PixiEditor/PixiEditor/Models/Tools/BitmapOperationTool.cs

using System;
using PixiEditor.Models.DataHolders;
using PixiEditor.Models.Layers;
using PixiEditor.Models.Position;
using PixiEditor.Models.Undo;
using SkiaSharp;
using System.Collections.Generic;
using PixiEditor.Models.Tools.ToolSettings.Settings;

namespace PixiEditor.Models.Tools
{
    public abstract class BitmapOperationTool : Tool
    {
        public bool RequiresPreviewLayer { get; set; }

        public bool ClearPreviewLayerOnEachIteration { get; set; } = true;

        public bool UseDefaultUndoMethod { get; set; } = true;

        public bool UseDocumentRectForUndo { get; set; } = false;

        private StorageBasedChange _change;

        public abstract void Use(Layer activeLayer, Layer previewLayer, IEnumerable<Layer> allLayers, IReadOnlyList<Coordinates> recordedMouseMovement, SKColor color);

        public override void BeforeUse()
        {
            if (UseDefaultUndoMethod && !RequiresPreviewLayer)
            {
                InitializeStorageBasedChange(SKRectI.Empty);
            }
        }

        /// <summary>
        /// Executes undo adding procedure.
        /// </summary>
        /// <remarks>When overriding, set UseDefaultUndoMethod to false.</remarks>
        public override void AfterUse(SKRectI sessionRect)
        {
            if (!UseDefaultUndoMethod)
                return;

            if (RequiresPreviewLayer)
            {
                InitializeStorageBasedChange(sessionRect);
            }

            var document = ViewModels.ViewModelMain.Current.BitmapManager.ActiveDocument;
            var args = new object[] { _change.Document };
            document.UndoManager.AddUndoChange(_change.ToChange(StorageBasedChange.BasicUndoProcess, args));
            _change = null;
        }

        private void InitializeStorageBasedChange(SKRectI toolSessionRect)
        {
            Document doc = ViewModels.ViewModelMain.Current.BitmapManager.ActiveDocument;
            var toolSize = Toolbar.GetSetting<SizeSetting>("ToolSize");
            SKRectI finalRect = toolSessionRect;
            if (toolSize != null)
            {
                int halfSize = (int)Math.Ceiling(toolSize.Value / 2f);
                finalRect.Inflate(halfSize, halfSize);
            }

            if (toolSessionRect.IsEmpty)
            {
                finalRect = SKRectI.Create(doc.ActiveLayer.OffsetX, doc.ActiveLayer.OffsetY, doc.ActiveLayer.Width, doc.ActiveLayer.Height);
            }

            if (UseDocumentRectForUndo)
            {
                finalRect = SKRectI.Create(0, 0, doc.Width, doc.Height);
            }

            _change = new StorageBasedChange(doc, new[] { new LayerChunk(doc.ActiveLayer, finalRect) });
        }
    }
}