Java – add graphics to JFrame using borderlayout
I'm trying to do a simple job where I display a line of text to show whether the door object is open Below it, I visually represent its (using drawRect) method At the bottom I have two buttons that can open or close the door to change the text and rectangle
Edit: list of codes that can now be compiled:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Test {
public static void main(String[] args) {
// Creates new JFrame called frame,with title "Door"
// (displayed at top of screen).
JFrame frame = new JFrame ("Door");
frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
TempDoorPanel panel = new TempDoorPanel();
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
}
class Door {
private String state;
private String message;
Door (String state) {
this.state = state;
message = "The door is currently closed.";
}
public boolean isopen() {
return state.equals ("open");
}
public boolean isClosed() {
return state.equals ("closed");
}
public void setState(String state) {
this.state = state;
}
public String getMessage() {
return message;
}
public void open() {
if (state.equals("open")) {
message = "The door is already open.";
}
else {
state = "open";
message = "The door has been opened.";
}
}
public void drawOpenDoor (Graphics page) {
page.drawRect(100,100,100);
}
}
class TempDoorPanel extends JPanel {
private Door door;
private JTextField currentStateOfDoor;
private JButton openDoor;
public TempDoorPanel() {
super.setLayout(new BorderLayout());
door = new Door("closed");
super.setBackground(Color.blue);
super.setPreferredSize(new Dimension (360,400));
currentStateOfDoor = new JTextField(14);
currentStateOfDoor.setText(door.getMessage());
super.add(currentStateOfDoor,BorderLayout.NORTH);
openDoor = new JButton("Open Door");
class openDoorListener implements ActionListener {
public void actionPerformed (ActionEvent event) {
door.open();
repaintText();
}
}
openDoorListener openlistener = new openDoorListener();
openDoor.addActionListener(openlistener);
JPanel holder = new JPanel();
holder.add(openDoor);
super.add(holder,BorderLayout.soUTH);
}
private void repaintText() {
currentStateOfDoor.setText(door.getMessage());
// These methods are from Door class.
}
public void paintComponent (Graphics page) {
super.paintComponent(page);
if (door.isopen())
door.drawOpenDoor(page);
// isOpen is a boolean method from Door class.
}
}
What works:
>The button appears in the correct position on the screen, in borderlayout South, one by one. > Jtextfield appears in borderlayout Correct position of North > finally, the blue area appears in the correct position in the center of the screen
Problems I am trying to solve:
>I don't know how to display the rectangle correctly in the middle of the blue area I've tried to change the coordinates and size of the rectangle, which won't change its size at all I can use it as drawRect (100100) and it doesn't change anything. > I also know that the rectangle is currently hidden behind the upper left corner of jtextfield, but I can't figure out how to move it into borderlayout
Question:
>How do I place a rectangle in borderlayout? > In such a layout, how to adjust the size of the rectangle drawn by drawrect()?
Solution
Because you add components to JPanel, what you draw on jtextfield will overwrite your drawing
Solution:
1) By checking drawRect (..) Method to compensate for this
Or better
2) Do not add components to the same JPanel you are drawing unless you cannot help
So basically, I asked your tempdoorpanel to add a new JPanel to borderlayout Center, this is the drawing panel we can now use drawRect (0,10,10), which will be displayed in the upper left corner of JPanel DrawingPanel
>Instead of calling setpreferredsize in JPanel, override getpreferredsize() and return dimensions that are appropriate for your drawing. > To call paintcomponent outside the class, simply call the repaint () instance
See example of using point 2:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class Test {
public static void main(String[] args) {
SwingUtilities.invokelater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame("Door");
frame.setDefaultCloSEOperation(JFrame.DISPOSE_ON_CLOSE);
TempDoorPanel panel = new TempDoorPanel();
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
});
}
}
class Door {
private String state;
private String message;
public Door(String state) {
this.state = state;
message = "The door is currently closed.";
}
public void drawOpenDoor(Graphics page) {
page.setColor(Color.GREEN);
page.drawRect(0,10);
}
}
class TempDoorPanel extends JPanel {
private Door door;
private JTextField currentStateOfDoor;
private JButton openDoor;
public TempDoorPanel() {
super.setLayout(new BorderLayout());
door = new Door("closed");
currentStateOfDoor = new JTextField(14);
//AcurrentStateOfDoor.setText(door.getMessage());
super.add(currentStateOfDoor,BorderLayout.NORTH);
openDoor = new JButton("Open Door");
final JPanel drawingPanel = new JPanel() {
@Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
// if (door.isopen()) {
door.drawOpenDoor(grphcs);
// }
// isOpen is a boolean method from Door class.
}
};
drawingPanel.setBackground(Color.blue);
add(drawingPanel);
class openDoorListener implements ActionListener {
public void actionPerformed(ActionEvent event) {
//door.open();
repaintText();
drawingPanel.repaint();//so paint component of drawing panel is called
}
}
openDoorListener openlistener = new openDoorListener();
openDoor.addActionListener(openlistener);
JPanel holder = new JPanel();
holder.add(openDoor);
super.add(holder,BorderLayout.soUTH);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(300,300);
}
private void repaintText() {
// currentStateOfDoor.setText(door.getMessage());
// These methods are from Door class.
}
}