I am trying to do a small app that compares two similar texts contained in 2 JTextarea. I am wondering if it's possible to select text from the first JTextarea and automatically select the text on the second JTeaxtarea (lets consider that it's guarantee that the 2 JTextarea will have the same text for now) ?
Should I share events or listeners ?
Thank you
This would be so much easier if JTextComponent supported a selection model...
Basically, what you can do is attach a ChangeListener to the JTextArea's Caret and monitor for changes to the Caret, changing the selection of the other JTextArea in response...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultHighlighter;
public class MirrorTextSelection {
public static void main(String[] args) {
new MirrorTextSelection();
}
public MirrorTextSelection() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JTextArea left;
private JTextArea right;
private DefaultHighlighter.DefaultHighlightPainter highlightPainter;
public TestPane() {
highlightPainter = new DefaultHighlighter.DefaultHighlightPainter(UIManager.getColor("TextArea.selectionBackground"));
left = new JTextArea(20, 20);
left.setWrapStyleWord(true);
left.setLineWrap(true);
right = new JTextArea(20, 20);
right.setWrapStyleWord(true);
right.setLineWrap(true);
left.setText("I am trying to do a small app that compares two similar texts contained in 2 JTextarea. I am wondering if it's possible to select text from the first JTextarea and automatically select the text on the second JTeaxtarea (lets consider that it's guarantee that the 2 JTextarea will have the same text for now) ? Should I share events or listeners ? Thank you");
right.setText("I am trying to do a small app that compares two similar texts contained in 2 JTextarea. I am wondering if it's possible to select text from the first JTextarea and automatically select the text on the second JTeaxtarea (lets consider that it's guarantee that the 2 JTextarea will have the same text for now) ? Should I share events or listeners ? Thank you");
setLayout(new GridLayout(0, 2));
add(new JScrollPane(left));
add(new JScrollPane(right));
left.getCaret().addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
int dot = left.getCaret().getDot();
int mark = left.getCaret().getMark();
right.setCaretPosition(mark);
right.moveCaretPosition(dot);
}
});
}
}
}
Now, when you run this, you will find that the right side doesn't seem to get highlighted...what?!
The selection is changing, it's just not been rendered because the component doesn't have focus...
Instead, you could use a Highlighter to highlight the text...
private DefaultHighlighter.DefaultHighlightPainter highlightPainter;
//...
highlightPainter = new DefaultHighlighter.DefaultHighlightPainter(UIManager.getColor("TextArea.selectionBackground"));
left.getCaret().addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
int dot = left.getCaret().getDot();
int mark = left.getCaret().getMark();
right.getHighlighter().removeAllHighlights();
try {
int start = Math.min(dot, mark);
int end = Math.max(dot, mark);
right.getHighlighter().addHighlight(start, end, highlightPainter);
} catch (BadLocationException ex) {
ex.printStackTrace();
}
}
});
Okay, this is now working and you can control the background color of the highlight...
There is another alternative...We can replace the Caret of the right JTextArea with one that doesn't hide the selection when focus is lost...
public class HighlightCaret extends DefaultCaret {
#Override
public void install(JTextComponent c) {
super.install(c);
setSelectionVisible(true);
}
#Override
public void focusGained(FocusEvent e) {
JTextComponent component = getComponent();
if (component.isEnabled()) {
if (component.isEditable()) {
setVisible(true);
}
setSelectionVisible(true);
}
}
#Override
public void focusLost(FocusEvent e) {
setVisible(false);
}
}
Then we set the Caret to right...
right.setCaret(nwe HighlightCaret());
This means we don't need the Highlighter code, we can stick with the original and we get control over not only the background selection color but also the foreground selection color as well...
Related
I'm working on an application that allows me to show and hide split planes.
I've read some articles on how to get this but its not what I'm looking for.
here's the code Ive written:
Im currently using netbeans.
private void jSplitPane1MouseEntered(java.awt.event.MouseEvent evt) {
if(MouseInfo.getPointerInfo().getLocation() == jSplitPane1.getLeftComponent().getLocation()){
jSplitPane1.setDividerLocation(100);
System.out.println("Mouse Entered");
}else{
jSplitPane1.setDividerLocation(20);
System.out.println("Mouse Exited");
}
}
I have referred to these posts:
How to make JSplitPane auto expand on mouse hover?
