An easy way for a user to resize a control?

[NOAH]

I am working on a Winform program, and I can't believe there isn't an easier way to accomplish what I'm trying. 

Basically, I want to display an image that will always be 640x480.  Then, I want to have another control on top of it that is nothing more than a selection area that the user can change its size & location inside that 640x480 area, and it will report back its pixel size & x/y location. 

Short of drawing all of the lines by hand and adding grips by hand, I can't seem to find an easy way to do this.  Am I overlooking something? 

[NOAH]

Apparently what I'm looking for is referred to by Microsoft as a Rubber Band Rectangle...  I still have not found a simple solution to use a control for this. 

[George]

Hi Noah,

Thank you for contacting us.

We do not have such a control in our suite so far. We do have a feature request for image editor control which seems to be related. If you find it useful, feel free to vote for it here: http://www.telerik.com/support/pits.aspx#/details/Issue=15947.

However, you can easily implement a custom control which can support the Rubber Band Selection. I have made a small example of such control. Here is the code for it:

[Browsable(true)]
public class RubberBandSelectionControl : RadControl
{
    private RubberBandSelectionElement rubberBandSelectionElement;

    protected override void CreateChildItems(RadElement parent)
    {
        this.rubberBandSelectionElement = new RubberBandSelectionElement();
        parent.Children.Add(this.rubberBandSelectionElement);
    }

    protected override Size DefaultSize
    {
        get
        {
            return new Size(200, 300);
        }
    }
}

public class RubberBandSelectionElement : LightVisualElement
{
    private bool isMouseDown;
    private Point startingPoint;
    private Point currentPoint;

    protected override void OnMouseDown(MouseEventArgs e)
    {
        base.OnMouseDown(e);

        if (e.Button == MouseButtons.Left)
        {
            this.isMouseDown = true;
            this.startingPoint = Control.MousePosition;
        }
    }

    protected override void OnMouseUp(MouseEventArgs e)
    {
        base.OnMouseUp(e);

        this.isMouseDown = false;
        this.currentPoint = Point.Empty;
    }

    protected override void OnMouseMove(MouseEventArgs e)
    {
        base.OnMouseMove(e);
        if (this.isMouseDown)
        {
            if (this.currentPoint != Point.Empty)
            {
                this.DrawRectangle(this.startingPoint, this.currentPoint);
            }

            this.currentPoint = Control.MousePosition;

            this.DrawRectangle(this.startingPoint, this.currentPoint);
        }
    }

    private void DrawRectangle(Point startingPoint, Point endingPoint)
    {
        Rectangle rect = new Rectangle();

        if (startingPoint.X < endingPoint.X)
        {
            rect.X = startingPoint.X;
            rect.Width = endingPoint.X - startingPoint.X;
        }
        else
        {
            rect.X = endingPoint.X;
            rect.Width = startingPoint.X - endingPoint.X;
        }
        if (startingPoint.Y < endingPoint.Y)
        {
            rect.Y = startingPoint.Y;
            rect.Height = endingPoint.Y - startingPoint.Y;
        }
        else
        {
            rect.Y = endingPoint.Y;
            rect.Height = startingPoint.Y - endingPoint.Y;
        }

        ControlPaint.DrawReversibleFrame(rect, Color.Black, FrameStyle.Dashed);
    }
}

You can drag it on a form, setup its BackgroudImage property and start making rectangles. 

I hope this helps.

Regards,
George
Telerik