update docs

Author: yunline

docs/reST/ref/sdl2_video.rst

@@ -101,14 +101,21 @@
 
    .. attribute:: grabbed
 
-      | :sl:`Get whether the mouse is confined to the window.`
+      | :sl:`Get whether the mouse is confined to the window. (**read-only**)`
       | :sg:`grabbed -> bool`
    
    .. attribute:: grab_mode
 
       | :sl:`Get or set whether the window is in grab mode.`
       | :sg:`grab_mode -> bool`
 
+      Get or set whether the window is in grab mode.
+      When set to ``True``, the window will be able to grab the mouse but
+      will not confine the mouse immediately. Once the window gains focus,
+      the mouse will be confined and :attr:`Window.grabbed` turns to ``True``.
+      Once this attribute is set to ``False`` or the window loses focus,
+      the mouse will be released and :attr:`Window.grabbed` turns to ``False``
+
    .. attribute:: relative_mouse
 
       | :sl:`Get or set the window's relative mouse mode state`

src_c/doc/sdl2_video_doc.h

@@ -5,7 +5,7 @@
 #define DOC_SDL2_VIDEO_GETDRIVERS "get_drivers() -> Iterator[RendererDriverInfo]\nYield info about the rendering drivers available for Renderer objects"
 #define DOC_SDL2_VIDEO_GETGRABBEDWINDOW "get_grabbed_window() -> Window or None\nGet the window with input grab enabled"
 #define DOC_SDL2_VIDEO_WINDOW "Window(title='pygame window', size=(640, 480), position=None, fullscreen=False, fullscreen_desktop=False, **kwargs) -> Window\npygame object that represents a window"
-#define DOC_SDL2_VIDEO_WINDOW_GRABBED "grabbed -> bool\nGet whether the mouse is confined to the window."
+#define DOC_SDL2_VIDEO_WINDOW_GRABBED "grabbed -> bool\nGet whether the mouse is confined to the window. (**read-only**)"
 #define DOC_SDL2_VIDEO_WINDOW_GRABMODE "grab_mode -> bool\nGet or set whether the window is in grab mode."
 #define DOC_SDL2_VIDEO_WINDOW_RELATIVEMOUSE "relative_mouse -> bool\nGet or set the window's relative mouse mode state"
 #define DOC_SDL2_VIDEO_WINDOW_TITLE "title -> str\nGet or set the window title"