I hope someone can help me out. Iam trying to create a "countrycombobox" with icons in Java Swing. I found some stuff, but nothing did work for me. Maybe the problem is, that Iam still "new" to Java.
I just want it simple like this: http://www.zomex.com/libs/images/layout/whmcs-template-language-select-w-flags-eco.jpg
Just the flags in front of the countrys.
I would really appreciate a working example. I really wonder, that there is no standard option or a good code snippet(used Google a lot to find help here) for stuff like this.
I found a better example and wanna share my stuff with you. There is just one problem left, that I dont get it sized.
package view;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CountryComboBox extends JPanel {
ImageIcon[] images;
String[] imgStrings = {"de"};
/*
* Despite its use of EmptyBorder, this panel makes a fine content
* pane because the empty border just increases the panel's size
* and is "painted" on top of the panel's normal background. In
* other words, the JPanel fills its entire background if it's
* opaque (which it is by default); adding a border doesn't change
* that.
*/
public CountryComboBox() {
super(new BorderLayout());
//Load the images and create an array of indexes.
images = new ImageIcon[imgStrings.length];
Integer[] intArray = new Integer[imgStrings.length];
for (int i = 0; i < imgStrings.length; i++) {
intArray[i] = new Integer(i);
images[i] = createImageIcon("/res/" + imgStrings[i] + ".png");
if (images[i] != null) {
images[i].setDescription(imgStrings[i]);
}
}
//Create the combo box.
JComboBox imgList = new JComboBox(intArray);
ComboBoxRenderer renderer= new ComboBoxRenderer();
imgList.setRenderer(renderer);
imgList.setMaximumRowCount(3);
//Lay out the demo.
add(imgList, BorderLayout.PAGE_START);
//setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
}
/** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = CountryComboBox.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}
class ComboBoxRenderer extends JLabel
implements ListCellRenderer {
private Font uhOhFont;
public ComboBoxRenderer() {
setOpaque(true);
setHorizontalAlignment(CENTER);
setVerticalAlignment(CENTER);
}
/*
* This method finds the image and text corresponding
* to the selected value and returns the label, set up
* to display the text and image.
*/
#Override
public Component getListCellRendererComponent(
JList list,
Object value,
int index,
boolean isSelected,
boolean cellHasFocus) {
//Get the selected index. (The index param isn't
//always valid, so just use the value.)
int selectedIndex = ((Integer)value).intValue();
if (isSelected) {
setBackground(list.getSelectionBackground());
setForeground(list.getSelectionForeground());
} else {
setBackground(list.getBackground());
setForeground(list.getForeground());
}
//Set the icon and text. If icon was null, say so.
ImageIcon icon = images[selectedIndex];
String img = imgStrings[selectedIndex];
setIcon(icon);
if (icon != null) {
setText(img);
setFont(list.getFont());
} else {
setUhOhText(img + " (no image available)",
list.getFont());
}
return this;
}
//Set the font and text when no image was found.
protected void setUhOhText(String uhOhText, Font normalFont) {
if (uhOhFont == null) { //lazily create this font
uhOhFont = normalFont.deriveFont(Font.ITALIC);
}
setFont(uhOhFont);
setText(uhOhText);
}
}
}
I call it in a JPanel with absolute layout:
JComponent newContentPane = new CountryComboBox();
newContentPane.setOpaque(true); //content panes must be opaque
newContentPane.setBounds(10, 75, 50, 26);
contentPane.add(newContentPane);
setBounds isnt working, just to get the right position. I cant size it with this.
Best regards
Acanis
Related
I have a JFileChooser. I am trying to add a zoom feature to the files JList.
I would like to change the scale factor of the file name and of the file icon, for each element of the list.
How could we achieve this ?
Should I make a custom renderer like here [JList custom renderer example] (http://www.codejava.net/java-se/swing/jlist-custom-renderer-example)
or change the list Model ?
Well, I found out some ugly lazy hacks to do it.
It might not be just what you want, but it's a good starting point (and fairly simple):
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.plaf.basic.BasicListUI;
public class TJFileChooserDemo {
//Obtains the (first) JList which is found inside the component/container:
public static JList getFirstJList(final Component component) {
if (component instanceof JList)
return (JList) component;
if (component instanceof Container)
for (int i=0; i<((Container)component).getComponentCount(); ++i) {
final JList list = getFirstJList(((Container)component).getComponent(i));
if (list != null)
return list;
}
return null;
//As you can see, it's a bit lazy hack, which has to run for every JFileChooser once at start-up.
