Added layer removal

Paint_2/Form1.Designer.cs

@@ -67,12 +67,12 @@
             this.label1 = new System.Windows.Forms.Label();
             this.button2 = new System.Windows.Forms.Button();
             this.panel3 = new System.Windows.Forms.Panel();
+            this.pnlLayers = new System.Windows.Forms.Panel();
             this.btnLayerRemove = new System.Windows.Forms.Button();
             this.BtnAddLayer = new System.Windows.Forms.Button();
             this.label2 = new System.Windows.Forms.Label();
             this.button1 = new System.Windows.Forms.Button();
             this.DebugLabel = new System.Windows.Forms.Label();
-            this.pnlLayers = new System.Windows.Forms.Panel();
             ((System.ComponentModel.ISupportInitialize)(this.canvas)).BeginInit();
             this.panelFile.SuspendLayout();
             this.panelDrawing.SuspendLayout();
@@ -95,7 +95,7 @@
             this.tbxProjectName.Location = new System.Drawing.Point(11, 3);
             this.tbxProjectName.Margin = new System.Windows.Forms.Padding(2, 3, 2, 3);
             this.tbxProjectName.Name = "tbxProjectName";
-            this.tbxProjectName.Size = new System.Drawing.Size(253, 32);
+            this.tbxProjectName.Size = new System.Drawing.Size(253, 38);
             this.tbxProjectName.TabIndex = 0;
             this.tbxProjectName.Text = "Untitled Project";
             // 
@@ -146,7 +146,7 @@
             this.lblSelectedColor.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.lblSelectedColor.Location = new System.Drawing.Point(7, 28);
             this.lblSelectedColor.Name = "lblSelectedColor";
-            this.lblSelectedColor.Size = new System.Drawing.Size(234, 17);
+            this.lblSelectedColor.Size = new System.Drawing.Size(288, 20);
             this.lblSelectedColor.TabIndex = 1;
             this.lblSelectedColor.Text = "Hex:FFFFFF R:255 G:255 B:255";
             // 
@@ -194,7 +194,7 @@
             this.lblHeight.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.lblHeight.Location = new System.Drawing.Point(3, 40);
             this.lblHeight.Name = "lblHeight";
-            this.lblHeight.Size = new System.Drawing.Size(60, 17);
+            this.lblHeight.Size = new System.Drawing.Size(74, 20);
             this.lblHeight.TabIndex = 34;
             this.lblHeight.Text = "H:2000";
             // 
@@ -204,7 +204,7 @@
             this.lblWidth.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.lblWidth.Location = new System.Drawing.Point(3, 8);
             this.lblWidth.Name = "lblWidth";
-            this.lblWidth.Size = new System.Drawing.Size(64, 17);
+            this.lblWidth.Size = new System.Drawing.Size(77, 20);
             this.lblWidth.TabIndex = 33;
             this.lblWidth.Text = "W:2000";
             // 
@@ -239,7 +239,7 @@
             this.label14.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.label14.Location = new System.Drawing.Point(7, 6);
             this.label14.Name = "label14";
-            this.label14.Size = new System.Drawing.Size(120, 18);
+            this.label14.Size = new System.Drawing.Size(150, 22);
             this.label14.TabIndex = 29;
             this.label14.Text = "Selected color";
             // 
@@ -273,7 +273,7 @@
             this.lblHoveringColor.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.lblHoveringColor.Location = new System.Drawing.Point(8, 28);
             this.lblHoveringColor.Name = "lblHoveringColor";
-            this.lblHoveringColor.Size = new System.Drawing.Size(234, 17);
+            this.lblHoveringColor.Size = new System.Drawing.Size(288, 20);
             this.lblHoveringColor.TabIndex = 1;
             this.lblHoveringColor.Text = "Hex:FFFFFF R:255 G:255 B:255";
             // 
@@ -284,7 +284,7 @@
             this.label15.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.label15.Location = new System.Drawing.Point(8, 6);
             this.label15.Name = "label15";
-            this.label15.Size = new System.Drawing.Size(120, 18);
+            this.label15.Size = new System.Drawing.Size(150, 22);
             this.label15.TabIndex = 29;
             this.label15.Text = "Hovering color";
             // 
@@ -306,7 +306,7 @@
             0,
             0});
             this.nupPencilWidth.Name = "nupPencilWidth";
-            this.nupPencilWidth.Size = new System.Drawing.Size(71, 27);
+            this.nupPencilWidth.Size = new System.Drawing.Size(71, 33);
