Showing progress bar in a status bar pane (2)

and updated by
Michael Martin.


Download source files or
demo project

Adding a CProgressCtrl to the status bar has already been addressed
by Brad Mann. His method involved modifying the status bar and messing
around with the resource editor. I developed a separate CProgressBar
class in order to allow the programmer to just drop in a progress bar
whereever they wanted using a single “CProgressBar Bar(…)” declaration,
which would initialise and display itself and clean up after itself
after it was done. The progress bar can also be created once (say as a
member variable) and reused multiple times. This new version of the
progress bar also resizes itself if the status bar size changes.

The progress bar lets you specify a message (displayed to the left of the bar)
and a Progress Control bar in the any pane of your applications status bar
(if it has one – thanks to Patty You for a bug fix on that one). The message
for the progress bar can be changed at any time, as can the size and range
of the bar.

Construction

	CProgressBar();
	CProgressBar(LPCTSTR strMessage, int nSize=100, int MaxValue=100, BOOL bSmooth=FALSE, int nPane=0);
	BOOL Create(LPCTSTR strMessage, int nSize=100, int MaxValue=100, BOOL bSmooth=FALSE, int nPane=0);

Construction is either via the constructor or a two-step process using the
constructor and the “Create” function. “strMessage” is the message to be
displayed, “nSize” is the percentage width of the status bar that will be
occupied by the bar (including the text), and “MaxValue” is the maximum
range of the bar.

“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.

New additions to version 1.1

The progress bar now makes use of the PBM_SETRANGE32 message to allow the
range to be set from -0x7FFFFFFF to 0x7FFFFFFF. This will only be used if the
the PBM_SETRANGE32 macro is defined.

Two new functions SetBarColour and SetBkColour have been added, but are only
effective if the new macros PBM_SETBARCOLOR and PBM_SETBKCOLOR are defined.

New additions to version 1.2

The progress bar can now be placed in any pane of the status bar. (Thanks to
Michael Martin). I also did a bit of a code cleanup.

Operations

	BOOL Success()                      // Construction successful?

	COLORREF SetBarColour(COLORREF clrBar);  // Set Bar colour, returns previous
	COLORREF SetBkColour(COLORREF clrBar);   // Set background colour, returns previous

	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 Clear();                       // Clear the status bar
	void SetRange(int nLower, int nUpper, int nStep = 1);
	                                    // Set min, max and step size
	void SetText(LPCTSTR strMessage);   // Set the message
	void SetSize(int nSize);            // Set the bar size

To use the bar, just do something like:

	CProgressBar Bar("Testing", 40, 1000);

	for (int i = 0; i < 1000; i++) {
	    // perform operation
	    Bar.StepIt();
	}

or it can be done two stage as:

	CProgressBar bar;

	bar.Create("Processing", 40, 1000);
	for (int i = 0; i < 1000; i++) {
	    // perform operation
	    bar.StepIt();
	}

	bar.SetText("Writing");
	for (int i = 0; i < 1000; i++) {
	    // perform operation
	    bar.StepIt();
	    PeekAndPump();	// Message pump
	}
	bar.Clear();

In the above case, PeekAndPump() is a function which simply peeks and pumps
messages, allowing user interaction with the window during a lengthy process.
If the window size changes during the processing, the progress bar size will
alsow change.

Last update: August 25, 1998

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