/src/LayerControl.cs

/////////////////////////////////////////////////////////////////////////////////

// Paint.NET                                                                   //

// Copyright (C) dotPDN LLC, Rick Brewster, Tom Jackson, and contributors.     //

// Portions Copyright (C) Microsoft Corporation. All Rights Reserved.          //

// See src/Resources/Files/License.txt for full licensing and attribution      //

// details.                                                                    //

// .                                                                           //

/////////////////////////////////////////////////////////////////////////////////



using System;

using System.Collections;

using System.Collections.Generic;

using System.ComponentModel;

using System.Drawing;

using System.Windows.Forms;

using System.Diagnostics;



namespace PaintDotNet

{

    internal class LayerControl 

        : UserControl

    {

        private class PanelWithLayout

            : PanelEx

        {

            private LayerControl parentLayerControl;

            public LayerControl ParentLayerControl

            {

                get

                {

                    return this.parentLayerControl;

                }



                set

                {

                    this.parentLayerControl = value;

                }

            }



            public PanelWithLayout()

            {

                this.HideHScroll = true;

            }



            public void PositionLayers()

            {

                if (this.parentLayerControl != null &&

                    this.parentLayerControl.layerControls != null)

                {

                    int cursor = this.AutoScrollPosition.Y;

                    int newWidth = this.ClientRectangle.Width;



                    for (int i = this.parentLayerControl.layerControls.Count - 1; i >= 0; --i)

                    {

                        LayerElement lec = this.parentLayerControl.layerControls[i];

                        lec.Width = newWidth;

                        lec.Top = cursor;

                        cursor += lec.Height;

                    }

                }

            }



            protected override void OnResize(EventArgs eventargs)

            {

                SystemLayer.UI.SuspendControlPainting(this);

                PositionLayers();

                this.AutoScrollPosition = new Point(0, -this.AutoScrollOffset.Y);

                base.OnResize(eventargs);

                SystemLayer.UI.ResumeControlPainting(this);

                Invalidate(true);

            }



            protected override void OnLayout(LayoutEventArgs levent)

            {

                PositionLayers();

                base.OnLayout(levent);

            }

        }



        public void PositionLayers()

        {

            this.layerControlPanel.PositionLayers();

        }



        private EventHandler elementClickDelegate;

        private EventHandler elementDoubleClickDelegate;

        private EventHandler documentChangedDelegate;

        private EventHandler<EventArgs<Document>> documentChangingDelegate;

        private EventHandler layerChangedDelegate;

        private KeyEventHandler keyUpDelegate;

        private IndexEventHandler layerInsertedDelegate;

        private IndexEventHandler layerRemovedDelegate;

        

        private int elementHeight;

        private int thumbnailSize;

        

        private AppWorkspace appWorkspace;

        private Document document;



        private List<LayerElement> layerControls;

        private PanelWithLayout layerControlPanel;



        private ThumbnailManager thumbnailManager;



        [Browsable(false)]

        public LayerElement[] Layers

        {

            get

            {

                if (layerControls == null)

                {

                    return new LayerElement[0];

                }

                else

                {

                    return this.layerControls.ToArray();

                }

            }

        }



        public Layer ActiveLayer

        {

            get

            {

                int[] selected = SelectedLayerIndexes;



                if (selected.Length == 1)

                {

                    return this.Layers[selected[0]].Layer;

                }

                else

                {

                    return null;

                }

            }

        }



        public int ActiveLayerIndex

        {

            get

            {

                int[] selected = SelectedLayerIndexes;



                if (selected.Length == 1)

                {

                    return selected[0];

                }

                else

                {

                    return -1;

                }

            }

        }



        private int[] SelectedLayerIndexes

        {

            get

            {

                LayerElement[] layers = this.Layers;

                List<int> layerIndexes = new List<int>();



                for (int i = 0; i < layers.Length; ++i)

                {

                    if (layers[i].IsSelected)

                    {

                        layerIndexes.Add(i);

                    }

                }



                return layerIndexes.ToArray();

            }

        }



        public void ClearLayerSelection()

        {

            LayerElement[] layers = this.Layers;



            for (int i = 0; i < layers.Length; ++i)

            {

                layers[i].IsSelected = false;

            }

        }



        public new BorderStyle BorderStyle

        {

            get

            {

                return layerControlPanel.BorderStyle;

            }



            set

            {

                layerControlPanel.BorderStyle = value;

            }

        }



        /// <summary> 

        /// Required designer variable.

