Control gets old clicks when enabled -flush buffer?

[Mike Doty]

CONTROL DISABLE CBHNDL, %IDC_EXECUTE
How do you flush the mouse buffer so if someone clicks on a disabled button control it isn't executed as soon as the button is enabled?
Is there a flush mouse buffer command?

[Michael Mattias]

That should not be occurring... a disabled control does not send WM_COMMAND and AFAIK sends exactly nothing.

Show failing code.

[Mike Doty]

DOEVENTS fixes the problem, but not sure why needed.

The DOEVENTS loop keeps extra keystrokes from executing the button
when it is enabled and also gets the first page of the LISTVIEW
to display immediately.
'First page displays immediately and extra keystrokes not accepted if this is used
FOR x = 1 TO 4IALOG DOEVENTS:NEXT
Without DOEVENTS it can be executed many times and first page doesn't appear until done.
%IDC_LISTVIEW = 2001 'listview
%IDC_EXECUTE = 4007 'button

'This has turned into a pretty nice listview
'

FUNCTION DisplayRecordSet(hDlg AS DWORD) AS DWORD
  CONTROL DISABLE hDlg, %IDC_EXECUTE 'actually caller does this
  LOCAL row AS DWORD, col AS LONG, ColumnCount AS LONG
 
  LOCAL x AS LONG
 
  ColumnCount = slGetColumnCount
  IF ColumnCount THEN
    MOUSEPTR 11
    'CONTROL SHOW STATE hDlg, %IDC_LISTVIEW, %SW_HIDE
 
    LISTVIEW RESET hDLG, %IDC_LISTVIEW
    LISTVIEW SET STYLE hDlg, %IDC_LISTVIEW, %LVS_EX_GRIDLINES
    FOR col = 1 TO ColumnCount   'Insert columns with column names
      LISTVIEW DELETE COLUMN hDlg, %IDC_LISTVIEW,col
      LISTVIEW INSERT COLUMN hDlg, %IDC_LISTVIEW,col,slGetColumnName(col),100,0
    NEXT
  ELSE
    ? "No columns"
    EXIT FUNCTION
  END IF
 
  DO WHILE slGetRow
    INCR row
    LISTVIEW INSERT ITEM hDlg, %IDC_LISTVIEW,row, 0 , slF(1) 'Insert row, 0=no image
    FOR col = 2 TO ColumnCount                               'add text into columns
      LISTVIEW SET TEXT hdlg, %IDC_LISTVIEW, row, col,slF(col)
    NEXT
 
    IF row = 100 OR row MOD 1000 = 0  THEN          'refresh screen every so often
      '
      'First page displays immediately and extra keystrokes not accepted if this is used
      FOR x = 1 TO 4
        DIALOG DOEVENTS
        Message hDlg, "Records for far" + STR$(row)
       NEXT
    '
    END IF
  LOOP
  CONTROL SHOW STATE hdlg, %IDC_LISTVIEW, %SW_HIDE
  FOR col = 1 TO ColumnCount   'fit columns
    LISTVIEW FIT CONTENT hDlg, %IDC_LISTVIEW, col
  NEXT
  CONTROL SHOW STATE hDlg, %IDC_LISTVIEW, %SW_SHOW
 
  MOUSEPTR 1
  FUNCTION = row
 
END FUNCTION

[Mike Doty]

I'll try to work up another example without a listview to see if I can duplicate it.

[Mike Doty]

Buffered mouse clicks?

'Click button quickly after being disabled.
'It appears clicks are buffered.