}
private static final double SCALE_STEP_SIZE = 0.125; //Smaller values of this makes zooming slower. Greater values makes zooming faster.
private static double scaleFactor = 1;
public static class TJListCellRenderer extends DefaultListCellRenderer {
public TJListCellRenderer() {
//Ensure every pixel is painted starting from the top-left corner of the label:
super.setVerticalAlignment(JLabel.TOP);
super.setHorizontalAlignment(JLabel.LEFT);
//We need to do this, because the scaling in paintComponent() is also relative to the top-left corner.
}
#Override
public void paintComponent(final Graphics g) {
//setRenderingHints here? Probably for ANTIALIAS...
((Graphics2D)g).scale(scaleFactor, scaleFactor); //Let's scale everything that is painted afterwards:
super.paintComponent(g); //Let's paint the (scaled) JLabel!
}
#Override
public Dimension getPreferredSize() {
final Dimension superPrefDim = super.getPreferredSize(); //Handles automatically insets, icon size, text font, etc.
final double w = superPrefDim.width * scaleFactor, //And we just scale the preferred size.
h = superPrefDim.height * scaleFactor; //And we just scale the preferred size.
return new Dimension((int)w + 5, (int)h + 5); //Add 5 extra pixels to spare.
}
#Override
public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
// System.out.println(value.getClass()); //Something ugly...
return super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
}
}
public static class TJListUI extends BasicListUI {
#Override
public void updateLayoutState() {
super.updateLayoutState(); //Just make the following method public.
/*Note: this is not really needed here:
The method could remain protected, but in the case you want this
code to be a bit more reusable, then you shall make it public.*/
}
}
public static void main(final String[] args) {
final JFileChooser jfc = new JFileChooser();
jfc.setDialogType(JFileChooser.OPEN_DIALOG);
final TJListUI ui = new TJListUI();
final JList list = getFirstJList(jfc);
list.setUI(ui);
list.setCellRenderer(new TJListCellRenderer());
final JButton buttonZoomIn = new JButton("Zoom in"),
buttonZoomOut = new JButton("Zoom out"),
buttonResetZoom = new JButton("Reset zoom");
buttonZoomIn.addActionListener(e -> {
scaleFactor = scaleFactor + SCALE_STEP_SIZE;
ui.updateLayoutState(); //Read the preferred sizes from the cell renderer.
list.revalidate(); //Update the JScrollPane.
list.repaint(); //Repaint the list.
});
buttonZoomOut.addActionListener(e -> {
scaleFactor = Math.max(scaleFactor - SCALE_STEP_SIZE, SCALE_STEP_SIZE); //Do not allow underflow.
ui.updateLayoutState(); //Read the preferred sizes from the cell renderer.
list.revalidate(); //Update the JScrollPane.
list.repaint(); //Repaint the list.
});
buttonResetZoom.addActionListener(e -> {
scaleFactor = 1;
ui.updateLayoutState(); //Read the preferred sizes from the cell renderer.
list.revalidate(); //Update the JScrollPane.
list.repaint(); //Repaint the list.
});
final JPanel buttons = new JPanel(); //FlowLayout.
buttons.add(buttonZoomIn);
buttons.add(buttonZoomOut);
buttons.add(buttonResetZoom);
final JPanel panel = new JPanel(new BorderLayout());
panel.add(buttons, BorderLayout.PAGE_START);
panel.add(jfc, BorderLayout.CENTER);
final JFrame frame = new JFrame("JFileChooser's JList cell sizes demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
Alternatively you can check my answer here about individually resizable cells of a JList.
You can also probably add the JFileChooser's buttons for zooming in/out as an accessory. Read this simple example for how to do it.
Test this code, and I am waiting for comments...
In the end, I realized scaling the text wasn't needed.
To obtain the image files thumbnail, I used the code in making JFileChooser show image thumbnails - check BoffinbraiN answer.
