praktikum-holons/src/holeg/ui/view/canvas/AbstractCanvas.java

package holeg.ui.view.canvas;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.TimerTask;
import java.util.stream.Stream;

import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.Timer;

import holeg.model.AbstractCanvasObject;
import holeg.model.Edge;
import holeg.model.GroupNode;
import holeg.model.HolonObject;
import holeg.model.Node;
import holeg.ui.controller.Control;
import holeg.ui.model.GuiSettings;
import holeg.ui.model.Model;
import holeg.utility.math.vector.Vec2i;

/**
 * Collection of methods and values needed in both <code>MyCanvas</code> and
 * <code>UpperNodeCanvas</code>
 * <p>
 * Although Java works on references we chose to add explicit return values for
 * clearer code understanding in most cases
 *
 * @author: I. Dix
 */
public abstract class AbstractCanvas extends JPanel {
	/**
	 * Version
	 */
	private static final long serialVersionUID = 1L;

	final JMenuItem itemCut = new JMenuItem("Cut");
	final JMenuItem itemCopy = new JMenuItem("Copy");
	public final JMenuItem itemPaste = new JMenuItem("Paste");
	final JMenuItem itemDelete = new JMenuItem("Delete");
	final JMenuItem itemGroup = new JMenuItem("Group");
	final JMenuItem itemUngroup = new JMenuItem("Ungroup");
	final JMenuItem itemAlign = new JMenuItem("Align selected");
	final JMenuItem itemCreateTemplate = new JMenuItem("Create Template");

	final int ANIMTIME = 500; // animation Time
	private final int animFPS = 60;
	final int animDelay = 1000 / animFPS; // animation Delay
	protected Model model;
	protected Control control;
	protected int x = 0;
	protected int y = 0;
	// Selection
	//TODO(Tom2021-12-20): remove tmpCps or make is optional 
	public AbstractCanvasObject tempCps = null;

	// Replacement
	/**
	 * the CpsObject that might be replaced by drag&drop
	 */
	public AbstractCanvasObject mayBeReplaced = null;

	// PopUpMenu
	JPopupMenu popmenu = new JPopupMenu();
	// Tooltip
	boolean toolTip; // Tooltip on or off
	Vec2i toolTipPos = new Vec2i(); // Tooltip Position
	String toolTipText = "";
	protected Set<AbstractCanvasObject> tempSelected = new HashSet<>();
	boolean showConnectionInformation;
	boolean dragging = false; // for dragging
	boolean dragged = false; // if an object/objects was/were dragged
	boolean drawEdge = false; // for drawing edges
	boolean doMark = false; // for double click
	public Edge edgeHighlight = null;
	Point mousePosition = new Point(); // Mouse Position when
	ArrayList<Vec2i> savePos;
	// edge Object Start Point
	int cx, cy;
	int sx, sy; // Mark Coords
	Vec2i unPos;
	// Animation
	Timer animT; // animation Timer
	int animDuration = ANIMTIME; // animation Duration
	int animSteps = animDuration / animDelay; // animation Steps;
	List<AbstractCanvasObject> animCps = null;
	// Graphics
	Image img = null; // Contains the image to draw on the Canvas
	Graphics2D g2; // For Painting
	float scalediv20 = GuiSettings.getPictureScale() / 20;
	// Mouse
	private boolean click = false;

	// ------------------------------------------ METHODS
	// ------------------------------------------

	class ACpsHandle {
		public AbstractCanvasObject object;

		ACpsHandle(AbstractCanvasObject object) {
			this.object = object;
		}

		public String toString() {
			return object.toString();
		}
	}

	void drawMarker() {
		if (sx > x && sy > y) {
			g2.drawRect(x, y, sx - x, sy - y);
		} else if (sx < x && sy < y) {
			g2.drawRect(sx, sy, x - sx, y - sy);
		} else if (sx >= x) {
			g2.drawRect(x, sy, sx - x, y - sy);
		} else if (sy >= y) {
			g2.drawRect(sx, y, x - sx, sy - y);
		}
	}

	/**
	 * @deprecated
	 * @param g
	 */
	void showTooltip(Graphics g) {
		if (toolTip) {
			g2.setColor(new Color(255, 225, 150));
			g2.setStroke(new BasicStroke(1));
			int textWidth = g.getFontMetrics().stringWidth(toolTipText) + 2; // Text
			// width

