Announcement

**Dale Yarker** · 30 Oct 2008, 12:13 PM

Wish I'd seen this thread first. It might have something to do with WHY PB used %BN_CLICKED vs %STN_CLICKED in help for CONTROL ADD Label.

**Dave Biggs** · 30 Oct 2008, 01:33 PM

Something like this perhaps?

Code:

    Case %WM_COMMAND
      IF CbCtlMsg = %STN_DBLCLK  Then
          KillTimer CbHndl, 1
          Dialog Set Text CbHndl, "DBLCLK: " + FORMAT$(%STN_DBLCLK)
          Sleep 100 : Dialog Set Text CbHndl, ""
      ELSEIF CbCtlMsg = %STN_CLICKED Then
          SetTimer CbHndl, 1, GetDoubleClickTime, 0
      END IF
 
    Case %WM_TIMER
      KillTimer CbHndl, 1 
      Dialog Set Text CbHndl, "CLICKED: " + FORMAT$(%STN_CLICKED)
      Sleep 100 : Dialog Set Text CbHndl, ""

**Rodney Hicks** · 30 Oct 2008, 02:00 PM

I'll give that a workout tonight, thank you.

**Gösta H. Lovgren-2** · 30 Oct 2008, 10:45 PM

Dave, I pasted your code suggestion into some sample code. It works fine. However I'm not understanding the concept of Timer.

There's a '<< remark with the relevant SDK lines from the help file and
'<<<<<<<<<<<<<<<<<< Creates it here in ID_Label? Why?
is what I'm not getting. Could you explain it for me? Also why KILL it? Thanks.

(I posted the whole example in case newbies and any other dummies (like me) want to follow along.)
'

Code:

'PBWIN 9.00 - WinApi 05/2008 - XP Pro SP3
#Dim All 
#Compile Exe  
#Include "WIN32API.INC"
'
Global hdlg As Dword                
 
%Id_Exit_Btn = 1000
%Id_Sample_Textbox = 1001
%Id_Show_Result_Btn = 1002
%Id_Label = 1003
' 
Macro Common_Locals 'Macro easier than retyping and maintains coding consistency
  Global Dlg_hght, Dlg_Wd As Long 'Global in case want to use in Controls
  Local Row, col, hght, wd, Longest,ctr, ln, ln1, i As Long
  Local  l, s As String
End Macro  
'
CallBack Function Dialog_Processor              
  Common_Locals
  Select Case CbMsg     'This is TO determine the message TYPE 
     '
     Case %WM_TIMER
      KillTimer CbHndl, 1 '<< destroys the specified timer. (Win32 PR)
      Dialog Set Text CbHndl, "CLICKED: " + Format$(%STN_CLICKED)
      Sleep 1000 : Dialog Set Text CbHndl, ""
     '
     Case %WM_COMMAND  'This processes command messages
       Select Case CbCtl
         Case %Id_Label
            If CbCtlMsg = %STN_DBLCLK  Then
                KillTimer CbHndl, 1  '<< destroys the specified timer. (Win32 PR)
                Dialog Set Text CbHndl, "DBLCLK: " + Format$(%STN_DBLCLK)
                Sleep 1000 : Dialog Set Text CbHndl, ""
            ElseIf CbCtlMsg = %STN_CLICKED Then
                SetTimer _    '<< creates a timer with the specified time-out value. 
                        CbHndl, _ '<< Creates it here in ID_Label? Why?
                         1,      _
                         GetDoubleClickTime, 0 '<<retrieves the current double-click time for the mouse. 
            End If
 
 
         Case %Id_Show_Result_Btn 
            Control Get Text CbHndl, %Id_Sample_Textbox To l$
              ? l$, , FuncName$
         Case %Id_Exit_Btn
           Select Case CbCtlMsg        
              Case 0
                Dialog End CbHndl
           End Select
       End Select
  End Select
End Function
'
Function PBMain
  Common_Locals
  Dlg_hght = 400
  Dlg_Wd = 400
  Dialog New Pixels, hdlg, "Demo", , , Dlg_Wd, Dlg_Hght, %WS_SYSMENU To hdlg 'centered
 