Then for scaling :
1) add an ActionListener to the buttons of ThumbnailFileChooser.
public class ZoomListener implements ActionListener {
private boolean zoomIn = false;
private IconScaleManager iconScaleManager = null;
public ZoomListener(boolean zoom, IconScaleManager renderer) {
zoomIn = zoom;
iconScaleManager = renderer;
}
#Override
public void actionPerformed(ActionEvent e) {
iconScaleManager.scaleButton(zoomIn);
}
}
2) ActionListener::actionPerformed() calls a scale method of a ScaleManager.
#Override
public void actionPerformed(ActionEvent e) {
iconScaleManager.scaleButton(zoomIn);
}
3) The ScaleManager method changes and update the cells of the ThumbnailFileChooser's Jlist (the list is an attribute of the ScaleManager)
public class IconScaleManager {
static final int[] iconScales = new int[]{ 16, 32, 64, 128, 256, 512, 1024, 2048 };
private int scaleIndex = 4;
private JList fileList = null;
public IconScaleManager(JList list) {
fileList = list;
setFixedCellDimension();
}
public void scaleButton(boolean zoomIn) {
if (zoomIn && scaleIndex < iconScales.length - 1) {
scaleIndex++;
setFixedCellDimension();
} else if (!zoomIn && 0 < scaleIndex) {
scaleIndex--;
setFixedCellDimension();
}
}
private void setFixedCellDimension() {
fileList.setFixedCellWidth(iconScales[scaleIndex]);
fileList.setFixedCellHeight(iconScales[scaleIndex]);
}
}
Thank you #thanopi57 for your help. I didn't really use what you provided, but I appreciate your support.
Also, I will have to make sure that it works, because there might not be a JList for all JFileChooser
In a project I've been working on, I noticed that all the JList items in my JScrollPane are hidden until the JScrollPane/JList has been clicked. The weird part is it's not completely covered. There's this white box with a transparent border that spreads out over the whole thing, covering all but a few pixels on all edges.
Pictures:
As you can see, there is this white block in the middle - notice the pink "border":
Now, once I click that white box, it goes away:
I know the magenta looks horrible, but I'm using it for contrast.
Which leads me to my question: how do I get rid of that obnoxious white box?
Here is my code:
public static void listJars(File f)
{
JCheckBox firstBox = null;
DefaultListModel<JCheckBox> model = new DefaultListModel<>();
if(mainGUI.checkList != null)
{
//System.out.println("Already exists lol: " + mainGUI.checkList.getName());
mainGUI.pluginList.remove(mainGUI.checkList);
}
//mainGUI.pluginList.repaint();
File[] files = new File(f.getPath()).listFiles();
if (files != null)
{
for (File file : files)
{
if (file.getName().endsWith(".jar") || file.getName().endsWith("._jar"))
{
JCheckBox cb = new JCheckBox(file.getName());
if(firstBox == null)
{
firstBox = cb;
}
cb.setSelected(file.getName().endsWith(".jar"));
cb.setVisible(true);
cb.setText(file.getName());
model.addElement(cb);
cb.repaint();
}
}
}
JCheckBoxList jCheckBoxList = new JCheckBoxList(model, mainGUI.textField1.getText());
jCheckBoxList.setName("pluginCheckboxList");
jCheckBoxList.setSize(mainGUI.pluginList.getSize());
mainGUI.pluginList.add(jCheckBoxList);
mainGUI.checkList = jCheckBoxList;
jCheckBoxList.setVisible(true);
jCheckBoxList.setVisibleRowCount(10);
}
And ten there's my JCheckBoxList class.
