简介
GridBagLayout
网格组布局
java 核心编程
code
/*
* @Author: your name
* @Date: 2020-11-08 12:48:42
* @LastEditTime: 2020-11-08 12:49:12
* @LastEditors: your name
* @Description: In User Settings Edit
* @FilePath: /java/swing/FontFrame.java
*/
package swing;
import java.awt.Font;
import java.awt.GridBagLayout;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextArea;
/**
* A frame that uses a grid bag layout to arrange font selection components.
*/
public class FontFrame extends JFrame {
public static final int TEXT_ROWS = 10;
public static final int TEXT_COLUMNS = 20;
private JComboBox<String> face;
private JComboBox<Integer> size;
private JCheckBox bold;
private JCheckBox italic;
private JTextArea sample;
public FontFrame() {
var layout = new GridBagLayout();
setLayout(layout);
ActionListener listener = event -> updateSample();
// construct components
var faceLabel = new JLabel("Face: ");
face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced", "Dialog", "DialogInput" });
face.addActionListener(listener);
var sizeLabel = new JLabel("Size: ");
size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 });
size.addActionListener(listener);
bold = new JCheckBox("Bold");
bold.addActionListener(listener);
italic = new JCheckBox("Italic");
italic.addActionListener(listener);
sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
sample.setText("The quick brown fox jumps over the lazy dog");
sample.setEditable(false);
sample.setLineWrap(true);
sample.setBorder(BorderFactory.createEtchedBorder());
// add components to grid, using GBC convenience class
add(faceLabel, new GBC(0, 0).setAnchor(GBC.EAST));
add(face, new GBC(1, 0).setFill(GBC.HORIZONTAL).setWeight(100, 0).setInsets(1));
add(sizeLabel, new GBC(0, 1).setAnchor(GBC.EAST));
add(size, new GBC(1, 1).setFill(GBC.HORIZONTAL).setWeight(100, 0).setInsets(1));
add(bold, new GBC(0, 2, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
add(italic, new GBC(0, 3, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
add(sample, new GBC(2, 0, 1, 4).setFill(GBC.BOTH).setWeight(100, 100));
pack();
updateSample();
}
public void updateSample() {
var fontFace = (String) face.getSelectedItem();
int fontStyle = (bold.isSelected() ? Font.BOLD : 0) + (italic.isSelected() ? Font.ITALIC : 0);
int fontSize = size.getItemAt(size.getSelectedIndex());
var font = new Font(fontFace, fontStyle, fontSize);
sample.setFont(font);
sample.repaint();
}
}
package swing;
import java.awt.*;
/**
* This class simplifies the use of the GridBagConstraints class.
*
* @version 1.01 2004-05-06
* @author Cay Horstmann
*/
public class GBC extends GridBagConstraints {
/**
* Constructs a GBC with a given gridx and gridy position and all other grid bag
* constraint values set to the default.
*
* @param gridx the gridx position
* @param gridy the gridy position
*/
public GBC(int gridx, int gridy) {
this.gridx = gridx;
this.gridy = gridy;
}
/**
* Constructs a GBC with given gridx, gridy, gridwidth, gridheight and all other
* grid bag constraint values set to the default.
*
* @param gridx the gridx position
* @param gridy the gridy position
* @param gridwidth the cell span in x-direction
* @param gridheight the cell span in y-direction
*/
public GBC(int gridx, int gridy, int gridwidth, int gridheight) {
this.gridx = gridx;
this.gridy = gridy;
this.gridwidth = gridwidth;
this.gridheight = gridheight;
}
/**
* Sets the anchor.
*
* @param anchor the anchor value
* @return this object for further modification
*/
public GBC setAnchor(int anchor) {
this.anchor = anchor;
return this;
}
/**
* Sets the fill direction.
*
* @param fill the fill direction
* @return this object for further modification
*/
public GBC setFill(int fill) {
this.fill = fill;
return this;
}
/**
* Sets the cell weights.
*
* @param weightx the cell weight in x-direction
* @param weighty the cell weight in y-direction
* @return this object for further modification
*/
public GBC setWeight(double weightx, double weighty) {
this.weightx = weightx;
this.weighty = weighty;
return this;
}
/**
* Sets the insets of this cell.
*
* @param distance the spacing to use in all directions
* @return this object for further modification
*/
public GBC setInsets(int distance) {
this.insets = new Insets(distance, distance, distance, distance);
return this;
}
/**
* Sets the insets of this cell.
*
* @param top the spacing to use on top
* @param left the spacing to use to the left
* @param bottom the spacing to use on the bottom
* @param right the spacing to use to the right
* @return this object for further modification
*/
public GBC setInsets(int top, int left, int bottom, int right) {
this.insets = new Insets(top, left, bottom, right);
return this;
}
/**
* Sets the internal padding
*
* @param ipadx the internal padding in x-direction
* @param ipady the internal padding in y-direction
* @return this object for further modification
*/
public GBC setIpad(int ipadx, int ipady) {
this.ipadx = ipadx;
this.ipady = ipady;
return this;
}
}
/*
* @Author: your name
* @Date: 2020-11-08 12:50:49
* @LastEditTime: 2020-11-08 12:51:16
* @LastEditors: your name
* @Description: In User Settings Edit
* @FilePath: /java/swing/GridBagLayoutTest.java
*/
package swing;
import java.awt.EventQueue;
import javax.swing.JFrame;
/**
* @version 1.36 2018-04-10
* @author Cay Horstmann
*/
public class GridBagLayoutTest {
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
var frame = new FontFrame();
frame.setTitle("GridBagLayoutTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
});
}
}