对于我的二叉树程序，我一直在使用JTextFields作为节点，并且我已经设法做到了这一点，因此当我单击左键并选择两个JTextFields时，它将在它们之间画一条线。问题是，如果我想拖动 JtextField，我希望这条线也跟随 JTextField 的两个中点之间。 我不知道是否可能仅使用paintComponent。我确实尝试过，但它就像一次性的东西，它会留下所有以前绘制的线条的痕迹。这是到目前为止的代码，还有其他类，所以有些位不起作用。代码也经过了一些修改以进行测试。
public class BinaryTreeMainPnl extensions JPanel {
public static Graphics g1;
public int Width = 75;
public int Height = 45;
public String tempNode1 = "";
public int tempNode1Pos = 0;
public int tempNode2Pos = 0;
public String tempNode2 = "";
public static boolean leftBtnSelected;
public static boolean rightBtnSelected;
private static int x1, y1 = 50;
private static int x2, y2 = 500;
JToggleButton leftBtn = new JToggleButton("Left");
JToggleButton rightBtn = new JToggleButton("Right");
JTextField[] myArray = new JTextField[60];
ArrayList<String> nodeNames = new ArrayList<String>();
JFrame MainFrame;
JTextField txtFld1 = new JTextField("Enter Questions here");
JButton btn1 = new JButton("Submit");
public BinaryTreeMainPnl(JFrame frame) {
super();
setSize(800, 700);
MainFrame = frame;
readInput();
leftBtn.setFont(new Font("Arial", Font.BOLD, 15));
leftBtn.setForeground(Color.blue);
leftBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
rightBtn.setSelected(false);
leftBtnSelected = leftBtn.getModel().isSelected();
rightBtnSelected = false;
System.out.println(leftBtnSelected);
System.out.println(rightBtnSelected);
}
});
add(leftBtn);
rightBtn.setFont(new Font("Arial", Font.BOLD, 15));
rightBtn.setForeground(Color.green);
rightBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
leftBtn.setSelected(false);
rightBtnSelected = rightBtn.getModel().isSelected();
leftBtnSelected = false;
System.out.println(leftBtnSelected);
System.out.println(rightBtnSelected);
}
});
add(rightBtn);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
updateLine(g);
}
public void readInput() {
btn1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
identifyNodeNames(txtFld1.getText());
displayNodes(nodeNames);
new TreeSorting().treeSort(nodeNames);
}
});
this.add(txtFld1);
this.add(btn1);
}
public void displayNodes(ArrayList<String> nodeNames) {
for (int i = 0; i < nodeNames.size(); i++) {
String currentSetText = nodeNames.get(i);
myArray[i] = new JTextField(currentSetText);
myArray[i].setEditable(false);
}
for (int i = 0; i < nodeNames.size(); i++) {
int I = i;
myArray[I].addMouseMotionListener(new MouseAdapter() {
@Override
public void mouseDragged(MouseEvent evt) {
int x = evt.getX() + myArray[I].getX();
int y = evt.getY() + myArray[I].getY();
myArray[I].setBounds(x, y, myArray[I].getWidth(), myArray[I].getWidth());
System.out.println(myArray[I] + "dragged");
}
});
myArray[I].addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent evt) {
if (leftBtnSelected) {
if (tempNode1.equals("")) {
tempNode1 = myArray[I].getText();
System.out.println(tempNode1 + "clicked");
} else {
tempNode2 = myArray[I].getText();
System.out.println(tempNode2 + "Clicked as well");
leftBtn.setSelected(false);
leftBtnSelected = false;
x1 = 40;
y1 = 40;
x2 = 400;
y2 = 400;
updateLine(g1);
System.out.println("asdasd");
}
}
if (rightBtnSelected) {
}
}
public void moveComponent(MouseEvent evt) {
}
});
System.out.println("I " + I);
System.out.println(myArray[I].getText());
add(myArray[I]);
}
MainFrame.revalidate();
}
public int findMidPoint(JTextField temp) {
Point p = temp.getLocation();
Dimension d = temp.getSize();
return p.x + (d.width) / 2;
}
int coun = 0;
public void updateLine(Graphics g) {
g.drawLine(x1, x2, y1, y2);
x1 = x1 + 10;
y1 = y1 + 10;
y2 = y2 + 10;
x2 = x2 + 10;
System.out.println("Line Updated" + coun);
coun++;
}
public void identifyNodeNames(String answer) {
int arrayCounter = 0;
int lastNodePosition = 0;
for (int i = 0; i < answer.length(); i++) {
char c = answer.charAt(i);
if (c == ',') {
