Added DocumentViewModelBuilder

src/PixiEditor/Helpers/DocumentViewModelBuilder.cs

@@ -0,0 +1,239 @@
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using ChunkyImageLib;
+using ChunkyImageLib.DataHolders;
+using PixiEditor.ChangeableDocument.Enums;
+using PixiEditor.ViewModels.SubViewModels.Document;
+
+namespace PixiEditor.Helpers;
+
+internal class DocumentViewModelBuilder : ChildrenBuilder
+{
+    public int Width { get; set; }
+
+    public int Height { get; set; }
+
+    public DocumentViewModelBuilder WithSize(int width, int height)
+    {
+        Width = width;
+        Height = height;
+
+        return this;
+    }
+
+    public abstract class StructureMemberBuilder
+    {
+        private MaskBuilder maskBuilder;
+        
+        public string Name { get; set; }
+        
+        public bool IsVisible { get; set; }
+        
+        public float Opacity { get; set; }
+        
+        public BlendMode BlendMode { get; set; }
+
+        public bool HasMask => maskBuilder is not null;
+
+        [NotNull]
+        public MaskBuilder Mask => maskBuilder ??= new MaskBuilder();
+
+        public Guid GuidValue { get; set; }
+        
+        public StructureMemberBuilder WithName(string name)
+        {
+            Name = name;
+            return this;
+        }
+        
+        public StructureMemberBuilder WithVisibility(bool visibility)
+        {
+            IsVisible = visibility;
+            return this;
+        }
+        
+        public StructureMemberBuilder WithOpacity(float opacity)
+        {
+            Opacity = opacity;
+            return this;
+        }
+        
+        public StructureMemberBuilder WithBlendMode(BlendMode blendMode)
+        {
+            BlendMode = blendMode;
+            return this;
+        }
+        
+        public StructureMemberBuilder WithMask(Action<MaskBuilder> mask)
+        {
+            mask(Mask);
+            return this;
+        }
+        
+        public StructureMemberBuilder WithGuid(Guid guid)
+        {
+            GuidValue = guid;
+            return this;
+        }
+    }
+
+    public class LayerBuilder : StructureMemberBuilder
+    {
+        private int? width;
+        private int? height;
+        
+        public SurfaceBuilder Surface { get; set; }
+
+        public int Width
+        {
+            get => width ?? default;
+            set => width = value;
+        }
+
+        public int Height
+        {
+            get => height ?? default;
+            set => height = value;
+        }
+        
+        public int OffsetX { get; set; }
+        
+        public int OffsetY { get; set; }
+        
+        public new LayerBuilder WithName(string name) => base.WithName(name) as LayerBuilder;
+        
+        public new LayerBuilder WithVisibility(bool visibility) => base.WithVisibility(visibility) as LayerBuilder;
+        
+        public new LayerBuilder WithOpacity(float opacity) => base.WithOpacity(opacity) as LayerBuilder;
+        
+        public new LayerBuilder WithBlendMode(BlendMode blendMode) => base.WithBlendMode(blendMode) as LayerBuilder;
+        
+        public new LayerBuilder WithMask(Action<MaskBuilder> mask) => base.WithMask(mask) as LayerBuilder;
+        
+        public new LayerBuilder WithGuid(Guid guid) => base.WithGuid(guid) as LayerBuilder;
+        
+        public LayerBuilder WithSurface(Surface surface)
+        {
+            Surface = new(surface);
+            return this;
+        }
+
+        public LayerBuilder WithSize(int width, int height)
+        {
+            Width = width;
+            Height = height;
+            return this;
+        }
+        
+        public LayerBuilder WithRect(int width, int height, int offsetX, int offsetY)
+        {
+            Width = width;
+            Height = height;
+            OffsetX = offsetX;
+            OffsetY = offsetY;
+            return this;
+        }
+        
+        public LayerBuilder WithSurface(Action<SurfaceBuilder> surface)
+        {
+            if (width is null || height is null)
+            {
+                throw new InvalidOperationException("You must first set the width and height of the layer. You can do this by calling WithRect() or setting the Width and Height properties.");
+            }
+            
+            var surfaceBuilder = new SurfaceBuilder(new Surface(new VecI(Width, Height)));
+            surface(surfaceBuilder);
+            Surface = surfaceBuilder;
+            return this;
+        }
+    }
+
+    public class FolderBuilder : StructureMemberBuilder
+    {
+        public IEnumerable<StructureMemberBuilder> Children { get; set; }
+
+        public new FolderBuilder WithName(string name) => base.WithName(name) as FolderBuilder;
+        
+        public new FolderBuilder WithVisibility(bool visibility) => base.WithVisibility(visibility) as FolderBuilder;
+        
+        public new FolderBuilder WithOpacity(float opacity) => base.WithOpacity(opacity) as FolderBuilder;
+        
+        public new FolderBuilder WithBlendMode(BlendMode blendMode) => base.WithBlendMode(blendMode) as FolderBuilder;
+        
+        public new FolderBuilder WithMask(Action<MaskBuilder> mask) => base.WithMask(mask) as FolderBuilder;
+        
+        public new FolderBuilder WithGuid(Guid guid) => base.WithGuid(guid) as FolderBuilder;
+        
+        public FolderBuilder WithChildren(Action<ChildrenBuilder> children)
+        {
+            return this;
+        }
+    }
+
+    public class SurfaceBuilder
+    {
+        public Surface Surface { get; set; }
+
+        public SurfaceBuilder(Surface surface)
+        {
+            Surface = surface;
+        }
+
+        public SurfaceBuilder WithImage(ReadOnlySpan<byte> buffer) => WithImage(buffer, 0, 0);
+        
+        public SurfaceBuilder WithImage(ReadOnlySpan<byte> buffer, int x, int y)
+        {
+            Surface.SkiaSurface.Canvas.DrawBitmap(SKBitmap.Decode(buffer), 0, 0);
+            return this;
+        }
+    }
+
+    public class MaskBuilder
+    {
+        public bool IsVisible { get; set; }
+        
+        public SurfaceBuilder Surface { get; set; }
+        
+        public MaskBuilder WithVisibility(bool isVisible)
+        {
+            IsVisible = isVisible;
+            return this;
+        }
+        
+        public MaskBuilder WithSurface(Surface surface)
+        {
+            Surface = new SurfaceBuilder(surface);
+            return this;
+        }
+        
+        public MaskBuilder WithSurface(int width, int height, Action<SurfaceBuilder> surface)
+        {
+            var surfaceBuilder = new SurfaceBuilder(new Surface(new VecI(width, height)));
+            surface(surfaceBuilder);
+            Surface = surfaceBuilder;
+            return this;
+        }
+    }
+    
+}
+
+internal class ChildrenBuilder
+{
+    public ICollection<DocumentViewModelBuilder.StructureMemberBuilder> Children { get; set; } = new List<DocumentViewModelBuilder.StructureMemberBuilder>();
+        
+    public ChildrenBuilder WithLayer(Action<DocumentViewModelBuilder.LayerBuilder> layer)
+    {
+        var layerBuilder = new DocumentViewModelBuilder.LayerBuilder();
+        layer(layerBuilder);
+        Children.Add(layerBuilder);
+        return this;
+    }
+        
+    public ChildrenBuilder WithFolder(Action<DocumentViewModelBuilder.FolderBuilder> folder)
+    {
+        var folderBuilder = new DocumentViewModelBuilder.FolderBuilder();
+        folder(folderBuilder);
+        Children.Add(folderBuilder);
+        return this;
+    }
+}

