SetWindowCallback()

Syntax

SetWindowCallback(@ProcedureName() [, #Window])

For experienced programmers only. It's only supported on Microsoft Windows.

Normal events should be handled with the regular WaitWindowEvent() or WindowEvent().

This function associates a callback to handle the events of the all open windows. All the events are caught by this callback and can be processed here. To set a callback for a specific window only, the optional parameter can be used to pass the PB window number.

To remove/disable a previous set Callback just call SetWindowCallback(0 [, #Window]).

Warning: this way is lowlevel. Incorrect handling of the messages in the callback can interfere with PB's own message processing.

Parameters

@ProcedureName()

The callback procedure to use. It must have 4 parameters. Here is a sample code to use a callback correctly: Procedure MyWindowCallback(WindowID, Message, WParam, LParam) Result = #PB_ProcessPureBasicEvents ; ; you code here ; ProcedureReturn Result EndProcedure Here you see a working example checking some window parameters (using Windows API constants): Procedure WinCallback(hWnd, uMsg, WParam, LParam) ; Windows fills the parameter automatically, which we will use in the callback... If uMsg = #WM_SIZE Select WParam Case #SIZE_MINIMIZED Debug "Window was minimized" Case #SIZE_RESTORED Debug "Window was restored" Case #SIZE_MAXIMIZED Debug "Window was maximized" EndSelect EndIf ProcedureReturn #PB_ProcessPureBasicEvents EndProcedure If OpenWindow(0, 0, 0, 200, 100, "Messages", #PB_Window_MinimizeGadget | #PB_Window_MaximizeGadget) SetWindowCallback(@WinCallback()) ; activate the callback Repeat Select WaitWindowEvent() Case #PB_Event_CloseWindow End EndSelect ForEver EndIf

#Window (optional)

A specific window to associate the callback to. If omitted the callback will be called for any window.

Return value

None.

Supported OS

Windows