Sample Image

Introduction

There are many occasions where it's nice to have a popup window that shows the progress of a lengthy operation. Incorporating a dialog resource with a progress control and cancel button, then linking up the control messages for every project you wish to have the progress window can get monotonous and messy.

The class CProgressWnd is a simple drop in window that contains a progress control, a cancel button and a text area for messages. The text area can display 4 lines of text as default, although this can be changed usingCProgressWnd::SetWindowSize() (below)

Construction

    CProgressWnd(); 
    CProgressWnd(CWnd* pParent, LPCTSTR strTitle, BOOL bSmooth=FALSE);
    BOOL Create(CWnd* pParent, LPCTSTR strTitle, BOOL bSmooth=FALSE);

Construction is either via the constructor or a two-step process using the constructor and the Create function.pParent is the parent of the progress window,strTitle is the window caption title. bSmooth will only be effective if you have the header files and commctrl32.dll from IE 3.0 or above (no problems for MS VC 5.0). It specifies whether the progress bar will be smooth or chunky.

Operations

    BOOL GoModal(LPCTSTR strTitle = _T("Progress"), BOOL bSmooth=FALSE); 
                                        // Make window modal

    int  SetPos(int nPos);              // Same as CProgressCtrl
    int  OffsetPos(int nPos);           // Same as CProgressCtrl
    int  SetStep(int nStep);            // Same as CProgressCtrl
    int  StepIt();                      // Same as CProgressCtrl
    void SetRange(int nLower, int nUpper, int nStep = 1);
                                        // Set min, max and step size

    void Hide();                        // Hide the window
    void Show();                        // Show the window
    void Clear();                       // Clear the text and reset the 
                                        // progress bar
    void SetText(LPCTSTR fmt, ...);     // Set the text in the text area

    BOOL Cancelled()                    // Has the cancel button been pressed?

    void SetWindowSize(int nNumTextLines, int nWindowWidth = 390);
                                        // Sets the size of the window 
                                        // according to the number of text 
                                        // lines specifed and the
                                        // desired window size in pixels.

    void PeekAndPump(BOOL bCancelOnESCkey = TRUE);  
                                        // Message pumping, with options of
                                        // allowing Cancel on ESC key.

The PeekAndPump function allows messages to be pumped during long operations. The first parameter allows the window to be cancelled by pressing the ESC key.

You can also make the window modal by creating the window and calling GoModal(). This will disable the main window, and re-enable the main window when this window is destroyed. See the demo app for example code.

The window will also store and restore its position to and from the registry between incantations.

To use the window, just do something like:

    CProgressWnd wndProgress(this, "Progress");

    // wndProgress.GoModal(); // Call this if you want a modal window
    wndProgress.SetRange(0,5000);
    wndProgress.SetText("Processing...");         

    for (int i = 0; i < 5000; i++) {
        wndProgress.StepIt();
        wndProgress.PeekAndPump();

        if (wndProgress.Cancelled()) {
            MessageBox("Progress Cancelled");
            break;
        }
    }

or it can be done two stage as:

    CProgressWnd wndProgress;
    
    if (!wndProgress.Create(this, "Progress"))
        return;

    wndProgress.SetRange(0,5000);
    wndProgress.SetText("Processing...");

History

  • 13 Apr 2002 - added SaveSettings call to OnCancel. Updated project for VC.NET.
  • 22 Apr 2002 - minor mods by Luke Gabello