InteractiveSketchAssistant/SketchAssistant/SketchAssistantWPF/MVP_Model.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace SketchAssistantWPF
{
    public class MVP_Model
    {
        /// <summary>
        /// The Presenter of the MVP-Model.
        /// </summary>
        MVP_Presenter programPresenter;
        /// <summary>
        /// History of Actions
        /// </summary>
        ActionHistory historyOfActions;
        /// <summary>
        /// The assistant responsible for the redraw mode
        /// </summary>
        //RedrawAssistant redrawAss;

        /*******************/
        /*** ENUMERATORS ***/
        /*******************/

        /***********************/
        /*** CLASS VARIABLES ***/
        /***********************/

        /// <summary>
        /// If the program is in drawing mode.
        /// </summary>
        bool inDrawingMode;
        /// <summary>
        /// If the mouse is currently pressed or not.
        /// </summary>
        bool mousePressed;
        /// <summary>
        /// Size of deletion area
        /// </summary>
        int deletionRadius = 5;
        /// <summary>
        /// Size of areas marking endpoints of lines in the redraw mode.
        /// </summary>
        int markerRadius = 10;
        /// <summary>
        /// The Position of the Cursor in the right picture box
        /// </summary>
        Point currentCursorPosition;
        /// <summary>
        /// The Previous Cursor Position in the right picture box
        /// </summary>
        Point previousCursorPosition;
        /// <summary>
        /// Queue for the cursorPositions
        /// </summary>
        Queue<Point> cursorPositions = new Queue<Point>();
        /// <summary>
        /// Lookup Matrix for checking postions of lines in the image
        /// </summary>
        bool[,] isFilledMatrix;
        /// <summary>
        /// Lookup Matrix for getting line ids at a certain postions of the image
        /// </summary>
        HashSet<int>[,] linesMatrix;
        /// <summary>
        /// List of items which will be overlayed over the right canvas.
        /// </summary>
        List<Tuple<bool, HashSet<Point>>> overlayItems;
        /// <summary>
        /// Width of the LeftImageBox.
        /// </summary>
        public int leftImageBoxWidth;
        /// <summary>
        /// Height of the LeftImageBox.
        /// </summary>
        public int leftImageBoxHeight;
        /// <summary>
        /// Width of the RightImageBox.
        /// </summary>
        public int rightImageBoxWidth;
        /// <summary>
        /// Height of the RightImageBox.
        /// </summary>
        public int rightImageBoxHeight;

        public ImageDimension leftImageSize { get; private set; }

        public ImageDimension rightImageSize { get; private set; }
        /// <summary>
        /// Indicates whether or not the canvas on the right side is active.
        /// </summary>
        public bool canvasActive {get; set;}
        /// <summary>
        /// Indicates if there is a graphic loaded in the left canvas.
        /// </summary>
        public bool graphicLoaded { get; set; }

        //Images
        Image leftImage;

        List<InternalLine> leftLineList;

        Image rightImageWithoutOverlay;

        Image rightImageWithOverlay;

        List<Tuple<bool, InternalLine>> rightLineList;

        List<Point> currentLine = new List<Point>();



        public MVP_Model(MVP_Presenter presenter)
        {
            programPresenter = presenter;
            historyOfActions = new ActionHistory();
            //redrawAss = new RedrawAssistant();
            //overlayItems = new List<Tuple<bool, HashSet<Point>>>();
            rightLineList = new List<Tuple<bool, InternalLine>>();
            canvasActive = false;
            UpdateUI();
            rightImageSize = new ImageDimension(0, 0);
            leftImageSize = new ImageDimension(0, 0);
        }

        /**************************/
        /*** NEW INTERNAL FUNCTIONS ***/
        /**************************/


        /// <summary>
        /// Change the status of whether or not the lines are shown.
        /// </summary>
        /// <param name="lines">The HashSet containing the affected Line IDs.</param>
        /// <param name="shown">True if the lines should be shown, false if they should be hidden.</param>
        private void ChangeLines(HashSet<int> lines, bool shown)
        {
            foreach (int lineId in lines)
            {
                if (lineId <= rightLineList.Count - 1 && lineId >= 0)
                {
                    rightLineList[lineId] = new Tuple<bool, InternalLine>(shown, rightLineList[lineId].Item2);
                }
            }
        }

