ Do not call 'WindowUtils.OnSize', use `Browser.SetBounds` instead.
 
 This function can sometimes cause app hanging during window resize.
-Call instead the new `WindowUtils`.[UpdateBrowserSize](../api/WindowUtils.md#updatebrowsersize)
-function. Except when you use the `pywin32.py` example, in such case
-`WindowUtils.OnSize` must be called.
-See [Issue #464](../../../issues/464) for more details.
+Call instead the new `Browser`.[SetBounds](../api/Browser.md#setbounds)
+function. Except for when you use the `pywin32.py` example, in such case
+`WindowUtils.OnSize` must be called. See
+[Issue #464](../../../issues/464) for more details.

examples/gtk2.py

@@ -160,9 +160,7 @@ def on_vbox_size_allocate(self, _, data):
             y = data.y + self.menubar_height
             width = data.width
             height = data.height - self.menubar_height
-            if WINDOWS:
-                WindowUtils.OnSize(self.get_window_handle(), 0, 0, 0)
-            elif LINUX:
+            if WINDOWS or LINUX:
                 self.browser.SetBounds(x, y, width, height)
 
     def on_menubar_size_allocate(self, _, data):

examples/gtk3.py

@@ -125,9 +125,7 @@ def on_configure(self, *_):
 
     def on_size_allocate(self, _, data):
         if self.browser:
-            if WINDOWS:
-                WindowUtils.OnSize(self.win32_handle, 0, 0, 0)
-            elif LINUX:
+            if WINDOWS or LINUX:
                 self.browser.SetBounds(data.x, data.y,
                                        data.width, data.height)
 

examples/hello_world.py

@@ -10,8 +10,8 @@ def main():
     check_versions()
     sys.excepthook = cef.ExceptHook  # To shutdown all CEF processes on error
     cef.Initialize()
-    cef.CreateBrowserSync(url="https://www.google.com/",
-                          window_title="Hello World!")
+    browser = cef.CreateBrowserSync(url="https://www.google.com/",
+                                    window_title="Hello World!")
     cef.MessageLoop()
     cef.Shutdown()
 

examples/qt.py

@@ -191,6 +191,7 @@ def setupLayout(self):
     def closeEvent(self, event):
         # Close browser (force=True) and free CEF reference
         if self.cef_widget.browser:
+            self.cef_widget.browser.SetUserData("closing-browser", True)
             self.cef_widget.browser.CloseBrowser(True)
             self.clear_browser_references()
 
@@ -218,6 +219,7 @@ def focusInEvent(self, event):
             if WINDOWS:
                 WindowUtils.OnSetFocus(self.getHandle(), 0, 0, 0)
             self.browser.SetFocus(True)
+        super(CefWidget, self).focusInEvent(event)
 
     def focusOutEvent(self, event):
         # This event seems to never get called on Linux, as CEF is
@@ -226,6 +228,7 @@ def focusOutEvent(self, event):
             print("[qt.py] CefWidget.focusOutEvent")
         if self.browser:
             self.browser.SetFocus(False)
+        super(CefWidget, self).focusOutEvent(event)
 
     def embedBrowser(self):
         if (PYSIDE2 or PYQT5) and LINUX:
@@ -266,27 +269,24 @@ def getHandle(self):
                 return ctypes.pythonapi.PyCapsule_GetPointer(
                         self.winId(), None)
 
-    def moveEvent(self, _):
+    def moveEvent(self, event):
         self.x = 0
         self.y = 0
         if self.browser:
-            if WINDOWS:
-                WindowUtils.OnSize(self.getHandle(), 0, 0, 0)
-            elif LINUX:
+            if WINDOWS or LINUX:
                 self.browser.SetBounds(self.x, self.y,
                                        self.width(), self.height())
             self.browser.NotifyMoveOrResizeStarted()
+        super(CefWidget, self).moveEvent(event)
 
     def resizeEvent(self, event):
         size = event.size()
         if self.browser:
-            if WINDOWS:
-                WindowUtils.OnSize(self.getHandle(), 0, 0, 0)
-            elif LINUX:
+            if WINDOWS or LINUX:
                 self.browser.SetBounds(self.x, self.y,
                                        size.width(), size.height())
             self.browser.NotifyMoveOrResizeStarted()
-
+        super(CefWidget, self).resizeEvent(event)
 
