Calculator with Proportionaly Resizable Controls. Using Hashtable() to store default locations of controls.

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Introduction

The best way to resize controls that are of different size and type would be – to store the default (start) value of every Control that needs to be resized. It is particularly useful when working with Controls of different sizes and locations. This can be achieved either by performing a deep copy of the original object or copying the parameters of the original object into a custom object. Because Button doesn’t support Clone(), a custom object needs to be created:

public class DefLocation
{

    int defW,defH,defCX,defCY; 
    public void setDefW(int dw){
       defW = dw;
    }
    public void setDefH(int dh){
       defH = dh;
    }
    public void setDefCX(int dcx){
       defCX = dcx;
    }
    public void setDefCY(int dcy){
       defCY = dcy;
    }

    public int getDefW(){return defW;}
    public int getDefH(){return defH;}
    public int getDefCX(){return defCX;}
    public int getDefCY(){return defCY;}
}

… cycle through the Controls copying their values and store them in a HashTable hash for future retrieval.

Hashtable hash = new Hashtable();
………
    public void InitDefLoc()
    {
        foreach(Control cl in Controls)
        {
            if ((cl is Button) ^ (cl is TextBox))
            {
                DefLocation dl = new DefLocation();
                dl.setDefW(cl.Width);
                dl.setDefH(cl.Height);
                dl.setDefCX(cl.Location.X);
                dl.setDefCY(cl.Location.Y);
                hash.Add(cl,dl);
            }
        }
    }

Now every Button and every TextBox have their default parameters saved inside the HashTable hash. Now – the most exciting part – the resizing routine…

private void Form1_Resize(object sender, System.EventArgs e)
{
    // calculate the resize ratio
    int widthRatio = ClientRectangle.Width * 100 / startW;
    //startW/H – hardcoded size of the application
    int heightRatio = ClientRectangle.Height * 100 / startH;
    foreach (Control ctl in Controls)
    {
        if ((ctl is Button)^(ctl is TextBox))
        {
            // for every control, access its default values stored in hash
            DefLocation dl2 = (DefLocation)hash[ctl];

            // need a new Point
            Point pnt = new Point((dl2.getDefCX() * widthRatio / 100),
                               (dl2.getDefCY() * heightRatio / 100));

            ctl.Width = dl2.getDefW() * widthRatio / 100;
            ctl.Height = dl2.getDefH() * heightRatio / 100;
            ctl.Location = pnt;
        }
    }
}