SetCapture by Dominic

Category: Mouse

Date: 02-16-2022

'Compiler Comments:
'This code was written to compilete in PBWin10. To compile with PBWin9, split pt
'into pt.x and pt.y as arguments wherever the PtInRect() API is used (one place).

'Compilable Example:  (Jose Includes)
#Compiler PBWin 10
#Compile EXE
#Dim All
%Unicode=1
#Include "WIN32API.INC"
Global hDlg As Dword

Function PBMain
   Local Result As Long
   Dialog New 0, "", , , 200, 60, %WS_OverlappedWindow To hDlg
   Dialog Show Modal hDlg Call DlgProc
End Function

CallBack Function DlgProc()
   Local trc As Rect, tpt As PointAPI

   Select Case Cb.Msg
      Case %WM_LButtonDown
         SetFocus hDlg      'why?
         SetCapture hDlg    'start capturing, so can detect LButtonUp when it occurs

      Case %WM_MouseMove
         If GetCapture() = hDlg Then   'app has capture    'why?
            ' Drawing and dragging operations
         End If

      Case %WM_LButtonUp
         ReleaseCapture  'generates a WM_CAPTURECHANGED message  'why not do my mouse up stuff here?

      Case %WM_CaptureChanged
         'sent to window losing the mouse capture
         'window receives this message if it calls ReleaseCapture itself
         GetClientRect hDlg, trc                             'relative coordinates of hDlg client area
         MapWindowPoints hDlg, %NULL, ByVal VarPtr(trc), 2   'screen coordinate of hDlg client area
         GetCursorPos tpt                                    'screen coordinates of cursor
         If PtInRect(trc, tpt) Then
            Dialog Set Text hDlg, "Inside"
         Else
            Dialog Set Text hDlg, "Outside"
         End If

      Case %WM_CancelMode
         'msg received when system windows (Task Mgr, Task Switch, ...) pop up
   End Select
End Function

'gbs_01032
'Date: 03-10-2012

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