This section describes the Microsoft Windows Shell messages and notifications.
ABM_ACTIVATE
Notifies the system that an appbar has been activated. An appbar should call this message in response to the WM_ACTIVATE message.
ABM_GETAUTOHIDEBAR
Retrieves the handle to the autohide appbar associated with an edge of the screen.
ABM_GETSTATE
Retrieves the autohide and always-on-top states of the Windows taskbar.
ABM_GETTASKBARPOS
Retrieves the bounding rectangle of the Windows taskbar.
ABM_NEW
Registers a new appbar and specifies the message identifier that the system should use to send it notification messages. An appbar should send this message before sending any other appbar messages.
ABM_QUERYPOS
Requests a size and screen position for an appbar. When the request is made, the message proposes a screen edge and a bounding rectangle for the appbar. The system adjusts the bounding rectangle so that the appbar does not interfere with the Windows taskbar or any other appbars.
ABM_REMOVE
Unregisters an appbar by removing it from the system's internal list. The system no longer sends notification messages to the appbar or prevents other applications from using the screen area occupied by the appbar.
ABM_SETAUTOHIDEBAR
Registers or unregisters an autohide appbar for an edge of the screen.
ABM_SETPOS
Sets the size and screen position of an appbar. The message specifies a screen edge and the bounding rectangle for the appbar. The system may adjust the bounding rectangle so that the appbar does not interfere with the Windows taskbar or any other appbars.
ABM_SETSTATE
Sets the autohide and always-on-top states of the Windows taskbar.
ABM_WINDOWPOSCHANGED
Notifies the system when an appbar's position has changed. An appbar should call this message in response to the WM_WINDOWPOSCHANGED message.
ABN_FULLSCREENAPP
Notifies an appbar when a full-screen application is opening or closing. This notification is sent in the form of an application-defined message that is set by the ABM_NEW message.
ABN_POSCHANGED
Notifies an appbar when an event has occurred that may affect the appbar's size and position. Events include changes in the taskbar's size, position, and visibility state, as well as the addition, removal, or resizing of another appbar on the same side of the screen.
ABN_STATECHANGE
Notifies an appbar that the taskbar's autohide or always-on-top state has changed
ABN_WINDOWARRANGE
Notifies an appbar that the user has selected the Cascade, Tile Horizontally, or Tile Vertically command from the taskbar's shortcut menu.