[API categories](API-categories.md) | [API index](API-index.md)
# WindowUtils (class)
All methods of this class are static. Many of the Windows-only functions here are utilized in the PyWin32 example.
Table of contents:
* [Methods](#methods)
* [OnSetFocus (Win)](#onsetfocus-win)
* [OnSize (Win)](#onsize-win)
* [OnEraseBackground (Win)](#onerasebackground-win)
* [SetTitle (Win)](#settitle-win)
* [SetIcon (Win)](#seticon-win)
* [GetParentHandle](#getparenthandle)
* [IsWindowHandle](#iswindowhandle)
* [gtk_plug_new (Linux)](#gtk_plug_new-linux)
* [gtk_widget_show (Linux)](#gtk_widget_show-linux)
* [InstallX11ErrorHandlers (Linux)](#installx11errorhandlers-linux)
## Methods
### OnSetFocus (Win)
| Parameter | Type |
| --- | --- |
| windowHandle | int |
| msg | long |
| wparam | long |
| lparam | long |
| __Return__ | void |
Windows-only. This method processes WM_SETFOCUS message which is sent to a window after it has gained the keyboard focus.
### OnSize (Win)
| Parameter | Type |
| --- | --- |
| windowHandle | int |
| msg | long |
| wparam | long |
| lparam | long |
| __Return__ | void |
Windows-only. This method processes WM_SIZE message which is sent to a window after its size has changed.
### OnEraseBackground (Win)
| Parameter | Type |
| --- | --- |
| windowHandle | int |
| msg | long |
| wparam | long |
| lparam | long |
| __Return__ | void |
Windows-only. This method processes WM_ERASEBKGND message which is sent when the window background must be erased (for example, when a window is resized).
### SetTitle (Win)
| Parameter | Type |
| --- | --- |
| browser | [Browser](Browser.md) |
| title | str |
| __Return__ | void |
Windows-only. Set the title for the main window or popup window. The default implementation of [DisplayHandler](DisplayHandler.md).OnTitleChange() calls this method to set the title for a window.
### SetIcon (Win)
| Parameter | Type |
| --- | --- |
| browser | [Browser](Browser.md) |
| icon="inherit" | string |
| __Return__ | void |
Windows-only. Set the icon for the popup window. The default implementation of [DisplayHandler](DisplayHandler.md).OnTitleChange() calls this method to set the icon for a window that wasn't created explicitily (for example a popup window), the icon is inherited from the parent window. Icon parameter accepts only "inherit", you cannot pass here a path to an icon (currently not implemented).
### GetParentHandle
| Parameter | Type |
| --- | --- |
| windowHandle | int |
| __Return__ | void |
Get a parent handle.
On Linux and Mac this method always returns 0. @TODO.
### IsWindowHandle
| Parameter | Type |
| --- | --- |
| windowHandle | int |
| __Return__ | void |
Check whether this is a valid window handle.
On Linux and Mac this method always returns True. @TODO.
### gtk_plug_new (Linux)
| Parameter | Type |
| --- | --- |
| long GdkNativeWindow | long |
| __Return__ | void |
Linux-only.
### gtk_widget_show (Linux)
| Parameter | Type |
| --- | --- |
| long GtkWidget* | long |
| __Return__ | void |
Linux-only.
### InstallX11ErrorHandlers (Linux)
| | |
| --- | --- |
| __Return__ | void |
Linux-only. Install xlib error handlers so that the application
won't be terminated on non-fatal errors. Must be done after
initializing GTK.
CEF Python calls this function automatically during a call to
Initialize, so there is no more need to call it manually in
most cases.