cursor-guardrail-utility/source/MainForm.cs

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using System.Windows.Forms;
using RyzStudio.Windows.Forms;

namespace CursorGuardRail
{
    public partial class MainForm : Form
    {
        [StructLayout(LayoutKind.Sequential)]
        public struct RECT
        {
            public int Left;
            public int Top;
            public int Right;
            public int Bottom;
        }

        [DllImport("user32.dll", SetLastError = true)]
        private static extern bool ClipCursor(ref RECT lpRect);

        [DllImport("user32.dll", SetLastError = true)]
        private static extern bool ClipCursor(IntPtr lpRect);


        private bool _requestExit = false;
        private Rectangle? _lockCursorArea;
        private readonly Timer _timer;


        public MainForm()
        {
            InitializeComponent();

            notifyIcon1.Visible = this.ShowTrayIcon;

            screensLayout1.Padding = new Padding(10);

            _timer = new() { Interval = 150 };
            _timer.Tick += (_, _) =>
            {
                if (Cursor.Clip != _lockCursorArea.Value)
                {
                    ClipCursor(_lockCursorArea.Value);
                }
            };
        }

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            ClipCursor(Rectangle.Empty);
        }

        protected async override void OnShown(EventArgs e)
        {
            base.OnShown(e);

            await Task.Run(() =>
            {
                UIControl.Invoke(screensLayout1, (_) => screensLayout1.InvalidateScreens());
            });
        }

        protected override void OnFormClosing(FormClosingEventArgs e)
        {
            if ((this.HideOnClose && !_requestExit) || _timer.Enabled)
            {
                e.Cancel = true;

                this.Hide();
                return;
            }

            if (_timer.Enabled) _timer.Stop();

            ClipCursor(Rectangle.Empty);

            base.OnFormClosing(e);
        }

        protected override void OnResize(EventArgs e)
        {
            if (this.WindowState == FormWindowState.Minimized)
            {
                if (this.ShowTrayIcon) this.Hide();
            }

            base.OnResize(e);
        }

        public new void Show()
        {
            notifyIcon1.Visible = this.ShowTrayIcon || _timer.Enabled;

            this.WindowState = FormWindowState.Normal;
            this.BringToFront();

            base.Show();
        }

        public new void Hide()
        {
            notifyIcon1.Visible = true;

            this.WindowState = FormWindowState.Normal;

            base.Hide();
        }


        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never), DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public bool IsCursorLocked
        {
            get => field;
            set
            {
                field = value;

                dialogFooter1.Button1.Checked = value;
                dialogFooter1.Button1Text = value ? "&Unlock Cursor" : "&Lock Cursor";

                if (value)
                {
                    _lockCursorArea = GetMaxScreenBound();
                    if (!_lockCursorArea.HasValue || _lockCursorArea == Rectangle.Empty)
                    {
                        this.IsCursorLocked = false;
                        screensLayout1.ShowArea = false;
                        return;
                    }

                    _timer.Start();
                    screensLayout1.ShowArea = true;

                    if (this.HideOnLock) this.Close();
                }
                else
                {
                    _lockCursorArea = null;

                    ClipCursor(Rectangle.Empty);

                    notifyIcon1.Visible = value || !this.Visible;

                    if (_timer.Enabled) _timer.Stop();

                    screensLayout1.ShowArea = false;
                }
            }
        } = false;

        public bool HideOnLock { get; private set; } = true;

        public bool HideOnClose { get; private set; } = false;

        public bool ShowTrayIcon
        {
            get => field;
            private set
            {
                field = value;

                notifyIcon1.Visible = value || _timer.Enabled;
            }
        } = false;




        private void menuStrip1_MenuActivate(object sender, EventArgs e)
        {
            toolStripMenuItem3.Checked = this.IsCursorLocked;
            hideOnLockToolStripMenuItem.Checked = this.HideOnLock;
            hideOnCloseToolStripMenuItem.Checked = this.HideOnClose;
            alwaysShowSystemTrayIconToolStripMenuItem.Checked = this.ShowTrayIcon;
        }

        private void contextMenuStrip1_Opening(object sender, CancelEventArgs e)
        {
            toolStripMenuItem2.Checked = this.IsCursorLocked;
        }