             this.nupPencilWidth.TabIndex = 17;
             this.nupPencilWidth.Value = new decimal(new int[] {
             10,
@@ -361,7 +361,7 @@
             this.label4.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.label4.Location = new System.Drawing.Point(7, 3);
             this.label4.Name = "label4";
-            this.label4.Size = new System.Drawing.Size(105, 16);
+            this.label4.Size = new System.Drawing.Size(135, 20);
             this.label4.TabIndex = 1;
             this.label4.Text = "Colors history";
             // 
@@ -496,10 +496,10 @@
             this.lsbTools.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
             this.lsbTools.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.lsbTools.FormattingEnabled = true;
-            this.lsbTools.ItemHeight = 17;
+            this.lsbTools.ItemHeight = 20;
             this.lsbTools.Location = new System.Drawing.Point(10, 33);
             this.lsbTools.Name = "lsbTools";
-            this.lsbTools.Size = new System.Drawing.Size(179, 121);
+            this.lsbTools.Size = new System.Drawing.Size(179, 102);
             this.lsbTools.TabIndex = 32;
             this.lsbTools.SelectedIndexChanged += new System.EventHandler(this.lsbTools_SelectedIndexChanged);
             // 
@@ -536,7 +536,7 @@
             this.label1.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
             this.label1.Location = new System.Drawing.Point(8, 10);
             this.label1.Name = "label1";
-            this.label1.Size = new System.Drawing.Size(84, 16);
+            this.label1.Size = new System.Drawing.Size(108, 20);
             this.label1.TabIndex = 36;
             this.label1.Text = "Paint tools";
             // 
@@ -569,10 +569,17 @@
             this.panel3.Size = new System.Drawing.Size(200, 175);
             this.panel3.TabIndex = 37;
             // 
+            // pnlLayers
+            // 
+            this.pnlLayers.AutoScroll = true;
+            this.pnlLayers.Location = new System.Drawing.Point(10, 10);
+            this.pnlLayers.Name = "pnlLayers";
+            this.pnlLayers.Size = new System.Drawing.Size(178, 121);
+            this.pnlLayers.TabIndex = 39;
+            // 
             // btnLayerRemove
             // 
             this.btnLayerRemove.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(59)))), ((int)(((byte)(59)))), ((int)(((byte)(59)))));
-            this.btnLayerRemove.Enabled = false;
             this.btnLayerRemove.FlatStyle = System.Windows.Forms.FlatStyle.Popup;
             this.btnLayerRemove.Font = new System.Drawing.Font("Cascadia Code", 10.2F);
             this.btnLayerRemove.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(247)))), ((int)(((byte)(247)))), ((int)(((byte)(247)))));
@@ -604,7 +611,7 @@
             this.label2.Font = new System.Drawing.Font("Cascadia Code", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
             this.label2.Location = new System.Drawing.Point(8, 10);
             this.label2.Name = "label2";
-            this.label2.Size = new System.Drawing.Size(0, 16);
+            this.label2.Size = new System.Drawing.Size(0, 20);
             this.label2.TabIndex = 36;
             // 
             // button1
@@ -626,21 +633,13 @@
             this.DebugLabel.AutoSize = true;
             this.DebugLabel.Location = new System.Drawing.Point(12, 555);
             this.DebugLabel.Name = "DebugLabel";
-            this.DebugLabel.Size = new System.Drawing.Size(54, 17);
+            this.DebugLabel.Size = new System.Drawing.Size(65, 20);
             this.DebugLabel.TabIndex = 38;
             this.DebugLabel.Text = "Debug";
             // 
-            // pnlLayers
-            // 
-            this.pnlLayers.AutoScroll = true;
-            this.pnlLayers.Location = new System.Drawing.Point(10, 10);
-            this.pnlLayers.Name = "pnlLayers";
-            this.pnlLayers.Size = new System.Drawing.Size(178, 121);
-            this.pnlLayers.TabIndex = 39;
-            // 
             // PaintForm
             // 
-            this.AutoScaleDimensions = new System.Drawing.SizeF(9F, 17F);
+            this.AutoScaleDimensions = new System.Drawing.SizeF(11F, 20F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
             this.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(34)))), ((int)(((byte)(34)))), ((int)(((byte)(34)))));
             this.ClientSize = new System.Drawing.Size(1132, 655);