  Row = 10
  col = 10
  Wd = 40
  Hght = 12
  Control Add Label, hdlg, %Id_Label, " Name & Address ", Col, Row, Wd, Hght,  %SS_Notify
 
  s$ = "Brown, Kevin" & $CrLf & _
       "123 PBWin Avenue" & $CrLf & _
       "PowerBasic, FL 12345"
 
  Col = Col + Wd + 10 'just past label 
  Hght = 15 * 10 'Plenty room for 10 lines of text
  Wd = Dlg_Wd - 40 - 30 'minus the label and leave a little
  Control Add TextBox, hdlg, %Id_Sample_Textbox, s$, Col, Row, Wd, Hght, %ES_WantReturn Or %ES_MultiLine
 
   hght = 25   
   Wd = Dlg_Wd - 20
   Col = 10 'center
 
   Row = Dlg_hght - (Hght * 2) - 4 'Just off bottom
     Control Add Button, hdlg, %Id_Show_Result_Btn, "Show Textbox Results", col, row, Wd, Hght
 
   Row = Dlg_hght - Hght - 2 'Just off bottom
     Control Add Button, hdlg, %Id_Exit_Btn, "Abandon Ship", col, row, Wd, Hght
 
     Dialog Show Modal hDlg   Call Dialog_Processor
End Function
'

=============================================
"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)
=============================================

**Dave Biggs** · 30 Oct 2008, 11:48 PM

Hi Gösta,

The problem is that the label always responds to the first click (and a STN_CLICKED notification is generated) even when that click is actually part of a double-click by the user. A double-click actually causes two notifications so how do we ignore the first when it's appropriate to do so?

What I was suggesting is starting a timer to delay the response to the first click in case another is 'just coming'.

So.
1. Start the timer on the first click.

2. If not killed by a second click (ie STN_DBLCLK notification) the timer fires after a suitable wait and we can respond to the single-click event.
(GetDoubleClickTime = the maximum number of milliseconds that may occur between the first and second click of a double-click - a system parameter that defaults to about 500ms. It can be changed by the operator adjusting the Mouse Properties in the control panel).

3. If the timer does fire, kill it so we can start over (at t-zero as it were) the next time a click is announced.

4. If a double-click event does occur, kill the timer (started by the first click, but not yet fired) and respond to the double-click event.

- Something like that anyway

**Rodney Hicks** · 31 Oct 2008, 12:19 AM

Thank you Gosta for testing that and posting the code. It saved me some time, and it is delightful to see it work.

Nice work Dave.

Hope Dave's explanation answered all for you Gosta.

**Clay Clear** · 31 Oct 2008, 01:41 AM

For double mouse clicks, Windows sends more than one message. It's been ages since I wrote the test code, but I believe that before Windows sends the DBLCLICK message, it will send the normal clicked messages. I presume that this is because, upon the first click notification from the mouse driver, Windows might not yet realize that it is a double click, and therefore sends the normal click message, and after realizing it is a double click message, it then sends a double click message. This is only a theory of mine, though.

**Rodney Hicks** · 31 Oct 2008, 02:51 AM

It seems that the second click of the double is completely discarded, else the single click event would repeat or the double click event would happen in that case, IMO. It seems that the message is sent on a WM_LBUTTONDOWN
kind of thingy.

But I got to wondering, what if a person wanted to test for all four possible messages in the same select/case block? Without Dave's %WM_TIMER all I get is the %STN_CLICKED response, but my code may be suspect.

More thinking is in order on my part.

**Dave Biggs** · 31 Oct 2008, 04:48 AM

Rod,

If you replace your original MsgBox's with 'Dialog Set Text's' you'll see that indeed both messages are generated on a double-click. The STN_CLICKED MsgBox interupts the double-click.

To get all the mouse messages you'll probably have to subclass the label?

**Dave Biggs** · 31 Oct 2008, 05:55 AM

To see all four 'STN_xxx' messages..

