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**Borje Hagsten** · 25 Apr 2001, 02:46 AM

Never seen anything but 0, 0 with GetClientRect. Waistful implementation,
IMO. Left and top position on parent would have been far more useful there.
GetWindowRect() together with MapWindowPoints() maybe?

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**Chris Boss** · 25 Apr 2001, 05:05 AM

Semen (I am sure you know most of this, but for the sake of lurkers);

GetClientRect always returns 0,0 for .nLeft and .nTop !

Only GetWindowRect returns non zero values for those elements !

Each function is very important in their own right.

GetClientRect returns coordinates which are unique the the window
which is why the .nLeft and .nRight members are always zero.

GetWindowRect returns values which are Screen coordinates, which
means they can't be used Directly with the GDI to draw unless
you use the desktops DC.

I find that GetClientRect is the most useful for most drawing
functions.

GetWindowRect is more useful for finding the overall location of
a window and possibly moving or sizing it.

The ScreenToClient and ClientToScreen functions are very important
for conversion back and forth between them.

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**Chris Boss** · 25 Apr 2001, 05:08 AM

As far as Regions, you can use GetClientRect !

I have a custom control which is a Drag Handle control which uses
Regions and I use GetClientRect for building the Regions.

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**Paul Noble** · 25 Apr 2001, 05:30 AM

Chris,

I'm sure you and Semen don't need this, but as we're on the subject, I find this little function quite useful -

Code:

sub GetRelativeRect( byval hParent as long, byval hChild as long, byref rResult as RECT )

  'Purpose : For window <hChild>, determines its RECT relative to the client area of <hParent>.
  '
  'Returns : Byref <rResult> receives the result
  '
  'Remarks : The results hold good even when the two windows aren't related or don't overlap. 
  '          Parent / child is simply the anticipated usage.
  '
  '          Note that this is NOT the same as calling GetWindowRect for the pair, then obtaining
  '          a relative rectangle with SubtractRect.
  '
  local rParent as RECT
  local rChild  as RECT
  local p       as POINTAPI
	
  'Measure the child's rectangle in screen co-ordinates...
  GetWindowRect hChild, rChild
	
  'Convert the top-left corner to the parent's client co-ordinates...
  p.x = rChild.nLeft
  p.y = rChild.nTop
  ScreenToClient hParent, p	
  rResult.nLeft = p.x
  rResult.nTop  = p.y
	
  'And the bottom-right corner...
  p.x = rChild.nRight
  p.y = rChild.nBottom
  ScreenToClient hParent, p	
  rResult.nRight  = p.x
  rResult.nBottom = p.y

end sub

Cheers -

Paul

**Semen Matusovski** · 25 Apr 2001, 07:11 AM

Chris --
1) rc.nLeft / rc.nTop <> 0
I asked, because, as I remember, somebody told that this can happend, if OS supports two monitors (not very actual case).
But if nobody know another variant, it's good.

2) Regions and non-client area.
For top-level windows all area is under region's control. It's visible.

Code:

#Compile Exe
#Register None
#Dim all
#Include "WIN32API.INC"

Function PbMain () As Long
  Dim hDlg   As Long, rc As RECT, hRgn As Long, Pt(1:4) As POINTAPI
  Dialog New 0, "Test", ,, 200, 150, %WS_SYSMENU, 0 To hDlg
  GetWindowRect hDlg, rc
  pt(1).x = 0: pt(1).y = 0
  pt(2).x = (rc.nRight - rc.nLeft) / 2:  pt(2).y = (rc.nBottom - rc.nTop)
  pt(3).x = (rc.nRight - rc.nLeft): pt(3).y = 0
  
  hRgn = CreatePolygonRgn(Pt(1), 3, %ALTERNATE)
  SetWindowRgn hDlg, hRgn, 1
  Dialog Show Modal hDlg

End Function

Child windows ... Imagine WS_BORDER or %WS_EX_CLIENTEDGE.
As I understand, borders belong to non-client area. Is it so ?
If so, there are any documents, which confirm that for regions (0,0) is the same point as (0,0) for client area ?

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E-MAIL: [email protected]

**Lance Edmonds** · 26 Apr 2001, 02:11 AM

In the past few days I finally got my Matrox G450 dualhead card running, so I now have multiple desktops (although the latest drivers are pretty buggy and unstable it is working after a fashion).

Anyway, I'm interested in this topic. Sem,en, can you be more specific about the multiple desktop situation? I'm willing to run a few test apps for you if you wish.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Semen Matusovski** · 26 Apr 2001, 03:07 AM

Lance --
Unf. I have no multiply monitors and can't test.
I remember only a phrase, something "it's not safety to assume that rc.nLeft = 0 ...".
Which OS ? Why ? - no idea. ("one woman said")

So, pls, simply test ClientRect for child windows, located on secondary monitor.

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E-MAIL: [email protected]

**Peter Scheutz** · 26 Apr 2001, 04:31 AM

Originally posted by Semen Matusovski:
Lance --
Unf. I have no multiply monitors and can't test.
I remember only a phrase, something "it's not safety to assume that rc.nLeft = 0 ...".
Which OS ? Why ? - no idea. ("one woman said")

So, pls, simply test ClientRect for child windows, located on secondary monitor.

I might have been that person, I corrected the post some time ago.

AFAIK (and according to MSDN) GetClientRect always returns (0,0) for upper left corner.
If you post runnable code that you want tested on a dual monitor setup, I can do that too.

------------------
Best Regards
Peter Scheutz

**Semen Matusovski** · 26 Apr 2001, 06:20 AM

Peter --

About MSDN ...

From one side,

The GetClientRect function retrieves the coordinates of a window's client area.
The client coordinates specify the upper-left and lower-right corners of the client area. Because client coordinates are relative to the upper-left corner of a window's client area, the coordinates of the upper-left corner are (0,0).

From another side, in samples

Code:

   ' Get the dimensions of the client area.
   r = GetClientRect(hWnd_SrcWindow, RectClient)
   Client_Width = Abs(RectClient.Right - RectClient.Left)
   Client_Height = Abs(RectClient.Bottom - RectClient.Top)

or

Code:

GetClientRect(hwnd, &r); 
TextOut(hdc, r.left, r.top, "Defenestration can be hazardous", 4);

A test can be enough simple

Code:

#Compile Exe
#Register None
#Dim All
#Include "WIN32API.INC"

CallBack Function TestProc
  Dim rc As Rect, i As Static Long
  GetClientRect GetDlgItem(CbHndl, %IDOK), rc
  Incr i
  If rc.nLeft <> 0 Or rc.nTop <> 0 Then MsgBox "Ah" Else SetWindowText CbHndl, "Ok" + Str$(i)
End Function

Function PbMain () As Long
  Dim hDlg   As Long
  Dialog New 0, "Test", ,, 70, 50, %WS_SYSMENU, 0 To hDlg
  Control Add Button, hDlg, %IDOK, "Test", 10, 10, 50, 14 Call TestProc
  Dialog Show Modal hDlg
End Function

Hope, it's never say "Oh", even you will move it to secondary monitor.

Guys --
what about regions ? I mean non-client area for WS_CHILD.
(0,0) for region is (0,0) for client area or left-upper point (in non-client area) ?

[This message has been edited by Semen Matusovski (edited April 26, 2001).]

Announcement

GetClientRect, rc.nLeft, rc.nTop

GetClientRect, rc.nLeft, rc.nTop

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