C# - Docked External application - Mouse events

Question

I have a winform application (.NET C#). From this application I have started another process (notepad.exe) and docked it to my window - similar to how it was done here: Docking Window inside another Window.

Now my question is, how can I catch/handle mouse events made on this docked application? What I've tried:

• creating a transparent panel over the docking panel. The issue arose when I couldn't click (or do anything else) "through" the invisible panel
• global mouse hook. I didn't like this solution because I'm only interested in the mouse position within my form. Plus, I need the mouse position relative to the window.

For context, what I'm trying to achieve is to have a constant tooltip next to my mouse informing me of the mouse position relative to the panel. See the code bellow:

ToolTip trackTip;
public Form1
{
  trackTip = new ToolTip();
  transparentPanel1.MouseMove += new MouseEventHandler((object s, System.Windows.Forms.MouseEventArgs e) => trackTip.Hide(this));
  transparentPanel1.MouseLeave += new EventHandler(TransparentPanel1_MouseLeave);
}


void TransparentPanel1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
  String tipText = String.Format("({0}, {1})", e.X, e.Y);
  trackTip.Show(tipText, this, e.Location);
}

I've found a viable solution, however I would very much like to avoid injecting code into the process and I feel as though there must be a better solution to my specific problem.

I'd appreciate any pointers you could give me. I'm new to .NET programming.

Answer 1

For reference, I'm combining two answers together to one here:

Getting mouse position in c#

How to get window's position?

Using the global position of the mouse and the position of the window we can calculate the relative position of the mouse. Heres some sample code with really basic boundary handling and no real error handling for if the handle gets closed, etc. But should get you started.

First, basically a copy of the above answers bringing in windows APIs to get the window and mouse positions:

    [StructLayout(LayoutKind.Sequential)]
    public struct POINT
    {
        public int X;
        public int Y;

        public static implicit operator Point(POINT point)
        {
            return new Point(point.X, point.Y);
        }
    }

    [DllImport("user32.dll")]
    public static extern bool GetCursorPos(out POINT lpPoint);

    public static Point GetCursorPosition()
    {
        POINT lpPoint;
        GetCursorPos(out lpPoint);

        return lpPoint;
    }

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr FindWindow(string strClassName, string strWindowName);

    [DllImport("user32.dll")]
    public static extern bool GetWindowRect(IntPtr hwnd, ref Rect rectangle);

    public struct Rect
    {
        public int Left { get; set; }
        public int Top { get; set; }
        public int Right { get; set; }
        public int Bottom { get; set; }
    }

Then a bit of math between the two:

    public Point GetRelativeMousePosition(IntPtr windowPtr)
    {
        Rect windowPostion = new Rect();
        GetWindowRect(windowPtr, ref windowPostion);
        var mousePosition = GetCursorPosition();

        var result = new Point();
        result.X = mousePosition.X - windowPostion.Left;
        result.Y = mousePosition.Y - windowPostion.Top;

        // set some boundaries so we can't go outside.
        if (result.X < 0)
            result.X = 0;

        var maxWidth = windowPostion.Right - windowPostion.Left;
        if (result.X > maxWidth)
            result.X = maxWidth;

        if (result.Y < 0)
            result.Y = 0;

        var maxHeight = windowPostion.Bottom - windowPostion.Top;
        if (result.Y > maxHeight)
            result.Y = maxHeight;

        return result;
    }

and then putting it all together:

    private void Sample()
    {
        Process[] processes = Process.GetProcessesByName("notepad");
        Process lol = processes[0];
        var ptr = lol.MainWindowHandle; // getting this reference is expensive. Better to store and reuse if possible.
        var relativePoint = GetRelativeMousePosition(ptr);
        Console.WriteLine($"relative mouse x:{relativePoint.X} y:{relativePoint.Y}");
    }