        #region Main Menu

        /// <summary>
        /// New
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void newToolStripMenuItem_Click(object sender, EventArgs e)
        {
            refreshToolStripMenuItem_Click(sender, e);
        }

        /// <summary>
        /// Close
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void exitToolStripMenuItem2_Click(object sender, EventArgs e)
        {
            _requestExit = true;

            this.Close();
        }


        /// <summary>
        /// Refresh
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void refreshToolStripMenuItem_Click(object sender, EventArgs e)
        {
            await Task.Run(() =>
            {
                this.IsCursorLocked = false;

                ClipCursor(Rectangle.Empty);

                UIControl.Invoke(screensLayout1, (_) => screensLayout1.InvalidateScreens());
            });
        }


        /// <summary>
        /// Hide on lock
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void hideOnLockToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.HideOnLock = !this.HideOnLock;
        }

        /// <summary>
        /// Hide on close
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void hideOnCloseToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.HideOnClose = !this.HideOnClose;
        }

        /// <summary>
        /// Always show system tray icon
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void alwaysShowSystemTrayIconToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.ShowTrayIcon = !this.ShowTrayIcon;
        }

        /// <summary>
        /// Options
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void optionsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            // Do nothing
        }


        /// <summary>
        /// Help
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void viewHelpToolStripMenuItem1_Click(object sender, EventArgs e)
        {
            RyzStudio.Diagnostics.Process.Execute(AppResource.AppHelpURL);
        }

        /// <summary>
        /// About
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void aboutToolStripMenuItem1_Click(object sender, EventArgs e)
        {
            var form = new RyzStudio.Forms.T3AboutForm();
            form.ProductURL = AppResource.AppProductURL;
            form.AuthorURL = AppResource.AppAuthorURL;
            form.CompanyURL = AppResource.AppCompanyURL;
            form.ProductCopyrightStartYear = 2026;
            form.ProductLogo = AppResource.icon_64;

            form.ShowDialog();
        }

        #endregion


        /// <summary>
        /// Refresh
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void button1_MouseClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                refreshToolStripMenuItem_Click(sender, e);
            }
        }

        /// <summary>
        /// Open display settings
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void button2_MouseClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                try
                {
                    Process.Start(new ProcessStartInfo
                    {
                        FileName = "ms-settings:display",
                        UseShellExecute = true
                    });
                }
                catch (Exception)
                {
                    // Do nothing
                }
            }
        }


        /// <summary>
        /// Lock/unlock cursor
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolStripMenuItem2_Click(object sender, EventArgs e)
        {
            this.IsCursorLocked = !this.IsCursorLocked;
        }


        #region System tray icon

        /// <summary>
        /// Hide/show
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (this.Visible)
            {
                this.Hide();
            }
            else
            {
                this.Show();
            }
        }

        /// <summary>
        /// Show
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolStripMenuItem5_Click(object sender, EventArgs e)
        {
            this.Show();
        }

        #endregion


        /// <summary>
        /// Enable
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void dialogFooter1_OnButton1Click(object sender, MouseEventArgs e)
        {
            this.IsCursorLocked = !this.IsCursorLocked;
        }

        /// <summary>
        /// Close
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void dialogFooter1_OnButton2Click(object sender, MouseEventArgs e)
        {
            this.Close();
        }


        private Rectangle GetMaxScreenBound()
        {
            Rectangle? rect = null;

            for (var i = 0; i < screensLayout1.Screens.Count; i++)
            {
                if (!screensLayout1.Screens[i].IsSelected)
                {
                    continue;
                }

                if (rect == null)
                {
                    rect = Screen.AllScreens[i].Bounds;
                }
                else
                {
                    rect = Rectangle.Union(Screen.AllScreens[i].Bounds, rect.Value);
                }
            }

            return rect ?? Rectangle.Empty;
        }

        private void ClipCursor(Rectangle rect)
        {
            if (rect == Rectangle.Empty)
            {
                ClipCursor(IntPtr.Zero);
            }
            else
            {
                var rect2 = new RECT
                {
                    Left = rect.Left,
                    Top = rect.Top,
                    Right = rect.Right,
                    Bottom = rect.Bottom
                };

                ClipCursor(ref rect2);
            }
        }

    }
}