Fix for #53 Double-clicking the tooltip makes it flicker

Author: hell-racer

Source/ExcelDna.IntelliSense/ToolTipForm.cs

@@ -65,44 +65,46 @@ public ToolTipForm(IntPtr hwndOwner)
             _borderLightPen = new Pen(Color.FromArgb(225, 225, 225));
             SetStyle(ControlStyles.UserMouse | ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint, true);
             Debug.Print($"Created ToolTipForm with owner {hwndOwner}");
-        }
-
-        protected override void WndProc(ref Message m)
-        {
-            const int WM_MOUSEACTIVATE = 0x21;
-            const int WM_MOUSEMOVE = 0x0200;
-            const int WM_LBUTTONDOWN = 0x0201;
-            const int WM_LBUTTONUP = 0x0202;
-            const int WM_SETCURSOR = 0x20;
-            const int MA_NOACTIVATE = 0x0003;
-
-            switch (m.Msg)
-            {
-                // Prevent activation by mouse interaction
-                case WM_MOUSEACTIVATE:
-                    m.Result = (IntPtr)MA_NOACTIVATE;
-                    return;
-                // We're never active, so we need to do our own mouse handling
-                case WM_LBUTTONDOWN:
-                    MouseButtonDown(GetMouseLocation(m.LParam));
-                    return;
-                case WM_MOUSEMOVE:
-                    MouseMoved(GetMouseLocation(m.LParam));
-                    return;
-                case WM_LBUTTONUP:
-                    MouseButtonUp(GetMouseLocation(m.LParam));
-                    return;
-                case WM_SETCURSOR:
-                    // We need to handle this message to prevent flicker (possibly because we're not 'active').
-                    m.Result = new IntPtr(1); //Signify that we dealt with the message.
-                    return;
-                default:
-                    base.WndProc(ref m);
-                    return;
-            }
-        }
-
-        void ShowToolTip()
+        }
+
+		protected override void WndProc(ref Message m)
+		{
+			const int WM_MOUSEACTIVATE = 0x21;
+			const int WM_MOUSEMOVE = 0x0200;
+			const int WM_LBUTTONDOWN = 0x0201;
+			const int WM_LBUTTONUP = 0x0202;
+			const int WM_LBUTTONDBLCLK = 0x203;
+			const int WM_SETCURSOR = 0x20;
+			const int MA_NOACTIVATE = 0x0003;
+
+			switch (m.Msg)
+			{
+				// Prevent activation by mouse interaction
+				case WM_MOUSEACTIVATE:
+					m.Result = (IntPtr)MA_NOACTIVATE;
+					return;
+				// We're never active, so we need to do our own mouse handling
+				case WM_LBUTTONDOWN:
+					MouseButtonDown(GetMouseLocation(m.LParam));
+					return;
+				case WM_MOUSEMOVE:
+					MouseMoved(GetMouseLocation(m.LParam));
+					return;
+				case WM_LBUTTONUP:
+					MouseButtonUp(GetMouseLocation(m.LParam));
+					return;
+				case WM_SETCURSOR:
+				case WM_LBUTTONDBLCLK:
+					// We need to handle this message to prevent flicker (possibly because we're not 'active').
+					m.Result = new IntPtr(1); //Signify that we dealt with the message.
+					return;
+				default:
+					base.WndProc(ref m);
+					return;
+			}
+		}
+
+		void ShowToolTip()
         {
             try
             {