Get Mouse Position
What I want to happen is when I mouse over the left side of the jSplitPane, I would get the divider to extend to 100 as per my first if statement, and when it exists the left side, it contracts back to divider location 20.
This is really, really tricky.
You could use a MouseListener on the "left" component and monitor the mouseEntered and mouseExited events, but these will also get triggered when when you move into and out of a child component which has a MouseListener of it's own (like a JButton).
Okay, you could use a MouseMotionListener on the JSplitPane and monitor for the mouseMoved event and check where the mouse cursor is, but this goes to hell the moment the components (left/right) get their own MouseListener, as the MouseEvents are no longer delivered to the JSplitPane
So, one of the last options you have is to attach a global AWTListener to the event queue and monitor for events which occur on the JSplitPane itself, for example...
import java.awt.AWTEvent;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
JSplitPane pane = new JSplitPane();
pane.setLeftComponent(makePane(Color.RED));
pane.setRightComponent(makePane(Color.BLUE));
Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {
#Override
public void eventDispatched(AWTEvent event) {
if (event instanceof MouseEvent) {
MouseEvent me = (MouseEvent) event;
if (pane.getBounds().contains(me.getPoint())) {
System.out.println("Global Motion in the pane...");
me = SwingUtilities.convertMouseEvent(me.getComponent(), me, pane);
Component left = pane.getLeftComponent();
if (left.getBounds().contains(me.getPoint())) {
pane.setDividerLocation(100);
} else {
pane.setDividerLocation(20);
}
}
}
}
}, MouseEvent.MOUSE_MOTION_EVENT_MASK);
// You don't need this, this is to demonstrate
// that mouse events aren't hitting your component
// via the listener
pane.addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
System.out.println("Motion in the pane...");
Component left = pane.getLeftComponent();
if (left.getBounds().contains(e.getPoint())) {
pane.setDividerLocation(100);
} else {
pane.setDividerLocation(20);
}
}
});
pane.setDividerLocation(20);
add(pane);
}
protected JPanel makePane(Color background) {
JPanel pane = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(100, 100);
}
};
pane.setLayout(new GridBagLayout());
pane.add(new JButton("..."));
pane.setBackground(background);
pane.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
System.out.println("...");
}
});
return pane;
}
}
}
I use a JTable with two buttons(Active & Inactive Buttons) . When I click on the Inactive button I hide the first column of the table. Also I try to show the first column when I click on the Active button. But the problem is , when I click on the Active button I couldn't display the first column with its preferred size .
This is the code for hide the first column,
expTable.getColumnModel().getColumn(0).setMinWidth(0);
expTable.getColumnModel().getColumn(0).setMaxWidth(0);
expTable.getColumnModel().getColumn(0).setWidth(0);
This is the code for get back fist column,
expTable.getColumnModel().getColumn(0).setMinWidth(0);
expTable.getColumnModel().getColumn(0).setMaxWidth(300);
expTable.getColumnModel().getColumn(0).setWidth(100);
First I click on the Inactive button and then I click on the Active button . But this is not working .
Have any idea to how to do above .
private void inactiveButtonActionPerformed(java.awt.event.ActionEvent evt){
expTable.getColumnModel().getColumn(0).setMinWidth(0);
expTable.getColumnModel().getColumn(0).setMaxWidth(0);
expTable.getColumnModel().getColumn(0).setWidth(0);
}
private void activeButtonActionPerformed(java.awt.event.ActionEvent evt)
{
expTable.getColumnModel().getColumn(0).setMinWidth(0);
expTable.getColumnModel().getColumn(0).setMaxWidth(300);
expTable.getColumnModel().getColumn(0).setWidth(100);
}
Don't attempt to "hide" a TableColumn by playing with the width. The TableColumn is still part of the table so when the user tabs from column to column, focus will go to the hidden column and disappear from the users view which is very confusing.
Instead you should remove the TableColumn from the TableColumnModel. Then you can add the TableColumn back to the TableColumnModel when needed.