nodeNames.add(arrayCounter, answer.substring(lastNodePosition, i + 1).replaceAll(",", "").replaceAll(" ", ""));
lastNodePosition = i + 1;
arrayCounter++;
}
if (i == answer.length() - 1) {
nodeNames.add(arrayCounter, answer.substring(lastNodePosition, answer.length()).replaceAll(" ", ""));
}
}
}
}
import java.util.ArrayList;
公共类树排序 {
public static int arrayLength;
String[][] Child;
String root = "";
boolean nodeSorted = false;
int parentCounter = 1;
public void treeSort(ArrayList<String> passedQuestions) {
// declaring nodes
arrayLength = passedQuestions.size();
System.out.println(arrayLength + "ARRAY LENGTH");
Child = new String[arrayLength][3];
for (int i = 0; i < arrayLength; i++) {
Child[i][0] = passedQuestions.get(i);
}
//initially calling the mainprocess with parentCounter 1;
root = Child[0][0];
mainProcess(1);
}
public void mainProcess(int parentCounter) {
if (parentCounter < Child.length) {
System.out.println(parentCounter);
sortingTree(Child[parentCounter][0], root, 0); //where the next node is passed on the tree is sorted recursively
for (int i = 0; i < Child.length; i++) {
System.out.println(Child[i][0]);
System.out.println(Child[i][1] + "," + Child[i][2]);
}
}
}
public void sortingTree(String CurrentNode, String PreviousNode, int PreviousPosition) {
nodeSorted = false;// node is not sorted in the beginning
if (isAfter(CurrentNode.toLowerCase(), PreviousNode.toLowerCase())) {
System.out.println(Child[PreviousPosition][2]);
if (Child[PreviousPosition][2] == null) { //checks if the right of the node is empty, if found empty the node is placed there.
Child[PreviousPosition][2] = CurrentNode;
nodeSorted = true; // if the node finds a position in the array node is sorted.
} else {
sortingTree(CurrentNode, Child[PreviousPosition][2], getPositionInArray(Child[PreviousPosition][2]));
//if the array position was not empty, the loop will process again this time with the item found in the filled position.
}
} else if (Child[PreviousPosition][1] == null) { // if the left of the node is empty, the item will be placed there
Child[PreviousPosition][1] = CurrentNode;
nodeSorted = true;
} else {
sortingTree(CurrentNode, Child[PreviousPosition][1], getPositionInArray(Child[PreviousPosition][1]));
//if the array position was not empty, the loop will process again this time with the item found in the filled position.
}
if (nodeSorted) { // if the node finds a position in the array, the nodeCounter increments and the next node in the question is processed.
parentCounter++;
mainProcess(parentCounter);
}
}
public int getPositionInArray(String node) {
int position = 0;
loop:
for (int i = 0; i < Child.length; i++) {
if (Child[i][0].equals(node)) {
position = i;
break loop;
}
}
return position;
}
public boolean isAfter(String CurrentNode, String PreviousNode) {
int loopLength = determineLoopLength(CurrentNode, PreviousNode);
boolean result = false;
String tempCheck = "";
loop:
for (int i = 0; i < loopLength; i++) {
if ((int) CurrentNode.charAt(i) > (int) PreviousNode.charAt(i)) {
result = true;
break loop;
}
if ((int) CurrentNode.charAt(i) < (int) PreviousNode.charAt(i)) {
result = false;
break loop;
} else if (CurrentNode.charAt(i) == PreviousNode.charAt(i) && CurrentNode.length() > PreviousNode.length()) {
System.out.println("I'm here");
tempCheck = tempCheck + CurrentNode.charAt(i) + "";
if (i == loopLength - 1 && tempCheck.equals(PreviousNode)) {
result = true;
break loop;
}
}
}
return result;
}
public int determineLoopLength(String CurrentNode, String PreviousNode) {
int loopLength = 0;
if (CurrentNode.length() < PreviousNode.length()) {
loopLength = CurrentNode.length();
}
if (PreviousNode.length() < CurrentNode.length()) {
loopLength = PreviousNode.length();
} else {
loopLength = CurrentNode.length();
}
return loopLength;
}
}
WTF一直在研究这个问题,.....
