Trapping all events

[gm_raju]

Let me put the problem with one simple example.

I have a form 'Form1' with two controls, one text box control 'Text1' and a command button 'Command1'. I have a method :
Sub TrapEvent()
' need to find which event is to occur, and for what
' object: Text1, Command1 or Form1
End sub

As we know each object has its own set of events, here the case with Text1 and Command1. Lets take simple Click events :
Sub Text1_Click()
' some statements
End Sub
Sub Command1_Click()
' some statements
End Sub

Now When Command1 is clicked, Command1_Click() event will be triggered and when Text1 is clicked Text1_Click event will be triggered. What I need now is on whatever object(Text1, Command1, Form1) I clicked, my TrapEvent() method should be executed before executing the _Click event of the corresponding controls and thereby I should be able to determine which event ('Click' in this case) is occured and for what control object.

This is the problem. So all the VB experts are requested to give its solution.

Thank you all.

[SkippySolutions]

Hey GM,

My best guess is to change Trap Event a little:

Public Sub TrapEvent(ByRef ctlCurrent AS Control, psEvent as String)

   If TypeOf ctlCurrent is TextBox then
      Select Case psEvent
         Case "Click"
            MsgBox ctlCurrent.Name & " Click event fired"
      End Select
   Endif
   
End Sub

And then put the following code in your event:

   Sub Text1_Click() 
      Call TrapEvent(Text1, "Click")   

      ' some statements 
   End Sub

The TrapError procedure could also be changed to a function that returns a boolean and then you can change your code to:

   Sub Text1_Click() 
      If TrapEvent(Text1, "Click") = True then
         ' some statements 
      Else
         'som statements
      Endif
   End Sub

Also, the ByRef in the TrapError procedure allows you to make changes to that control if there is a problem in the information stored in it.

Hope this helps.

[Edited by SkippySolutions on 05-31-2000 at 10:43 AM]

[gm_raju]

Thanks to Skippy Solutions for the suggestion. But the solution is not as I expected. I think my question was not clear. My intention is to trap all events that will be occured in any controls in the form by my own procedure i.e. TrapEvent(). In such a case it won't be wise to call the procedure explicitely in every event of every control on the form. I need such a solution with which the system automatically takes the control to the TrapEvent() procedure when any event occured. In this procedure I sould be able to know which event is occured for what control and accordingly I should be able to cancel the event or allow to proceed as usual to corresponding event procedure of the control.

I hope the question is clear now. I need the solution urgently. So the experts are again requested for this.

[SkippySolutions]

Other than the last solution, the only other thing I can think of is to create a hook into the Window's message queue and monitor that. It may take a bit of coding, perhaps a little more than you want to do, but this is the only other solution that I can think of.

[Thomas Halsvik]

HEY. I have a lead for you. This code should set you in the right direction. Didn't know of it's potential before now. I'm looking for the same thing your'e looking for.
It traps all events in the program you're running. When the program ends, the eventhandling ends too ( i think. or else i gotta find a way to shut it down. To get a number of the type of event, just read the aMsg.message. Ie a mousemove has value 512)

Option Explicit

Private Declare Function GetMessage Lib "user32" Alias "GetMessageA" (lpMsg As Msg, ByVal hwnd As Long, ByVal wMsgFilterMin As Long, ByVal wMsgFilterMax As Long) As Long
Private Declare Function DispatchMessage Lib "user32" Alias "DispatchMessageA" (lpMsg As Msg) As Long

Const WM_KEYDOWN = &H100
Const WM_KEYFIRST = &H100
Const WM_KEYLAST = &H108
Const WM_KEYUP = &H101
Const WM_LBUTTONDBLCLK = &H203
Const WM_LBUTTONDOWN = &H201
Const WM_LBUTTONUP = &H202
Const WM_MBUTTONDBLCLK = &H209
Const WM_MBUTTONDOWN = &H207
Const WM_MBUTTONUP = &H208
Const WM_MOUSEMOVE = &H200

Private Type POINTAPI
  x As Long
  y As Long
End Type

Private Type Msg
  hwnd As Long
  message As Long
  wParam As Long
  lParam As Long
  time As Long
  pt As POINTAPI
End Type

Sub GetMessage2()
  Dim aMsg As Msg
  Do While GetMessage(aMsg, 0, 0, 0)
    If aMsg.message = WM_KEYDOWN Then
      If aMsg.wParam = 27 Then MsgBox "ESCAPE pressed"
      MsgBox "KeyDown"
    End If
    If aMsg.message = 1026 Then Exit Do    'if X in the corner is pressed
    Debug.Print aMsg.message
    DispatchMessage aMsg
  Loop 'Loops until program is closed
End Sub

[Edited by Thomas Halsvik on 06-07-2000 at 08:36 AM]