package Components;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.File;
#SuppressWarnings("serial")
public class JCheckBoxList extends JList<JCheckBox>
{
protected static Border noFocusBorder = new EmptyBorder(1, 1, 1, 1);
protected String lastPath;
public JCheckBoxList(final String lastPath)
{
this.lastPath = lastPath;
setCellRenderer(new CellRenderer());
setBackground(Color.magenta);
addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
int index = locationToIndex(e.getPoint());
if (index != -1)
{
JCheckBox checkBox = getModel().getElementAt(index);
checkBox.setSelected(!checkBox.isSelected());
repaint();
final String oldname = checkBox.getText();
if (!checkBox.isSelected())
{
checkBox.setName(checkBox.getText().substring(0, checkBox.getText().length() - 4) + "._jar");
}
else
{
checkBox.setName(checkBox.getText().substring(0, checkBox.getText().length() - 5) + ".jar");
}
System.out.println("Changed! Sel: " + checkBox.isSelected() + ", Name: " + checkBox.getName());
checkBox.setText(checkBox.getName());
String base = new File(lastPath).getParent() + "/plugins/";
boolean rename = new File(base + oldname).renameTo(new File(base + checkBox.getText()));
}
}
});
setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
}
public JCheckBoxList(ListModel<JCheckBox> model, String lastPath)
{
this(lastPath);
setModel(model);
}
protected class CellRenderer implements ListCellRenderer<JCheckBox>
{
public Component getListCellRendererComponent(
JList<? extends JCheckBox> list, JCheckBox value, int index,
boolean isSelected, boolean cellHasFocus)
{
//Drawing checkbox, change the appearance here
value.setBackground(isSelected ? getSelectionBackground()
: getBackground());
value.setForeground(isSelected ? getSelectionForeground()
: getForeground());
value.setEnabled(isEnabled());
value.setFont(getFont());
value.setFocusPainted(false);
value.setBorderPainted(true);
value.setBorder(BorderFactory.createEmptyBorder(0, 10, 5, 0));
return value;
}
}
}
And then there's my scroll pane, which has these settings (using the Intelliji IDEA UI designer):
Any ideas?
mainGUI.pluginList.add(jCheckBoxList);
mainGUI.checkList = jCheckBoxList;
jCheckBoxList.setVisible(true);
jCheckBoxList.setVisibleRowCount(10);
Looks to me like you are dynamically adding components to a visible GUI.
When you do this the basic code is:
panel.add(...);
panel.revalidate();
panel.repaint();
You should set the visibleRowCount() before the above code is executed.
Also:
Swing components are visible by default so you don't need the setVisible(true).
You may want to consider using a one column JTable since it already supports a checkbox renderer and editor.
Edit:
The solution I gave you above is the general solution. A scroll pane is different, you should only ever add a component to the viewport.
Based on your incorrect solution you should be using:
//mainGUI.pluginList.add(jCheckBoxList);
mainGUI.pluginList.setViewportView(jCheckBoxList);
The problem with posting only a few random lines of code is that we don't know the full context of the code. I did not realize "pluginList" was actually a scrollpane. Usually the variable name will have scroll or scrollpane in the name.
mainGUI.pluginList.setViewportView(mainGUI.checkList); // pluginList is the JScrollPane.
Do that, and it fixes everything! Put it in with my listJars method.
I'm trying to create this basic photo editing app via java swing. I have my code to work somewhat for when 1 picture is imported; I have 3 views - photo view which displays the photo only, thumbnail view which should display thumbnails of the pictures and split view which should be a combination of photo in BorderLayout.CENTER and thumbnail in BorderLayout.SOUTH. I've put in images and code excerpts as to why this isn't working the way it should. I can't upload any images but hopefully the excerpts provide much detail.
Split View Related Excerpts:
public void changeMode(boolean p, boolean b, boolean s){
/*
* Photo View will display a single PhotoComponent2 in a large area.
*/
isPhoto = p;
if (isPhoto){
//have a child JPanel set as CENTER component of BorderLayout of the JScrollPane (scroll)
childPhoto = new JPanel();
childPhoto.add(displayPhotos.get(getCurrentPhoto()), BorderLayout.CENTER);
System.out.println("in lc photo view class");
}
/*
* Browser View will hold all the images.
*/
isBrowse = b;
if(isBrowse){
//have a child JPanel set as CENTER component of BorderLayout to hold grid of thumbnails within
// JScrollPanel (scroll)
this.removeAll();
childBrowse = new JPanel();
tc2 = new ThumbnailComponent(displayPhotos.get(getCurrentPhoto()));
childBrowse.setLayout(new WrapLayout());
childBrowse.add(tc2);
// for(int i = 0; i < displayThumbs.size(); i++){
// childBrowse.add(displayThumbs.get(i));
// System.out.println(displayThumbs.get(i));
// }
System.out.println("in lc browser view class");
}
/*
* Split View is a combination of Photo and Browser View in that the top half
* is Photo View and the bottom half is Browser View.