Paint_2/Form1.cs

@@ -38,19 +38,19 @@ namespace Paint_2
         private Color _hoveringColor;
         private Project _project;
         private int _selectedLayer;
-        private List<int> _selectedLayers;
+        private List<string> _selectedLayers;
 
         public Color HoveringColor { get => _hoveringColor; set => _hoveringColor = value; }
         public Project Project { get => _project; set => _project = value; }
         public int SelectedLayer { get => _selectedLayer; set => _selectedLayer = value; }
-        public List<int> SelectedLayers { get => _selectedLayers; set => _selectedLayers = value; }
+        public List<string> SelectedLayers { get => _selectedLayers; set => _selectedLayers = value; }
 
         public PaintForm()
         {
             InitializeComponent();
             Project = new Project("Untitled project", canvas.Size);
-            SelectedLayers = new List<int>();
+            SelectedLayers = new List<string>();
-            SelectedLayers.Add(0);
+            SelectedLayers.Add(Project.GetAllLayers()[0].Id);
             RefreshUi();
         }
         private Point MousePositionToCanvasPosition()
@@ -62,7 +62,7 @@ namespace Paint_2
             Color hoveringColor = GetHoverColor();
             Point mousePosition = MousePositionToCanvasPosition();
             int toolWidth = (int)nupPencilWidth.Value;
-            Project.MouseDown(SelectedLayers,hoveringColor, mousePosition, toolWidth);
+            Project.MouseDown(SelectedLayers, hoveringColor, mousePosition, toolWidth);
             RefreshUi();
         }
         private void canvas_MouseUp(object sender, MouseEventArgs e)
@@ -102,10 +102,8 @@ namespace Paint_2
         private void RefreshUi()
         {
             lsbTools.DataSource = Project.AvaibleTools;
-            //DebugLabel.Text = Project.PrintAllLayers();
             DebugLabel.Text = "";
 
-            //canvas.Image = Project.PaintAllLayers();
             canvas.Image = Project.PaintLayers();
 
             lblSelectedColor.Text = ColorToString(Project.GetCurrentToolColor(SelectedLayers));
@@ -243,23 +241,30 @@ namespace Paint_2
 
         private void PaintForm_Load(object sender, EventArgs e)
         {
-            //lsbTools.DataSource = Project.AvaibleTools;
-            //lsbLayers.DataSource = Project.Layers;
-
-            //lsbLayers.DataSource = Project.Layers[0].ToolList;
             tmrRefresh.Enabled = true;
             DisplayLayers();
         }
 
         private void btnLayerRemove_Click(object sender, EventArgs e)
         {
-            //Project.RemoveLayer(lsbLayers.SelectedIndex);
+            int layersCount = SelectedLayers.Count;
-            //foreach (int id in SelectedLayers)
+            List<String> LayersToRemove = new List<string>();
-            for(int id = 0;id < SelectedLayers.Count;id++)
+            foreach (string layer in SelectedLayers)
             {
-                SelectedLayers.Remove(id);
+                LayersToRemove.Add(layer);
-                Project.RemoveLayer(id);
             }
+            for (int id = layersCount -1; id >= 0; id--)
+            {
+                if (Project.RemoveLayer(LayersToRemove[id]))
+                {
+                    SelectedLayers.RemoveAt(id);
+                }
+                else
+                {
+                    Console.WriteLine("Could not delete the layer");
+                } 
+            }
+            
             DisplayLayers();
             RefreshUi();
         }
@@ -275,17 +280,19 @@ namespace Paint_2
         {
             int Yoffset = 25;
             int Xoffset = 10;
-            
+
             int blocsCount = 1;
             int btnWidth = 75;
             int labelWidth = 70;
             int BtnXoffset = labelWidth;
-            int ChkXOffset = BtnXoffset + btnWidth + Xoffset /2;
+            int ChkXOffset = BtnXoffset + btnWidth + Xoffset / 2;
             int ChkWidth = 20;
 