Code:

#Compile Exe
#Dim All
#Include "WIN32API.INC"
 
%BTN_Test      = 102
%LBL_LABEL1    = 101
'------------------/
 
CallBack Function DlgProc()
  Select Case As Long CbMsg
    Case %WM_INITDIALOG
    Case %WM_COMMAND
      If CbCtl = %LBL_LABEL1 Then
        If CbCtlMsg = %STN_ENABLE Then
            Dialog Set Text CbHndl, ""
            Dialog Set Text CbHndl, "LBL Enabled"
        End If
        If CbCtlMsg = %STN_DISABLE Then
            Dialog Set Text CbHndl, ""
            Dialog Set Text CbHndl, "LBL Disabled"
        End If
        If CbCtlMsg = %STN_DBLCLK  Then
            KillTimer CbHndl, 1
            Dialog Set Text CbHndl, "" : Sleep 100
            Dialog Set Text CbHndl, "DBLCLK: " + Format$(%STN_DBLCLK)
        ElseIf CbCtlMsg = %STN_CLICKED Then
            SetTimer CbHndl, 1, GetDoubleClickTime, 0                     ' Comment out for test
            'Dialog Set Text CbHndl, "" : Sleep 100                       ' Remove comment for test
            'Dialog Set Text CbHndl, "CLICKED: " + Format$(%STN_DBLCLK)   ' Remove comment for test
        End If
      End If 
      If CbCtl = %BTN_TEST Then
       Local BtnDown As Long
        If CbCtlMsg = %BN_CLICKED Then
          Control Get Check CbHndl, %BTN_Test To BtnDown
          If BtnDown  Then
              Control Disable CbHndl, %LBL_Label1
          Else 
              Control Enable CbHndl, %LBL_Label1
          End If 
        End If
      End If
 
    Case %WM_TIMER
      KillTimer CbHndl, 1
      Dialog Set Text CbHndl, "" : Sleep 100
      Dialog Set Text CbHndl, "CLICKED: " + Format$(%STN_CLICKED)
 
    Case %WM_SYSCOMMAND
      If (CbWParam And &HFFF0) = %SC_CLOSE Then
        Dialog End CbHndl
      End If
 
  End Select
End Function
'------------------/DlgProc
 
Function PBMain()
 Local hDlg  As Dword
 
  Dialog New 0, "Test", , , 200, 120, %WS_CAPTION Or %WS_SYSMENU, To hDlg
  Control Add Label,  hDlg, %LBL_LABEL1, "Click Me !!", 50, 25, 120, 20, %SS_NOTIFY
  Control Add Button,  hDlg, %BTN_Test, "En/Dis-able", 75, 60, 50, 15, %BS_PUSHLIKE Or %BS_AUTOCHECKBOX
 
  Dialog Show Modal hDlg, Call DlgProc
 
End Function
'------------------/PbMain

**Rodney Hicks** · 31 Oct 2008, 06:11 AM

Your right Dave, so it's back to the drawing board. I shoulda oughta read a little more in the SDK.

**Michael Mattias** · 31 Oct 2008, 09:09 AM

A double-click actually causes two notifications so how do we ignore the first when it's appropriate to do so

"They" say you should design so that a double-click does two things.. one on click, one on the second click, if that second click occurs.

So the answer is, you don't put yourself in a situation where it is appropriate to ignore the first click.

But I would think just ignoring the (single) click would do it. I know that works for me with listview controls... the first click simply selects the 'row of interest' which is the default behavior provided by windows, the second click - if it happens - does something.

Never tried it with label controls, though; although they can report clicks, they cannot receive the keyboard focus, so the "select on first click" thing does not apply.

MCM

**Dave Biggs** · 31 Oct 2008, 11:20 AM

with label controls, though; although they can report clicks, they cannot receive the keyboard focus

Not quite true - see this discussion. http://www.powerbasic.com/support/pb...ad.php?t=36894

**Rodney Hicks** · 31 Oct 2008, 11:38 AM

Micheal, that "it does one thing on first click, another on second" is the issue I was not aware of, with them being messages I just assumed that each could be handled separately.
It is easier now to think of it(the doubleclick) as a double message, because even if you are only going to use one of the messages, the other is there.
So I do things the opposite of my original plan, in the end, it'll look like I planned it this way.