#PBFORMS CREATED V1.51
'------------------------------------------------------------------------------
#COMPILE EXE
#DIM ALL
'Created using PBWIN9
'------------------------------------------------------------------------------
'   ** Includes **
'------------------------------------------------------------------------------
#PBFORMS BEGIN INCLUDES
%USEMACROS = 1
#IF NOT %DEF(%WINAPI)
    #INCLUDE "WIN32API.INC"
#ENDIF
#IF NOT %DEF(%COMMCTRL_INC)
    #INCLUDE "COMMCTRL.INC"
#ENDIF
#INCLUDE "PBForms.INC"
#PBFORMS END INCLUDES
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'   ** Constants **
'------------------------------------------------------------------------------
#PBFORMS BEGIN CONSTANTS
%IDD_DIALOG1  =  101
%IDC_BUTTON1  = 1001
%IDC_LISTVIEW = 1002
#PBFORMS END CONSTANTS
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'   ** Declarations **
'------------------------------------------------------------------------------
DECLARE CALLBACK FUNCTION ShowDIALOG1Proc()
DECLARE FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
#PBFORMS DECLARATIONS
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'   ** Main Application Entry Point **
'------------------------------------------------------------------------------
FUNCTION PBMAIN()
    PBFormsInitComCtls (%ICC_WIN95_CLASSES OR %ICC_DATE_CLASSES OR %ICC_INTERNET_CLASSES)
    ShowDIALOG1 %HWND_DESKTOP
END FUNCTION
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'   ** CallBacks **
'------------------------------------------------------------------------------
CALLBACK FUNCTION ShowDIALOG1Proc()
    SELECT CASE AS LONG CBMSG
        CASE %WM_INITDIALOG
            ' Initialization handler
        CASE %WM_NCACTIVATE
            STATIC hWndSaveFocus AS DWORD
            IF ISFALSE CBWPARAM THEN
                ' Save control focus
                hWndSaveFocus = GetFocus()
            ELSEIF hWndSaveFocus THEN
                ' Restore control focus
                SetFocus(hWndSaveFocus)
                hWndSaveFocus = 0
            END IF
        CASE %WM_COMMAND
            ' Process control notifications
            SELECT CASE AS LONG CBCTL

                CASE %IDC_BUTTON1
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                        CONTROL DISABLE CBHNDL, %IDC_BUTTON1
                        CALL DisplayRecordSet(CBHNDL)
                        BEEP
                        CONTROL ENABLE CBHNDL, %IDC_BUTTON1
                    END IF
            END SELECT
    END SELECT
END FUNCTION
'------------------------------------------------------------------------------
'------------------------------------------------------------------------------
'   ** Dialogs **
'------------------------------------------------------------------------------
FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
    LOCAL lRslt AS LONG
#PBFORMS BEGIN DIALOG %IDD_DIALOG1->->
    LOCAL hDlg  AS DWORD
    DIALOG NEW hParent, "Dialog1", 25, 52, 527, 305, %WS_POPUP OR %WS_BORDER _
        OR %WS_DLGFRAME OR %WS_SYSMENU OR %WS_MINIMIZEBOX OR %WS_MAXIMIZEBOX _
        OR %WS_CLIPSIBLINGS OR %WS_VISIBLE OR %DS_MODALFRAME OR %DS_3DLOOK _
        OR %DS_NOFAILCREATE OR %DS_SETFONT, %WS_EX_CONTROLPARENT OR _
        %WS_EX_LEFT OR %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR, TO hDlg
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON1, "Button1", 245, 30, 50, 15
    CONTROL ADD "SysListView32", hDlg, %IDC_LISTVIEW, "SysListView32_1", 80, _
        95, 400, 145, %WS_CHILD OR %WS_VISIBLE OR %WS_TABSTOP OR %LVS_REPORT _
        OR %LVS_SHOWSELALWAYS, %WS_EX_LEFT OR %WS_EX_CLIENTEDGE OR _
        %WS_EX_RIGHTSCROLLBAR
#PBFORMS END DIALOG
    DIALOG SHOW MODAL hDlg, CALL ShowDIALOG1Proc TO lRslt
#PBFORMS BEGIN CLEANUP %IDD_DIALOG1
#PBFORMS END CLEANUP
    FUNCTION = lRslt
END FUNCTION
'------------------------------------------------------------------------------

FUNCTION DisplayRecordSet(hDlg AS DWORD) AS DWORD
  LOCAL row AS DWORD, col AS LONG, ColumnCount AS LONG
  LOCAL x AS LONG, rows AS LONG
  'so you know it was called