Check out the Table Column Manager which manages this concept for you. If you don't use the full functionality of the class you can use the hideColumn(...) and showColumn(...) to do a simple toggle on the first column.
In the past when I've need to do something like, I've simply removed and re-added the TableColumn
This is a pretty crude example of the concept...
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JToggleButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
DefaultTableModel model = new DefaultTableModel();
model.addColumn("Column 1");
model.addColumn("Column 2");
model.addColumn("Column 3");
model.addColumn("Column 4");
model.setRowCount(100);
JTable table = new JTable(model);
add(new JScrollPane(table));
JToggleButton toggle = new JToggleButton("Toggle");
toggle.addActionListener(new ActionListener() {
private TableColumn column;
#Override
public void actionPerformed(ActionEvent e) {
TableColumnModel columnModel = table.getColumnModel();
if (toggle.isSelected()) {
column = columnModel.getColumn(0);
table.getColumnModel().removeColumn(column);
} else if (column != null) {
columnModel.addColumn(column);
columnModel.moveColumn(columnModel.getColumnCount() - 1, 0);
}
}
});
add(toggle, BorderLayout.SOUTH);
}
}
}
I actually spent sometime putting together a custom TableModel which provide the ability to hide and show columns, which basically wrapped this functionality up in a nice reusable package
I am trying to create a JTextArea which scrolls to bottom every time a text is appended to that text area. Otherwise, the user should be able to scroll top and see previous message. I used this code:
JTextArea terminalText = new JTextArea();
JPanel terminal = new JPanel();
terminal.setLayout(new BorderLayout());
add(terminal); //Adds the terminal to mother JPanel
//I added scrollbar to my JTextArea
JScrollPane scroll = new JScrollPane(terminalText);
terminal.add(scroll, BorderLayout.CENTER);
scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scroll.getVerticalScrollBar().addAdjustmentListener(new AdjustmentListener() {
public void adjustmentValueChanged(AdjustmentEvent e) {
e.getAdjustable().setValue(e.getAdjustable().getMaximum());
}});
So far this code seems to make my text area scroll to bottom of the terminalText text area every time I append something to terminalText using terminalText.append.
However, the user cannot use scroll bar to scroll to the top to see previous message. Is there a way to fix this? Should I be using DocumentListener to achieve this?
Check out Smart Scrolling.
If the scrollbar is at the bottom, then as text is appended you will see the new text.
If the user has scrolled to a different position, then the viewport will stay there until the user scrolls back to the bottom.
As a simple (and rough) proof of concept...
This basically adds a DocumentListener to the JTextArea and on any Document event, use setCaretPosition to move the caret to the end of the document.
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Date;
import java.util.WeakHashMap;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.JTextComponent;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JTextArea ta = new JTextArea(10, 20);
ta.setWrapStyleWord(true);
ta.setLineWrap(true);
MoveToTheBottom.install(ta);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new JScrollPane(ta));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
Timer timer = new Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
ta.append(new Date().toString() + "\n");
}
});
timer.start();
}
});
}
public static class MoveToTheBottom implements DocumentListener {
private static WeakHashMap<JTextComponent, DocumentListener> registry = new WeakHashMap<>(25);
private JTextComponent parent;
protected MoveToTheBottom(JTextComponent parent) {
this.parent = parent;
parent.getDocument().addDocumentListener(this);
}
public static void install(JTextComponent parent) {
MoveToTheBottom bottom = new MoveToTheBottom(parent);
registry.put(parent, bottom);
}
public static void uninstall(JTextComponent parent) {
DocumentListener listener = registry.remove(parent);
if (listener != null) {
parent.getDocument().removeDocumentListener(listener);
}
}
#Override
public void insertUpdate(DocumentEvent e) {
parent.setCaretPosition(e.getDocument().getLength());
}
#Override
public void removeUpdate(DocumentEvent e) {
parent.setCaretPosition(e.getDocument().getLength());
}
#Override
public void changedUpdate(DocumentEvent e) {
parent.setCaretPosition(e.getDocument().getLength());
}
}
}
The example demonstrates a possible re-usable API which you can use to "install" and "uninstall" the support as reqiured
I am familiar that you can input text before hand into a JTextField. This text will be displayed in the JTextField and has to be manually deleted when having to input your own text into the JTextField. For example, consider this JTextField:
cruiseSel = new JTextField ("Selected Cruise:");
cruiseSel.setEditable(false);
centerP12.add(cruiseSel);
contentPane12.add(centerP12, BorderLayout.CENTER);
Frame12.setVisible(true);
Upon running the above, a JTextField will appear with "Selected Cruise:" written within it. This text then has to be manually deleted to clear the text field.
