Moveable Dialog without a Caption bar?

Thanks Lance! Your code, of course, works. It seems easier to me, however to use:

  SELECT CASE CBMSG
     CASE %WM_LBUTTONDOWN
       SendMessage ghDlg, %WM_NCLBUTTONDOWN, %HTCAPTION, BYVAL %NULL
  END SELECT

which also works. Is there anything that makes (your) subclassing method 'better', 'safer', etc. ?

Thanks!

William Fletcher

[Lance Edmonds]

DDT does withhold %WM_NCHITTEST messages from your dialog callback... the easy solution is to subclass the DDT dialog... with DDT this is really easy as we can use a CALLBACK function for the subclass procedure.

Try this example:

#COMPILE EXE
#INCLUDE "win32api.INC"
 
GLOBAL oldproc AS LONG
 
CALLBACK FUNCTION DlgProc
  IF CBMSG = %WM_COMMAND AND CBCTL = %IDOK THEN DIALOG END CBHNDL
  IF CBMSG = %WM_DESTROY THEN SetWindowLong CBHNDL, %GWL_WNDPROC, oldproc
END FUNCTION
 
CALLBACK FUNCTION subclass
  IF CBMSG = %WM_NCHITTEST THEN
      FUNCTION = %HTCAPTION
  ELSE
      FUNCTION = CallWindowProc(oldproc, CBHNDL, CBMSG, CBWPARAM, CBLPARAM)
  END IF
END FUNCTION
 
FUNCTION PBMAIN
    DIALOG NEW 0, "HTCAPTION test", , , 100, 200, %WS_BORDER TO hDlg&
    CONTROL ADD BUTTON, hDlg&, %IDOK, "&Quit", 30, 90, 40, 14
    OldProc = SetWindowLong(hDlg&, %GWL_WNDPROC, CODEPTR(subclass))
    DIALOG SHOW MODAL hDlg&, CALL DlgProc
END FUNCTION

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

[Chris Boss]

Maybe it is a DDT thing !

WM_NCHITTEST should work the way you use it if it was in a normal Dialog Procedure (SDK style). You may need to ask someone who knows DDT well, if DDT does any other processing of the message .

Dominic: when I use the following code (inserted above) in PBdll6 the dialog still cannot be moved -

CALLBACK FUNCTION DlgProc () AS LONG

  SELECT CASE CBCTL
    CASE %ID_OK_BUTTON
      DIALOG END ghDlg, 1
  END SELECT
  
  SELECT CASE CBMSG
    CASE %WM_CREATE

    CASE %WM_NCHITTEST
      FUNCTION = %HTCAPTION
      EXIT FUNCTION
  END SELECT

END FUNCTION  'DlgProc

Am I doing something wrong?

William Fletcher

[Jules Marchildon]

william, here is a nice example of putting together a window with
a tiny caption bar for your floating toolbar application. you can
extract/modify what you need and adjust the caption height to your
specifications.

http://www.powerbasic.com/support/pb...ad.php?t=22550

regards, jules

[Dominic Mitchell]

Chris;

This would allow you to click on a control (ie. Static Label, Bitmap) and then drag
the window. You could simulate your own "smaller" Caption bar.

You can accomplish all that and much more without using SendMessage.
The forms designer part of the package I am writing is as sophisticated as the one
in Visual Basic but it does not use SendMessage anywhere. It all depends on hit
testing code and a couple of the mouse messages.
SendMessage has a major drawback in that you need to have a valid window handle. How
would you implement lightweight control such as lines, ellipses, bezier curves and polygons
using SendMessage?

[Chris Boss]

While it normally doesn't matter which method you use, there is an advantage of using SendMessage. This would allow you to click on a control (ie. Static Label, Bitmap) and then drag the window. You could simulate your own "smaller" Caption bar.

By using SendMessage, windows won't care "where" you clicked.

