I am trying to make a chat window, but I can't seem to figure out how to make JTextArea occupy a maximum of 80% of the width space available in GridBagLayout. In other words, if the text seems to occupy the entire width of the window, it should only be able to occupy 80% of the width and just wrap the lines. Also, if the text is less than 80%, say 40%, then the JTextArea should only wrap 40% and not the whole 80%.
I'm using GridBagLayout and I've set GridBagConstraints weightx to 1.0 and the fill to HORIZONTAL with an inset of 40 either left or right, depends on the user. But I can't seem to make JTextArea to wrap the text and to allow it to use 80% of the width on the window if it needs it, otherwise wrap around the text.
Here is what my current chat window looks like:
Notice how the first entry by David should not occupy the entire width. It should only wrap the text.
Here is what I'm trying to accomplish:
Below is the current code I wrote:
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import java.awt.Rectangle;
import java.util.LinkedList;
import java.util.List;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.Scrollable;
import javax.swing.SwingUtilities;
public class ChatWindow {
private JFrame mMainFrame;
public ChatWindow(List<ChatEntry> chatContentList) {
// Create JFrame, set window size and center on screen.
mMainFrame = new JFrame();
mMainFrame.setTitle("Chat Window");
mMainFrame.setSize(360, 600);
mMainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mMainFrame.setLocationRelativeTo(null);
// Create parent container JPanel for all other JComponents.
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.weightx = 1.0;
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;
mainPanel.add(buildChatUI(chatContentList), gbc);
// Add empty JPanel as an object to fill the empty space available.
gbc.fill = GridBagConstraints.BOTH;
gbc.weighty = 1.0;
mainPanel.add(new JPanel(), gbc);
mMainFrame.getContentPane().add(new JScrollPane(new VerticalScrollPane(mainPanel)));
mMainFrame.setVisible(true);
}
public JPanel buildChatUI(List<ChatEntry> chatContentList) {
JPanel chatPanel = new JPanel();
chatPanel.setLayout(new GridBagLayout());
chatPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
GridBagConstraints gbc = new GridBagConstraints();
for (ChatEntry chatEntry : chatContentList) {
JLabel nameLabel = new JLabel(chatEntry.name);
JTextArea contentTextArea = new JTextArea();
contentTextArea.setText(chatEntry.content);
contentTextArea.setOpaque(true);
contentTextArea.setLineWrap(true);
contentTextArea.setWrapStyleWord(true);
contentTextArea.setEditable(false);
// Arrange each chat entry based on the user.
if (chatEntry.type == 1) {
contentTextArea.setBackground(Color.YELLOW);
gbc.anchor = GridBagConstraints.WEST;
}
else {
contentTextArea.setBackground(Color.CYAN);
gbc.anchor = GridBagConstraints.EAST;
}
gbc.insets.set(0, 0, 0, 0);
gbc.weightx = 1.0;
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.NONE;
chatPanel.add(nameLabel, gbc);
if (gbc.anchor == GridBagConstraints.WEST) {
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.insets.set(0, 0, 0, 40);
chatPanel.add(contentTextArea, gbc);
}
else {
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.insets.set(0, 40, 0, 0);
chatPanel.add(contentTextArea, gbc);
}
}
return chatPanel;
}
/**
* This class is used to make the JTextArea lines wrap every time the window
* is resized. Without this, the JTextArea lines will not shrink back if the
* parent window shrinks. This is achieved by returning true on getScrollableTracksViewportWidth();
*/
private class VerticalScrollPane extends JPanel implements Scrollable {
private static final long serialVersionUID = 7477168367035025136L;
public VerticalScrollPane() {
this(new GridLayout(0, 1));
}
public VerticalScrollPane(LayoutManager lm) {
super(lm);
}
public VerticalScrollPane(Component comp) {
this();
add(comp);
}
@Override
public Dimension getPreferredScrollableViewportSize() {
return getPreferredSize();
}
@Override
public int getScrollableUnitIncrement(Rectangle visibleRect,
int orientation, int direction) {
return 10;
}
@Override
public int getScrollableBlockIncrement(Rectangle visibleRect,
int orientation, int direction) {
return 100;
}
@Override
public boolean getScrollableTracksViewportWidth() {
return true;
}
@Override
public boolean getScrollableTracksViewportHeight() {
return false;
}
}
/**
* Class structure for storing a single chat entry in a full conversation.
*/
public static class ChatEntry {
public String name;
public String content;
// For type 0=sent, 1=received.
public int type;
public ChatEntry(String name, String content, int type) {
this.name = name;
this.content = content;
this.type = type;
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
// Simulate a conversation between two users and pass it on to the
// chat window to test the UI.
List<ChatEntry> chatContentList = new LinkedList<>();
chatContentList.add(new ChatEntry("David", "Hey Lori, how are you?", 0));
chatContentList.add(new ChatEntry("Lori", "Hi David, I'm good. What have you been up to?", 1));
chatContentList.add(new ChatEntry("David", "I've been super busy with work.", 0));
chatContentList.add(new ChatEntry("David", "Haven't had much free time to even go out to eat.", 0));
chatContentList.add(new ChatEntry("Lori", "I know what you mean, I've had to work on projects after projects.", 1));
chatContentList.add(new ChatEntry("David", "Let's make some time and go to lunch tomorrow!", 0));
chatContentList.add(new ChatEntry("Lori", "That sounds great, let's do 12pm. I know a great food truck by my building.", 1));
chatContentList.add(new ChatEntry("David", "Perfect, I'll meet you at the entrance of your building.", 0));
chatContentList.add(new ChatEntry("Lori", "Awesome, see you tomorrow :)", 1));
new ChatWindow(chatContentList);
}
});
}
}
