Squashed 'FSI.Lib/' content from commit 6aa4846

git-subtree-dir: FSI.Lib
git-subtree-split: 6aa48465a834a7bfdd9cbeae8d2e4f769d0c0ff8

FSI.Lib/Wpf/WindowExtensions.cs

@@ -0,0 +1,138 @@
+using System;
+using System.Runtime.InteropServices;
+using System.Windows;
+
+namespace FSI.Lib.Wpf.ExtensionMethods
+{
+    public static class WindowExtensions
+    {
+        #region Public Methods
+
+        public static bool ActivateCenteredToMouse(this Window window)
+        {
+            ComputeTopLeft(ref window);
+            return window.Activate();
+        }
+
+        public static void ShowCenteredToMouse(this Window window)
+        {
+            // in case the default start-up location isn't set to Manual
+            WindowStartupLocation oldLocation = window.WindowStartupLocation;
+            // set location to manual -> window will be placed by Top and Left property
+            window.WindowStartupLocation = WindowStartupLocation.Manual;
+            ComputeTopLeft(ref window);
+            window.Show();
+            window.WindowStartupLocation = oldLocation;
+        }
+
+        #endregion
+
+        #region Methods
+
+        private static void ComputeTopLeft(ref Window window)
+        {
+            W32Point pt = new W32Point();
+            if (!GetCursorPos(ref pt))
+            {
+                Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
+            }
+
+            // 0x00000002: return nearest monitor if pt is not contained in any monitor.
+            IntPtr monHandle = MonitorFromPoint(pt, 0x00000002);
+            W32MonitorInfo monInfo = new W32MonitorInfo();
+            monInfo.Size = Marshal.SizeOf(typeof(W32MonitorInfo));
+
+            if (!GetMonitorInfo(monHandle, ref monInfo))
+            {
+                Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
+            }
+
+            // use WorkArea struct to include the taskbar position.
+            W32Rect monitor = monInfo.WorkArea;
+            double offsetX = Math.Round(window.Width / 2);
+            double offsetY = Math.Round(window.Height / 2);
+
+            double top = pt.Y - offsetY;
+            double left = pt.X - offsetX;
+
+            Rect screen = new Rect(
+                new Point(monitor.Left, monitor.Top),
+                new Point(monitor.Right, monitor.Bottom));
+            Rect wnd = new Rect(
+                new Point(left, top),
+                new Point(left + window.Width, top + window.Height));
+
+            window.Top = wnd.Top;
+            window.Left = wnd.Left;
+
+            if (!screen.Contains(wnd))
+            {
+                if (wnd.Top < screen.Top)
+                {
+                    double diff = Math.Abs(screen.Top - wnd.Top);
+                    window.Top = wnd.Top + diff;
+                }
+
+                if (wnd.Bottom > screen.Bottom)
+                {
+                    double diff = wnd.Bottom - screen.Bottom;
+                    window.Top = wnd.Top - diff;
+                }
+
+                if (wnd.Left < screen.Left)
+                {
+                    double diff = Math.Abs(screen.Left - wnd.Left);
+                    window.Left = wnd.Left + diff;
+                }
+
+                if (wnd.Right > screen.Right)
+                {
+                    double diff = wnd.Right - screen.Right;
+                    window.Left = wnd.Left - diff;
+                }
+            }
+        }
+
+        #endregion
+
+        #region W32 API
+
+        [DllImport("user32.dll", SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool GetCursorPos(ref W32Point pt);
+
+        [DllImport("user32.dll", SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool GetMonitorInfo(IntPtr hMonitor, ref W32MonitorInfo lpmi);
+
+        [DllImport("user32.dll")]
+        private static extern IntPtr MonitorFromPoint(W32Point pt, uint dwFlags);
+
+        [StructLayout(LayoutKind.Sequential)]
+        public struct W32Point
+        {
+            public int X;
+            public int Y;
+        }
+
+        [StructLayout(LayoutKind.Sequential)]
+        internal struct W32MonitorInfo
+        {
+            public int Size;
+            public W32Rect Monitor;
+            public W32Rect WorkArea;
+            public uint Flags;
+        }
+
+        [StructLayout(LayoutKind.Sequential)]
+        internal struct W32Rect
+        {
+            public int Left;
+            public int Top;
+            public int Right;
+            public int Bottom;
+        }
+
+        #endregion
+    }
+}