mouse over

[Michael Clease]

I will keep it simple.

I have a dialog window with a button and I want to know when the mouse pointer is on top of the button.

Do I %WM_Command to find the button control
or
%WM_MOUSEMOVE and then find the button control.

I know XP has NMBCHOTITEM http://msdn2.microsoft.com/en-us/library/bb775959.aspx but I am not sure how to implement that.

Anyone care to point me in the right direction.

[sandyrepope]

Abraxas, I've been waiting for someone to give an answer because I don't understand just what you are trying to do. I am dying of curiosity.... What exactly are you trying to do?

Thanks
Sandy

[Michael Clease]

Sandy you will have to wait and see. ;D

I am getting there but its not quite working.

[ErosOlmi]

Abraxas,

sorry for the delay I take to reply on this.
I looked at NMBCHOTITEM (that I didn't know) and it is valid only from Win2K up. So not sure if it is a valid road.

I have this idea. Use %WM_MOUSEMOVE return message. It returns in LParam the x/y coordinates of the mouse relative to the client area of the window. That use ChildWindowFromPoint function (see declaration below) to get the handle of the child window (any control is in reality a window) where the mouse is located. If it correspond to the button you need than bingo.

Of course you need to know the windows handle of your button and this can be achieve using CONTROL HANDLE statement passing the window handle and the control ID. Also consider that all CONTROL ADD ... functions from thinBasic stable version 1.5.0.0 automatically return the window handle of the control just added.

DECLARE FUNCTION ChildWindowFromPoint LIB "USER32.DLL" _
                   ALIAS "ChildWindowFromPoint" _
                   (BYVAL hwndParent AS DWORD, BYVAL x AS LONG, BYVAL y AS LONG) AS DWORD

I didn't test my idea so far, so, please, let me know if it works or not.
Ciao
Eros

[ErosOlmi]

Forget my previous idea, I was not able to make it working.
Anyhow, here a 99% of the times working example. There are some cases that will not work, for example when you window is not the current one but below some other. In this case some side effects can take place.

 uses "UI"

 TYPE RECT
  nLeft AS LONG
  nTop AS LONG
  nRight AS LONG
  nBottom AS LONG
 END TYPE

 TYPE POINTAPI
  x AS LONG
  y AS LONG
 END TYPE

 DECLARE FUNCTION PtInRect    LIB "USER32.DLL" ALIAS "PtInRect"    (lpRect AS RECT, BYVAL ptx AS LONG, BYVAL pty AS LONG) AS LONG
 DECLARE FUNCTION SetCapture   LIB "USER32.DLL" ALIAS "SetCapture"   (BYVAL hWnd AS DWORD) AS LONG
 DECLARE FUNCTION ReleaseCapture LIB "USER32.DLL" ALIAS "ReleaseCapture" () AS LONG
 DECLARE FUNCTION GetCursorPos  LIB "USER32.DLL" ALIAS "GetCursorPos"  (lpPoint AS POINTAPI) AS LONG
 DECLARE FUNCTION GetWindowRect LIB "USER32.DLL" ALIAS "GetWindowRect" (BYVAL hWnd AS DWORD, lpRect AS RECT) AS LONG
  
 %btn_OK    = 101
 %txt_Result  = 102

 MAIN

 FUNCTION MAIN() as long
  DIM Msg    AS LONG
  DIM wParam  AS LONG
  DIM lParam  AS LONG
  DIM hDlg   AS DWORD

  dim hBtn_OK  as dword
  dim pt    as POINTAPI
  dim rc    as RECT

  DIALOG NEW 0, "MouseOver test", -1, -1, _
    100, 100, %WS_SYSMENU or %ds_center OR %WS_CAPTION TO hDlg

  CONTROL ADD textbox , hDlg, %txt_Result , ""  , 10, 10, 80, 14, %WS_TABSTOP
  CONTROL ADD BUTTON , hDlg, %btn_OK   , "OK" , 25, 80, 50, 14, %WS_TABSTOP

  control handle hDlg, %btn_OK to hBtn_OK 


  DIALOG SHOW MODELESS hDlg
  
  '---Start the main message loop
  WHILE IsWindow(hDlg)         
  
   '---Get the message and fill wParam and lParam
   Msg = GetMessage(hDlg, wParam, lParam) 
      
   SELECT CASE Msg

    case %WM_MOUSEMOVE
     
     SetCapture hDlg
     
      GetCursorPos pt
      GetWindowRect hBtn_OK, rc

      IF ptInRect(rc,pt.x,pt.y) THEN
       control set text hDlg, %txt_Result, "Bingo"
      ELSE
       control set text hDlg, %txt_Result, ""
      END IF 
     
     ReleaseCapture
     
    CASE %WM_COMMAND

     '---Test which control has been clicked
     SELECT CASE wParam

      CASE %btn_OK
       exit while
       
     END SELECT

    CASE %WM_SYSCOMMAND

     SELECT CASE wParam
       
      CASE %SC_CLOSE
       EXIT WHILE

        
     END SELECT

    CASE ELSE
    
   END SELECT
   
  WEND

  DIALOG END hDlg


 END FUNCTION

[Petr Schreiber]

Hi Eros,

here it works even if window is partially covered.
Really nice sample, thanks !


Petr