*/
isSplit = s;
if(isSplit){
//have a child JPanel in CENTER to hold PhotoComponent plus a child JPanel in SOUTH to hold thumbnails
containsAll = new JPanel();
containsAll.setLayout(new BorderLayout());
containsAll.add(childPhoto, BorderLayout.CENTER);
containsAll.add(childBrowse, BorderLayout.SOUTH);
System.out.println("in lc split view class");
}
}
This is basically all of my problems right now. Currently the thumbnails that are being created are based on the current image. If I go to photo view and and change the image being displayed with my forward/backward buttons and then go back to browser view I get the thumbnail of the respective image. However, I want to be able to create thumbnails for all images being imported and then display it. I tried the for loop (which I've commented out) and that didn't help either. The other code associated with this are my main class that creates the JFrame and the buttons,etc., the photoComponent that has my paintComponent method I use in my thumbnails and lightComponent classes.
MyPhotos3:
view = new JMenu("View");
mbar.add(view);
pv = new JRadioButton("Photo Viewer");
pv.addActionListener(new ActionListener(){ //change status
public void actionPerformed(ActionEvent e){
sbar.setText("Status: By clicking this, you'll be able to view your photos one at a time");
boolean p = true;
boolean b = false;
boolean s = false;
lc.changeMode(p,b,s);
scroll.add(lc.childPhoto);
scroll.setViewportView(lc.childPhoto);
scroll.getViewport().setBackground(Color.BLUE);
scroll.revalidate();
scroll.repaint();
}
});
b = new JRadioButton("Browser");
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){ //change status
sbar.setText("Status: By clicking this, you'll be able to view all your photos as thumbnails");
boolean p = false;
boolean b = true;
boolean s = false;
lc.changeMode(p,b,s);
scroll.setViewportView(lc.childBrowse);
scroll.getViewport().setBackground(Color.BLUE);
scroll.revalidate();
scroll.repaint();
}
});
sm = new JRadioButton("Split Mode");
sm.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){ //change status
sbar.setText("Status: By clicking this, you'll be able to view a single photo with a film strip dimensional view");
boolean p = false;
boolean b = false;
boolean s = true;
lc.changeMode(p,b,s);
scroll.setViewportView(lc.containsAll);
scroll.getViewport().setBackground(Color.BLUE);
scroll.revalidate();
scroll.repaint();
}
});
PhotoComponent:
public PhotoComponent2(boolean f, Image img){
isFlip = f;
init = img;
x = init.getWidth(null);
y = init.getHeight(null);
setPreferredSize(new Dimension (x,y));
bi = new BufferedImage(init.getWidth(null),init.getHeight(null),BufferedImage.TYPE_INT_ARGB);
newIcon = new ImageIcon(bi);
img1 = new JLabel("", newIcon, JLabel.CENTER);
image = img1;
this.add(img1);
this.addKeyListener(this);
this.setFocusable(true);
this.requestFocus(true);
//System.out.println("In constructor");
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.drawImage(init, 0, 0, null);
this.addMouseListener(this);
this.addMouseMotionListener(this);
//System.out.println("In paintComponent");
Thumbnails:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import javax.swing.JComponent;
public class ThumbnailComponent extends JComponent{
/**
* ThumbnailComponent class is a way to create smaller versions of each photo passed in.
*
* #author Puja Sheth
* #version 1.0 10/16/2014
*/
private static final long serialVersionUID = 1L;
PhotoComponent2 pc;
Image img;
double x;
double y;
int newX;
int newY;
public ThumbnailComponent(PhotoComponent2 input){
pc = input;
img = pc.init;
x = (img.getWidth(null))/(.5);
y = (img.getHeight(null))/(.5);
newX = (int)x;
newY = (int)y;
setPreferredSize(new Dimension (newX,newY));
// add(input);
}
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics gCopy = g.create();
Graphics2D g2d = (Graphics2D)gCopy;
g2d.scale(.5,.5);
pc.paintComponent(g2d);
}
}
Any help would be greatly appreciated!!!!
