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Ich schrieb ein Programm, mit dem ein Benutzer Knoten hinzufügen und sie mit Kanten mit einer GUI-Schnittstelle verbinden kann. Der erste Knoten ist immer mit "0" gekennzeichnet. Wenn ich die findPath-Methode aufruft, zeigt sie jedoch den gesamten Pfad an, ohne die 0 zu haben. Wenn ich zum Beispiel den Pfad von 0-4 finden will und sie alle numerisch verbunden sind, wird [1,2,3,4 angezeigt ]. Um nach dem Verbinden der Knoten einen korrekten Pfad zu erhalten, müssen Sie die Druck-Adjazenz-Schaltfläche drücken. Alles andere läuft wie erwartet, aber ich kann nicht herausfinden, warum der erste Knoten nicht hinzugefügt wird.GUI Edge to Node Rekursiver Pfad nicht ersten Index des Pfades
Danke Jungs!
import javax.swing.JFrame;//imports JFrame package
public class Graph//class header
{
public static void main (String[] args)//main method
{
JFrame frame = new JFrame ("Directed Graph");//sets variable frame to a JFrame object and titles it
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);//exits application when it is closed
frame.getContentPane().add (new GraphPanel());//adding GraphPanel() to the frame
frame.setLocationRelativeTo(null);//sets location to the center
frame.pack();//packs the frame, fits everything inside
frame.setVisible(true);//makes frame visible
}
}
import java.util.ArrayList;//all of these are the required to get classes from other packages
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JPanel;
public class GraphPanel extends JPanel
{
private final int SIZE = 10; // radius of each node
private double alpha; // double variable to define later
private JButton print, create, delete, path1; //allpath;//button variables
private JTextField label, label1;
boolean mode = true;//sets boolean for entire class to true, until later when I define it as false for certain methods to be complete
String x1, y1;
String str1 = new String("Mode Chosen Is : create");//when you choose create it will print this instead
String str2 = new String("Mode Chosen Is : delete");//when you choose delete it will print this
int x, y;
int mode1 = 1; // int mode1 variable, will comment why i need this when it is later defined/changed
private Point point1 = null, point2 = null, point3 = null;//makes pointers null, i added a third pointer to put the distance from the first drawn string at the top right, but no longer needed it
//keeping it incase I wanted to add it again
private ArrayList<Point> nodeList; // Graph nodes
private ArrayList<Edge> edgeList; // Graph edges
static private int[][] a = new int[100][100]; // Graph adjacency matrix
static ArrayList<Integer> path = new ArrayList<Integer>();
public GraphPanel()
{
nodeList = new ArrayList<Point>();//declares ArrayList<Point>
edgeList = new ArrayList<Edge>();//declares ArrayList<Edge>
GraphListener listener = new GraphListener();//assigns 'listener' to a Graphlistener object
addMouseListener (listener);//accepts and reads mouseListener methods to the GraphListener object
addMouseMotionListener (listener);//accepts and reads MouseMotionListener methods to the GraphListener object
label = new JTextField (1);
label1 = new JTextField (1);
//allpath = new JButton ("Find All Paths");
path1 = new JButton ("Find Path");//path button
create = new JButton("Create");//declares 'create' as a JButton object with text on it that says 'create'
delete = new JButton("Delete");//declares 'delete' as a JButton object with text that says 'delete'
JButton print = new JButton("Print adjacency matrix");//declares 'print' as a JButton object with text that reads 'print adjacency matrix'
print.addActionListener (new ButtonListener());//adds an action listener to the print button from the buttonlistener object
create.addActionListener (new ButtonListener1());//adds an actionListener to the create button from the buttonlistener1 object
delete.addActionListener (new ButtonListener2());//adds an actionliseneer to the delete button from the buttonlistener2 object
path1.addActionListener (new ButtonListener3());//adds button that will find path of nodes
//allpath.addActionListener (new ButtonListener4());
setBackground (Color.black);//sets backround as black
setPreferredSize (new Dimension(400, 300));//this is preferred size of graphpanel
add(print);//these next six add()'s add each button to GraphPanel
add(delete);//
add(create);//
//add(allpath);
add(path1);
add(label);
add(label1);
}
public static boolean findPath(int x, int y) //boolean method findpath that takes two ints as parameters
{
boolean found = false;