        /// </summary>

        private System.ComponentModel.Container components = null;



        public LayerControl()

        {

            this.elementHeight = 6 + SystemLayer.UI.ScaleWidth(LayerElement.ThumbSizePreScaling);



            // This call is required by the Windows.Forms Form Designer.

            InitializeComponent();



            elementClickDelegate = new EventHandler(ElementClickHandler);

            elementDoubleClickDelegate = new EventHandler(ElementDoubleClickHandler);

            documentChangedDelegate = new EventHandler(DocumentChangedHandler);

            documentChangingDelegate = DocumentChangingHandler;

            layerInsertedDelegate = new IndexEventHandler(LayerInsertedHandler);

            layerRemovedDelegate = new IndexEventHandler(LayerRemovedHandler);

            layerChangedDelegate = new EventHandler(LayerChangedHandler);

            keyUpDelegate = new KeyEventHandler(KeyUpHandler);



            this.thumbnailManager = new ThumbnailManager(this);

            this.thumbnailSize = SystemLayer.UI.ScaleWidth(LayerElement.ThumbSizePreScaling);

            layerControls = new List<LayerElement>();

        }



        private void SetupNewDocument(Document newDocument)

        {

            //this.thumbnailManager.ClearQueue();



            // Subscribe to the eevents

            this.document = newDocument;

            this.document.Layers.Inserted += layerInsertedDelegate;

            this.document.Layers.RemovedAt += layerRemovedDelegate;



            SystemLayer.UI.SuspendControlPainting(this.layerControlPanel);



            for (int i = 0; i < this.document.Layers.Count; ++i)

            {

                this.LayerInsertedHandler(this, new IndexEventArgs(i));

            }



            if (this.appWorkspace != null)

            {

                foreach (LayerElement lec in layerControls)

                {

                    if (lec.Layer == appWorkspace.ActiveDocumentWorkspace.ActiveLayer)

                    {

                        lec.IsSelected = true;

                    }

                    else

                    {

                        lec.IsSelected = false;

                    }

                }

            }



            SystemLayer.UI.ResumeControlPainting(this.layerControlPanel);

            this.layerControlPanel.Invalidate(true);



            OnActiveLayerChanged(ActiveLayer);

        }



        private void TearDownOldDocument()

        {

            SuspendLayout();



            foreach (LayerElement lec in this.layerControls)

            {

                lec.Click -= elementClickDelegate;

                lec.DoubleClick -= elementDoubleClickDelegate;

                lec.KeyUp -= keyUpDelegate;

                lec.Layer = null;

                layerControlPanel.Controls.Remove(lec);

                lec.Dispose();

            }



            ResumeLayout(true);



            this.layerControls.Clear();



            //this.thumbnailManager.ClearQueue();



            // Unsubscribe to the Events

            if (this.document != null)

            {

                this.document.Layers.Inserted -= layerInsertedDelegate;

                this.document.Layers.RemovedAt -= layerRemovedDelegate;

                this.document = null;

            }

        }

        

        private void DocumentChangingHandler(object sender, EventArgs<Document> e)

        {

            TearDownOldDocument();

        }



        private void DocumentChangedHandler(object sender, EventArgs e)

        {

            SetupNewDocument(appWorkspace.ActiveDocumentWorkspace.Document);

        }



        private void LayerRemovedHandler(object sender, IndexEventArgs e)

        {

            LayerElement lec = layerControls[e.Index];

            this.thumbnailManager.RemoveFromQueue(lec.Layer);

            lec.Click -= this.elementClickDelegate;

            lec.DoubleClick -= this.elementDoubleClickDelegate;

            lec.KeyUp -= keyUpDelegate;

            lec.Layer = null;

            layerControls.Remove(lec);

            layerControlPanel.Controls.Remove(lec);

            lec.Dispose();

            PerformLayout();

        }



        private void InitializeLayerElement(LayerElement lec, Layer l)

        {

            lec.Height = elementHeight;

            lec.Layer = l;

            lec.Click += elementClickDelegate;

            lec.DoubleClick += elementDoubleClickDelegate;

            lec.KeyUp += keyUpDelegate;

            lec.IsSelected = false;