Won't solve your problem, but a few general comments about your code:
scroll.add(lc.childPhoto);
scroll.setViewportView(lc.childPhoto);
scroll.revalidate();
scroll.repaint();
You should never add a component to a scrollpane. The only line of code you need is:
scroll.setViewportView(lc.childPhoto);
The scrollpane will automatically revalidate() and repaint() itself when the viewport view is changed.
super.paintComponent(g);
g.drawImage(init, 0, 0, null);
this.addMouseListener(this);
this.addMouseMotionListener(this);
Never add listener to a component is a painting method. Painting methods are for painting only. A listener has nothing to do with painting. Also, the painting methods are invoked whenever Swing determines the component needs to be repainted so you will be adding multiple listeners to the component.
I created a custom ListCellRenderer that extends Jidesoft's StyledLabel. The JList my renderer is used in is a fixed width, so in my renderer I attempt to shorten text based on this width. I call setText in getListCellRendererComponent, which sometimes works. When I select a cell, the text acts as if I had never shortened it at all. There is no branching related to the setText and text-shortening.
I attempted to use the solutions in this somewhat-related answer discussing custom rendering and cell heights, but it didn't work consistently on select either.
edit: some code
public class CustomListCellRenderer extends StyledLabel implements ListCellRenderer {
public Component getListCellRendererComponent(
JList list,
Object value,
int index,
boolean isSelected,
boolean cellHasFocus) {
setText(shortenName(value.toString(), 150));
return this;
}
private String shortenName(String name, int width) {
if(this.getGraphics() != null) {
final FontMetrics fontMetrics = this.getFontMetrics(this.getFont());
String end = name.substring(name.length()/2);
String beginning = name.substring( 0, name.length()/2);
int stringWidth = SwingUtilities.computeStringWidth(fontMetrics, name);
if(stringWidth < width)
return name;
do {
end = end.substring(1);
beginning = beginning.substring(0, beginning.length() - 1);
stringWidth = SwingUtilities.computeStringWidth(fontMetrics, beginning + "..." + end);
} while (stringWidth > width);
return beginning + "..." + end;
}
return name;
}
public static void main(String[] args) {
JFrame frame = new JFrame();
JList list = new JList(new String[] {
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
"yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy",
"zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"});
list.setCellRenderer(new CustomListCellRenderer());
frame.getContentPane().add(list);
frame.setVisible(true);
}
}
In your implementation of ListCellRenderer you're relying on the getGraphics() of the label. Sometimes, getGraphics() is null which is OK, but you're not entering the if(this.getGraphics() != null) condition and simply returning the unmodified string. That is why you get inconsistent results. Commenting out this condition solved the problem in the posted code. You should not rely on getGraphics() its value is out of your control.
I`ve got a mysterious problem with my custom JTable and a custom TableRenderer.
In 95%-99,99% it works perfectly, but sometimes the renderer just stops doing his job, and leaves a portion of the table (which is inside a JScrollPane) blank.
The problem case looks like that:
In all other cases, and after a slight resize of the window, the Table look like that:
Now both columns has a TextAreaCellRenderer associated to, which works as follows:
public class TextAreaCellRenderer extends JTextArea implements TableCellRenderer {
private final Color evenColor = new Color(252, 248, 202);
public TextAreaCellRenderer() {
super();
setLineWrap(true);
setBorder(BorderFactory.createEmptyBorder(2, 2, 2, 2));
}
#Override
public Component getTableCellRendererComponent(final JTable table, final Object value, final boolean isSelected, final boolean hasFocus, final int row, final int column) {
if (isSelected) {
setForeground(table.getSelectionForeground());
setBackground(table.getSelectionBackground());
} else {
setForeground(table.getForeground());
setBackground(table.getBackground());
setBackground((row % 2 == 0) ? evenColor : getBackground());
}
setWrapStyleWord(true);
setFont(table.getFont());
setText((value == null) ? "" : value.toString());
return this;
}
}
I also have to override the doLayout method of the JTable to be able to calculate the hight of a cell depending on the content. The custom table looks like that:
public class MediaMetaDataTable extends JTable {
#Override
