using System;
using System.Windows.Forms;
using System.Drawing;
using Imsl.Chart2D;

public class SampleZoom : FrameChart
{
    private Panel panel;
    private AxisXY axis;
    private int xFirst, yFirst;
    private int xLast, yLast;
    private System.Collections.Stack stack;
	private MouseEventHandler mouseMoveHandler;

    public SampleZoom()
    {
        panel = this.Panel;
        Chart chart = this.Chart;
        axis = new AxisXY(chart);
        int n = 1000;
        double[] x = new double[n];
        double[] y = new double[n];
        Random ran = new Random();
        for (int k = 0;  k < n;  k++) {
            x[k] = 10.0 * ran.NextDouble();
            y[k] = 10.0 * ran.NextDouble();
        }
        Data data = new Data(axis, x, y);
        data.DataType = Data.DATA_TYPE_MARKER;

        // add menu "Zoom" menu
        MenuItem menuZoom = new MenuItem();
        menuZoom.Text = "&Zoom";
        menuZoom.Shortcut = Shortcut.CtrlZ;
        AddMenuItem(menuZoom, "Out", Shortcut.CtrlO);
        AddMenuItem(menuZoom, "Restore", Shortcut.CtrlR);
        this.Menu.MenuItems.Add(menuZoom);

        // save x-axis and y-axis Window attributes on this stack.
        // they are used to zoom out one level.
        stack = new System.Collections.Stack();

        // listen for mouse press events
        panel.MouseDown += new MouseEventHandler(Panel_MouseDown);
        panel.MouseUp += new MouseEventHandler(Panel_MouseUp);

		mouseMoveHandler = new MouseEventHandler(panel_MouseMove);
    }

    // Add a menu item
    private void AddMenuItem(MenuItem menuZoom, string title, Shortcut sc)
    {
        MenuItem menuItem = new MenuItem(title);
        menuItem.Text = title;
        menuItem.Shortcut = sc;
        menuZoom.MenuItems.Add(menuItem);
        menuItem.Click += new EventHandler(menuItem_Click);
    }

    // A mouse press starts the zoom
    // Record location of this point and listen for drag (motion) events.
    void Panel_MouseDown(object sender, MouseEventArgs e)
    {
        xFirst = xLast = e.X;
        yFirst = yLast = e.Y;
        panel.MouseMove += mouseMoveHandler;
    }

    // Releasing the mouse button ends the zoom
    // Stop listening for move events and update the Window attributes
    void Panel_MouseUp(object sender, MouseEventArgs e)
    {
        panel.MouseMove -= mouseMoveHandler;

        // ignore degenerate zooms
        if (xFirst == xLast || yFirst == yLast)
        {
            Refresh();
            return;
        }

        // get window and convert to user coordinates
        double[] windowX = (double[])axis.AxisX.GetWindow();
        double[] windowY = (double[])axis.AxisY.GetWindow();

        // save the windows on the stack (for zoom out option)
        stack.Push(windowX);
        stack.Push(windowY);

        // get user coordinate of left-upper corner of the box
        // limit it to stay inside current window
        double[] boxLU = new double[2];
        int x = Math.Min(xFirst, xLast);
        int y = Math.Min(yFirst, yLast);
        axis.MapDeviceToUser(x, y, boxLU);

        // get user coordinate of right-lower corner of the box
        // limit it to stay inside current window
        double[] boxRL = new double[2];
        x = Math.Max(xFirst, xLast);
        y = Math.Max(yFirst, yLast);
        axis.MapDeviceToUser(x, y, boxRL);

        // set axis window to range of rubber-band box
        // and disable autoscale to force use of window settings
        axis.AutoscaleInput = ChartNode.AUTOSCALE_OFF;
        double xa = Math.Max(windowX[0], boxLU[0]);
        double xb = Math.Min(windowX[1], boxRL[0]);
        double ya = Math.Max(windowY[0], boxRL[1]);
        double yb = Math.Min(windowY[1], boxLU[1]);
        axis.AxisX.SetWindow(xa, xb);
        axis.AxisY.SetWindow(ya, yb);

        // force redraw of the chart
        Refresh();
    }

    // Moving the mouse after a click continues the zoom.
    // Erase the old rubber band box and draw a new one
    // Also keep track of the location of this event
    void panel_MouseMove(object sender, MouseEventArgs e)
    {
        // erase previous rectangle
        Graphics g = panel.CreateGraphics();
        DrawBox(g, Color.White);

        // draw new rectangle
        xLast = e.X;
        yLast = e.Y;
        DrawBox(g, Color.Red);
    }

    // Draw a box with (xFirst, yFirst) and (xLast, yLast) as its corners
    private void DrawBox(Graphics g, Color color)
    {
        int x = Math.Min(xFirst, xLast);
        int y = Math.Min(yFirst, yLast);
        int w = Math.Abs(xLast - xFirst);
        int h = Math.Abs(yLast - yFirst);
        g.DrawRectangle(new Pen(color), x, y, w, h);
    }

    void menuItem_Click(object sender, EventArgs e)
    {
        string cmd = ((MenuItem)sender).Text;
        if (cmd.Equals("Out"))
        {
            try
            {
                // zoom out by restoring window settings from the stack
                axis.AxisY.SetWindow((double[])stack.Pop());
                axis.AxisX.SetWindow((double[])stack.Pop());
            }
            catch (System.InvalidOperationException)
            {
                // no more levels to zoom out
                // restore original setting by turning on autoscale
                axis.AutoscaleInput = ChartNode.AUTOSCALE_DATA;
            }
        }
        else if (cmd.Equals("Restore"))
        {
            // restore original setting by turning on autoscale an empty stack
            axis.AutoscaleInput = ChartNode.AUTOSCALE_DATA;
            stack.Clear();
        }
        // force redraw of the chart
        Refresh();
    }

    public static void Main(string[] argv)
    {
        System.Windows.Forms.Application.Run(new SampleZoom());
    }
}