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
@SuppressWarnings("serial")
public class DragMyFields extends JPanel {
private static final int PREF_W = 1000;
private static final int PREF_H = 800;
private static final int COLS = 8;
private static final int DELTA_Y = 120;
private static final int MAX_DEPTH = 3;
private MySimpleTreeNode<JTextField> treeRoot = new MySimpleTreeNode<>();
private MyMouse myMouse = new MyMouse();
public DragMyFields() {
setLayout(null); // this is *** BAD ***
// much better would be to create a custom layout
JTextField field = new JTextField(COLS);
field.addMouseListener(myMouse);
field.addMouseMotionListener(myMouse);
field.setSize(field.getPreferredSize());
int x = (PREF_W - field.getPreferredSize().width) / 2;
int y = DELTA_Y;
field.setLocation(x, y);
add(field);
treeRoot.setNode(field);
recursiveCreateTree(treeRoot, MAX_DEPTH, x, y);
}
private void recursiveCreateTree(MySimpleTreeNode<JTextField> node, int depth, int x, int y) {
if (depth == 0) {
return;
}
JTextField leftField = new JTextField(COLS);
JTextField rightField = new JTextField(COLS);
MySimpleTreeNode<JTextField> leftNode = new MySimpleTreeNode<>(leftField);
MySimpleTreeNode<JTextField> rightNode = new MySimpleTreeNode<>(rightField);
node.setLeft(leftNode);
node.setRight(rightNode);
int multiplier = 4;
for (int i = 0; i < MAX_DEPTH - depth; i++) {
multiplier *= 2;
}
int xL = x - getPreferredSize().width / multiplier;
int xR = x + getPreferredSize().width / multiplier;
y += DELTA_Y;
leftField.setSize(leftField.getPreferredSize());
rightField.setSize(rightField.getPreferredSize());
leftField.setLocation(xL, y);
rightField.setLocation(xR, y);
leftField.addMouseListener(myMouse);
leftField.addMouseMotionListener(myMouse);
rightField.addMouseListener(myMouse);
rightField.addMouseMotionListener(myMouse);
add(leftField);
add(rightField);
recursiveCreateTree(leftNode, depth - 1, xL, y);
recursiveCreateTree(rightNode, depth - 1, xR, y);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
recursiveDraw(g, treeRoot);
}
private void recursiveDraw(Graphics g, MySimpleTreeNode<JTextField> node) {
MySimpleTreeNode<JTextField> left = node.getLeft();
MySimpleTreeNode<JTextField> right = node.getRight();
Point p = getNodeCenter(node);
if (left != null) {
Point p2 = getNodeCenter(left);
g.drawLine(p.x, p.y, p2.x, p2.y);
recursiveDraw(g, left);
}
if (right != null) {
Point p2 = getNodeCenter(right);
g.drawLine(p.x, p.y, p2.x, p2.y);
recursiveDraw(g, right);
}
}
private Point getNodeCenter(MySimpleTreeNode<JTextField> node) {
JTextField field = node.getNode();
Point location = field.getLocation();
Dimension size = field.getSize();
return new Point(location.x + size.width / 2, location.y + size.height / 2);
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private class MyMouse extends MouseAdapter {
Component source = null;
private Point pressedP;
private Point pressedLoc;
private Point parentP;
@Override
public void mousePressed(MouseEvent e) {
if (e.getButton() != MouseEvent.BUTTON1) {
return;
}
source = e.getComponent();
parentP = source.getParent().getLocationOnScreen();
pressedLoc = source.getLocationOnScreen();
pressedP = e.getLocationOnScreen();
}
@Override
public void mouseReleased(MouseEvent e) {
moveComponent(e);
source = null;
pressedP = null;
pressedLoc = null;
}
@Override
public void mouseDragged(MouseEvent e) {
if (source == null) {
return;
}
moveComponent(e);
}
private void moveComponent(MouseEvent e) {
Point p = e.getLocationOnScreen();
int x = pressedLoc.x + p.x - pressedP.x - parentP.x;
int y = pressedLoc.y + p.y - pressedP.y - parentP.y;
Point newP = new Point(x, y);
source.setLocation(newP);
repaint();
}
}
private static void createAndShowGui() {
DragMyFields mainPanel = new DragMyFields();
JFrame frame = new JFrame("DragMyFields");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
createAndShowGui();
});
}
}
class MySimpleTreeNode<T> {
private T node;
private MySimpleTreeNode<T> left;
private MySimpleTreeNode<T> right;
public MySimpleTreeNode() {
// default constructor
}
public MySimpleTreeNode(T node) {
this.node = node;
}
public void setNode(T node) {
this.node = node;
}
public T getNode() {
return node;
}
public MySimpleTreeNode<T> getLeft() {
return left;
}
public void setLeft(MySimpleTreeNode<T> left) {
this.left = left;
}
public MySimpleTreeNode<T> getRight() {
return right;
}
public void setRight(MySimpleTreeNode<T> right) {
this.right = right;
}
}