 class CefApplication(QApplication):
     def __init__(self, args):
@@ -351,7 +351,10 @@ def OnSetFocus(self, **_):
     def OnGotFocus(self, browser, **_):
         if cef.GetAppSetting("debug"):
             print("[qt.py] FocusHandler.OnGotFocus")
-        self.cef_widget.setFocus()
+        # Check if browser is not closing otherwise error occurs in PySide:
+        # > RuntimeError: Internal C++ object (CefWidget) already deleted.
+        if not browser.GetUserData("closing-browser") and self.cef_widget:
+            self.cef_widget.setFocus()
         # Temporary fix no. 1 for focus issues on Linux (Issue #284)
         if LINUX:
             browser.SetFocus(True)

examples/screenshot.py

@@ -153,11 +153,24 @@ def save_screenshot(browser):
     # "OnPaint.buffer_string" data is set in RenderHandler.OnPaint.
     buffer_string = browser.GetUserData("OnPaint.buffer_string")
     if not buffer_string:
-        raise Exception("buffer_string is empty, OnPaint never called?")
+        # Sometimes LoadHandler.OnLoadingStateChange gets called
+        # before RenderHandler.OnPaint.
+        if not browser.GetUserData("save_screenshot.delay_printed"):
+            sys.stdout.write("[screenshot.py] Delay")
+            sys.stdout.flush()
+            browser.SetUserData("save_screenshot.delay_printed", True)
+        else:
+            sys.stdout.write(".")
+            sys.stdout.flush()
+        cef.PostDelayedTask(cef.TID_UI, 13, save_screenshot, browser)
+        return
     image = Image.frombytes("RGBA", VIEWPORT_SIZE, buffer_string,
                             "raw", "RGBA", 0, 1)
     image.save(SCREENSHOT_PATH, "PNG")
+    sys.stdout.write(os.linesep)
     print("[screenshot.py] Saved image: {path}".format(path=SCREENSHOT_PATH))
+    # See comments in exit_app() why PostTask must be used
+    cef.PostTask(cef.TID_UI, exit_app, browser)
 
 
 def open_with_default_application(path):
@@ -187,10 +200,9 @@ def OnLoadingStateChange(self, browser, is_loading, **_):
         if not is_loading:
             # Loading is complete
             sys.stdout.write(os.linesep)
+            sys.stdout.flush()
             print("[screenshot.py] Web page loading is complete")
             save_screenshot(browser)
-            # See comments in exit_app() why PostTask must be used
-            cef.PostTask(cef.TID_UI, exit_app, browser)
 
     def OnLoadError(self, browser, frame, error_code, failed_url, **_):
         """Called when the resource load for a navigation fails
@@ -225,7 +237,10 @@ def OnPaint(self, browser, element_type, paint_buffer, **_):
             sys.stdout.write(".")
             sys.stdout.flush()
         else:
+            if browser.GetUserData("save_screenshot.delay_printed"):
+                sys.stdout.write(os.linesep)
             sys.stdout.write("[screenshot.py] OnPaint")
+            sys.stdout.flush()
             self.OnPaint_called = True
         if element_type == cef.PET_VIEW:
             # Buffer string is a huge string, so for performance

examples/snippets/window_size.py

@@ -15,20 +15,15 @@ def main():
     cef.Initialize()
     window_info = cef.WindowInfo()
     parent_handle = 0
-    # This call has effect only on Mac and Linux.
+    # SetAsChild() call has effect only on Mac and Linux.
     # All rect coordinates are applied including X and Y parameters.
     window_info.SetAsChild(parent_handle, [0, 0, 900, 640])
     browser = cef.CreateBrowserSync(url="https://www.google.com/",
                                     window_info=window_info,
                                     window_title="Window size")
     if platform.system() == "Windows":
-        window_handle = browser.GetOuterWindowHandle()
-        insert_after_handle = 0
-        # X and Y parameters are ignored by setting the SWP_NOMOVE flag
-        SWP_NOMOVE = 0x0002
-        # noinspection PyUnresolvedReferences
-        ctypes.windll.user32.SetWindowPos(window_handle, insert_after_handle,
-                                          0, 0, 900, 640, SWP_NOMOVE)
+        # X and Y parameters are ignored.
+        browser.SetBounds(0, 0, 900, 640)
     cef.MessageLoop()
     del browser
     cef.Shutdown()

examples/tkinter_.py

@@ -204,11 +204,7 @@ def on_root_configure(self):
 
     def on_mainframe_configure(self, width, height):
         if self.browser:
-            if WINDOWS:
-                ctypes.windll.user32.SetWindowPos(
-                    self.browser.GetWindowHandle(), 0,
-                    0, 0, width, height, 0x0002)
-            elif LINUX:
+            if WINDOWS or LINUX:
                 self.browser.SetBounds(0, 0, width, height)
             self.browser.NotifyMoveOrResizeStarted()