			// fixed x and y Position to the screen
			int fixXPos = toolTipPos.getX() - (textWidth >> 1) + GuiSettings.getPictureScaleDiv2();
			int fixYPos = toolTipPos.getY();

			if (fixXPos < 0) {
				fixXPos = 0;
			} else if (fixXPos + textWidth + 1 > this.getWidth()) {
				fixXPos -= (fixXPos + textWidth + 1) - this.getWidth();
			}
			if (fixYPos + 16 > this.getHeight()) {
				fixYPos -= (fixYPos + 16) - this.getHeight();
			}
			g2.fillRect(fixXPos, fixYPos, textWidth, 15);
			g2.setColor(Color.BLACK);
			g2.drawRect(fixXPos, fixYPos, textWidth, 15);
			g2.drawString(toolTipText, fixXPos + 2, fixYPos + 12);
		}
	}

	void setRightClickMenu(MouseEvent e) {
		if (e.getButton() == MouseEvent.BUTTON3) {
			itemPaste.setEnabled(true);
			if (tempCps != null) {
				itemPaste.setEnabled(true);
				itemDelete.setEnabled(true);
				itemCut.setEnabled(true);
				itemCopy.setEnabled(true);
				itemAlign.setEnabled(true);
				// tracking
				if (tempCps != null) {
					itemGroup.setEnabled(true);
				}
				// ungrouping
				if (tempCps instanceof GroupNode)
					itemUngroup.setEnabled(true);
				else
					itemUngroup.setEnabled(false);
				if (GuiSettings.getSelectedObjects().isEmpty()) {
					control.addSelectedObject(tempCps);
				}
				if (tempCps instanceof HolonObject) {
					itemCreateTemplate.setEnabled(true);
				} else {
					itemCreateTemplate.setEnabled(false);
				}
			} else {
				itemAlign.setEnabled(false);
				itemCut.setEnabled(false);
				itemCopy.setEnabled(false);
				itemGroup.setEnabled(false);
				itemUngroup.setEnabled(false);
				itemCreateTemplate.setEnabled(false);
				if (edgeHighlight != null) {
					itemDelete.setEnabled(true);
					itemPaste.setEnabled(false);
				} else {
					itemDelete.setEnabled(false);
					itemPaste.setEnabled(true);
				}
			}
			mousePosition = this.getMousePosition();
			popmenu.show(e.getComponent(), e.getX(), e.getY());
		}
	}

	void markObjects() {
		if (doMark) {
			doMark = false;
			if (!tempSelected.isEmpty()) {
				control.toggleSelectedObjects(tempSelected);
				control.getObjectsInDepth();
				tempSelected.clear();
			}
			
		}
	}

	int[] determineMousePositionOnEdge(Edge p) {
		int lx, ly, hx, hy;

		if (p.getA().getPosition().getX() > p.getB().getPosition().getX()) {
			hx = p.getA().getPosition().getX() + GuiSettings.getPictureScaleDiv2() + 7;
			lx = p.getB().getPosition().getX() + GuiSettings.getPictureScaleDiv2() - 7;
		} else {
			lx = p.getA().getPosition().getX() + GuiSettings.getPictureScaleDiv2() - 7;
			hx = p.getB().getPosition().getX() + GuiSettings.getPictureScaleDiv2() + 7;
		}
		if (p.getA().getPosition().getY() > p.getB().getPosition().getY()) {
			hy = p.getA().getPosition().getY() + GuiSettings.getPictureScaleDiv2() + 7;
			ly = p.getB().getPosition().getY() + GuiSettings.getPictureScaleDiv2() - 7;
		} else {
			ly = p.getA().getPosition().getY() + GuiSettings.getPictureScaleDiv2() - 7;
			hy = p.getB().getPosition().getY() + GuiSettings.getPictureScaleDiv2() + 7;
		}

		return new int[] { lx, ly, hx, hy };
	}

	/**
	 * Checks if a double click was made.
	 *
	 * @return true if doublecklick, false if not
	 */
	boolean doubleClick() {
		if (click) {
			click = false;
			return true;
		} else {
			click = true;
			java.util.Timer t = new java.util.Timer("doubleclickTimer", false);
			t.schedule(new TimerTask() {
				@Override
				public void run() {
					click = false;
				}
			}, 500);
		}
		return false;
	}



	abstract void drawDeleteEdge();