    ColumnCount = 13
    rows = 10000
  IF ColumnCount THEN
    MOUSEPTR 11
    'CONTROL SHOW STATE hDlg, %IDC_LISTVIEW, %SW_HIDE
    LISTVIEW RESET hDLG, %IDC_LISTVIEW
    LISTVIEW SET STYLE hDlg, %IDC_LISTVIEW, %LVS_EX_GRIDLINES
    FOR col = 1 TO ColumnCount   'Insert columns with column names
      LISTVIEW DELETE COLUMN hDlg, %IDC_LISTVIEW,col
      LISTVIEW INSERT COLUMN hDlg, %IDC_LISTVIEW,col,"Col" + STR$(col),100,0
    NEXT
  ELSE
    ? "No columns"
    EXIT FUNCTION
  END IF
  row = 0
  DO WHILE row < rows
    INCR row
    LISTVIEW INSERT ITEM hDlg, %IDC_LISTVIEW,row, 0 , "ROW" + STR$(row) + " COLUMN 1"
    FOR col = 2 TO ColumnCount                               'add text into columns
      LISTVIEW SET TEXT hdlg, %IDC_LISTVIEW, row, col,"COLUMN" + STR$(col)
    NEXT
    'This fixes problem
    'IF row = 100 OR row MOD 1000 = 0  THEN          'refresh screen every so often
    '  FOR x = 1 TO 4
    '    DIALOG DOEVENTS
    '   NEXT
    'END IF
  LOOP
 ' CONTROL SHOW STATE hdlg, %IDC_LISTVIEW, %SW_HIDE
 ' FOR col = 1 TO ColumnCount   'fit columns
 '   LISTVIEW FIT CONTENT hDlg, %IDC_LISTVIEW, col
 ' NEXT
  'CONTROL SHOW STATE hDlg, %IDC_LISTVIEW, %SW_SHOW
  'DIALOG DOEVENTS
  'MOUSEPTR 1
  FUNCTION = row
END FUNCTION

[Michael Mattias]

CASE %IDC_BUTTON1
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
[COLOR="Red"]                        CONTROL DISABLE CBHNDL, %IDC_BUTTON1
                        CALL DisplayRecordSet(CBHNDL)
                        BEEP
                        CONTROL ENABLE CBHNDL, %IDC_BUTTON1[/COLOR]
                    END IF

The reason users are clicking on this button twice (or more?) is because the DisplayRecordSet() function is taking "too long" for them; and yes, those 'clicks' will queue up as described if the control is not disabled, so disabling is required..... unless.......

You can disparage users from clicking again either showing the "WAIT" cursor or by running the 'displayrecordset' function as a "background" task in a separate thread of execution. See GUI + Worker Thread + Abort Demo 11-24-07. Disable the button, start the worker thread function, and re-enable the button when the thread function completes and posts the PWM_THREAD_COMPLETE message back to your dialog procedure.

MCM

[Michael Mattias]

That you are doing the "displayrecordset" during the processing of a notification message (WM_COMMAND) is also why your screen does not update until everything is done unless you insert DIALOG DOEVENTS statements. (the calling thread processes additional notification messages,e.g. "update this control")

By performing the 'display' from a separate thread of execution, this problem automatically goes away.

If you are in fact catering to thousands of records (the 'MOD 1000' in the code suggests this), the famous "1/10 second" rule is almost certainly being broken.

MCM

[Michael Mattias]

Amazing just how much you can figure out when sufficient code is posted, huh?

[Mike Doty]

Separate thread coming soon.
The record sets could be huge and will soon be done using a virtual grid.
Filling the listview takes much longer than getting the data. I also
need to write some code to fill a disk file instead of memory when using SQLitening to return some record sets.

Also, the delete columns method used above is wrong and will be corrected.

[Michael Mattias]

The record sets could be huge and will soon be done using a virtual grid

The Listview control using style LVS_OWNERDATA (virtual) can make your code really, really fast. I used this in the EDI Pal(tm) ANSI ASC X12 Viewer-Editor-Printer to correct user complaints about a control "loads too slow." (And it did - it was really pretty crummy).

(My "torture" test file results in 1.1 million rows).


MCM