On-Screen Keyboard for POS

On a POS system, since we are dealing with touch screens, then we need to have a keyboard on screen so our users, in addition to barcode scanning, can do other more works.  And for that what we normally do is create our own on-screen keyboards.  Or utilize the built-in OSK that comes along with Windows that can be simply called via RUN /N OSK.EXE.

What is more appealing though is to make said OSK appear to be really a part of our form and this can be done via embedding said OSK.EXE within our form.  However, embedding Microsoft's OSK is easier said than done.

Good news then, here is an alternative to Microsoft's OSK (On-Screen Keyboard) that can be easily embedded inside our forms.  Further good news is that this one is free: http://freevirtualkeyboard.com/

For the embedding need inside our form, I will refer you to the codes  graciously shared to us by a good friend Vilhelm-Ion Praisach.  In addition to the tricks he used there, I like his subtle touch here on the usage of a timer instead of my SLEEP() way on the embedding 3rd party apps within our forms blog.

Codes:

* Author:  Vilhelm-Ion Praisach

* Date: March 4, 2015

Declare Integer ShellExecute In shell32 Integer hWindow, String lpOperation, String lpFile, String lpParameters, String lpDirectory, Integer nShowCmd

Declare Integer SetParent In User32 Integer HWnd, Integer ParenthWnd

Declare Integer FindWindow In user32 String lpClassName, String lpWindowName

Declare Integer GetWindowLong In user32 Integer HWnd, Integer nIndex

Declare Integer SetWindowLong In user32 Integer HWnd, Integer nIndex, Integer dwNewLong

Declare Integer SetFocus In user32 Integer

Declare Integer SetWindowPos In user32 INTEGER HWnd, INTEGER hWndInsertAfter, INTEGER x, INTEGER Y, INTEGER cx, INTEGER cy, INTEGER uFlags

Declare Integer GetWindowThreadProcessId in Win32API Integer hWnd, Integer @lpdwProcessId

Declare Integer OpenProcess in Win32API Integer dwDesiredAccess, Integer bInheritHandle, Integer dwProcessID

Declare Integer TerminateProcess in Win32API Integer hProcess, Integer uExitCode

Clear

Public ofrm

ofrm = Createobject("MyForm")

ofrm.Show()

Define Class MyForm As Form

      Width = 900

      Height=430

      hOsk = 0

      nOskHeight = 200

      ShowWindow = 2

      Desktop = .T.

      AutoCenter = .T.

      Add Object txt As TextBox

      Add Object cmd As CommandButton With Top = 50 , Caption = "\<Click"

      Add Object tmr As Timer With Interval = 300

     

      Procedure Load

            = ShellExecute(0, "open", "freevk.exe", "", "", 1) && this should be inside among your VFP paths

      ENDPROC

     

      Procedure tmr.Timer

            LOCAL nStyle

            ThisForm.hOsk = FindWindow (.Null., "Free Virtual Keyboard (www.FreeVirtualKeyboard.com)")

            nStyle = GetWindowLong (ThisForm.hOsk, -16)

            SetWindowLong (ThisForm.hOsk, -16, Bitset(m.nStyle,30)) && set child

            SetWindowLong (ThisForm.hOsk, -16, Bitclear(m.nStyle,31)) && remove popup

            SetParent(ThisForm.hOsk, Thisform.HWnd) && change parent

            SetWindowLong (ThisForm.hOsk, -16, BITAND(m.nStyle,2^32-1-0xCF0000)) && remove the title bar

            SetWindowPos(ThisForm.hOsk, 0, 0, ThisForm.Height-ThisForm.nOskHeight,ThisForm.width, ThisForm.nOskHeight,  0x0020+0x0040) && move to the bottom of the form and show

            This.Enabled = .F.

            SetFocus(Thisform.HWnd) && set focus to the VFP window

      ENDPROC

      PROCEDURE destroy

            LOCAL lnProcessID

            lnProcessID = 0       

            GetWindowThreadProcessId(ThisForm.hOsk, @lnProcessID)       

            TerminateProcess(OpenProcess(1, 1, m.lnProcessID) , 0)

      ENDPROC

      PROCEDURE resize

            SetWindowPos(ThisForm.hOsk, 0, 0, ThisForm.Height-ThisForm.nOskHeight,ThisForm.width, ThisForm.nOskHeight,  0x0020+0x0040+0x0010) && move to the bottom of the form, and show, and SWP_NOACTIVATE

      ENDPROC

Enddefine

Hope this helps!  Cheers!