             pnlLayers.Controls.Clear();
 
-            foreach (Sketch layer in Project.Layers)
+            List<Sketch> layers = Project.GetAllLayers();
+
+            foreach (Sketch layer in layers)
             {
                 Label name = new Label();
                 name.AutoSize = false;
@@ -293,12 +300,12 @@ namespace Paint_2
                 name.Text = layer.Name;
                 name.BackColor = Color.Transparent;
                 pnlLayers.Controls.Add(name);
-                name.Location = new Point(0,blocsCount * Yoffset);
+                name.Location = new Point(0, blocsCount * Yoffset);
 
                 Button btn = new Button();
-                btn.Name = (blocsCount - 1).ToString();
+                btn.Name = "ChkLayerVisible:" + layer.Id;
                 btn.Click += LayerSelection;
-                if (Project.LayersToPrint.Contains(Convert.ToInt32(btn.Name)))
+                if (Project.LayersToPrint.Contains(layer.Id))
                 {
                     btn.Text = "Visible";
                 }
@@ -308,13 +315,13 @@ namespace Paint_2
                 }
                 pnlLayers.Controls.Add(btn);
                 btn.BackColor = Color.FromArgb(59, 59, 59);
-                btn.Location = new Point(BtnXoffset,blocsCount * Yoffset);
+                btn.Location = new Point(BtnXoffset, blocsCount * Yoffset);
                 btn.Width = btnWidth;
                 btn.FlatStyle = FlatStyle.Popup;
 
                 Button chk = new Button();
                 chk.Click += LayerCheck;
-                if (SelectedLayers.Contains(blocsCount-1))
+                if (SelectedLayers.Contains(layer.Id))
                 {
                     chk.BackColor = Color.Green;
                 }
@@ -328,7 +335,7 @@ namespace Paint_2
                 chk.Text = "";
                 chk.FlatStyle = FlatStyle.Popup;
                 chk.Width = ChkWidth;
-                chk.Name = "C" + (blocsCount -1).ToString();
+                chk.Name = "ChkLayerSelected:" + layer.Id;
 
                 blocsCount++;
             }
@@ -337,17 +344,19 @@ namespace Paint_2
         {
             //We assume that the id of the layer is the name of the button
             Button btn = sender as Button;
-            int id = Convert.ToInt32(btn.Name);
+            string rawId = btn.Name;
+            string id = rawId.Replace("ChkLayerVisible:", String.Empty);
             Project.SwitchLayer(id);
             DisplayLayers();
         }
         private void LayerCheck(object sender, EventArgs e)
         {
-            //We assume that the id of the layer is the name with the 'c' removed
+            // We should receive "CheckBox:937r9837r893"
             Button btn = sender as Button;
-            string cleanedName = btn.Name.Remove(0,1);
+            //MessageBox.Show("Btn " + btn.Name + " pressed");
-            int id = Convert.ToInt32(cleanedName);
+            string rawId = btn.Name;
-            //MessageBox.Show("Select or Deslect layer "+id);
+            string id = rawId.Replace("ChkLayerSelected:", String.Empty);
+            //MessageBox.Show("Select or Deslect layer n:"+id);
             if (SelectedLayers.Contains(id))
             {
                 SelectedLayers.Remove(id);