Is there a way to input text in an JTextField, so once the GUI opens, the text will be displayed, but when the JTextField is selected to input manual text, the text vanishes?
You could use a FocusListener and when the JTextField receives focus, empty the text.
Of course you will want a state marker to indicate it has the default text and not do this once you have user entered text. Either that or after the FocusListener is hit the first time, remove it.
textField.addFocusListener(new FocusAdapter() {
public void focusGained(FocusEvent e) {
JTextField source = (JTextField)e.getComponent();
source.setText("");
source.removeFocusListener(this);
}
});
What you are looking for is called placeholder. I've written this class a while ago:
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
/**
* #author xehpuk
*/
public class PlaceholderTextField extends JTextField {
private static final long serialVersionUID = -5529071085971698388L;
/**
* The placeholder to be displayed if the text field is empty.
*/
private String placeholder;
/**
* Determines whether the placeholder should be displayed even on focus.
*/
private boolean paintingOnFocus;
/**
* The color the placeholder should be displayed in.
*/
private Color placeholderColor;
public String getPlaceholder() {
return placeholder;
}
public void setPlaceholder(final String placeholder) {
this.placeholder = placeholder;
repaint();
}
public boolean isPaintingOnFocus() {
return paintingOnFocus;
}
public void setPaintingOnFocus(final boolean paintingOnFocus) {
this.paintingOnFocus = paintingOnFocus;
repaint();
}
public Color getPlaceholderColor() {
return placeholderColor;
}
public void setPlaceholderColor(final Color placeholderColor) {
this.placeholderColor = placeholderColor;
repaint();
}
public PlaceholderTextField() {
super();
}
public PlaceholderTextField(final Document doc, final String text, final int columns) {
super(doc, text, columns);
}
public PlaceholderTextField(final int columns) {
super(columns);
}
public PlaceholderTextField(final String text, final int columns) {
super(text, columns);
}
public PlaceholderTextField(final String text) {
super(text);
}
{
addFocusListener(new RepaintFocusListener());
}
#Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
if (getPlaceholder() != null && getText().isEmpty() && (isPaintingOnFocus() || !isFocusOwner())) {
try {
final Rectangle rect = getUI().modelToView(this, 0);
final Insets insets = getInsets();
g.setFont(getFont());
g.setColor(getPlaceholderColor() == null ? getForeground() : getPlaceholderColor());
((Graphics2D) g).setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g.drawString(getPlaceholder(), rect.x, getHeight() - insets.top - insets.bottom - rect.y);
} catch (final BadLocationException e) {
throw new RuntimeException(e);
}
}
}
private class RepaintFocusListener implements FocusListener {
#Override
public void focusGained(final FocusEvent e) {
repaint();
}
#Override
public void focusLost(final FocusEvent e) {
repaint();
}
}
}
You can choose the text and the color and whether it should be painted even if the text field has focus.
The crucial part is the overriding of paintComponent(Graphics).
