将“路径”从2Darrays网格存储到列表中
在我用JLabel制作的2D网格作为单元格时，我让单元格的邻居形成一个“路径”，然后在该路径之后绘制一个多边形，其中单元格的中心为点。 我使用一个分层窗格（JPanel）将两个面板一个放在另一个上面以便能够绘制多边形和一个GridBagLayout以允许将两个组件一个放在另一个上面。 一切都按预期工作。
问题是，每当我点击一个空单元格时，前一条路径就会被清除，同时也会清除多边形。 但是不清除单元格内容。
现在，我希望将已绘制的路径/多边形保存在列表中，以便可以再次重新绘制它们。
我希望有一个类似“历史”的东西，它将包含所有找到的路径。 有关如何实现这一点的任何想法？
在路径之后绘制的多边形由位于该路径中包含的单元格中心的点（JLabel）形成：
Point[] polygon = new Point[path.size()]; //calculate points to construct lines along the path for(int[] address : path) { //get cell location (row / col) int row = address[0]; int col = address[1]; //get label in that location JLabel label = grid[row][col]; //add center of label as a point in polygon polygon[i++] = getComponentCenter(label.getBounds()); } 我现在想将这些多边形存储在列表中。
我正在考虑下面的事情，但我完全糊涂了：
private List<List> history; public DrawJPanel() { history = new ArrayList(); } public void setPath(List path) { List copied = new ArrayList(path); copied.add(path.get(0)); history.add(copied); repaint(); }
没有看到上下文或mcve就不容易回答，所以我不得不复制以前答案中的完整代码：
import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.Point; import java.awt.RenderingHints; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.geom.Line2D; import java.awt.image.BufferedImage; import java.beans.PropertyChangeListener; import java.util.ArrayList; import java.util.EnumMap; import java.util.List; import java.util.Map; import java.util.Stack; import java.util.StringJoiner; import javax.swing.BorderFactory; import javax.swing.Icon; import javax.swing.ImageIcon; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.SwingUtilities; public class View extends JPanel { public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { DrawLines drawLines = new DrawLines(); JFrame frame = new JFrame(); frame.setGlassPane(drawLines); frame.add(new View(20, 20, drawLines)); frame.getGlassPane().setVisible(true); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } enum Token { VIDE, CERCLE_BLEU, CERCLE_ROUGE } private static final int ICON_W = 20; public static final String CELL_SELECTION = "cell selection"; private int rows; private Token[][] tokens; private JLabel[][] grid; private Map iconMap = new EnumMap<>(Token.class); private int selectedRow; private int selectedCol; private DrawLines drawLines; View(int rows, int cols, DrawLines drawLines) { this.drawLines = drawLines; iconMap.put(Token.VIDE, createIcon(new Color(0, 0, 0, 0))); iconMap.put(Token.CERCLE_BLEU, createIcon(Color.BLUE)); iconMap.put(Token.CERCLE_ROUGE, createIcon(Color.RED)); createGrid(rows, cols); } private Icon createIcon(Color color) { BufferedImage img = new BufferedImage(ICON_W, ICON_W, BufferedImage.TYPE_INT_ARGB); Graphics2D g2 = img.createGraphics(); g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g2.setColor(color); g2.fillOval(1, 1, ICON_W - 2, ICON_W - 2); g2.dispose(); return new ImageIcon(img); } void createGrid(int rows, int cols) { tokens = new Token[rows][cols]; MyMouseListener listener = new MyMouseListener(); setRows(rows); setLayout(new GridLayout(rows, cols, 1, 1)); setBorder(BorderFactory.createLineBorder(Color.BLACK)); setBackground(Color.DARK_GRAY); grid = new JLabel[rows][cols]; for (int r = 0; r < grid.length; r++) { for (int c = 0; c < grid[r].length; c++) { grid[r][c] = new JLabel(iconMap.get(Token.VIDE)); grid[r][c].addMouseListener(listener); grid[r][c].setOpaque(true); grid[r][c].setBackground(Color.WHITE); grid[r][c].setPreferredSize(new Dimension(ICON_W, ICON_W)); add(grid[r][c]); } } set(6, 6, Token.CERCLE_ROUGE); set(6, 7, Token.CERCLE_ROUGE); set(6, 8, Token.CERCLE_ROUGE); set(6, 9, Token.CERCLE_ROUGE); set(7, 9, Token.CERCLE_ROUGE); set(8, 9, Token.CERCLE_ROUGE); set(9, 9, Token.CERCLE_ROUGE); set(10, 9, Token.CERCLE_ROUGE); set(10, 6, Token.CERCLE_ROUGE); set(10, 7, Token.CERCLE_ROUGE); set(10, 8, Token.CERCLE_ROUGE); set(10, 9, Token.CERCLE_ROUGE); set(7, 6, Token.CERCLE_ROUGE); set(8, 6, Token.CERCLE_ROUGE); set(9, 6, Token.CERCLE_ROUGE); Path path = new Path(tokens); if (path.findPath(new int[]{6, 6})) { addPath(path.getPath()); } } void set(int row, int col, Token token) { grid[row][col].setIcon(iconMap.get(token)); tokens[row][col] = token; } int getSelectedRow() { return selectedRow; } int getSelectedCol() { return selectedCol; } void setCell(Token token, int row, int col) { grid[row][col].setIcon(iconMap.get(token)); } int getRows() { return rows; } void setRows(int rows) { this.rows = rows; } //added to each cell to listen to mouse clicks //fires property change with cell index private class MyMouseListener extends MouseAdapter { @Override public void mousePressed(MouseEvent e) { JLabel selection = (JLabel) e.getSource(); for (int r = 0; r < grid.length; r++) { for (int c = 0; c < grid[r].length; c++) { if (selection == grid[r][c]) { selectedRow = r; selectedCol = c; int index = (r * grid[r].length) + c; selection.setIcon(iconMap.get(Token.CERCLE_BLEU)); tokens[selectedRow][selectedCol] = Token.CERCLE_BLEU; System.out.println(c + "x" + r + " = " + index); firePropertyChange(CELL_SELECTION, -1, index); Path path = new Path(tokens); if (path.findPath(new int[]{selectedRow, selectedCol})) { addPath(path.getPath()); } } } } } } //add listener to listen to property changes fired by MyMouseListener @Override public void addPropertyChangeListener(PropertyChangeListener viewListener) { addPropertyChangeListener(viewListener); } private void addPath(ArrayList path) { if (path != null) { List labels = new ArrayList<>(25); for (Cell cell : path) { JLabel label = grid[cell.y][cell.x]; label.setBackground(Color.YELLOW); labels.add(label); } for (int r = 0; r < grid.length; r++) { for (int c = 0; c < grid[r].length; c++) { if (!path.contains(new Cell(c, r))) { grid[r][c].setBackground(Color.WHITE); } } } drawLines.addPath(labels); } } public static class DrawLines extends JLabel { private List> history; DrawLines(){ history = new ArrayList<>(); } public void addPath(List path) { path.add(path.get(0)); //add path origin as target history.add(path); repaint(); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); if ((history == null) || history.isEmpty()) { return; } Graphics2D g2d = (Graphics2D) g.create(); for(List path : history) { Point startPoint = null; for (JLabel label : path) { g2d.setColor(Color.DARK_GRAY); Point endPoint = label.getLocation(); endPoint.x += (label.getWidth() / 2); endPoint.y += (label.getHeight() / 2); if (startPoint != null) { g2d.draw(new Line2D.Float(startPoint, endPoint)); } startPoint = endPoint; } } g2d.dispose(); } } class Cell { private int x, y; public Cell(int x, int y) { this.x = x; this.y = y; } public int getX() { return x; } public int getY() { return y; } @Override public int hashCode() { int hash = 7; return hash; } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } final Cell other = (Cell) obj; if (x != other.x) { return false; } if (y != other.y) { return false; } return true; } @Override public String toString() { return x + "x" + y; } } class Path extends Stack| { private Token[][] grid; //a path shorter than min can not surround any cell private static final int MIN_PATH_LEGTH = 3; //a collection of cells that has been tested private ArrayList | checked; //represents the cell where the search starts from Cell origin; //represents the token of the origin Token originToken; private int rows; private int cols; Path(Token[][] grid) { this.grid = grid; rows = grid.length; cols = grid[0].length; } //search for a path boolean findPath(int[] origin) { int row = origin[0], col = origin[1]; this.origin = new Cell(col, row); //represents the token of the origin originToken = grid[row][col]; //initialize list of checked items checked = new ArrayList<>(); boolean found = findPath(row, col); if (found) { printPath(); } else { System.out.println("No path found"); } return found; } //recursive method to find path. a cell is represented by its row, col //returns true when path was found private boolean findPath(int row, int col) { //check if cell has the same token as origin if (grid[row][col] != originToken) { return false; } Cell cell = new Cell(col, row); //check if this cell was tested before to avoid checking again if (checked.contains(cell)) { return false; } //get cells neighbors ArrayList | neighbors = getNeighbors(row, col); //check if solution found. If path size > min and cell //neighbors contain the origin it means that path was found if ((size() >= MIN_PATH_LEGTH) && neighbors.contains(origin)) { add(cell); return true; } //add cell to checked list checked.add(cell); //add cell to path add(cell); //if path was not found check cell neighbors for (Cell neighbor : neighbors) { boolean found = findPath(neighbor.getY(), neighbor.getX()); if (found) { return true; } } //path not found pop(); //remove last element from stack return false; } //return a list of all neighbors of cell row, col private ArrayList | getNeighbors(int row, int col) { ArrayList | neighbors = new ArrayList<>(); for (int colNum = col - 1; colNum <= (col + 1); colNum += 1) { for (int rowNum = row - 1; rowNum <= (row + 1); rowNum += 1) { if (!((colNum == col) && (rowNum == row))) { if (withinGrid(rowNum, colNum)) { neighbors.add(new Cell(colNum, rowNum)); } } } } return neighbors; } private boolean withinGrid(int colNum, int rowNum) { if ((colNum < 0) || (rowNum < 0)) { return false; } if ((colNum >= cols) || (rowNum >= rows)) { return false; } return true; } //use for testing private void printPath() { StringJoiner sj = new StringJoiner(",", "Path: ", ""); for (Cell cell : this) { sj.add(cell.toString()); } System.out.println(sj); } public ArrayList | getPath() { ArrayList | cl = new ArrayList<>(); cl.addAll(this); return cl; } } } | |