Hide cursor over specific gadget

[kenmo]

I know you can use ShowCursor_() to hide the mouse cursor over a window, but is there a simple way to hide it only when it is over a certain gadget?

I'm wondering what the simplest method would be, and Windows-only is fine (I'm writing an MDI based program).

Ideas?

[IdeasVacuum]

Hi Kenmo

Here is one way. In a Repeat loop, test for the cursor position:

Code: Select all

iCursorX =   WindowMouseX(#WIN)
iCursorY =   WindowMouseY(#WIN)

Then test to see if the cursor is inside the 'hot spot' where you don't want it displayed (unusual?) or want to change the cursor graphic:

Code: Select all

If (iCursorX > 15) And (iCursorX < 75) And (iCursorY > 20) And (iCursorY < 40)

                 SetCursor_(ighHandCursor)

 ElseIf (iCursorX > 750) And (iCursorX < 771) And (iCursorY > 20) And (iCursorY < 40)

                  SetCursor_(ighHandCursor)

Else
                  SetCursor_(ighCrossCursor)

 EndIf

The above is not a working code snippet, just a guide to the method.

[netmaestro]

Code: Select all

Procedure SubClassProc(hwnd, msg, wparam, lparam)
  oldproc = GetProp_(hwnd, "oldproc")
  Select msg
    Case #WM_NCDESTROY
      RemoveProp_(hwnd, "oldproc")
      
    Case #WM_SETCURSOR
      SetCursor_(0)
      ProcedureReturn 0
    
  EndSelect   
  ProcedureReturn CallWindowProc_(oldproc, hwnd, msg, wparam, lparam)
EndProcedure


OpenWindow(0,0,0,800,600,"",#PB_Window_ScreenCentered|#PB_Window_SystemMenu)
hwnd = ImageGadget(0,100,100,0,0,LoadImage(0, #PB_Compiler_Home+"Examples\sources\data\background.bmp"))
SetProp_(hwnd, "oldproc", SetWindowLongPtr_(hwnd, #GWL_WNDPROC, @SubClassProc()))

Repeat:Until WaitWindowEvent()=#PB_Event_CloseWindow

[IdeasVacuum]

That is a very nice way netmaestro.
To handle more than one gadget:

Code: Select all

Procedure SubClassProc(hwnd, msg, wparam, lparam)
  oldproc = GetProp_(hwnd, msg)
  Select msg
    Case #WM_NCDESTROY
      RemoveProp_(hwnd, msg)
     
    Case #WM_SETCURSOR
      SetCursor_(0)
      ProcedureReturn 0
   
  EndSelect   
  ProcedureReturn CallWindowProc_(oldproc, hwnd, msg, wparam, lparam)
EndProcedure

It's feels a bit weird to lose your cursor though! What is the benefit of hiding the cursor over a gadget kenmo?

[kenmo]

I have an ImageGadget that is updated in near-realtime and draws at the cursor position... I just don't want the Windows cursor to be over it.

Thanks for the examples guys, I'll give them a try.

[IdeasVacuum]

Oh I see. Perhaps you could 'park' the cursor away from the action, or offset it's location by a few pixels, or change the cursor to cross-hair so that it does not obscure so much.