Paint_2/Project.cs

@@ -15,8 +15,8 @@ namespace Paint_2
         const int DEFAULT_WIDTH = 0;
 
         private List<PaintTool> _avaibleTools;
-        private List<int> _selectedLayers;
+        private List<string> _selectedLayers;
-        //private Sketch _currentSketch;
+        private Guid uniqIdGenerator;
         private List<Sketch> _layers;
         private bool _eyedropping;
         private bool _randomColor;
@@ -34,7 +34,7 @@ namespace Paint_2
         public Random Random { get => _random; set => _random = value; }
         public bool Drawing { get => _drawing; set => _drawing = value; }
         public string Name { get => _name; set => _name = value; }
-        public List<int> LayersToPrint { get => _selectedLayers; set => _selectedLayers = value; }
+        public List<string> LayersToPrint { get => _selectedLayers; set => _selectedLayers = value; }
 
         public Project(string name, Size canvasSize)
         {
@@ -47,11 +47,12 @@ namespace Paint_2
             AvaibleTools.Add(new DotPencil("Dotted Line"));
             AvaibleTools.Add(new BezierPencil("Bezier Generator"));
             //We create a single first layer with the default toolSet
+            
             Layers = new List<Sketch>();
+            LayersToPrint = new List<string>();
+
             AddLayer();
-            //CurrentLayer = Layers[0];
+            LayersToPrint.Add(Layers[0].Id);
-            LayersToPrint = new List<int>();
-            LayersToPrint.Add(0);
         }
         public void AddLayer()
         {
@@ -60,28 +61,53 @@ namespace Paint_2
             {
                 newTools.Add((PaintTool)tool.Clone());
             }
-            Layers.Add(new Sketch(String.Concat("Layer", Layers.Count + 1), CanvasSize, newTools));
+            uniqIdGenerator = Guid.NewGuid();
+            string test = uniqIdGenerator.ToString();
+            Layers.Add(new Sketch(String.Concat("Layer", Layers.Count + 1), CanvasSize, newTools, uniqIdGenerator.ToString()));
         }
-        public void RemoveLayer(int layerId)
+        public bool RemoveLayer(string layerId)
         {
-            if (layerId >= 0 && layerId < Layers.Count)
+            Sketch layer = FindSketch(Layers, layerId);
+            if (layer != null)
             {
-                Layers.RemoveAt(layerId);
+                Layers.Remove(layer);
+                return true;
+            }
+            else
+            {
+                return false;
             }
         }
-        /*
+        public Sketch FindSketch(List<Sketch> layers, string id)
-        public void ChangeLayer(int idLayer)
         {
-            CurrentLayer = Layers[idLayer];
+            foreach (Sketch layer in layers)
+            {
+                if (layer.Id == id)
+                {
+                    return layer;
+                }
+            }
+            return null;
+        }
+        public bool IsSketchPresent (List<string> layers, string id)
+        {
+            foreach (string layer in layers)
+            {
+                if (layer == id)
+                {
+                    return true;
+                }
+            }
+            return false;
         }
-        */
         public List<Sketch> GetAllLayers()
         {
             return Layers;
         }
-        public void SwitchLayer(int idLayer)
+        public void SwitchLayer(string idLayer)
         {
-            if (LayersToPrint.Contains(idLayer))
+            bool present = IsSketchPresent(LayersToPrint,idLayer);
+            if (present)
             {
                 LayersToPrint.Remove(idLayer);
             }
@@ -90,18 +116,19 @@ namespace Paint_2
                 LayersToPrint.Add(idLayer);
             }
         }
-        public void MouseDown(List<int> selectedLayers, Color hoveringColor, Point mousePosition, int toolWidth)
+        public void MouseDown(List<string> selectedLayers, Color hoveringColor, Point mousePosition, int toolWidth)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
                     if (Eyedropping)
                     {
                         Color pointedColor = hoveringColor;
-                        if (Layers[layer].CurrentTool.Color != pointedColor)
+                        if (layer.CurrentTool.Color != pointedColor)
                         {
-                            Layers[layer].ChangePaintToolColor(pointedColor);
+                            layer.ChangePaintToolColor(pointedColor);
                         }
                     }
                     else
@@ -109,73 +136,78 @@ namespace Paint_2
                         Drawing = true;
                         if (RandomColor)
                         {
-                            Layers[layer].StartDrawing(mousePosition, Color.FromArgb(Random.Next(0, 256), Random.Next(0, 256), Random.Next(0, 256)), toolWidth);
+                            layer.StartDrawing(mousePosition, Color.FromArgb(Random.Next(0, 256), Random.Next(0, 256), Random.Next(0, 256)), toolWidth);
                         }
                         else
                         {
-                            Layers[layer].StartDrawing(mousePosition, Layers[layer].CurrentTool.Color, toolWidth);
+                            layer.StartDrawing(mousePosition, layer.CurrentTool.Color, toolWidth);
                         }
                     }
+
                 }
             }
-
         }
-        public void MouseUp(List<int> selectedLayers, Point mousePosition)
+        public void MouseUp(List<string> selectedLayers, Point mousePosition)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
                     if (!Eyedropping)
                     {
-                        Layers[layer].AddDrawingPoint(mousePosition);
+                        layer.AddDrawingPoint(mousePosition);
                         Drawing = false;
-                        Layers[layer].StopDrawing();
+                        layer.StopDrawing();
                     }
                 }
             }
         }
-        public void TimerTick(List<int> selectedLayers, Point mousePosition)
+        public void TimerTick(List<string> selectedLayers, Point mousePosition)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
                     if (Drawing)
                     {
-                        Layers[layer].AddDrawingPoint(mousePosition);
+                        layer.AddDrawingPoint(mousePosition);
                     }
                 }
             }
 
