Rectangle bounds = BFS.Monitor.GetMonitorWorkAreaByWindow(windowHandle);

using System;
using System.Drawing;

// The 'windowHandle' parameter will contain the window handle for the:
//   - Active window when run by hotkey
//   - Window Location target when run by a Window Location rule
//   - TitleBar Button owner when run by a TitleBar Button
//   - Jump List owner when run from a Taskbar Jump List
//   - Currently focused window if none of these match
public static class DisplayFusionFunction
{
public static void Run(IntPtr windowHandle)
{
//get the window styles
BFS.WindowEnum.WindowStyle style = BFS.Window.GetWindowStyle(windowHandle);

//if the window has any borders and titles, make it full screen
if(BFS.Window.HasWindowStyle(BFS.WindowEnum.WindowStyle.WS_CAPTION, windowHandle) ||
BFS.Window.HasWindowStyle(BFS.WindowEnum.WindowStyle.WS_SYSMENU, windowHandle) ||
BFS.Window.HasWindowStyle(BFS.WindowEnum.WindowStyle.WS_THICKFRAME__SIZEBOX, windowHandle) ||
BFS.Window.HasWindowStyle(BFS.WindowEnum.WindowStyle.WS_MINIMIZEBOX, windowHandle) ||
BFS.Window.HasWindowStyle(BFS.WindowEnum.WindowStyle.WS_MAXIMIZEBOX, windowHandle))
{
//save the size and position of the window
SaveWindowSize(windowHandle);

//make sure to remove the styles. just toggling these settings may turn on something we dont want
style &= ~BFS.WindowEnum.WindowStyle.WS_CAPTION;
style &= ~BFS.WindowEnum.WindowStyle.WS_SYSMENU;
style &= ~BFS.WindowEnum.WindowStyle.WS_THICKFRAME__SIZEBOX;
style &= ~BFS.WindowEnum.WindowStyle.WS_MINIMIZEBOX;
style &= ~BFS.WindowEnum.WindowStyle.WS_MAXIMIZEBOX;

//set the window style
BFS.Window.SetWindowStyle(style, windowHandle);

//get the bounds of the monitor that the window is in
Rectangle bounds = BFS.Monitor.GetMonitorBoundsByWindow(windowHandle);

//size and position the window to be fullscreen within the monitor
BFS.Window.SetSizeAndLocation(windowHandle, bounds.X, bounds.Y, bounds.Width, bounds.Height);
}
else
{
//if we got here, then the window must already be fullscreen.
//add non-fullscreen styles back to the window
style |= BFS.WindowEnum.WindowStyle.WS_CAPTION;
style |= BFS.WindowEnum.WindowStyle.WS_SYSMENU;
style |= BFS.WindowEnum.WindowStyle.WS_THICKFRAME__SIZEBOX;
style |= BFS.WindowEnum.WindowStyle.WS_MINIMIZEBOX;
style |= BFS.WindowEnum.WindowStyle.WS_MAXIMIZEBOX;

//try and load saved window size and position
bool isMaximized;
Rectangle bounds = GetSavedWindowSize(windowHandle, out isMaximized);

//set the window style
BFS.Window.SetWindowStyle(style, windowHandle);

//if we couldnt load the size, exit the script
if(bounds.Equals(Rectangle.Empty))
return;

//if the window was maximized, maximize it, otherwise set the window size and location with the values we loaded
if(isMaximized)
BFS.Window.Maximize(windowHandle);
else
BFS.Window.SetSizeAndLocation(windowHandle, bounds.X, bounds.Y, bounds.Width, bounds.Height);
}
}

//this is a function that will save the window size and position in window properties
private static void SaveWindowSize(IntPtr windowHandle)
{
Rectangle bounds = BFS.Window.GetBounds(windowHandle);
BFS.Window.SetWindowProperty(windowHandle, "ToggleFullscreen_X", new IntPtr(bounds.X));
BFS.Window.SetWindowProperty(windowHandle, "ToggleFullscreen_Y", new IntPtr(bounds.Y));
BFS.Window.SetWindowProperty(windowHandle, "ToggleFullscreen_Width", new IntPtr(bounds.Width));
BFS.Window.SetWindowProperty(windowHandle, "ToggleFullscreen_Height", new IntPtr(bounds.Height));
BFS.Window.SetWindowProperty(windowHandle, "ToggleFullscreen_IsMaximized", new IntPtr(BFS.Window.IsMaximized(windowHandle) ? 1 : 0));
}

private static Rectangle GetSavedWindowSize(IntPtr windowHandle, out bool isMaximized)
{
Rectangle bounds = new Rectangle();
bounds.X = BFS.Window.GetWindowProperty(windowHandle, "ToggleFullscreen_X").ToInt32();
bounds.Y = BFS.Window.GetWindowProperty(windowHandle, "ToggleFullscreen_Y").ToInt32();
bounds.Width = BFS.Window.GetWindowProperty(windowHandle, "ToggleFullscreen_Width").ToInt32();
bounds.Height = BFS.Window.GetWindowProperty(windowHandle, "ToggleFullscreen_Height").ToInt32();
isMaximized = (BFS.Window.GetWindowProperty(windowHandle, "ToggleFullscreen_IsMaximized").ToInt32() == 1);
return bounds;
}
}