**Gösta H. Lovgren-2** · 31 Oct 2008, 10:25 PM

Dave, thanks for the explanation. If I understand correctly, effectively setting the timer "suspends" new msgs to the Callback FOR THAT ID (%Id_Label in this case) for the duration of GetDoubleClickTime (50 ms or whatever the OpSys has it set for). Other msgs already in the queue FOR THAT ID (%Id_Label in this case) will get processed. and since DoubleClick is the next msg after SingleClick, it gets processed.

IOW we tell the Callback to wait a beat to check for a DoubleClick JIC.

IOW (again) The %Wm_Timer becomes the Single_Click for our purposes here. {???}

Here's the revised code that led me to those conclusions.

Code:

     Case %WM_COMMAND  'This processes command messages
       Select Case CbCtl
         Case %Id_Label      
'>>> if msg = Double Click then kill the Timer set up on the first click         
            If CbCtlMsg = %Stn_Dblclk  Then
               KillTimer CbHndl, 1  '<< stop the timer se by the first click
                Dialog Set Text CbHndl, "Double Clicked in Name" 
                Sleep 1000 : Dialog Set Text CbHndl, "" 'show for a second then erase
            End If
'>>> Since we don't know yet at this point if single click or a double click, we sort of give
'>>> the Callback time to check for a double click.            
            If CbCtlMsg = %Stn_Clicked Then 
                SetTimer _    '<< creates a timer with the specified time-out value. 
                        CbHndl, _ 
                         1,      _
                         GetDoubleClickTime, 0 '<<retrieves an sets the current double-click time for the mouse. 
            End If
 
         '
         Case %Id_Show_Result_Btn 
            Control Get Text CbHndl, %Id_Sample_Textbox To l$
              ? l$, , FuncName$
         Case %Id_Exit_Btn
           Select Case CbCtlMsg        
              Case 0
                Dialog End CbHndl
           End Select
       End Select
     '                                                   
     Case %WM_TIMER
'>>> Since the Timer was set above we know it must have been a single click because
'>>> Timer is still active. Had there been a DoubleClick received msg before the %WM_Timer msg
'>>> was received, the Timer would have been killed in the DoubleClick response above.    
      KillTimer CbHndl, 1 '<< destroys the specified timer. (Win32 PR)
      Dialog Set Text CbHndl, "Single CLICKED: Timer Killed "
      Sleep 1000 : Dialog Set Text CbHndl, "" 'show for a second then erase

======================================================
"I am become death,
shatterer of worlds."
Robert J. Oppenheimer (1904-1967)
(citing from the Bhagavad Gita,
after witnessing the world's first nuclear explosion)
======================================================

**Rodney Hicks** · 1 Nov 2008, 12:04 AM

IOW (again) The %Wm_Timer becomes the Single_Click for our purposes here. {???}

Yes. And I see no reason why a person couldn't create a SELECT CASE CB.CTL block to handle different IDs under the %WM_TIMER.(With some careful coding)

**Dave Biggs** · 1 Nov 2008, 02:20 AM

IOW (again) The %Wm_Timer becomes the Single_Click for our purposes here. {???}

Yes the processing of the single-click event has been delayed and shifted out of the WM_COMMAND case block. Fun eh!

**Michael Mattias** · 1 Nov 2008, 09:02 AM

Have you ever had to "double click again" even though you were sure you had double-clicked, but then decided you must have only single-clicked? Or cursed a designer for creating a hard-to-use screen?

I sure have.

And now you want to throw in a timer to further 'un-enhance' the 'user experience?'

This really sounds like a screen screaming for a separate BUTTON to do the "double click" thing, and then you won't care if the user clicked on the label on not.

That, or a non-optimal choice of controls. Insufficient information available to make suggestion.

MCM

**Rodney Hicks** · 1 Nov 2008, 09:09 AM

Gösta,
In case your going further with this:
I have re-learned something after posting this statement:

And I see no reason why a person couldn't create a SELECT CASE CB.CTL block to handle different IDs under the %WM_TIMER.

Once you're under the %WM_TIMER the CB.CTL returns the timer's ID, ergo you'll have to carry the CTL from the %WM_COMMAND if you're going to handle multiple ID's with the timer. You can possibly do something for the single click prior to setting the timer.

Announcement

%STN_CLICKED or %STN_DBLCLK(label)

%STN_CLICKED or %STN_DBLCLK(label)

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