Resizing Controls at Runtime


With a couple of lines of code, you can give your end-users the ability to resize any control.

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 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 shown in the image above). The first thing, you'll need 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 only two events that are needed to be handled:
  • 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.

  • LButtonDown
  • 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 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) ;
    

Downloads

Download demo project - 9 Kb


Comments

  • memleaks

    Posted by Kerberos on 12/20/2012 02:33am

    You created memleaks by allocating RECT struct - dynamic allocation not needed at all...

    Reply
  • How to use CRectracker in CSrollView

    Posted by Legacy on 11/15/2003 12:00am

    Originally posted by: khurramMir

    Can AnyBody Help me How to Use CRectTracker in CsrollView
    

    Reply
  • Good one.

    Posted by Legacy on 08/01/2002 12:00am

    Originally posted by: Guru

    This one helped me..
    Thanks

    Reply
  • Can this Possible?.........

    Posted by Legacy on 01/15/2002 12:00am

    Originally posted by: Nagesh

    Hi
    I want to reieze my dialog depend upon the resolution used by the moniter in runtime. And even is it possible to resize dialog depend upon length and resolution of moniter.(i.e 14" Moniter with 1024*... resoliton /..etc)..
    waiting for reply
    Regds
    Nagesh

    Reply
  • Scroll within a view

    Posted by Legacy on 08/08/2001 12:00am

    Originally posted by: Jerome

    I have tried to use CRectTracker within a view to do something similar.
    What I would kie to achieve is that the tracker automatically scrolls the view when the mouse gets out of the boundaries.
    How could I achieve this ?
    Thanks,
    Jerome

    Reply
  • No RC

    Posted by Legacy on 07/20/2001 12:00am

    Originally posted by: Steve

    Unfortunately, you did not include the resouce files in the zip.

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • The impact of a data loss event can be significant. Real-time data is essential to remaining competitive. Many companies can no longer afford to rely on a truck arriving each day to take backup tapes offsite. For most companies, a cloud backup and recovery solution will eliminate, or significantly reduce, IT resources related to the mundane task of backup and allow your resources to be redeployed to more strategic projects. The cloud - can now be comfortable for you – with 100% recovery from anywhere all …

  • When it comes to desktops – physical or virtual – it's all about the applications. Cloud-hosted virtual desktops are growing fast because you get local data center-class security and 24x7 access with the complete personalization and flexibility of your own desktop. Organizations make five common mistakes when it comes to planning and implementing their application management strategy. This eBook tells you what they are and how to avoid them, and offers real-life case studies on customers who didn't …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds