Mouse Capture and Selection

Question

I have a control, that moves around alot of different controls inside of it in the form of a grid. So basically, none of the container control is shown at any point. But i do have capture of all the mousedown and mousemove events of the controls inside. What id like to do, is create an effect alot like the desktop of a windows computer, where you can drag, and every control that is inside of the mouse's drag will be thrown in a list, and when the mouse is released i can perform an action on all the selected items. Is this possible?

Answer 1

Register for OnMouseDown, OnMouseMove, OnMouseUp events.

1. OnMouseDown get the control's position and focus underneath the mouse.
2. OnMouseMove, set the position of the control with mouse position.
3. OnMouseUp release the control focus.

Checkout the example.

Answer 2

Well with some trial and error i solved my own question. in each of my childs controls, i did this:

    protected override void OnMouseDown(MouseEventArgs e)
    {
        Point pnt = this.PointToScreen(e.Location);
        base.OnMouseDown(new MouseEventArgs(e.Button, e.Clicks, pnt.X, pnt.Y, e.Delta));
    }
    protected override void OnMouseMove(MouseEventArgs e)
    {
        Point pnt = this.PointToScreen(e.Location);
        base.OnMouseMove(new MouseEventArgs(e.Button, e.Clicks, pnt.X, pnt.Y, e.Delta));
    }

to make the cursor position usable from the container control, and in the container i did this:

        #region Lambda
        item.MouseDown += new MouseEventHandler((a, b) =>
        {
            MessageBase hovering = this.GetChildAtPoint(tr_MouseCurrentPoint) as MessageBase;
            if (b.Button == MouseButtons.Left)
            {
                tr_MouseDown = true;
                tr_MouseDownPoint = this.PointToClient(b.Location);
                mouseupdate();
                foreach (var t in tr_CurrentlySelected)
                {
                    t.Key.Selected = false;
                }
                tr_CurrentlySelected.Clear();
                if (hovering != null && tr_CurrentlySelected.ContainsKey(hovering) == false)
                {
                    tr_CurrentlySelected.Add(hovering, new MouseCoordinateStore(tr_MouseDown, tr_MouseDownPoint, tr_MouseCurrentPoint, tr_MouseDifference));
                    hovering.Selected = true;
                    tr_LastHoveredOver = hovering;
                }
            }
            else if (b.Button == MouseButtons.Right)
            {
                if (hovering.Selected == true)
                {
                    MessageBox.Show("Show Right Click Logic Here");
                }
                else
                {
                    foreach (var t in tr_CurrentlySelected)
                    {
                        t.Key.Selected = false;
                    }
                    tr_CurrentlySelected.Clear();
                    if (hovering != null && tr_CurrentlySelected.ContainsKey(hovering) == false)
                    {
                        tr_CurrentlySelected.Add(hovering, new MouseCoordinateStore(tr_MouseDown, tr_MouseDownPoint, tr_MouseCurrentPoint, tr_MouseDifference));
                        hovering.Selected = true;
                        tr_LastHoveredOver = hovering;
                    }
                    MessageBox.Show("Show Right Click Logic Here");
                }
            }
        });
        item.MouseUp += new MouseEventHandler((a, b) => { tr_MouseDown = false; mouseupdate(); });
        item.MouseMove += new MouseEventHandler((a, b) => { 
            tr_MouseCurrentPoint = this.PointToClient(b.Location); 
            mouseupdate();
            if (tr_MouseDown)
            {
                MessageBase hovering = this.GetChildAtPoint(tr_MouseCurrentPoint) as MessageBase;
                if (hovering != null)
                {
                    if (tr_CurrentlySelected.ContainsKey(hovering) == false)
                    {
                        tr_CurrentlySelected.Add(hovering, new MouseCoordinateStore(tr_MouseDown, tr_MouseDownPoint, tr_MouseCurrentPoint, tr_MouseDifference));
                        tr_LastHoveredOver = hovering;
                        hovering.Selected = true;
                    }
                    else
                    {
                        int ind = hovering.Index;
                        List<MessageBase> ItemsToRemove = new List<MessageBase>();
                        if (tr_MouseDifference.Y < 0) // Y is negative
                        {
                            foreach (var dic in tr_CurrentlySelected)
                            {
                                if (dic.Key.Index < ind)
                                {
                                    ItemsToRemove.Add(dic.Key);
                                }
                            }
                        }
                        else //Y is positive
                        {
                            foreach (var dic in tr_CurrentlySelected)
                            {
                                if (dic.Key.Index > ind)
                                {
                                    ItemsToRemove.Add(dic.Key);
                                }
                            }
                        }
                        foreach (var dic in ItemsToRemove)
                        {
                            tr_CurrentlySelected.Remove(dic);
                            dic.Selected = false;
                        }
                    }
                }
            }
        });
        item.KeyDown += new KeyEventHandler((a, b) =>
        {
            try
            {
                if (b.KeyData == Keys.Down)
                {
                    MessageBase hovering = ControlCollection[tr_LastHoveredOver.Index + 1];
                    foreach (var t in tr_CurrentlySelected)
                    {
                        t.Key.Selected = false;
                    }
                    tr_CurrentlySelected.Clear();
                    if (hovering != null && tr_CurrentlySelected.ContainsKey(hovering) == false)
                    {
                        tr_CurrentlySelected.Add(hovering, null);
                        hovering.Selected = true;
                        tr_LastHoveredOver = hovering;
                    }
                }
                else if (b.KeyData == Keys.Up)
                {
                    MessageBase hovering = ControlCollection[tr_LastHoveredOver.Index - 1];
                    foreach (var t in tr_CurrentlySelected)
                    {
                        t.Key.Selected = false;
                    }
                    tr_CurrentlySelected.Clear();
                    if (hovering != null && tr_CurrentlySelected.ContainsKey(hovering) == false)
                    {
                        tr_CurrentlySelected.Add(hovering, null);
                        hovering.Selected = true;
                        tr_LastHoveredOver = hovering;
                    }
                }
            }
            catch { }
        });
        #endregion

obviously there is some other things happening elsewhere, but thats the basic just of it. Thanks for the one answer i got, allthough i already knew about that i appriciate every and all answers i get :) thanks guys!