ZoomGesture

[Alfonso]

Is there any way to catch the ZoomGesture in desktop App? i mean not in touch input device

On the other hand, how can i make zoom to specific area of data? without zoomfactor

[Dess | Tech Support Engineer, Principal]

Hello Alfonso,

Thank you for contacting Telerik Support.

ZoomGesture occurs when a zoom gesture was sent by a touch input device only. However, it is possible to catch zooming on MouseWheel event if the ControlKey is pressed:

public partial class Form1 : Form
{
    bool IsCtrlPressed = false;

    public Form1()
    {
        InitializeComponent();

        BarSeries barSeries = new BarSeries("Performance", "RepresentativeName");
        barSeries.Name = "Q1";
        barSeries.DataPoints.Add(new CategoricalDataPoint(177, "Harley"));
        barSeries.DataPoints.Add(new CategoricalDataPoint(128, "White"));
        barSeries.DataPoints.Add(new CategoricalDataPoint(143, "Smith"));
        barSeries.DataPoints.Add(new CategoricalDataPoint(111, "Jones"));
        barSeries.DataPoints.Add(new CategoricalDataPoint(118, "Marshall"));
        this.radChartView1.Series.Add(barSeries);

        BarSeries barSeries2 = new BarSeries("Performance", "RepresentativeName");
        barSeries2.Name = "Q2";
        barSeries2.DataPoints.Add(new CategoricalDataPoint(153, "Harley"));
        barSeries2.DataPoints.Add(new CategoricalDataPoint(141, "White"));
        barSeries2.DataPoints.Add(new CategoricalDataPoint(130, "Smith"));
        barSeries2.DataPoints.Add(new CategoricalDataPoint(88, "Jones"));
        barSeries2.DataPoints.Add(new CategoricalDataPoint(109, "Marshall"));
        this.radChartView1.Series.Add(barSeries2);

        radChartView1.ShowPanZoom = true;
        radChartView1.MouseWheel += radChartView1_MouseWheel;
        radChartView1.KeyDown += radChartView1_KeyDown;
    }

    private void radChartView1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyCode==Keys.ControlKey)
        {
             IsCtrlPressed = true;
        }
    }

    private void radChartView1_MouseWheel(object sender, MouseEventArgs e)
    {
        if (e.Button == System.Windows.Forms.MouseButtons.None && IsCtrlPressed)
        {
           // radChartView1.Zoom(3, 1);
        }

        IsCtrlPressed = false;
    }
}

On the other hand, you can make zoom to the specific area of mouse location:

public partial class Form1 : RadForm
{
    private Random rnd = new Random();

    public Form1()
    {
        InitializeComponent();

        BarSeries bar = new BarSeries();

        for (int i = 0; i < 5; i++)
        {
            CategoricalDataPoint point = new CategoricalDataPoint();
            point.Category = (char)(65 + i);
            point.Value = i * 10;

            bar.DataPoints.Add(point);
        }

        this.radChartView1.Series.Add(bar);

        this.radChartView1.MouseWheel += radChartView1_MouseWheel;
    }

    private void radChartView1_MouseWheel(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        SizeF newZoom = new SizeF(1f, 1f);

        if (e.Delta > 0)
        {
            // zoom in
            newZoom.Width = (float)((IChartView)this.radChartView1.View).ZoomWidth * 1.1f;
        }
        else
        {
            // zoom out
            float xZoom = (float)((IChartView)this.radChartView1.View).ZoomWidth / 1.1f;

            if (xZoom >= 1)
            {
                newZoom.Width = xZoom;
            }
            else
            {
                newZoom.Width = 1; // zoom out to max
            }
        }

        double oldStretchedAreaWidth = this.radChartView1.View.Viewport.Width * ((IChartView)this.radChartView1.View).ZoomWidth;
        Point point = e.Location;
        double ratio = (point.X - ((IChartView)this.radChartView1.View).PlotOriginX) / oldStretchedAreaWidth;

        this.radChartView1.Zoom(newZoom.Width, newZoom.Height);
        double newStretchedAreaWidth = this.radChartView1.View.Viewport.Width * newZoom.Width;
        double panOffset = ratio * newStretchedAreaWidth - point.X;

        this.radChartView1.Pan(-panOffset, 0);
    }
}

I hope this information helps. Should you have further questions, I would be glad to help.

Regards,
Desislava
Telerik