        /// <summary>
        /// A function that populates the matrixes needed for deletion detection with line data.
        /// </summary>
        private void RepopulateDeletionMatrixes()
        {
            if (canvasActive)
            {
                isFilledMatrix = new bool[rightImageSize.Width, rightImageSize.Height];
                linesMatrix = new HashSet<int>[rightImageSize.Width, rightImageSize.Height];
                foreach (Tuple<bool, InternalLine> lineTuple in rightLineList)
                {
                    if (lineTuple.Item1)
                    {
                        lineTuple.Item2.PopulateMatrixes(isFilledMatrix, linesMatrix);
                    }
                }
            }
        }

        /// <summary>
        /// Tells the Presenter to Update the UI
        /// </summary>
        private void UpdateUI()
        {
            programPresenter.UpdateUIState(inDrawingMode, historyOfActions.CanUndo(), historyOfActions.CanRedo(), canvasActive, graphicLoaded);
        }

        /// <summary>
        /// A function that checks the deletion matrixes at a certain point 
        /// and returns all Line ids at that point and in a square around it in a certain range.
        /// </summary>
        /// <param name="p">The point around which to check.</param>
        /// <param name="range">The range around the point. If range is 0, only the point is checked.</param>
        /// <returns>A List of all lines.</returns>
        private HashSet<int> CheckDeletionMatrixesAroundPoint(Point p, int range)
        {
            HashSet<int> returnSet = new HashSet<int>();

            foreach (Point pnt in GeometryCalculator.FilledCircleAlgorithm(p, (int)range))
            {
                if (pnt.X >= 0 && pnt.Y >= 0 && pnt.X < rightImageSize.Width && pnt.Y < rightImageSize.Height)
                {
                    if (isFilledMatrix[(int)pnt.X, (int)pnt.Y])
                    {
                        returnSet.UnionWith(linesMatrix[(int)pnt.X, (int)pnt.Y]);
                    }
                }
            }
            return returnSet;
        }

        /********************************************/
        /*** NEW FUNCTIONS TO INTERACT WITH PRESENTER ***/
        /********************************************/

        /// <summary>
        /// A function to reset the right image.
        /// </summary>
        public void ResetRightImage()
        {
            rightLineList.Clear();
            programPresenter.PassLastActionTaken(historyOfActions.Reset());
            programPresenter.ClearRightLines();
        }

        /// <summary>
        /// The function to set the left image.
        /// </summary>
        /// <param name="width">The width of the left image.</param>
        /// <param name="height">The height of the left image.</param>
        /// <param name="listOfLines">The List of Lines to be displayed in the left image.</param>
        public void SetLeftLineList(int width, int height, List<InternalLine> listOfLines)
        {
            leftImageSize = new ImageDimension(width, height);
            rightImageSize = new ImageDimension(width, height);
            leftLineList = listOfLines;
            graphicLoaded = true;
            programPresenter.UpdateLeftLines(leftLineList);
            CanvasActivated();
            /*
            var workingCanvas = GetEmptyCanvas(width, height);
            var workingGraph = Graphics.FromImage(workingCanvas);
            leftLineList = listOfLines;
            //redrawAss = new RedrawAssistant(leftLineList);
            //overlayItems = redrawAss.Initialize(markerRadius);
            //Lines
            foreach (InternalLine line in leftLineList)
            {
                line.DrawLine(workingGraph);
            }
            leftImage = workingCanvas;
            programPresenter.UpdateLeftImage(leftImage);
            //Set right image to same size as left image and delete linelist
            DrawEmptyCanvasRight();
            rightLineList = new List<Tuple<bool, InternalLine>>();
            */
        }

        /// <summary>
        /// A function to tell the model a new canvas was activated.
        /// </summary>
        public void CanvasActivated()
        {
            canvasActive = true;
            RepopulateDeletionMatrixes();
            UpdateUI();
        }

        /// <summary>
        /// Will undo the last action taken, if the action history allows it.
        /// </summary>
        public void Undo()
        {
            if (historyOfActions.CanUndo())
            {
                HashSet<int> affectedLines = historyOfActions.GetCurrentAction().GetLineIDs();
                SketchAction.ActionType undoAction = historyOfActions.GetCurrentAction().GetActionType();
                switch (undoAction)
                {
                    case SketchAction.ActionType.Delete:
                        //Deleted Lines need to be shown
                        ChangeLines(affectedLines, true);
                        break;
                    case SketchAction.ActionType.Draw:
                        //Drawn lines need to be hidden
                        ChangeLines(affectedLines, false);
                        break;
                    default:
                        break;
                }
                //TODO: Add check if overlay needs to be added
                programPresenter.UpdateRightLines(rightLineList);
            }
            RepopulateDeletionMatrixes();
            programPresenter.PassLastActionTaken(historyOfActions.MoveAction(true));
            UpdateUI();
        }

