How to arrange multiple panels in JFrame
I am trying to make a simple calculator to practice Graphics (i am a complete GUI noob). I am having some problems with having unneeded spaces after Polyashenkos Calulator and the text area and the space between the text area and the buttons. Also how do i keep that layout but eliminate the space and also make the bottom 3 buttons smaller. Any tips about what im doing or how i can do it better would be much appreciated. Thank you.
import javax.swing.*;
import java.awt.*;
public class calculator {
public static void main(String[] args) {
// creates the JFrame(a window with decorations)
JFrame frame = new JFrame("Calculator");
// stops the program when window is closed
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(377, 350);
// the main panel of the JFrame,
// remembet you cant add content directly to JFrame
JPanel content = new JPanel(new GridLayout(4, 0));
// panel for the text field
JPanel textarea = new JPanel(new GridLayout(4, 0));
// panel for the buttons,
// GridLayout(int rows, int cols, int horiz_gap, int vert_gap)
JPanel buttonarea = new JPanel(new GridLayout(4, 5, 2, 2));
// the panel for the bigger bottom buttons
JPanel secondbuttonarea = new JPanel(new GridLayout(1, 1, 2, 2));
// the panel for the text on top
JPanel label = new JPanel();
content.add(label);
content.add(textarea);
content.add(buttonarea);
content.add(secondbuttonarea);
JLabel words = new JLabel("Polyashenko's Calculator", JLabel.CENTER);
label.add(words);
JTextField enterhere = new JTextField("0.", JTextField.CENTER);
// will set the curser of the text bar on right side
enterhere.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
textarea.add(enterhere);
// makes a button called b1 with text in it
JButton b1 = new JButton("BkSP");
// adds the backspace button to the buttonarea panel
buttonarea.add(b1);
JButton b2 = new JButton("CE");
buttonarea.add(b2);
JButton b3 = new JButton("C");
buttonarea.add(b3);
JButton b4 = new JButton("/");
buttonarea.add(b4);
JButton b5 = new JButton("sqrt");
buttonarea.add(b5);
JButton b6 = new JButton("7");
buttonarea.add(b6);
JButton b7 = new JButton("8");
buttonarea.add(b7);
JButton b8 = new JButton("9");
buttonarea.add(b8);
JButton b9 = new JButton("*");
buttonarea.add(b9);
JButton b10 = new JButton("%");
buttonarea.add(b10);
JButton b11 = new JButton("4");
buttonarea.add(b11);
JButton b12 = new JButton("5");
buttonarea.add(b12);
JButton b13 = new JButton("6");
buttonarea.add(b13);
JButton b14 = new JButton("-");
buttonarea.add(b14);
JButton b15 = new JButton("1/x");
buttonarea.add(b15);
JButton b16 = new JButton("1");
buttonarea.add(b16);
JButton b17 = new JButton("2");
buttonarea.add(b17);
JButton b18 = new JButton("3");
buttonarea.add(b18);
JButton b19 = new JButton("+");
buttonarea.add(b19);
JButton b20 = new JButton("+/-");
buttonarea.add(b20);
JButton b21 = new JButton("0");
secondbuttonarea.add(b21);
JButton b22 = new JButton(".");
secondbuttonarea.add(b22);
JButton b23 = new JButton("=");
secondbuttonarea.add(b23);
// adds the buttonarea panel to the main panel
frame.getContentPane().add(content);
// makes the window visible, put at end of program
frame.setVisible(true);
}
}
Answer
one of lessons by Hovercraft Full Of Eels (-: forums.sun.com :-)
import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Window;
import java.awt.event.*;
import javax.swing.*;
public class SciCalc {
private static void createAndShowUI() {
SciCalcGui gui = new SciCalcGui();
SciCalcMenu menu = new SciCalcMenu(gui);
JFrame frame = new JFrame("Calculator");
frame.getContentPane().add(gui.getMainPanel());
frame.setJMenuBar(menu.getJMenuBar());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
createAndShowUI();
}
});
}
private SciCalc() {
}
}
class SciCalcGui {
private static final String[][] STANDARD_BTN_TEXTS = {
{"7", "8", "9", "/"}, {"4", "5", "6", "*"},
{"1", "2", "3", "-"}, {"0", ".", "=", "+"}};
private static final String[][] SCIENTIFIC_BTN_TEXTS = {
{"sqrt", "1/x", "sin"}, {"%", "Exp", "cos"},
{"x^y", "ln", "tan"}, {"x^2", "n!", "sec"}};
private static final int GAP = 5;
private static final Font BTN_FONT = new Font(Font.DIALOG, Font.BOLD, 20);
private JPanel mainPanel = new JPanel();
private JPanel sciPanel;
private JTextField display = new JTextField();
SciCalcGui() {
display.setFont(BTN_FONT);
JPanel standardPanel = createBtnPanel(STANDARD_BTN_TEXTS, "Standard");
sciPanel = createBtnPanel(SCIENTIFIC_BTN_TEXTS, "Scientific");
mainPanel.setLayout(new BorderLayout());
mainPanel.setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
mainPanel.add(standardPanel, BorderLayout.CENTER);
mainPanel.add(sciPanel, BorderLayout.WEST);
mainPanel.add(display, BorderLayout.NORTH);
sciPanel.setVisible(false);
}
public void sciPanelSetVisible(boolean visible) {
sciPanel.setVisible(visible);
Window win = SwingUtilities.getWindowAncestor(mainPanel);
win.pack();
}
public JPanel getMainPanel() {
return mainPanel;
}
private JPanel createBtnPanel(String[][] texts, String title) {
JPanel btnPanel = new JPanel();
int rows = texts.length;
int cols = texts[0].length;
btnPanel.setLayout(new GridLayout(rows, cols, GAP, GAP));
for (int row = 0; row < texts.length; row++) {
for (int col = 0; col < texts[row].length; col++) {
JButton btn = new JButton(texts[row][col]);
btn.setFont(BTN_FONT);
btnPanel.add(btn);
}
}
btnPanel.setBorder(BorderFactory.createTitledBorder(title));
return btnPanel;
}
}
class SciCalcMenu {
private static final String STANDARD = "Standard";
private static final String SCIENTIFIC = "Scientific";
private SciCalcGui gui;
private JMenuBar menuBar = new JMenuBar();
private JMenuItem standardView;
private JMenuItem scientificView;
SciCalcMenu(SciCalcGui gui) {
this.gui = gui;
standardView = new JMenuItem(STANDARD, KeyEvent.VK_T);
scientificView = new JMenuItem(SCIENTIFIC, KeyEvent.VK_S);
ViewAction viewAction = new ViewAction();
standardView.addActionListener(viewAction);
scientificView.addActionListener(viewAction);
standardView.setEnabled(false);
JMenu viewMenu = new JMenu("View");
viewMenu.setMnemonic(KeyEvent.VK_V);
viewMenu.add(standardView);
viewMenu.add(scientificView);
menuBar.add(new JMenu("Edit"));
menuBar.add(viewMenu);
menuBar.add(new JMenu("Help"));
}
public JMenuBar getJMenuBar() {
return menuBar;
}
private class ViewAction implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
String command = e.getActionCommand();
if (command.equals(STANDARD)) {
gui.sciPanelSetVisible(false);
standardView.setEnabled(false);
scientificView.setEnabled(true);
} else if (command.equals(SCIENTIFIC)) {
gui.sciPanelSetVisible(true);
standardView.setEnabled(true);
scientificView.setEnabled(false);
}
}
}
}