CentralizedControl/HandyControl/HandyControl_Shared/Tools/Helper/ScreenHelper.cs

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Windows;
using HandyControl.Tools.Interop;

namespace HandyControl.Tools;

internal class ScreenHelper
{
    internal static void FindMaximumSingleMonitorRectangle(Rect windowRect, out Rect screenSubRect, out Rect monitorRect)
    {
        var windowRect2 = new InteropValues.RECT(windowRect);
        FindMaximumSingleMonitorRectangle(windowRect2, out var rect, out var rect2);
        screenSubRect = new Rect(rect.Position, rect.Size);
        monitorRect = new Rect(rect2.Position, rect2.Size);
    }

    private static void FindMaximumSingleMonitorRectangle(InteropValues.RECT windowRect, out InteropValues.RECT screenSubRect, out InteropValues.RECT monitorRect)
    {
        var rects = new List<InteropValues.RECT>();
        InteropMethods.EnumDisplayMonitors(IntPtr.Zero, IntPtr.Zero,
            delegate (IntPtr hMonitor, IntPtr hdcMonitor, ref InteropValues.RECT rect, IntPtr lpData)
            {
                var monitorInfo = default(InteropValues.MONITORINFO);
                monitorInfo.cbSize = (uint) Marshal.SizeOf(typeof(InteropValues.MONITORINFO));
                InteropMethods.GetMonitorInfo(hMonitor, ref monitorInfo);
                rects.Add(monitorInfo.rcWork);
                return true;
            }, IntPtr.Zero);

        var num = 0L;

        screenSubRect = new InteropValues.RECT
        {
            Left = 0,
            Right = 0,
            Top = 0,
            Bottom = 0
        };

        monitorRect = new InteropValues.RECT
        {
            Left = 0,
            Right = 0,
            Top = 0,
            Bottom = 0
        };

        foreach (var current in rects)
        {
            var rect = current;
            InteropMethods.IntersectRect(out var rECT2, ref rect, ref windowRect);
            var num2 = (long) (rECT2.Width * rECT2.Height);
            if (num2 > num)
            {
                screenSubRect = rECT2;
                monitorRect = current;
                num = num2;
            }
        }
    }

    internal static void FindMonitorRectsFromPoint(Point point, out Rect monitorRect, out Rect workAreaRect)
    {
        var intPtr = InteropMethods.MonitorFromPoint(new InteropValues.POINT
        {
            X = (int) point.X,
            Y = (int) point.Y
        }, 2);

        monitorRect = new Rect(0.0, 0.0, 0.0, 0.0);
        workAreaRect = new Rect(0.0, 0.0, 0.0, 0.0);

        if (intPtr != IntPtr.Zero)
        {
            InteropValues.MONITORINFO monitorInfo = default;
            monitorInfo.cbSize = (uint) Marshal.SizeOf(typeof(InteropValues.MONITORINFO));
            InteropMethods.GetMonitorInfo(intPtr, ref monitorInfo);
            monitorRect = new Rect(monitorInfo.rcMonitor.Position, monitorInfo.rcMonitor.Size);
            workAreaRect = new Rect(monitorInfo.rcWork.Position, monitorInfo.rcWork.Size);
        }
    }
}