         }
-        public void ChangeColor(List<int> selectedLayers, Color newColor)
+        public void ChangeColor(List<string> selectedLayers, Color newColor)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
-                    Layers[layer].ChangePaintToolColor(newColor);
+                    layer.ChangePaintToolColor(newColor);
                 }
             }
         }
-        public void ChangeWidth(List<int> selectedLayers, int width)
+        public void ChangeWidth(List<string> selectedLayers, int width)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
-                    Layers[layer].ChangePaintToolWidth(width);
+                    layer.ChangePaintToolWidth(width);
                 }
             }
         }
-        public void ChangeTool(List<int> selectedLayers, int toolId)
+        public void ChangeTool(List<string> selectedLayers, int toolId)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
-                    Layers[layer].ChangeTool(toolId);
+                    layer.ChangeTool(toolId);
                 }
             }
         }
@@ -193,11 +225,12 @@ namespace Paint_2
         {
             Bitmap result = new Bitmap(CanvasSize.Width, CanvasSize.Height);
             Graphics gr = Graphics.FromImage(result);
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string layerId in LayersToPrint)
             {
-                if (LayersToPrint.Contains(layer))
+                Sketch layer = FindSketch(Layers, layerId);
+                if (layer != null)
                 {
-                    gr.DrawImage(Layers[layer].ForcePaint(), Point.Empty);
+                    gr.DrawImage(layer.ForcePaint(), Point.Empty);
                 }
             }
             return result;
@@ -216,11 +249,12 @@ namespace Paint_2
         {
             Bitmap result = new Bitmap(CanvasSize.Width, CanvasSize.Height);
             Graphics gr = Graphics.FromImage(result);
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string layerId in LayersToPrint)
-            {   
+            {
-                if (LayersToPrint.Contains(layer))
+                Sketch layer = FindSketch(Layers, layerId);
+                if (layer != null)
                 {
-                    gr.DrawImage(Layers[layer].Paint(), Point.Empty);
+                    gr.DrawImage(layer.Paint(), Point.Empty);
                 }
             }
             return result;
@@ -232,37 +266,40 @@ namespace Paint_2
                 layer.Clear();
             }
         }
-        public Color GetCurrentToolColor(List<int> selectedLayers)
+        public Color GetCurrentToolColor(List<string> selectedLayers)
         {
-            if(selectedLayers.Count == 0)
+            if (Layers.Count == 0 || selectedLayers.Count == 0)
             {
                 return DEFAULT_COLOR;
             }
-            Sketch CurrentLayer = Layers[selectedLayers[0]];
+            else
-            return CurrentLayer.CurrentTool.Color;
+            {
+                //Sketch CurrentLayer = Layers[selectedLayers[0];
+                Sketch CurrentLayer = FindSketch(Layers,selectedLayers[0]);
+                return CurrentLayer.CurrentTool.Color;
+            }
         }
-        public int GetCurrentToolWidth(List<int> selectedLayers)
+        public int GetCurrentToolWidth(List<string> selectedLayers)
         {
             if (selectedLayers.Count == 0)
             {
                 return DEFAULT_WIDTH;
             }
-            Sketch CurrentLayer = Layers[selectedLayers[0]];
+            Sketch CurrentLayer = FindSketch(Layers, selectedLayers[0]);
             return CurrentLayer.CurrentTool.Width;
         }
-        public List<Color> GetLayerColorHistory(List<int> selectedLayers,int colorsCount)
+        public List<Color> GetLayerColorHistory(List<string> selectedLayers, int colorsCount)
         {
-            if(selectedLayers.Count == 0)
+            if (selectedLayers.Count == 0)
             {
                 List<Color> result = new List<Color>();
-                for (int i = 0;i < colorsCount;i++)
+                for (int i = 0; i < colorsCount; i++)
                 {
                     result.Add(DEFAULT_COLOR);
                 }
                 return result;
             }
-            
+            Sketch CurrentLayer = FindSketch(Layers, selectedLayers[0]);
-            Sketch CurrentLayer = Layers[selectedLayers[0]];
             return CurrentLayer.CurrentTool.GetLastColors(colorsCount);
         }
         public void Save(string fileName, Bitmap image)
@@ -310,23 +347,25 @@ namespace Paint_2
         {
             Eyedropping = !Eyedropping;
         }
-        public void Undo(List<int> selectedLayers)
+        public void Undo(List<string> selectedLayers)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
-                    Layers[layer].Undo();
+                    layer.Undo();
                 }
-            }  
+            }
         }
-        public void Redo(List<int> selectedLayers)
+        public void Redo(List<string> selectedLayers)
         {
-            for (int layer = 0; layer < Layers.Count; layer++)
+            foreach (string id in selectedLayers)
             {
-                if (selectedLayers.Contains(layer))
+                Sketch layer = FindSketch(Layers, id);
+                if (layer != null)
                 {
-                    Layers[layer].Redo();
+                    layer.Redo();
                 }
             }
         }