You can use SwingX Read on this How to set Text like Placeholder in JTextfield in swing
I include the sample code here for your use
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import org.jdesktop.swingx.prompt.PromptSupport;
public class PromptExample {
public static void main(String[] args) {
new PromptExample();
}
public PromptExample() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JTextField bunnies = new JTextField(10);
JTextField ponnies = new JTextField(10);
JTextField unicorns = new JTextField(10);
JTextField fairies = new JTextField(10);
PromptSupport.setPrompt("Bunnies", bunnies);
PromptSupport.setPrompt("Ponnies", ponnies);
PromptSupport.setPrompt("Unicorns", unicorns);
PromptSupport.setPrompt("Fairies", fairies);
PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.HIDE_PROMPT, bunnies);
PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.HIGHLIGHT_PROMPT, ponnies);
PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.SHOW_PROMPT, unicorns);
PromptSupport.setFontStyle(Font.BOLD, bunnies);
PromptSupport.setFontStyle(Font.ITALIC, ponnies);
PromptSupport.setFontStyle(Font.ITALIC | Font.BOLD, unicorns);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
frame.add(bunnies, gbc);
frame.add(ponnies, gbc);
frame.add(unicorns, gbc);
frame.add(fairies, gbc);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
Check out Text Prompt.
It supports this functionality along with a couple of features to customize the behaviour of the prompt.
To achieve something like this, you would generally need to create a certain type of event listener. In your case, the desired action needs to be triggered on a mouse event - thus the MouseAdapter event listener seems like a good fit (at first glance). To use the MouseAdapter
abstract class, you'd need to extend it and override the necessary methods (see here for a full list of available methods).
The shortest way of achieving this is via an anonymous class declaration, like so:
cruiseSel.addMouseListener(new MouseAdapter(){
#Override
public void mouseClicked(MouseEvent e){
cruiseSel.setText("");
}
});
(However, if you need to override multiple methods or the triggered logic feels complex enough, you might be better off creating a separate listener class.)
EDIT: Alternatively, as #HovercraftFullOfEels pointed out in the comment section, it would probably be wiser to apply the FocusAdapter class (see here) in an identical fashion:
cruiseSel.addFocusListener(new FocusAdapter(){
#Override
public void focusGained(FocusEvent e){
cruiseSel.setText("");
}
});
The problem with the first solution is that it is only concerned with listening for actual MOUSE CLICKS on the text field, while the latter listens for ANY types of focus-gains on it. Thus, when using the TAB key to switch between text fields, only the second solution would perform correctly.
When my jTextArea is in focus it allows text highlighting, but it doesn't show the text selection when it loses focus. Is it possible to continue displaying the text highlighting even if the user moves focus to another component on the related jFrame?
One simple workaround for caret selection is a simple subclassing of DefaultCaret:
textArea.setCaret(new DefaultCaret() {
#Override
public void setSelectionVisible(boolean visible) {
super.setSelectionVisible(true);
}
});
but doesn't show selection on text when looses focus.
there are three ways:
use JTextPane, see Oracle tutorial
easiest in the case that we talking about selection as painting artefact from Mouse Event see my question How to override DefaultCaret#setBlinkRate(), great knowledge and answer by #camickr
or programatically override Highlighter
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultHighlighter;
import javax.swing.text.Highlighter;
import javax.swing.text.JTextComponent;
public class MultiHighlight implements ActionListener {
private JTextComponent comp;
private String charsToHighlight;
public MultiHighlight(JTextComponent c, String chars) {
comp = c;
charsToHighlight = chars;
}
#Override
public void actionPerformed(ActionEvent e) {
Highlighter h = comp.getHighlighter();
h.removeAllHighlights();
String text = comp.getText().toUpperCase();
for (int j = 0; j < text.length(); j += 1) {
char ch = text.charAt(j);
if (charsToHighlight.indexOf(ch) >= 0) {
try {
h.addHighlight(j, j + 1, DefaultHighlighter.DefaultPainter);
} catch (BadLocationException ble) {
}
}
}
}
public static void main(String args[]) {
final JFrame frame = new JFrame("MultiHighlight");
frame.add(new JTextField("Another focusable JComponents"), BorderLayout.NORTH);
JTextArea area = new JTextArea(10, 20);
area.setText("This is the story\nof the hare who\nlost his spectacles."
+ "\nThis is the story\nof the hare who\nlost his spectacles.");
frame.getContentPane().add(new JScrollPane(area), BorderLayout.CENTER);
JButton b = new JButton("Highlight All Vowels");
b.addActionListener(new MultiHighlight(area, "aeiouAEIOU"));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(b, BorderLayout.SOUTH);
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
frame.pack();
frame.setVisible(true);
}
});
}
}