public void doLayout() {
TableColumn col = getColumnModel().getColumn(1);
for (int row = 0; row < getRowCount(); row++) {
Component c = prepareRenderer(col.getCellRenderer(), row, 1);
if (c instanceof JTextArea) {
JTextArea a = (JTextArea) c;
int h = getPreferredHeight(a) + getIntercellSpacing().height;
if (getRowHeight(row) != h) {
setRowHeight(row, h);
}
}
}
super.doLayout();
}
private int getPreferredHeight(final JTextComponent c) {
Insets insets = c.getInsets();
View view = c.getUI().getRootView(c).getView(0);
int preferredHeight = (int) view.getPreferredSpan(View.Y_AXIS);
return preferredHeight + insets.top + insets.bottom;
}
}
The table is instantiated once with the following parameters:
metaTable = new MediaMetaDataTable();
metaTable.setModel(new MediaMetaDataTableModel());
metaTable.setEnabled(false);
metaTable.setShowGrid(false);
metaTable.setTableHeader(null);
metaTable.getColumnModel().getColumn(0).setCellRenderer(new TextAreaCellRenderer());
metaTable.getColumnModel().getColumn(1).setCellRenderer(new TextAreaCellRenderer());
metaTable.setPreferredScrollableViewportSize(new Dimension(-1, -1));
metaTable.setShowHorizontalLines(false);
metaTable.setShowVerticalLines(false);
Each time the data to show changes i update table by replacing the underlying models data:
List<MediaMetaData> metaInformation = mediaSearchHit.getMetaInformation();
if (metaInformation != null) {
((MediaMetaDataTableModel) metaTable.getModel()).replaceMetaInfos(metaInformation);
}
On update the model itself fires a table data changed event:
public class MediaMetaDataTableModel extends AbstractTableModel {
private List<MediaMetaData> metaInfos = new LinkedList<MediaMetaData>();
public static final int COL_INDEX_NAME = 0;
public static final int COL_INDEX_VALUE = 1;
public void replaceMetaInfos(final List<MediaMetaData> metaInfos) {
this.metaInfos = null;
this.metaInfos = metaInfos;
fireTableDataChanged();
}
...
Now does anybody has a idea, what causes the described rendering problem?
Thanks for any advices.
I also have to override the doLayout method of the JTable to be able
to calculate the hight of a cell depending on the content.
To achieve this goal there's no need to override doLayout() method. I think the simplest way to do this is by adding the text area used to render the cell content into a JPanel with BorderLayout and set the row height based on the panel's preferred size. This way the layout manager will do the trick for you and all the cell's content will be visible:
#Override
public Component getTableCellRendererComponent(...) {
...
JPanel contentPane = new JPanel(new BorderLayout());
contentPane.add(this);
table.setRowHeight(row, contentPane.getPreferredSize().height); // sets row's height
return contentPane;
}
As #mKorbel pointed out, there's no need to make the renderer extend from JTextArea: a single variable will work. Keeping this in mind take a look to this implementation based on your work:
class TextAreaRenderer implements TableCellRenderer {
private JTextArea renderer;
private final Color evenColor = new Color(252, 248, 202);
public TextAreaRenderer() {
renderer = new JTextArea();
renderer.setLineWrap(true);
renderer.setWrapStyleWord(true);
renderer.setBorder(BorderFactory.createEmptyBorder(2, 2, 2, 2));
}
#Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
if (isSelected) {
renderer.setForeground(table.getSelectionForeground());
renderer.setBackground(table.getSelectionBackground());
} else {
renderer.setForeground(table.getForeground());
renderer.setBackground((row % 2 == 0) ? evenColor : table.getBackground());
}
renderer.setFont(table.getFont());
renderer.setText((value == null) ? "" : value.toString());
JPanel contentPane = new JPanel(new BorderLayout());
contentPane.add(renderer);
table.setRowHeight(row, contentPane.getPreferredSize().height); // sets row's height
return contentPane;
}
}
Screenshot
If I had to guess I would say it could be a concurency problem. Are you doing everything in the GUI-Thread? If yes, it can't be a concurency problem. Otherwhise try to call everything with Thread.InvokeLater() in an inital debug step, if you don't encounter the error anymore after a long time of testing, you know the cause of the problem.
In a second step you would then check exactly where it is necessary to make the calls with invokelater() and where not (because you shouldn't do that all the time, because it leads to very poor performance.
As I said, just a wild guess... It can of youre just be another bug. Are you using Java7? There are millions of Bugs in Swing with java 7 code (just all the code that from oracle came).