        /// <summary>
        /// Will redo the last action undone, if the action history allows it.
        /// </summary>
        public void Redo()
        {
            if (historyOfActions.CanRedo())
            {
                programPresenter.PassLastActionTaken(historyOfActions.MoveAction(false));
                HashSet<int> affectedLines = historyOfActions.GetCurrentAction().GetLineIDs();
                SketchAction.ActionType redoAction = historyOfActions.GetCurrentAction().GetActionType();
                switch (redoAction)
                {
                    case SketchAction.ActionType.Delete:
                        //Deleted Lines need to be redeleted
                        ChangeLines(affectedLines, false);
                        break;
                    case SketchAction.ActionType.Draw:
                        //Drawn lines need to be redrawn
                        ChangeLines(affectedLines, true);
                        break;
                    default:
                        break;
                }
                //TODO: Add check if overlay needs to be added
                programPresenter.UpdateRightLines(rightLineList);
                RepopulateDeletionMatrixes();
            }
            UpdateUI();
        }

        /// <summary>
        /// The function called by the Presenter to change the drawing state of the program.
        /// </summary>
        /// <param name="nowDrawing">The new drawingstate of the program</param>
        public void ChangeState(bool nowDrawing)
        {
            inDrawingMode = nowDrawing;
            UpdateUI();
        }
        
        /// <summary>
        /// Updates the current cursor position of the model.
        /// </summary>
        /// <param name="p">The new cursor position</param>
        public void SetCurrentCursorPosition(Point p)
        {
            currentCursorPosition = p;
        }

        /// <summary>
        /// Start a new Line, when the Mouse is pressed down.
        /// </summary>
        public void MouseDown()
        {
            mousePressed = true;
            if (inDrawingMode)
            {
                currentLine.Clear();
            }
        }

        /// <summary>
        /// Finish the current Line, when the pressed Mouse is released.
        /// </summary>
        public void MouseUp()
        {
            mousePressed = false;
            if (inDrawingMode && currentLine.Count > 0)
            {
                InternalLine newLine = new InternalLine(currentLine, rightLineList.Count);
                rightLineList.Add(new Tuple<bool, InternalLine>(true, newLine));
                newLine.PopulateMatrixes(isFilledMatrix, linesMatrix);
                programPresenter.PassLastActionTaken(historyOfActions.AddNewAction(new SketchAction(SketchAction.ActionType.Draw, newLine.GetID())));
                //TODO: Add check if overlay needs to be added
                programPresenter.UpdateRightLines(rightLineList);
                currentLine.Clear();
                programPresenter.UpdateCurrentLine(currentLine);
            }
            UpdateUI();
        }

        /// <summary>
        /// Method to be called every tick. Updates the current Line, or checks for Lines to delete, depending on the drawing mode.
        /// </summary>
        public void Tick()
        {
            if (cursorPositions.Count > 0) { previousCursorPosition = cursorPositions.Dequeue(); }
            else { previousCursorPosition = currentCursorPosition; }
            cursorPositions.Enqueue(currentCursorPosition);
            //Drawing
            if (inDrawingMode && mousePressed)
            {
                currentLine.Add(currentCursorPosition);
                programPresenter.UpdateCurrentLine(currentLine);
            }
            //Deleting
            if (!inDrawingMode && mousePressed)
            {
                List<Point> uncheckedPoints = GeometryCalculator.BresenhamLineAlgorithm(previousCursorPosition, currentCursorPosition);
                foreach (Point currPoint in uncheckedPoints)
                {
                    HashSet<int> linesToDelete = CheckDeletionMatrixesAroundPoint(currPoint, deletionRadius);
                    if (linesToDelete.Count > 0)
                    {
                        programPresenter.PassLastActionTaken(historyOfActions.AddNewAction(new SketchAction(SketchAction.ActionType.Delete, linesToDelete)));
                        foreach (int lineID in linesToDelete)
                        {
                            rightLineList[lineID] = new Tuple<bool, InternalLine>(false, rightLineList[lineID].Item2);
                        }
                        RepopulateDeletionMatrixes();
                        //TODO: Add check if overlay needs to be added
                        programPresenter.UpdateRightLines(rightLineList);
                    }
                }
            }
        }

