Gradient and Boxed ProgressBar

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Introduction

One basic limitation of ProgressBar Control provided by .Net is that it can't show the percentage on top of its rendered Background. Given this limitation i decided to create my own Control as an exersize. But System.Windows.Forms.ProgressBar does not allow extra drawing to be done so the new control must be created from scratch.

So I created a basic ProgressBar which has the basic Properties Minimum,Maximum,Value,Step and an inner function PerformsStep which advances the Value appropriatly.

Apearance Properties are provided for the aspects of Color,Border and the Percentage Text. The TextColorType specifies whether the text color used is the ForeColor or it is automatically generated based relatively to the background color that will be behind it.

Also Rolling functionality is supported but it should not be used because it uses a Timer rather than a thread.I was created for testing purposes only.

Also based on a tip I read, a Custom Dictionary of Brush and Pen is used from MyComponents.Objects namespace in order to maintain in memory every Bursh and Pen used. These dictionary's are optional to use and are automatically disposed.

This base control can be used in forms but its drawing is premetiv and resembles progressbars of Win3.1.

Rendering is done by the following functions. DrawBackgroundRolling,DrawBackground,DrawText,DrawBorder

DrawBackgroundRolling instead of DrawBackground is called when Rolling is enabled.

Any Custom ProgressBar that wants to use the functionality must override the implementation of these functions which are called from the OnPaint event in specific order and only if they are needed based on the relevant properties.

The first custom Progressbar I build was one with gradient between the color of the progress and the background.

Two Properties are introduced for this ProgressBarGradient 

PercentageWidth specifies how much of the control's width will be used for the gradience transition. GradientType specifies whether the PercentageWidth is 100% or specified.

Here is the Code for DrawBackground

        protected override void DrawBackground(Graphics g)
        {
            if (_iPercent == 0)
            {
                FillRectangle(g, ClientRectangle, xBrushes);
                //return;
            }
            Rectangle[] xRecs = null;
            xRecs = Prepare3Parts();
            Rectangle xRectLeft = xRecs[0];
            Rectangle xRectMiddle = xRecs[1];
            Rectangle xRectRight = xRecs[2];
            xRectLeft.Width++;
            BrushAndFill(g, xRectMiddle, _ColorProgress, BackColor);
            FillRectangle(g, xRectLeft, xBrushes);
            FillRectangle(g, xRectRight, xBrushes);

        }

Prepare3Parts creates the left,middle and right rectangles needed to draw the control.

The second Custom ProgressBar called ProgressBarBoxedand splits the control to boxes and fills them with the appropriate color relative to current percent.The properties introduced are

NumberOfBlocks specifies the number of blocks to split the Progressbar.
ActiveBlockColor specifies the last color of the box if the percantage is between 1 and 99.
InnerGridType specifies the type of grid used to separate the boxes.

Here is the implementation of DrawBackground

        protected override void DrawBackground(Graphics g)
        {
            if (_iPercent == 0)
            {
                FillRectangle(g, ClientRectangle, xBrushes);
            }
            for (int i = 0; i < _MaxBlockToDraw; i++)
            {
                FillRectangle(g, _BlockRects[i], xBrushes);
            }
            if(_MaxBlockToDraw<_NumberOfBlocks&&_MaxBlockToDraw>-1)
                FillRectangle(g, _BlockRects[_MaxBlockToDraw], xBrushes);

            DrawInnerGrid(g);
        }

Because the appearance of this control wan't change at every change of Value a trick is implemented to speed up the control.The base ProgressBar provides the functionallity by implementing the Invalide() of the control like this

        
        protected bool _TurnOffInvalidation;
        protected new void Invalidate()
        {
            if (!_TurnOffInvalidation)
                base.Invalidate();
            _TurnOffInvalidation = false;
        }
        

The FormProgressBarsTest created to test the three variations of these ProgressBars is derived form <CODE><CODE>MyComponents.Windows.BaseForms.PropertyGridForm which is a form i have created to provide functionallity for test forms of controls i create.

Finally in the Solution there is Project name Functions which i store every function that may be resud in my projects.