Auto scroll when selecting rows with mouse

[van]

Hi,

is it possible to auto scroll GridView when selecting data with mouse?
When I click on first row and first cell, hold the mouse button and drag with mouse to select more rows, I need that GridView auto scrolls to show me rows, which did not fit in a page.
Because now I cannot select rows which are not visible.

Van Elpho

[Emanuel Varga]

Hello van,

This behavior is not supported by default, and in my point of view could be very hard to understand for some users, but if you are sure you want this behavior just let me know and i will try to put together a sample project.

Hope this helps, if you have any other questions or comments, please let me know,

Best Regards,
Emanuel Varga

Telerik WinForms MVP

[van]

Hi Emanuel,

sample project would be great. This behavior is for example in Excel, so I thought it's a standard.

Best regards
Van Elpho

[Richard Slade]

Hello Van,

Can you also confirm as it may help Emanuel and anyone else looking at this what version you are using please? I know there are some scrolling issues (not related to this particulaly) in the current 2010 Q3 version that I understand are due to be looked at for the upcoming service pack due in mid December.

thanks
Richard

[van]

Hello Richard,

I am using version 2010.1.10.308.

Best regards
Van Elpho

[Jack]

Hello van,

Currently RadGridView does not support this feature. However, it is a nice feature and I added it in our issue tracking system. We will consider implementing it in one of our upcoming releases.

Should you have any further questions, do not hesitate to ask.

Greetings, Jack
the Telerik team

[Emanuel Varga]

Hello guys,

Sorry for the delay, but I've managed to put a very basic sample together, please take a look at the following example:

namespace SelectMultipleLinesByClicking
{
    using System;
    using System.ComponentModel;
    using System.Drawing;
    using System.Linq;
    using System.Windows.Forms;
    using Telerik.WinControls.UI;

    public partial class Form1 : Form
    {
        private RadGridView radGridView1;
        public Form1()
        {
            InitializeComponent();
            this.Controls.Add(radGridView1 = new RadGridView());
            radGridView1.Dock = DockStyle.Fill;

            this.radGridView1.MasterTemplate.AllowAddNewRow = false;
            this.radGridView1.EnableFiltering = true;
            radGridView1.GridBehavior = new CustomGridBehavior();
            radGridView1.MultiSelect = true;
            radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
        }

        protected override void OnLoad(EventArgs e)
        {
            radGridView1.DataSource = new TestsCollection();
        }
    }

    public class Test
    {
        public int Id { get; set; }

        public string name { get; set; }

        public Test(int id, string name)
        {
            this.Id = id; this.name = name;
        }
    }

    public class TestsCollection : BindingList<Test>
    {
        public TestsCollection()
        {
            for (int i = 0; i < 1000; i++)
            {
                this.Add(new Test(i, "Name" + i));
            }
        }
    }

    public class CustomGridBehavior : BaseGridBehavior
    {
        public bool IsMouseDown { get; set; }

        private Timer scrollTimer;

        public CustomGridBehavior()
        {
            scrollTimer = new Timer();
            scrollTimer.Interval = 200;
            scrollTimer.Tick += new EventHandler(scrollTimer_Tick);
        }

        void scrollTimer_Tick(object sender, EventArgs e)
        {
            if (!(scrollTimer.Tag is Point))
            {
                return;
            }

            var location = (Point)scrollTimer.Tag;
            var cell = this.GridControl.RootElement.ElementTree.GetElementAtPoint(location) as GridCellElement;
            if (cell != null)
            {
                var row = cell.RowInfo as GridViewRowInfo;
                if (row != null)
                {
                    if (this.GridControl.TableElement.VisualRows.Where(r=> this.GridControl.TableElement.VisualRows.Count - this.GridControl.TableElement.VisualRows.IndexOf(r) < 3).Any(r=>
                        r.RowInfo == row))
                    {
                        if (this.GridControl.Rows.Count > row.Index + 1)
                        {
                            row.IsSelected = true;
                            this.GridControl.Rows[row.Index + 1].EnsureVisible();
                        }
                    }
                }
            }
        }

        public override bool OnMouseUp(MouseEventArgs e)
        {
            IsMouseDown = false;
            scrollTimer.Enabled = false;
            return base.OnMouseUp(e);
        }

        public override bool OnMouseDown(MouseEventArgs e)
        {
            IsMouseDown = true;
            return base.OnMouseDown(e);
        }

        public override bool OnMouseMove(MouseEventArgs e)
        {
            if (IsMouseDown)
            {
                scrollTimer.Tag = e.Location;
                if (!scrollTimer.Enabled)
                    scrollTimer.Enabled = true;
            }

            return base.OnMouseMove(e);
        }
    }
}

Hope this helps, if you have any other questions or comments, please let me know,

Best Regards,
Emanuel Varga
Telerik WinForms MVP

[Jack]

Hi Emanuel, thank you for this solution. We will consider your code when implementing the feature.
 
Best wishes,
Jack
the Telerik team

[van]

Thank you Emanuel, that's exactly what I've been looking for.