CXWndAnimate: an alternative to CAnimateCtrl

Introduction

Recently I had to develop an processing indicator to show to the user that my application is doing some heavy calculations or retrieving lots of data from a database.

My first thought was about using the CAnimateCtrl. I must confess i tried, but without success. I couldn't make an AVI file with transparent background (maybe I'm too lazy). So I decided to develop my own Animate Control using bitmaps through an image list.

For each control of this I have a thread to constantly update the animation.

How to use

1. Call the static method RegisterWnd on the InitInstance of your CWinApp derived class
2. In dialogs: you have to place a custom control a give it the class name "X_WND_ANIMATE". Next you declare an CXWndAnimate member variable on your dialog class. On the OnInitDialog you have to subclass the control:

   m_ctrlAnimation.SubclassDlgItem(IDC_ANIMATION, this);

3. In Status Bar you have to create it on a pane. Also remember to correct the control's position when the StatusBar is resized.

   BOOL CMyStatusBar::CreateAnimation(int iIndex)
   {
   	CFrameWnd* pFrame = reinterpret_cast<CFRAMEWND*> (GetParent());
   	pFrame->RecalcLayout();
   
   	m_pwndBmpAnimate = new CWndBmpAnimate;
   
   	CRect rcItem;
   	GetItemRect(iIndex, &rcItem);
   	rcItem.right = rcItem.left + CX_ANIMATION;
   	rcItem.InflateRect(-1, -1);
   
   	BOOL bReturn = m_pwndBmpAnimate->Create(WND_BMP_ANIMATE, 
   			NULL, WS_CHILD | WS_VISIBLE, rcItem, this, 0);
   
   	ASSERT(bReturn);
   
   	return bReturn;
   }
   
   void CMyStatusBar::OnSize(UINT nType, int cx, int cy) 
   {
   	CStatusBar::OnSize(nType, cx, cy);
   		
   	// TODO: Add your message handler code here
   	if (m_pwndBmpAnimate)
   	{
   		CRect rcItem;
   		GetItemRect(CommandToIndex(ID_ANIMATED), &rcItem);
   		rcItem.right =  rcItem.left + CX_ANIMATION; 
   		rcItem.InflateRect(-1, -1);
   		m_pwndBmpAnimate->SetWindowPos(NULL, rcItem.left,
   			rcItem.top, 0, 0, SWP_NOZORDER | SWP_NOSIZE);
   	}
   }

4. To select the animation you must construct bitmaps files with the frames for the animation (like an animated gif). To set the images that are going to be used, do this:

   CImageList imgList;
   
   imgList.Create(IDB_BITMAP, 14, 0, RGB(255, 255, 255));
   m_ctrlAnimation.SetImageList(imgList.Detach());

   In this case the white color will be the transparent color. Each frame has 14 pixels width. If your animation need a total redrawing (redraw the background) make sure to call the method SetClearBackground.

The sample project demonstrates the use of the control in a dialog box.

Other relevants methods:

• BOOL IsRunning(): indicates if the animation is playing
• BOOL StartAnimation(short nStart, short nEnd = -1): Starts to play an animation. If nEnd if -1 the animation will play until it's end
• BOOL StopAnimation(BOOL bHideWindow = TRUE): Stops the animation and hide the window if bHideWindow is equal TRUE