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Resizing Controls at run time

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4.75/5 (15 votes)
30 Nov 2000 134.9K   3.3K   63   18
A method to allow the user to visually resize and position any control at run time.

Sample Image - resize_at_runtime.gif

Introduction

Suppose you wanted to give the user the ability to modify the size and position on a certain control? This example shows how to implement resizing controls on a dialog box as it is done when drawing controls on a dialog template or using Visual Basic at design time.

In order to accomplish this, we can use the class CRectTracker to manage all the drawing and resizing of a rectangular frame which also has (optional) 6 resize handlers (as in the image above). First thing to do is to invoke a CRectTracker and specify given coordinates:

LPRECT rect = new RECT;
CWnd* wnd = (CWnd*)(GetDlgItem(IDC_EDIT1));
wnd->GetWindowRect(rect);
ScreenToClient(rect);
m_tracker = new CRectTracker(rect,CRectTracker::dottedLine  | 
                CRectTracker::resizeOutside | 
                CRectTracker::hatchedBorder );
m_tracker->Draw(pDC);

There are two events that are needed to be taken care of:

  1. SetCursor
    if (pWnd == this && m_tracker->SetCursor(this, nHitTest))
        return TRUE;

    This is done in order to draw the correct mouse cursors when floating the mouse pointer over the rectangle.

  2. OnLButtonDown
    m_tracker->Track(this, point, TRUE);
    Invalidate(FALSE);
    CDC* pDC = GetDC();
    m_tracker->Draw(pDC);

    This will take care of the drawing of the rectangle with resizing it.

Once you have finished, all you have to do is draw the control with the new rectangle coordinates:

LPRECT rect = new RECT;
CWnd* wnd = (CWnd*)(GetDlgItem(IDC_EDIT1));
rect = LPRECT(m_tracker->m_rect); 
wnd->MoveWindow(rect,TRUE) ;

That's it!

License

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Comments and Discussions

 
Questiontracker is coveraged by the sibling object Pin
handsome0314-Jun-12 17:56
handsome0314-Jun-12 17:56 
GeneralActivex resize Pin
20-May-04 4:57
suss20-May-04 4:57 
GeneralActivex resize Pin
Anonymous20-May-04 4:45
Anonymous20-May-04 4:45 
Questionhow to use from c# application Pin
jbmeeh13-Feb-04 10:33
jbmeeh13-Feb-04 10:33 
QuestionHow to save the new dialog layout back to a resource? Pin
DJM5-Aug-03 1:25
DJM5-Aug-03 1:25 
AnswerRe: How to save the new dialog layout back to a resource? Pin
David Pritchard17-Nov-04 3:08
David Pritchard17-Nov-04 3:08 
GeneralCursor goes away when linked with Static Library Pin
cdsmith29-Apr-03 6:34
cdsmith29-Apr-03 6:34 
I am having a problem with CRectTracker. When I link with Shared DLL it works fine, when I link with Static Library the cursors (resize and move) do not show up when the mouse is over the tracking rect. I was going crazy thinking I was doing something wrong, but this code has exactly the same problem.

Anybody know why the cursors do not show up when statically linked?

Thanks!

Craig Smith
GeneralRe: Cursor goes away when linked with Static Library Pin
lesnikowski9-Jan-04 2:20
lesnikowski9-Jan-04 2:20 
GeneralRe: Cursor goes away when linked with Static Library Pin
tohichoi19-Sep-05 20:57
tohichoi19-Sep-05 20:57 
GeneralRe: Cursor goes away when linked with Static Library Pin
Artem Moroz11-Jul-08 6:56
Artem Moroz11-Jul-08 6:56 
AnswerRe: Cursor goes away when linked with Static Library Pin
Anthony Dunk1-Jul-09 19:34
Anthony Dunk1-Jul-09 19:34 
GeneralI have a problem Pin
BoscoW21-Feb-03 22:38
BoscoW21-Feb-03 22:38 
GeneralGreat job Pin
Synetech18-Feb-03 8:30
Synetech18-Feb-03 8:30 
GeneralNE?YO BLAD! Pin
Booooo18-Nov-02 6:12
Booooo18-Nov-02 6:12 
General<FONT COLOR="#FF0000">CRectTracker hidden when controls overlap </font> Pin
sanskypotov7-Jul-02 22:05
sanskypotov7-Jul-02 22:05 
GeneralProblem Pin
15-Jun-01 0:03
suss15-Jun-01 0:03 
GeneralRe: Problem Pin
15-Oct-01 21:38
suss15-Oct-01 21:38 
GeneralRe: Problem Pin
Member 969-Apr-02 14:10
Member 969-Apr-02 14:10 

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