Java，GridBagLayout.如何将组件正确添加到其他组件 [英] Java, GridBagLayout. How add components right to other component
问题描述
我正在学习JSwing，发现了GridBagLayout.
我正在尝试创建一个简单的计算器，我通过添加多个JPanel设置来做到这一点(每个preferredSize)，但是当我调整窗口框架的大小时，面板也不会调整大小.然后我找到了GridBagLayout.
但这就是我得到的:
i'm learning JSwing and i discovered the GridBagLayout.
I'm trying to create a simple calculator, i did it with adding multiple JPanel setting each preferedSize but when i resize the window frame the panels won't resize too. Then i found out the GridBagLayout.
But this i what i get: Wrong calculator with GridBagLayout
import javax.swing.*;
import java.awt.*;
public class Calc extends JFrame {
private final int WIDTH = 300;
private final int HEIGHT = 450;
public Calc(){
setSize(WIDTH, HEIGHT);
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BorderLayout());
mainPanel.add(createButtons(), BorderLayout.SOUTH);
add(mainPanel);
}
private JPanel createButtons(){
JPanel panel = new JPanel();
GridBagLayout layout = new GridBagLayout();
panel.setLayout(layout);
GridBagConstraints g = new GridBagConstraints();
g.gridx = 0;
g.gridy = 0;
for(int i = 0; i < 9; i++){
panel.add(new JButton(""+i), g);
g.gridx++;
if(g.gridx == 3) {
g.gridx = 0;
g.gridy++;
}
}
return panel;
}
public static void main(String... args){
Calc calc = new Calc();
calc.setVisible(true);
}
}
it should be something like this: Right calculator
i tried:
- to set an anchor... but it doesn't work,
- to create multiple JPanel(one with GridLayout) but doesn't work
if you don't want to spoon code, it's okay.. but from where should i start?
Edit: I figure out how to arrange the buttons... but i can't set the header to fill all the x-axis: Code:
import javax.swing.*;
import java.awt.*;
public class ButtonPanel extends JPanel {
JPanel top;
JPanel left;
JPanel right;
private class CButton extends JButton{
private Operation operation;
public CButton(){
}
}
public ButtonPanel(){
initComponent();
initLayout();
}
private void initLayout() {
GridBagLayout layout = new GridBagLayout();
this.setLayout(layout);
layout.columnWeights = new double[] {3,1};
layout.rowWeights = new double[] {1, 1};
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
c.fill = GridBagConstraints.BOTH;
c.weightx = 5;
this.add(top, c);
c.gridy++;
c.weighty=1;
this.add(left, c);
c.gridx++;
this.add(right, c);
}
private void initComponent() {
top = new JPanel();
top.setLayout(new GridLayout(1, 3));
for(int i = 0; i < 3; i++){
top.add(new JButton("bbb"));
}
left = new JPanel();
left.setLayout(new GridLayout(3,3));
for(int i = 0; i < 9; i++){
left.add(new JButton(""+i));
}
right = new JPanel();
right.setLayout(new GridLayout(3,1));
for(int i = 0; i < 3; i++){
JButton btn = new JButton("aa");
right.add(btn);
}
}
public static void main(String[] args) {
JFrame frame = new JFrame("test");
frame.setLayout(new BorderLayout());
frame.add(new ButtonPanel(), BorderLayout.SOUTH);
frame.setSize(300, 450);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
It should be: Image
You can probably do everything within a single panel, having some buttons that span over multiple columns.
So I give you a different example to layout buttons using a single GridBagLayout, here you can define your button arrangement as an array of values, check if it could be a good starting point for your project.
package test;
import static test.Calculator.Buttons.*;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.HashMap;
import java.util.Map;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Calculator extends JPanel {
//Here define all possible buttons with labels
public enum Buttons {
PERCENT("%"), CE("CE"), CLEAR("C"),
ONE("1"), TWO("2"), THREE("3"), FOUR("4"), FIVE("5"), SIX("6"), SEVEN("7"), EIGHT("8"), NINE("9"), ZERO("0"),
ADD("+"), SUB("-"), MULT("x"), DIV("/"), RESULT("="), DECPOINT(".");
protected String text;
Buttons(String txt) {
this.text=txt;
}
public String getText() {
return text;
}
};
//This array contains your keypad layout, contiguous repeated elements will span across multiple columns (e.g. ZERO).
protected Buttons[][] keyPad = {
{PERCENT, CE, CLEAR, DIV},
{SEVEN, EIGHT, NINE, MULT},
{FOUR, FIVE, SIX, ADD},
{ONE, TWO, THREE, SUB},
{ZERO, ZERO, DECPOINT, RESULT}
};
Map<JButton, Buttons> sourceMap=new HashMap<>();
ActionListener padListener=new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
onKeyPadPressed(sourceMap.get(e.getSource()));
}
};
public Calculator() {
setLayout(new GridBagLayout());
GridBagConstraints c=new GridBagConstraints();
c.weightx=1.0;
c.weighty=1.0;
c.fill=GridBagConstraints.BOTH;
for (int y=0;y<keyPad.length;y++) {
for (int x=0;x<keyPad[y].length;) {
Buttons b=keyPad[y][x];
if (b==null) {
continue;
}
JButton btn=new JButton(b.getText());
c.gridx=x;
c.gridy=y;
c.gridwidth=0;
while(x<keyPad[y].length&&keyPad[y][x]==b) {
c.gridwidth++;
x++;
}
add(btn,c);
sourceMap.put(btn,b);
btn.addActionListener(padListener);
}
}
}
//Callback method, whenever a button is clicked you get the associated enum value here
protected void onKeyPadPressed(Buttons b) {
System.out.println("Pressed "+b);
switch (b) {
// case ZERO:
// .... here your logic
}
}
public static void main(String[] args) {
JFrame frame=new JFrame("Calculator");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new Calculator());
frame.pack();
frame.setVisible(true);
}
}
The code above produces this result, but it's really easy to add/remove buttons and change the layout.
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