if (a[x][y]==1) //base case
{
//System.out.println(x + " -> " + y);//prints node -> node
found = true;//path is found
path.add(0,y);
}
else
{
int z;
for (z=0; !found& z<a.length; z++)
{
if (a[x][z]==1)
{
a[x][z]=2;
found = findPath(z,y);
}
if (found)
{
//System.out.println(x + " -> " + z);
path.add(0,z);
}
}
}
if (!found){
System.out.println("Path Does Not Exist");
}
return found;
}
// public static ArrayList findPath1(int x, int y, ArrayList path)
// {
// System.out.println("CALL FIND: " + path);
// ArrayList path2 = null;
// if (a[x][y]==1)
// {
// ArrayList path3 = (ArrayList)path.clone();
// path3.add(y);
// System.out.println("EXIT BASE: " + path3);
// path2 = path3;
// }
// else
// {
// int z;
// for (z=0; z<a.length; z++)
// if (a[x][z]==1)
// {
// ArrayList path3 = (ArrayList)path.clone();
// path3.add(z);
// path3 = findPath1(z,y,path3);
// System.out.println("EXIT RECU: " + path);
// path2 = path3;
// }
// }
// return path2;
// }
// Draws the graph
public void paintComponent (Graphics page)
{
super.paintComponent(page);//using parent methods
// Draws the edge that is being dragged
page.setColor (Color.green);//setting color of what will be drawn to green
if (mode1 == 1)//if mode1 is set to 1, which is when the create button is selected
{
page.drawString(str1, 125, 75);//then this is printed
}
if (mode1 == 2)//if mode1 is set to 2, which is when the delete button is selected
{
page.drawString(str2, 125, 75);//then this is printed
}
if (point1 != null && point2 != null)//if and only if both points are not null
{
page.drawLine (point1.x, point1.y, point2.x, point2.y);//then it draws the line from between point1(x, y cords), and point2(x, y cords)
page.fillOval (point2.x-3, point2.y-3, 6, 6);//fills this oval by the rectangle it is specified from
}
// Draws the nodes
for (int i=0; i<nodeList.size(); i++) //for loop going through the nodeList ArrayList
{
page.setColor (Color.green);//color is set to green
page.fillOval (nodeList.get(i).x-SIZE, nodeList.get(i).y-SIZE, SIZE*2, SIZE*2);//fills oval by subtracting the SIZE from the x, y and setting the height and width as two times the SIZE
page.setColor (Color.black);//sets next line to black
page.drawString (String.valueOf(i), nodeList.get(i).x-SIZE/2, nodeList.get(i).y+SIZE/2);//writes inside the node what number index it is from the ArrayList with black text
}
// Draws the edges
for (int i=0; i<edgeList.size(); i++) // for loop going through the edgeList ArrayList
{
page.setColor (Color.green);//sets the next line to green
page.drawLine (edgeList.get(i).a.x, edgeList.get(i).a.y,edgeList.get(i).b.x, edgeList.get(i).b.y);//draws the line from x and y cords of where it starts to end
//page.fillOval (edgeList.get(i).b.x-3, edgeList.get(i).b.y-3, 6, 6);
//page.drawString (String.valueOf(point1.x*(point2.y-point3.y)+point2.x*(point3.y-point1.y)+point3.x*(point1.y-point2.y)), 5, 15);
alpha = Math.atan((double)(edgeList.get(i).b.y-edgeList.get(i).a.y)/(edgeList.get(i).b.x-edgeList.get(i).a.x));//alpha = b.y-a.y cords/b.x-a.x chords as a double variable
if (edgeList.get(i).a.x > edgeList.get(i).b.x)//if the x chord of a is greater than the x cordinate of b
{
alpha = alpha + Math.PI;//then alpha = previously defined alpha multiplied by PI
}
if (edgeList.get(i).a.x < edgeList.get(i).b.x && edgeList.get(i).a.y > edgeList.get(i).b.y)//if a.x is less than b.x and a.y is less than b.y
{
alpha = alpha + 2*Math.PI;//then alpha becomes the previously defined alpha multiplied by 2 PI
}
arrow(page,edgeList.get(i).b.x,edgeList.get(i).b.y,0,1.57-alpha);//arrow method, taking a x(edgeList.get(i).b.x, y(edgeList.get(i).b.y, length = 0 so arrow is at the
// very end of the drawn line subtracted by a double aplha
}
}
// arrow method to call when making an arrow
private void arrow(Graphics page, int x, int y, int len, double alpha)//arrow method, taking a x, y, length and double parameter
{
page.setColor (Color.green);//sets arrow to green
int x1 = x+(int)(len*Math.sin(alpha));//x1 is set to x plus length *sin of alpha
int y1 = y+(int)(len*Math.cos(alpha));//y1 is set to y plus the length * cosin of alpha
page.drawLine (x, y, x1, y1);//drawa the x and y, and then previously defined x1, and y1
page.drawLine (x1, y1, x1+(int)(20*Math.sin(alpha+2.5)), y1+(int)(20*Math.cos(alpha+2.5)));//arithmatic to draw one side of the line for the arrow
page.drawLine (x1, y1, x1+(int)(20*Math.sin(alpha+3.7)), y1+(int)(20*Math.cos(alpha+3.7)));//arithmatic to draw the corresponding line for the arrow to complete the arrow
}
// The listener for mouse events.