        }



        private void SetActive(LayerElement lec)

        {

            SetActive(lec.Layer);

        }



        private void SetActive(Layer layer)

        {

            foreach (LayerElement lec in layerControls)

            {

                bool active = (lec.Layer == layer);

                lec.IsSelected = active;



                if (active)

                {

                    OnActiveLayerChanged(lec.Layer);

                    layerControlPanel.ScrollControlIntoView(lec);

                    lec.Select();

                    Update();

                }

            }

        }



        private void LayerInsertedHandler(object sender, IndexEventArgs e)

        {

            this.SuspendLayout();

            this.layerControlPanel.SuspendLayout();

            Layer layer = (Layer)this.document.Layers[e.Index];

            LayerElement lec = new LayerElement();

            lec.ThumbnailManager = this.thumbnailManager;

            lec.ThumbnailSize = this.thumbnailSize;

            InitializeLayerElement(lec, layer);

            layerControls.Insert(e.Index, lec);

            layerControlPanel.Controls.Add(lec);

            layerControlPanel.ScrollControlIntoView(lec);

            lec.Select();

            SetActive(lec);

            lec.RefreshPreview();

            this.layerControlPanel.ResumeLayout(false);

            this.ResumeLayout(false);

            this.layerControlPanel.PerformLayout();

            PerformLayout();



            Refresh();

        }



        public void RefreshPreviews()

        {

            for (int i = 0; i < this.layerControls.Count; ++i)

            {

                this.layerControls[i].RefreshPreview();

            }

        }



        public event EventHandler RelinquishFocus;

        protected void OnRelinquishFocus()

        {

            if (RelinquishFocus != null)

            {

                RelinquishFocus(this, EventArgs.Empty);

            }

        }



        protected override void OnClick(EventArgs e)

        {

            OnRelinquishFocus();

            base.OnClick(e);

        }



        /// <summary>

        /// This event is raised whenever the user clicks on a layer within the

        /// LayerControl to activate it.

        /// </summary>

        public event EventHandler<EventArgs<Layer>> ClickedOnLayer;

        private void OnClickedOnLayer(Layer layer)

        {

            if (ClickedOnLayer != null)

            {

                ClickedOnLayer(this, new EventArgs<Layer>(layer));

            }

        }



        /// <summary>

        /// This event is raised whenever the selected layer is changed. Note that

        /// this can occur without user intervention, which distinguishes this event

        /// from ClickedOnLayer.

        /// </summary>

        public event EventHandler<EventArgs<Layer>> ActiveLayerChanged;

        private void OnActiveLayerChanged(Layer layer)

        {

            if (ActiveLayerChanged != null)

            {

                ActiveLayerChanged(this, new EventArgs<Layer>(layer));

            }

        }



        public event EventHandler<EventArgs<Layer>> DoubleClickedOnLayer;

        private void OnDoubleClickedOnLayer(Layer layer)

        {

            if (DoubleClickedOnLayer != null)

            {

                DoubleClickedOnLayer(this, new EventArgs<Layer>(layer));

            }

        }



        private void ElementClickHandler(object sender, EventArgs e)

        {

            LayerElement lec = (LayerElement)sender;



            if (Control.ModifierKeys == Keys.Control)

            {

                lec.IsSelected = !lec.IsSelected;

            }

            else

            {

                ClearLayerSelection();

                lec.IsSelected = true;

            }



            SetActive(lec);

            OnClickedOnLayer(lec.Layer);

        }



        private void ElementDoubleClickHandler(object sender, EventArgs e)

        {

            OnDoubleClickedOnLayer(((LayerElement)sender).Layer);

        }

    

        private void LayerChangedHandler(object sender, EventArgs e)

        {

            SetActive(appWorkspace.ActiveDocumentWorkspace.ActiveLayer);

        }



        public void SuspendLayerPreviewUpdates()

        {

            foreach (LayerElement element in this.layerControls)

            {

                element.SuspendPreviewUpdates();

            }

        }



        public void ResumeLayerPreviewUpdates()

        {

            foreach (LayerElement element in this.layerControls)

            {

                element.ResumePreviewUpdates();

            }

        }



        private void KeyUpHandler(object sender, KeyEventArgs e)

        {

            this.OnKeyUp(e);

        }

    

        [Browsable(false)]

        public AppWorkspace AppWorkspace

        {

            get

            {

                return this.appWorkspace;

