PixiEditor/PixiEditor/ViewModels/SubViewModels/Main/IoViewModel.cs

using PixiEditor.Helpers;
using PixiEditor.Models.Controllers;
using PixiEditor.Models.Controllers.Shortcuts;
using System;
using System.Windows.Input;

namespace PixiEditor.ViewModels.SubViewModels.Main
{
    public class IoViewModel : SubViewModel<ViewModelMain>
    {
        public RelayCommand MouseMoveCommand { get; set; }

        public RelayCommand MouseDownCommand { get; set; }

        public RelayCommand MouseUpCommand { get; set; }

        public RelayCommand KeyDownCommand { get; set; }

        public RelayCommand KeyUpCommand { get; set; }

        private bool restoreToolOnKeyUp = false;

        private MouseInputFilter filter = new();

        public IoViewModel(ViewModelMain owner)
            : base(owner)
        {
            MouseDownCommand = new RelayCommand(filter.MouseDown);
            MouseMoveCommand = new RelayCommand(filter.MouseMove);
            MouseUpCommand = new RelayCommand(filter.MouseUp);
            GlobalMouseHook.OnMouseUp += filter.MouseUp;
            KeyDownCommand = new RelayCommand(OnKeyDown);
            KeyUpCommand = new RelayCommand(OnKeyUp);

            filter.OnMouseDown += OnMouseDown;
            filter.OnMouseMove += OnMouseMove;
            filter.OnMouseUp += OnMouseUp;
        }

        private void OnKeyDown(object parameter)
        {
            KeyEventArgs args = (KeyEventArgs)parameter;
            if (args.IsRepeat && !restoreToolOnKeyUp && Owner.ShortcutController.LastShortcut != null &&
                Owner.ShortcutController.LastShortcut.Command == Owner.ToolsSubViewModel.SelectToolCommand)
            {
                restoreToolOnKeyUp = true;
                ShortcutController.BlockShortcutExecution = true;
            }

            Owner.ShortcutController.KeyPressed(args.Key, Keyboard.Modifiers);

            if (Owner.BitmapManager.ActiveDocument != null)
                Owner.BitmapManager.InputTarget.OnKeyDown(args.Key);
        }

        private void OnKeyUp(object parameter)
        {
            KeyEventArgs args = (KeyEventArgs)parameter;
            if (restoreToolOnKeyUp && Owner.ShortcutController.LastShortcut != null &&
                Owner.ShortcutController.LastShortcut.ShortcutKey == args.Key)
            {
                restoreToolOnKeyUp = false;
                Owner.ToolsSubViewModel.SetActiveTool(Owner.ToolsSubViewModel.LastActionTool);
                ShortcutController.BlockShortcutExecution = false;
            }

            if (Owner.BitmapManager.ActiveDocument != null)
                Owner.BitmapManager.InputTarget.OnKeyUp(args.Key);
        }

        private void OnMouseDown(object sender, MouseButton button)
        {
            if (button == MouseButton.Left)
            {
                BitmapManager bitmapManager = Owner.BitmapManager;
                var activeDocument = bitmapManager.ActiveDocument;
                if (activeDocument == null)
                    return;

                bitmapManager.InputTarget.OnLeftMouseButtonDown(activeDocument.MouseXOnCanvas, activeDocument.MouseYOnCanvas);
            }
        }

        private void OnMouseMove(object sender, EventArgs args)
        {
            var activeDocument = Owner.BitmapManager.ActiveDocument;
            if (activeDocument == null)
                return;
            Owner.BitmapManager.InputTarget.OnMouseMove(activeDocument.MouseXOnCanvas, activeDocument.MouseYOnCanvas);
        }

        private void OnMouseUp(object sender, MouseButton button)
        {
            if (Owner.BitmapManager.ActiveDocument == null)
                return;
            if (button == MouseButton.Left)
                Owner.BitmapManager.InputTarget.OnLeftMouseButtonUp();
        }
    }
}