[Dominic Mitchell]

Why are you guys using SendMessage?
To return a value just do the following

  SELECT CASE lMsg
    CASE %WM_CREATE

    CASE %WM_NCHITTEST

      FUNCTION = %HTCAPTION 
      EXIT FUNCTION          <-- This is required so that execution does
  END SELECT                     not fall through to the default window procedure

Thanks Chris - that worked! BTW the ' in front of any code above is to include my failures as a demo in case there were any syntax errors someone else might catch.

I've updated the code (above) with your suggestion.

Thanks!

William Fletcher

[Chris Boss]

William;

Use the following code in your Dialog procedure:

    CASE %WM_LBUTTONDOWN        
        SendMessage hWnd, %WM_NCLBUTTONDOWN, %HTCAPTION, byval %NULL

In your sample code you had a ' in front the of the FUNCTION=%HTCAPTION line of code, so it was only a remark.

Help! - for the WM_NCHITTEST message, how do I "return" the HTCAPTION value?

Here's my setup:

GLOBAL ghDlg AS LONG
'----------------------------------------------------
CALLBACK FUNCTION DlgProc () AS LONG
  SELECT CASE CBMSG
'    CASE %WM_NCHITTEST
'     FUNCTION = %HTCAPTION
'       ---> no effect at all
'     CALL  SendMessage(ghDlg, %WM_SYSCOMMAND, %SC_MOVE, 0)
'       ---> constant "Move" cursor
'     CALL  SendMessage(ghDlg, %WM_SYSCOMMAND, %HTCAPTION, 0)
'       ---> no effect, it seems
'     CASE %WM_LBUTTONDOWN
'       ReleaseCapture
'       CALL  SendMessage(ghDlg, %WM_SYSCOMMAND, %SC_MOVE, 0)
'       ---> "Move" cursor appears but Dialog doesn't move

      CASE %WM_LBUTTONDOWN
        SendMessage ghDlg, %WM_NCLBUTTONDOWN, %HTCAPTION, BYVAL %NULL
'       ---> THIS WORKS!  (...thanks Chris)

  END SELECT       
END FUNCTION  'DlgProc
'----------------------------------------------------
FUNCTION PBMAIN () AS LONG
  LOCAL Style AS LONG
  Style = %WS_POPUP OR _
          %DS_SETFONT OR _
          %DS_NOFAILCREATE OR _
          %DS_MODALFRAME OR _
          %DS_3DLOOK
  DIALOG NEW 0,"",,,160,50,Style TO ghDlg
  DIALOG SHOW MODAL ghDlg, CALL DlgProc
END FUNCTION  'PBMAIN                   
'----------------------------------------------------

Thanks everyone for all the advice!

William Fletcher



[This message has been edited by William Fletcher (edited January 24, 2000).]

[Borje Hagsten]

The following also seems to work fine:

CASE %WM_LBUTTONDOWN
  ReleaseCapture
  CALL  SendMessage(hWnd, %WM_SYSCOMMAND, %SC_MOVE, 0)

[Lance Edmonds]

there is a toolbar "demo" in the source code forum which (if i remember)uses a conventional toolbar window approach (ws_ex_toolwindow).
http://www.powerbasic.com/support/pb...ad.php?t=25000

if you wish to move a dialog that has no caption bar, then respond to %wm_nchittest messages, and return the value %htcaption. this tricks windows into moving the window as it thinks the caption is being dragged.

-------------
lance
powerbasic support
mailto:[email protected][email protected]</a>

[Chris Boss]

William;


Process the

WM_NCHITTEST

message yourself

When the mouse is clicked this message is sent to the window to find out "where" the mouse was clicked. You can fool Windows by returning the


HTCAPTION value

when the mouse is clicked on the client area. This will tell windows that the mouse clicked on the Caption bar (which it didn't) and it will allow the window to be dragged by the client area.

Read the API docs about WM_NCHITTEST

I need to make a floating toolbar (actually a dialog with buttons) as small as possible, yet moveable. Can anyone suggest a way to make it moveable *without* the Caption bar?

Many TIA

William Fletcher