.net: mousewheel event problem

[ronald chong]

i've built a program with piccolo2d/.net and all was going well until i added winform widgets to the form (and outside of the canvas); see pic below. thanks to http://www.eqqon.com/index.php/Piccolo_Snippets, i had mousewheel zooming working well. but then i discovered that if i clicked on button1, and mouse back onto the canvas, i no longer get mousewheel events, although other mouse events (e.g. PNode entry/leave) still work. this tells me it's not that i needed to click on the canvas to move the focus.  but even after clicking on the canvas, the mousewheel is still dead.

as a sanity check, i tested the canvas's mousedown event and found it works fine after clicking button1. so only the mousewheel breaks. what am i doing wrong? below is minimalist code to demonstrate what i'm seeing.  

(as an aside, i see that the canvas does not raise "enter"/"leave" events consistently; i see one "enter" when the form loads and one "leave" if i click button1 but no more "enter"/"leave" if i go back and forth. further, when i click on button1, i raises its "enter" event but when i click back on the canvas, "button1" doesn't raise its "leave" event, which it does if i have other winform widgets on the form and i clicked on them.) thanks.

-ron

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Diagnostics;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using UMD.HCIL.Piccolo;

using UMD.HCIL.Piccolo.Event;

using UMD.HCIL.Piccolo.Nodes;

namespace piccolo_wheel_test {

    public partial class Form1 : Form {

        int mdown_count = 0;

        int mwheel_count = 0;

        public Form1() {

            InitializeComponent();

            PNode rect = PPath.CreateRectangle(40, 40, 20, 50);

            rect.Brush = Brushes.Blue;

            PNode circle = PPath.CreateEllipse(20, 20, 30, 30);

            circle.Brush = Brushes.Brown;

            pCanvas1.Layer.AddChild(rect);

            pCanvas1.Layer.AddChild(circle);

            pCanvas1.Camera.MouseWheel += new PInputEventHandler(Camera_MouseWheel);

            pCanvas1.Camera.MouseDown += new PInputEventHandler(Camera_MouseDown);

        }

        void Camera_MouseDown(object sender, PInputEventArgs e) {

            Debug.WriteLine("got mouse down: " + (mdown_count++).ToString());

        }

        void Camera_MouseWheel(object sender, PInputEventArgs e) {

            Debug.WriteLine("got mouse wheel: " + (mwheel_count++).ToString());

        }

        private void pCanvas1_Enter(object sender, EventArgs e) {

            Debug.WriteLine("enter pcanvas");

        }

        private void pCanvas1_Leave(object sender, EventArgs e) {

            Debug.WriteLine("leave pcanvas");

        }

        private void button1_Enter(object sender, EventArgs e) {

            Debug.WriteLine("enter button");

        }

        private void button1_Leave(object sender, EventArgs e) {

            Debug.WriteLine("leave button");

        }

    }

}