            }



            set

            {

                if (this.appWorkspace != value)

                {

                    if (this.appWorkspace != null)

                    {

                        TearDownOldDocument();



                        this.appWorkspace.ActiveDocumentWorkspaceChanging -= Workspace_ActiveDocumentWorkspaceChanging;

                        this.appWorkspace.ActiveDocumentWorkspaceChanged -= Workspace_ActiveDocumentWorkspaceChanged;

                    }



                    this.appWorkspace = value;



                    if (this.appWorkspace != null)

                    {

                        this.appWorkspace.ActiveDocumentWorkspaceChanging += Workspace_ActiveDocumentWorkspaceChanging;

                        this.appWorkspace.ActiveDocumentWorkspaceChanged += Workspace_ActiveDocumentWorkspaceChanged;



                        if (this.appWorkspace.ActiveDocumentWorkspace != null)

                        {

                            SetupNewDocument(this.appWorkspace.ActiveDocumentWorkspace.Document);

                        }

                    }

                }

            }

        }



        private void Workspace_ActiveDocumentWorkspaceChanging(object sender, EventArgs e)

        {

            TearDownOldDocument();



            if (this.appWorkspace.ActiveDocumentWorkspace != null)

            {

                this.appWorkspace.ActiveDocumentWorkspace.DocumentChanging -= documentChangingDelegate;

                this.appWorkspace.ActiveDocumentWorkspace.DocumentChanged -= documentChangedDelegate;

                this.appWorkspace.ActiveDocumentWorkspace.ActiveLayerChanged -= layerChangedDelegate;

            }

        }



        private void Workspace_ActiveDocumentWorkspaceChanged(object sender, EventArgs e)

        {

            if (this.appWorkspace.ActiveDocumentWorkspace != null)

            {

                appWorkspace.ActiveDocumentWorkspace.DocumentChanging += documentChangingDelegate;

                appWorkspace.ActiveDocumentWorkspace.DocumentChanged += documentChangedDelegate;

                appWorkspace.ActiveDocumentWorkspace.ActiveLayerChanged += layerChangedDelegate;



                if (appWorkspace.ActiveDocumentWorkspace.Document != null)

                {

                    SetupNewDocument(appWorkspace.ActiveDocumentWorkspace.Document);

                }

            }

        }



        [Browsable(false)]

        public Document Document

        {

            get

            {

                return this.document;

            }



            set

            {

                if (this.appWorkspace != null)

                {

                    throw new InvalidOperationException("Workspace property is already set");

                }



                if (this.document != null)

                {

                    TearDownOldDocument();

                }



                if (value != null)

                {

                    SetupNewDocument(value);

                }

            }

        }

        

        /// <summary> 

        /// Clean up any resources being used.

        /// </summary>

        protected override void Dispose(bool disposing)

        {

            if (disposing)

            {

                if (components != null)

                {

                    components.Dispose();

                    components = null;

                }



                if (this.thumbnailManager != null)

                {

                    this.thumbnailManager.Dispose();

                    this.thumbnailManager = null;

                }

            }



            base.Dispose(disposing);

        }



        private void LayerControlPanel_Click(object sender, EventArgs e)

        {

            OnRelinquishFocus();

        }



        #region Component Designer generated code

        /// <summary> 

        /// Required method for Designer support - do not modify 

        /// the contents of this method with the code editor.

        /// </summary>

        private void InitializeComponent()

        {

            this.layerControlPanel = new PanelWithLayout();

            this.SuspendLayout();

            // 

            // layerControlPanel

            // 

            this.layerControlPanel.AutoScroll = true;

            this.layerControlPanel.Dock = System.Windows.Forms.DockStyle.Fill;

            this.layerControlPanel.Location = new System.Drawing.Point(0, 0);

            this.layerControlPanel.Name = "layerControlPanel";

            this.layerControlPanel.ParentLayerControl = this;

            this.layerControlPanel.Size = new System.Drawing.Size(150, 150);

            this.layerControlPanel.TabIndex = 2;

            this.layerControlPanel.Click += new EventHandler(LayerControlPanel_Click);

            // 

            // LayerControl

            // 

            this.Controls.Add(this.layerControlPanel);

            this.Name = "LayerControl";

            this.ResumeLayout(false);



        }



        #endregion

    }

}