Line does more than advertised

[Gary Beene]

I don't know how useful this is, here's something I found out while playing with some code.

In the Help file I read that CONTROL SET COLOR won't work with line controls. I also read that the LINE control won't display text.

So I was playing around with code and tried this:

Control Add Line, hDlg, 507, "LINE", 200, 80, 40, 40, %ss_notify
Control Set Color hdlg, 507, %blue, %red

This gives me a colored line control with the word "LINE" in it.

I played some more with other style& values and found that %ss_notify enables the color/text display. I also tried some LABEL style& values and they worked too. I could center the text or get it to wordwrap, for example.

It's as though the line control works like a label control with the %ss_notify style& value added.

[Gary Beene]

The method works with a 1-pixel wide line too.

I'm still playing with it - looking for how to make a different colored border (without just putting two line controls, one over the other of different colors, one smaller than the other).

[Gary Beene]

One thing to do with this trick is to put a colored grid on a dialog, rather than using a separate graphic window or a graphic control. I tried it and it works. A thin grid was instantly drawn. A tight grid filled slowly - that's a lot of controls.

I guess pretty much anything you can do with a line/box on a graphic target is an option - but on a dialog.

Having just started using PowerBASIC I don't know if that's important or not.

[Gary Beene]

Except that a LINE control won't do angles. I can plot an angled line made of small LINEs, but a line on a graphic target should be tons faster.

[Barry Marks]

Finding something undocumented like this is real nice until a future version doesn't do it. I'd be careful not to use it in something that will continue to matter.

Barry

[Gary Beene]

In the FWIW column, the method still works. As Barry notes, use at your own risk.

These are all lines. The last 3 use the method described above.



Code used to create the image:

'Compilable Example:
#Compile Exe
#Dim All
#Include "Win32API.inc"
%IDC_LineA = 500 : %IDC_LineB = 501 : %IDC_LineC = 502 : %IDC_LineD = 503
%IDC_LineE = 504 : %IDC_LineF = 505 : %IDC_LineG = 506 : %IDC_LineH = 507 : %IDC_LineI = 508
Global hDlg As Dword
Function PBMain() As Long
   Dialog New Pixels, 0, "Test Code",300,300,200,300, %WS_OverlappedWindow To hDlg
   Control Add Line, hDlg, %IDC_LineA,"Push", 50,10,100,20, %SS_BlackFrame
   Control Add Line, hDlg, %IDC_LineB,"Push", 50,40,100,20, %SS_GrayFrame
   Control Add Line, hDlg, %IDC_LineC,"Push", 50,70,100,20, %SS_WhiteFrame

   Control Add Line, hDlg, %IDC_LineD,"Push", 50,100,100,20, %SS_BlackRect
   Control Add Line, hDlg, %IDC_LineE,"Push", 50,130,100,20, %SS_GrayRect
   Control Add Line, hDlg, %IDC_LineF,"Push", 50,160,100,20, %SS_WhiteRect

   Control Add Line, hDlg, %IDC_LineG,"", 50,190,100,20, %SS_Notify
   Control Set Color hDlg, %IDC_LineG, %Red, %Red
   Control Add Line, hDlg, %IDC_LineH,"", 50,220,100,20, %SS_Notify
   Control Set Color hDlg, %IDC_LineH, %Green, %Green
   Control Add Line, hDlg, %IDC_LineI,"", 50,250,100,20, %SS_Notify
   Control Set Color hDlg, %IDC_LineI, %Blue, %Blue

   Dialog Show Modal hDlg
End Function

[Gary Beene]

Another version ...

When I try to set the Line Control color from within WM_CtlColorStatic, I see the same result. Unless I add %SS_Notify to the Line control style, the color of the control does not change.

2nd Line control does not use %SS_Notify

'Compilable Example:
#Compile Exe
#Dim All
#Include "Win32API.inc"
%IDC_LineA = 500 : %IDC_LineB = 501 : %IDC_LineC = 502
Global hDlg,hDC,hBrush as Dword
Function PBMain() As Long
   Dialog New Pixels, 0, "Test Code",300,300,200,200, %WS_OverlappedWindow To hDlg
   Control Add Line, hDlg, %IDC_LineA,"", 50,10,100,20, %SS_Notify
   Control Add Line, hDlg, %IDC_LineB,"", 50,40,100,20
   Control Add Line, hDlg, %IDC_LineC,"", 50,70,100,20, %SS_Notify
   Dialog Show Modal hDlg Call DlgProc
End Function
CallBack Function DlgProc() As Long
   Select Case Cb.Msg
      Case %WM_CtlColorStatic   'wParam is hDC  lParam is hControl
         Select Case GetDlgCtrlID(Cb.lParam)
            Case %IDC_LineA 
               Function = GetStockObject(%White_Brush)   'has SS_Notify
            Case %IDC_LineB 
               Function = GetStockObject(%White_Brush)   'does NOT has SS_Notify
            Case %IDC_LineC
               hBrush = CreateSolidBrush(%RGB_DarkRed)   'has SS_Notify
               Function = hBrush
         End Select
      Case %WM_Destroy
         DeleteObject hBrush
   End Select
End Function

[Michael Mattias]

Case %IDC_LineC
               hBrush = CreateSolidBrush(%RGB_DarkRed)   'has SS_Notify
               Function = hBrush

= GDI Leak. A new GDI object is created each time you call CreateSolidBrush.