        /// <summary>
        /// A helper Function that updates the markerRadius & deletionRadius, considering the size of the canvas.
        /// </summary>
        /// <param name="CanvasSize">The size of the canvas</param>
        public void UpdateSizes(ImageDimension CanvasSize)
        {
            if (rightImageWithoutOverlay != null)
            {
                int widthImage = rightImageSize.Width;
                int heightImage = rightImageSize.Height;
                int widthBox = CanvasSize.Width;
                int heightBox = CanvasSize.Height;

                float imageRatio = (float)widthImage / (float)heightImage;
                float containerRatio = (float)widthBox / (float)heightBox;
                float zoomFactor = 0;
                if (imageRatio >= containerRatio)
                {
                    //Image is wider than it is high
                    zoomFactor = (float)widthImage / (float)widthBox;
                }
                else
                {
                    //Image is higher than it is wide
                    zoomFactor = (float)heightImage / (float)heightBox;
                }
                markerRadius = (int)(10 * zoomFactor);
                deletionRadius = (int)(5 * zoomFactor);
            }
        }

        /// <summary>
        /// If there is unsaved progress.
        /// </summary>
        /// <returns>True if there is progress that has not been saved.</returns>
        public bool HasUnsavedProgress()
        {
            return !historyOfActions.IsEmpty();
        }
    
        /**************************/
        /*** INTERNAL FUNCTIONS ***/
        /**************************/

        /*
    /// <summary>
    /// A function that returns a white canvas for a given width and height.
    /// </summary>
    /// <param name="width">The width of the canvas in pixels</param>
    /// <param name="height">The height of the canvas in pixels</param>
    /// <returns>The new canvas</returns>
    private Image GetEmptyCanvas(int width, int height)
    {
        Image image;
        WriteableBitmap newCanvas;
        try
        {
            newCanvas = new WriteableBitmap(width, height, 96, 96, PixelFormats.Bgra32, null);
            image = new Bitmap(width, height);
        }
        catch (ArgumentException e)
        {
            programPresenter.PassMessageToView("The requested canvas size caused an error: \n"
                + e.ToString() + "\n The Canvas will be set to match your window.");
            newCanvas = new WriteableBitmap(leftImageBoxWidth, leftImageBoxHeight, 96, 96, PixelFormats.Bgra32, null);
        }
        newCanvas.WritePixels()
        Graphics graph = Graphics.FromImage(image);
        graph.FillRectangle(Brushes.White, 0, 0, width + 10, height + 10);
        return image;
    }


    /// <summary>
    /// Creates an empty Canvas on the left
    /// </summary>
    /// <param name="width"> width of the new canvas in pixels </param>
    /// <param name="height"> height of the new canvas in pixels </param>
    private void DrawEmptyCanvasLeft(int width, int height)
    {
        if (width == 0)
        {
            leftImage = GetEmptyCanvas(leftImageBoxWidth, leftImageBoxHeight);
        }
        else
        {
            leftImage = GetEmptyCanvas(width, height);
        }
        programPresenter.UpdateLeftImage(leftImage);
    }

    /// <summary>
    /// Redraws all lines in rightLineList, for which their associated boolean value equals true and calls RedrawRightOverlay.
    /// </summary>
    private void RedrawRightImage()
    {
        var workingCanvas = GetEmptyCanvas(rightImageWithoutOverlay.Width, rightImageWithoutOverlay.Height);
        var workingGraph = Graphics.FromImage(workingCanvas);
        //Lines
        foreach (Tuple<bool, InternalLine> lineBoolTuple in rightLineList)
        {
            if (lineBoolTuple.Item1)
            {
                lineBoolTuple.Item2.DrawLine(workingGraph);
            }
        }
        //The Line being currently drawn
        if (currentLine != null && currentLine.Count > 0 && inDrawingMode && mousePressed)
        {
            var currLine = new InternalLine(currentLine);
            currLine.DrawLine(workingGraph);
        }
        rightImageWithoutOverlay = workingCanvas;
        //Redraw the Overlay if needed
        if (leftImage != null)
        {
            RedrawRightOverlay();
        }
        else
        {
            programPresenter.UpdateRightImage(rightImageWithoutOverlay);
        }
    }

