Java 画图板（基本图形、撤销、清空、重复）

package lab14; import java.awt.*; import javax.swing.*; public class Paint extends JPanel{ private int[] type = new int[100]; private int[] colorType = new int[100]; private int[] xStart = new int[100]; private int[] yStart = new int[100]; private int[][] xEnd = new int[100][10000]; private int[][] yEnd = new int[100][10000]; private int[] num = new int[100]; //每次画图实际经过的点数(除了开始那点外) private int[] x; //用于curve private int[] y; //用于curve private int count,count1; //前者记录清空后已画图形数目。后者记录某一次画的瞬间已经过的点数（除了开始点） private boolean isClear = false; //用于判断是否要清空。 public Paint(){ } void setColor(int number){ switch(number){ case 1: setForeground(Color.red); break; case 2: setForeground(Color.blue); break; case 0: setForeground(Color.black); } } void setType(int type, int colorType){ count++; if ((count) >= this.type.length){ this.type = expand(this.type); this.colorType = expand(this.colorType); xStart = expand(xStart); yStart = expand(yStart); xEnd = expand(xEnd); yEnd = expand(yEnd); num = expand(num); } this.type[count] = type; this.colorType[count] = colorType; } void setLocation1(int x1, int y1){ count1 = 0; if (type[count] !=4){ this.xStart[count] = x1; this.yStart[count] = y1; } else{ xEnd[count][0] = x1; yEnd[count][0] = y1; } } void setLocation2(int x2, int y2){ count1++; num[count] = count1; if (count1 >= xEnd[0].length){ xEnd = expand(xEnd); yEnd = expand(yEnd); } xEnd[count][count1] = x2; yEnd[count][count1] = y2; } void setIsClear(boolean isClear){ this.isClear = isClear; } void undo(){ if (count >= 1) count--; else return; } void redo(){ if(count < type.length && count >= 0) count++; else return; } protected void paintComponent(Graphics g){ super.paintComponent(g); if (isClear){ return; } else{ for (int i = 1;i <= count;i++){ setColor(colorType[i]); g.setColor(getForeground()); int j = num[i]; int xTemper = (xEnd[i][j] - xStart[i]) > 0? (xEnd[i][j] - xStart[i]): Math.abs(xEnd[i][j] - xStart[i]); int yTemper = (yEnd[i][j] - yStart[i]) > 0? (yEnd[i][j] - yStart[i]): Math.abs(yEnd[i][j] - yStart[i]); switch (type[i]){ case 1: g.drawLine(xStart[i], yStart[i], xEnd[i][j], yEnd[i][j]); break; case 2: if(xEnd[i][j] - xStart[i] > 0) g.drawRect(xStart[i], yStart[i], xTemper, yTemper); else g.drawRect(xEnd[i][j], yStart[i], xTemper, yTemper); break; case 3: if(xEnd[i][j] - xStart[i] > 0) g.drawOval(xStart[i], yStart[i], xTemper, yTemper); else g.drawOval(xEnd[i][j], yStart[i], xTemper, yTemper); break; case 4: convert(i , j); g.drawPolyline(x, y, x.length); } } } } void convert(int number1, int number2){ x = new int[number2 + 1]; y = new int[number2 + 1]; for(int i=0;i <= number2;i++){ x[i] = xEnd[number1][i]; y[i] = yEnd[number1][i]; } } void clear(){ for (int i = 0;i <= count; i++){ xStart[i] = 0; yStart[i] = 0; for (int j = 0; j <= num[i]; j++){ xEnd[i][j] = 0; yEnd[i][j] = 0; } num[i] = 0; } count = 0; count1 = 0; isClear = false; } int[] expand(int[] list){ int number = list.length; int[] temper = new int[2 * number]; for (int i = 0; i < number; i++){ temper[i] = list[i]; } return temper; } int[][] expand(int[][] list){ int number1 = list.length; int number2 = list[0].length; int[][] temper = new int[2 * number1][2 * number2]; for (int i = 0; i < number1; i++){ for (int j = 0; j < number2; j++){ temper[i][j] = list[i][j]; } } return temper; } }