	/**
	 * Checks if {@code draggedCps} or a new cpsObject at Position (x,y) could
	 * replace exactly one object in {@code objects}. Saves the object that would be
	 * replaced in {@link AbstractCanvas}.{@code MayBeReplaced}
	 * 
	 * @param objects    list of objects that could be replaced
	 * @param draggedCps Object that might replace
	 * @param x          Position of the objects that might replace
	 * @param y          Position of the objects that might replace
	 * @return true if exactly one Object could be replaced
	 */
	protected boolean checkForReplacement(Stream<AbstractCanvasObject> objects, AbstractCanvasObject draggedCps,
			int x, int y) {

		/** distance treshold for replacement */
		int treshhold = GuiSettings.getPictureScaleDiv2();

		/** number of Objects that might be replaced (should be 1) */
		int replaceCounter = 0;

		/** last object that could be replaced */
		AbstractCanvasObject toBeReplaced = null;

		/** Position of object that might be replaced */
		Vec2i p;

		/** for each cps on Canvas */
		if (draggedCps == null || !(draggedCps instanceof Node) && !(draggedCps instanceof Node)) {
			for (AbstractCanvasObject cps : objects.toList()) {
				/** same object -> ignore */
				if (cps == draggedCps)
					continue;

				/** set Position of object that might be replaced */
				p = cps.getPosition();

				/** if near enough */
				if (Math.abs(x - p.getX()) < treshhold && Math.abs(y - p.getY()) < treshhold) {
					replaceCounter++;
					toBeReplaced = cps;

					/**
					 * if too many Objects could be replaced: stop searching, because it would not
					 * be clear which one should be replaced
					 */
					if (replaceCounter > 1)
						break;
				}
			}
		}
		/**
		 * return true if exactly one obect would be replaced
		 */
		if (replaceCounter == 1 && toBeReplaced != null) {
			mayBeReplaced = toBeReplaced;
			return true;
		} else {
			mayBeReplaced = null;
			return false;
		}
	}

	/**
	 * Checks if an inserted new Object could replace exactly one object on the
	 * canvas. Saves the object that would be replaced in
	 * {@link AbstractCanvas}.{@code MayBeReplaced}
	 * 
	 * @param x Position of the objects that might replace
	 * @param y Position of the objects that might replace
	 * @return true if exactly one Object could be replaced
	 */
	public abstract boolean checkForReplacement(int x, int y);

	/**
	 * highlights the object that mayBeReplaced
	 * 
	 * @param g2
	 */
	protected void highlightMayBeReplaced(Graphics2D g2) {
		if (mayBeReplaced != null) {
			g2.setColor(Color.RED);
			g2.fillRect((int) (mayBeReplaced.getPosition().getX() - GuiSettings.getPictureScaleDiv2() - (scalediv20 + 3)),
					(int) (mayBeReplaced.getPosition().getY() - GuiSettings.getPictureScaleDiv2() - (scalediv20 + 3)),
					(int) (GuiSettings.getPictureScale() + ((scalediv20 + 3) * 2)),
					(int) (GuiSettings.getPictureScale() + ((scalediv20 + 3) * 2)));
		}
	}

	/**
	 * Align alle Objects on the Canvas to a Grid with objects every 10 pixels
	 */
	public abstract void tryToAlignObjects();

	/**
	 * Aligns the Object the a grid
	 * 
	 * @param cps      Object that should be aligned
	 * @param distance distance between the AlignmentGrid Lines. (objects every
	 *                 'distance' pixels
	 */
	protected void align(AbstractCanvasObject cps, int distance) {
		/** Position of the AbstractCpsObject which should be aligned */
		Vec2i p = cps.getPosition();

		// calculate how many pixels the cps should be decreased to align
		/** x offset relative to a grid with lines every distance pixels */
		int x_off = cps.getPosition().getX() % distance;

		/** y offset relative to a grid with lines every distance pixels */
		int y_off = cps.getPosition().getY() % distance;

		// align to the other Line, if it is nearer
		if (x_off > distance / 2)
			x_off -= distance;
		if (y_off > distance / 2)
			y_off -= distance;

		/** set new Position */
		cps.setPosition(p.getX() - x_off, p.getY() - y_off);
	}

	/**
	 * Closes a tab of the UpperNode with ID upperNodeID
	 * 
	 * @param upperNodeId
	 */
	public abstract void closeUpperNodeTab(int upperNodeId);
}