        /// <summary>
        /// Redraws all elements in the overlay items for which the respective boolean value is true.
        /// </summary>
        private void RedrawRightOverlay()
        {
            var workingCanvas = rightImageWithoutOverlay;
            var workingGraph = Graphics.FromImage(workingCanvas);
            foreach (Tuple<bool, HashSet<Point>> tup in overlayItems)
            {
                if (tup.Item1)
                {
                    foreach (Point p in tup.Item2)
                    {
                        workingGraph.FillRectangle(Brushes.Green, p.X, p.Y, 1, 1);
                    }
                }
            }
            rightImageWithOverlay = workingCanvas;
            programPresenter.UpdateRightImage(rightImageWithOverlay);
        }
    */




        /*
        /// <summary>
        /// Will calculate the start and endpoints of the given line on the right canvas.
        /// </summary>
        /// <param name="line">The line.</param>
        /// <param name="size">The size of the circle with which the endpoints of the line are marked.</param>
        private Tuple<HashSet<Point>, HashSet<Point>> CalculateStartAndEnd(Line line, int size)
        {
            var circle0 = GeometryCalculator.FilledCircleAlgorithm(line.GetStartPoint(), size);
            var circle1 = GeometryCalculator.FilledCircleAlgorithm(line.GetEndPoint(), size);
            var currentLineEndings = new Tuple<HashSet<Point>, HashSet<Point>>(circle0, circle1);
            return currentLineEndings;
        }
        */






        /********************************************/
        /*** FUNCTIONS TO INTERACT WITH PRESENTER ***/
        /********************************************/
        /*
        /// <summary>
        /// Creates an empty Canvas
        /// </summary>
        public void DrawEmptyCanvasRight()
        {
            if (leftImage == null)
            {
                rightImageWithoutOverlay = GetEmptyCanvas(leftImageBoxWidth, leftImageBoxHeight);
            }
            else
            {
                rightImageWithoutOverlay = GetEmptyCanvas(leftImage.Width, leftImage.Height);
            }
            RepopulateDeletionMatrixes();
            rightImageWithOverlay = rightImageWithoutOverlay;
            programPresenter.UpdateRightImage(rightImageWithOverlay);
        }


        /// <summary>
        /// A method to get the dimensions of the right image.
        /// </summary>
        /// <returns>A tuple containing the width and height of the right image.</returns>
        public Tuple<int, int> GetRightImageDimensions()
        {
            if (rightImageWithoutOverlay != null)
            {
                return new Tuple<int, int>(rightImageWithoutOverlay.Width, rightImageWithoutOverlay.Height);
            }
            else
            {
                return new Tuple<int, int>(0, 0);
            }
        }


        /// <summary>
        /// Method to be called every tick. Updates the current Line, or checks for Lines to delete, depending on the drawing mode.
        /// </summary>
        public void Tick()
        {
            if (cursorPositions.Count > 0) { previousCursorPosition = cursorPositions.Dequeue(); }
            else { previousCursorPosition = currentCursorPosition; }
            cursorPositions.Enqueue(currentCursorPosition);
            //Drawing
            if (inDrawingMode && mousePressed)
            {
                var rightGraph = Graphics.FromImage(rightImageWithoutOverlay);
                currentLine.Add(currentCursorPosition);
                InternalLine drawline = new InternalLine(currentLine);
                drawline.DrawLine(rightGraph);
                RedrawRightOverlay();
            }
            //Deleting
            if (!inDrawingMode && mousePressed)
            {
                List<Point> uncheckedPoints = GeometryCalculator.BresenhamLineAlgorithm(previousCursorPosition, currentCursorPosition);
                foreach (Point currPoint in uncheckedPoints)
                {
                    HashSet<int> linesToDelete = CheckDeletionMatrixesAroundPoint(currPoint, deletionRadius);
                    if (linesToDelete.Count > 0)
                    {
                        programPresenter.PassLastActionTaken(historyOfActions.AddNewAction(new SketchAction(SketchAction.ActionType.Delete, linesToDelete)));
                        foreach (int lineID in linesToDelete)
                        {
                            rightLineList[lineID] = new Tuple<bool, InternalLine>(false, rightLineList[lineID].Item2);
                        }
                        RepopulateDeletionMatrixes();
                        if (leftImage != null)
                        {
                            //Redraw overlay gets ticked
                            //overlayItems = redrawAss.Tick(currentCursorPosition, rightLineList, -1, false);
                        }
                        RedrawRightImage();
                    }
                }
            }
        }

    */


    }
}