Paint_2/Sketch.cs

@@ -20,6 +20,7 @@ namespace Paint_2
         bool _isDrawing;
         Bitmap _drawing;
         Size _sketchSize;
+        string id;
         string _name;
         internal List<PaintTool> ToolList { get => _toolList; set => _toolList = value; }
         public PaintTool CurrentTool { get => _currentTool; set => _currentTool = value; }
@@ -27,10 +28,12 @@ namespace Paint_2
         public Bitmap Drawing { get => _drawing; set => _drawing = value; }
         public Size SketchSize { get => _sketchSize; set => _sketchSize = value; }
         public string Name { get => _name; set => _name = value; }
+        public string Id { get => id; set => id = value; }
 
-        public Sketch(string name,Size sketchSize, List<PaintTool> toolList)
+        public Sketch(string name,Size sketchSize, List<PaintTool> toolList,string guid)
         {
             IsDrawing = false;
+            Id = guid;
             Name = name;
             SketchSize = sketchSize;
             Drawing = new Bitmap(SketchSize.Width, SketchSize.Height);
@@ -49,7 +52,7 @@ namespace Paint_2
                 CurrentTool = null;
             }
         }
-        public Sketch(List<PaintTool> toolList) : this("Layer 1",new Size(500, 500), toolList)
+        public Sketch(List<PaintTool> toolList,string guid) : this("Layer 1",new Size(500, 500), toolList,guid)
         {
             //empty
         }