src/PixiEditor/ViewModels/SubViewModels/Document/DocumentViewModel.cs

@@ -167,6 +167,78 @@ internal class DocumentViewModel : NotifyableObject
         PreviewSurface = SKSurface.Create(new SKImageInfo(previewSize.X, previewSize.Y, SKColorType.Bgra8888), PreviewBitmap.BackBuffer, PreviewBitmap.BackBufferStride);
     }
 
+    public static DocumentViewModel Build(Action<DocumentViewModelBuilder> builder)
+    {
+        var builderInstance = new DocumentViewModelBuilder();
+        builder(builderInstance);
+
+        var viewModel = new DocumentViewModel();
+        viewModel.Operations.ResizeCanvas(new VecI(builderInstance.Width, builderInstance.Height), ResizeAnchor.Center);
+
+        var acc = viewModel.Internals.ActionAccumulator;
+
+        AddMembers(viewModel.StructureRoot.GuidValue, builderInstance.Children);
+        
+        acc.AddFinishedActions(new DeleteRecordedChanges_Action());
+
+        return viewModel;
+
+        void AddMember(Guid parentGuid, DocumentViewModelBuilder.StructureMemberBuilder member)
+        {
+            acc.AddActions(
+                new CreateStructureMember_Action(parentGuid, member.GuidValue, 0, member is DocumentViewModelBuilder.LayerBuilder ? StructureMemberType.Layer : StructureMemberType.Folder),
+                new StructureMemberName_Action(member.GuidValue, member.Name)
+            );
+            
+            if (!member.IsVisible)
+                acc.AddActions(new StructureMemberIsVisible_Action(member.IsVisible, member.GuidValue));
+
+            if (member is DocumentViewModelBuilder.LayerBuilder layer)
+            {
+                PasteImage(member.GuidValue, layer.Surface, layer.Width, layer.Height, layer.OffsetX, layer.OffsetY, false);
+            }
+
+            if (member.HasMask)
+            {
+                var maskSurface = member.Mask.Surface.Surface;
+                
+                acc.AddActions(new CreateStructureMemberMask_Action(member.GuidValue));
+                
+                if (!member.Mask.IsVisible)
+                    acc.AddActions(new StructureMemberMaskIsVisible_Action(member.Mask.IsVisible, member.GuidValue));
+                
+                PasteImage(member.GuidValue, member.Mask.Surface, maskSurface.Size.X, maskSurface.Size.Y, 0, 0, true);
+            }
+            
+            acc.AddFinishedActions();
+            
+            if (member is DocumentViewModelBuilder.FolderBuilder { Children: not null } folder)
+            {
+                AddMembers(member.GuidValue, folder.Children);
+            }
+        }
+
+        void PasteImage(Guid guid, DocumentViewModelBuilder.SurfaceBuilder surface, int width, int height, int offsetX, int offsetY, bool onMask)
+        {
+            acc.AddActions(
+                new PasteImage_Action(surface.Surface, new(new RectD(new VecD(offsetX, offsetY), new(width, height))), guid, true, onMask),
+                new EndPasteImage_Action());
+        }
+
+        void AddMembers(Guid parentGuid, IEnumerable<DocumentViewModelBuilder.StructureMemberBuilder> builders)
+        {
+            foreach (var child in builders.Reverse())
+            {
+                if (child.GuidValue == default)
+                {
+                    child.GuidValue = Guid.NewGuid();
+                }
+
+                AddMember(parentGuid, child);
+            }
+        }
+    }
+
     public void MarkAsSaved()
     {
         lastChangeOnSave = Internals.Tracker.LastChangeGuid;