private class GraphListener implements MouseListener, MouseMotionListener//GraphListener which implements MouseListener and MouseMotionListener, meaning it takes methods from both of those classes
{
public void mouseClicked (MouseEvent event)//when mouse is clicked and released
{
if (mode == true)//if the mode is true
{
nodeList.add(event.getPoint());//the current point to the nodeList
repaint();//whenever you change the look of a componenet you call this method
}
if (mode == false)//if boolean mode is false
{
for (int i=0; i<nodeList.size(); i++)//for loop to go through the nodeList ArrayList
{
if (distance(nodeList.get(i), event.getPoint()) < SIZE)//if the distance between a specific node and the pointer is less than the radius of the node (SIZE)
nodeList.remove(i);//then remove that node
}
for (int i=0; i<edgeList.size(); i++)
{
if (distance(edgeList.get(i).a, event.getPoint())+distance(event.getPoint(), edgeList.get(i).b)-distance(edgeList.get(i).a, edgeList.get(i).b) < SIZE)
//if the (distance between starting point of that edgelist index and the current point) plus (the distance between the current point and ending point of that edgeList index)
//subtracted by the (distance of the starting and ending point of that edgeList index)(AB+BC-AC) is all less than the size
edgeList.remove(i);//then remove that index
}
}
}
public void mousePressed (MouseEvent event)//when the mouse is pressed down
{
if (mode == true)//if the mode is true
{
point1 = event.getPoint();//you start that point
}
}
public void mouseDragged (MouseEvent event)//when the mouse is dragged while pressed down
{
if (mode == true)//if the mode is true
{
point2 = event.getPoint();//then you get the second point
repaint();//must use this method because you are making a change to the component
}
}
public void mouseReleased (MouseEvent event)//when the mouse is released after being pressed (not to be confused with a click)
{
if (mode == true)//if the mode is true
{
point2 = event.getPoint();//then you set point2 to where that point landed
if (point1.x != point2.x && point1.y != point2.y)//if the points are not in the same spots
{
edgeList.add(new Edge(point1,point2));//then you add a new edgeList element to the ArrayList, by definition of Edge() object
repaint();//must use this method because changes to component have been made
}
}
}
public void mouseMoved (MouseEvent event)// if the mouse is moved, without it being clicked (not to be confused by mouseDragged)
{
point3 = event.getPoint();//point three is set to be where the mouse is at the current time(used this to find the distance of original edge drawn, keeping here incase I want to add)
repaint();//must use this method because changes were made to component
}
// Empty definitions for unused event methods.
public void mouseEntered (MouseEvent event){}//when the mouse enters a component
public void mouseExited (MouseEvent event) {}//when the mouse exits a component
private int distance(Point p1, Point p2) //private distance formula but inside of this class so i was able to use it for determining how to erase nodes and edges
{
return (int)Math.sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));//square root of x cordinants of first point minus second point times its self plus the y coordinates
//of first point minus second point times itself
}
}
// Represents the graph edges
private class Edge //defines how edges are made
{
Point a, b;
public Edge(Point a, Point b)
{
this.a = a;
this.b = b;
}
}
private class ButtonListener implements ActionListener
{
public void actionPerformed (ActionEvent event)
{
if (event.getSource()== create)
{
mode = true;
mode1 = 1;
}
if (event.getSource()==delete)
{
mode = !true;
mode1 = 2;
}
// Initializes graph adjacency matrix
for (int i=0; i<nodeList.size(); i++)
for (int j=0; j<nodeList.size(); j++) a[i][j]=0;
// Includes the edges in the graph adjacency matrix
for (int i=0; i<edgeList.size(); i++)
{
for (int j=0; j<nodeList.size(); j++)
if (distance(nodeList.get(j),edgeList.get(i).a)<=SIZE+3)
for (int k=0; k<nodeList.size(); k++)
if (distance(nodeList.get(k),edgeList.get(i).b)<=SIZE+3)
{
System.out.println(j+"->"+k);
a[j][k]=1;
}
}
if (event.getSource()==print)
{
// Prints the graph adjacency matrix
for (int i=0; i<nodeList.size(); i++)
{
for (int j=0; j<nodeList.size(); j++)
System.out.print(a[i][j]+"\t");
System.out.println();
}
}
}
// Euclidean distance function
private int distance(Point p1, Point p2)
{
return (int)Math.sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));
}
}
private class ButtonListener1 implements ActionListener
{
public void actionPerformed (ActionEvent event)
{
if (event.getSource()== create)//if create button is selected
{
mode = true;//then the mode is set to true
mode1 = 1;//and mode1 is set to 1
}
}
}
private class ButtonListener2 implements ActionListener
{
public void actionPerformed (ActionEvent event)
{
if (event.getSource()== delete)//if create button is selected
{
mode = !true;//then the mode is set to true
mode1 = 2;//and mode1 is set to 2, which would change the string that is output
}
}
}
private class ButtonListener3 implements ActionListener
{
public void actionPerformed (ActionEvent event)
{
x1 = label.getText();
y1 = label1.getText();
x = Integer.parseInt(x1);
y = Integer.parseInt(y1);
System.out.println("Path from " +x+" to " +y);
System.out.println(findPath(x,y));
System.out.println(path);
}
}
Dank Mann, aber ich versuchte es und es gab mir ein wenig mehr Probleme, war der Trick, um es einfach in der button Klasse hinzufügen, nachdem Sie FindPath rufen und dann das Array zu löschen, so dass, wenn Sie es klicken als Sobald es nicht weiter den gleichen Pfad hinzufügen und ein riesiges Array erstellen – alwaysquestioning
Nun, das ist auch eine Lösung. Aber ich bin nur neugierig, was war das Problem mit meinem Code? –