Develop Reference

How to make all images in Grid Overlay flush?

I am trying to implement a GUI for a maze-based game I created that meets the following specific conditions:
The GUI itself has a set size and is not resizable (line 41) .
The master panel (line 57) that contains all the maze images is scrollable. All maze image components are flush with each other.
If maze is small enough, then entire maze will be visible in master panel.
If maze is very large, then user would need to scroll.
The master panel needs to be accessed by a mouse listener (line 130) that returns the component that is being clicked.
The following code seems to meet criteria 1 and 3, but fails criteria 2:
public class MazeGui extends JFrame implements DungeonView {
private final Board board;
public MazeGui(ReadOnlyModel m) {
//this.setSize(m.getNumRows()*100, m.getNumCols()*100);
this.setSize(600, 600);
this.setLocation(200, 200);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setResizable(false);
this.board = new Board(m);
JScrollPane scroller = new JScrollPane(board);
this.add(scroller, BorderLayout.CENTER);
setTitle("Dungeon Escape");
}
private class Board extends JPanel {
private ReadOnlyModel m;
public Board(ReadOnlyModel m) {
this.m = m;
GridLayout layout = new GridLayout(m.getNumRows(),m.getNumCols(), 0, 0);
// layout.setHgap(-100);
// layout.setVgap(-100);
this.setLayout(layout);
this.setSize(m.getNumRows()*64,m.getNumCols()*64);
for (int i = 0; i < m.getNumRows() * m.getNumCols(); i++) {
try {
// load resource from the classpath instead of a specific file location
InputStream imageStream = getClass().getResourceAsStream(String.format("/images/%s.png", m.getRoomDirections(i + 1)));
// convert the input stream into an image
Image image = ImageIO.read(imageStream);
// add the image to a label
JLabel label = new JLabel(new ImageIcon(image));
label.setPreferredSize(new Dimension(64, 64));
JPanel panel = new JPanel();
panel.setSize(64, 64);
String name = String.format("%d", i);
panel.setName(name);
panel.add(label);
// add the label to the JFrame
//this.layout.addLayoutComponent(TOOL_TIP_TEXT_KEY, label);
this.add(panel);
} catch (IOException e) {
JOptionPane.showMessageDialog(this, e.getMessage());
e.printStackTrace();
}
}
}
}
#Override
public void addClickListener(DungeonController listener) {
Board board = this.board;
MouseListener mouseListener = new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
System.out.println(String.format("(%d,%d)", e.getX(), e.getY()));
JPanel panel = (JPanel) board.getComponentAt(e.getPoint());
System.out.println(panel.getName());
}
};
board.addMouseListener(mouseListener);
}
#Override
public void refresh() {
this.repaint();
}
#Override
public void makeVisible() {
this.setVisible(true);
}
}
Here is an image of what it produces:

First, I'd make use of a different layout manager, one which would try and expand to fit the size of the underlying container.
Then, I would let the components do their jobs. I don't know why you're adding the label to another panel, the panel doesn't seem to be adding additional functionality/features and is just adding to the complexity.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
List<Maze.Direction> directions = new ArrayList<>(32);
directions.add(Maze.Direction.EAST_SOUTH);
directions.add(Maze.Direction.EAST_SOUTH_WEST);
directions.add(Maze.Direction.EAST_SOUTH_WEST);
directions.add(Maze.Direction.EAST_SOUTH_WEST);
directions.add(Maze.Direction.EAST_SOUTH_WEST);
directions.add(Maze.Direction.SOUTH_WEST);
directions.add(Maze.Direction.NORTH_EAST_SOUTH);
directions.add(Maze.Direction.NORTH_EAST_SOUTH_WEST);
directions.add(Maze.Direction.NORTH_EAST_SOUTH_WEST);
directions.add(Maze.Direction.NORTH_EAST_SOUTH_WEST);
directions.add(Maze.Direction.NORTH_EAST_SOUTH_WEST);
directions.add(Maze.Direction.NORTH_SOUTH_WEST);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH_SOUTH);
directions.add(Maze.Direction.NORTH);
directions.add(Maze.Direction.NORTH);
directions.add(Maze.Direction.NORTH);
directions.add(Maze.Direction.NORTH);
directions.add(Maze.Direction.NORTH);
directions.add(Maze.Direction.NORTH);
System.out.println(directions.size());
Maze maze = new DefaultMaze(5, 6, directions);
MazeGui frame = new MazeGui(maze);
frame.addClickListener(null);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public interface Maze {
enum Direction {
EAST_SOUTH("EastSouth.png"), EAST_SOUTH_WEST("EastSouthWest.png"), SOUTH_WEST("SouthWest.png"),
NORTH_EAST_SOUTH("NorthEastSouth.png"), NORTH_EAST_SOUTH_WEST("NorthEastSouthWest.png"),
NORTH_SOUTH_WEST("NorthSouthWest.png"), NORTH_SOUTH("NorthSouth.png"), NORTH("North.png");
private BufferedImage image;
private Direction(String name) {
try {
image = ImageIO.read(getClass().getResource("/images/" + name));
} catch (IOException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
}
public BufferedImage getImage() {
return image;
}
}
public int getRows();
public int getColumns();
public Direction getRoomDirections(int index);
}
public class DefaultMaze implements Maze {
int rows;
int columns;
private List<Direction> directions;
public DefaultMaze(int rows, int columns, List<Direction> directions) {
this.rows = rows;
this.columns = columns;
this.directions = directions;
}
public int getRows() {
return rows;
}
public int getColumns() {
return columns;
}
#Override
public Direction getRoomDirections(int index) {
return directions.get(index);
}
}
public class MazeGui extends JFrame {
// Missing code
public interface DungeonController {
}
private final Board board;
public MazeGui(Maze m) {
this.setSize(600, 600);
this.setResizable(false);
this.board = new Board(m);
JScrollPane scroller = new JScrollPane(board);
this.add(scroller, BorderLayout.CENTER);
setTitle("Dungeon Escape");
}
public Board getBoard() {
return board;
}
public void addClickListener(DungeonController listener) {
Board board = getBoard();
board.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
Component cell = board.getComponentAt(e.getPoint());
System.out.println(cell.getName());
board.highlight(cell.getBounds());
}
});
}
private class Board extends JPanel {
private Rectangle selectedCell;
private Maze maze;
public Board(Maze maze) {
this.maze = maze;
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
for (int index = 0; index < maze.getRows() * maze.getColumns(); index++) {
Maze.Direction direction = maze.getRoomDirections(index);
JLabel label = new JLabel(new ImageIcon(direction.getImage()));
label.setName(direction.name());
add(label, gbc);
gbc.gridx++;
if (gbc.gridx >= maze.getColumns()) {
gbc.gridx = 0;
gbc.gridy++;
}
}
// addMouseListener(new MouseAdapter() {
// #Override
// public void mouseClicked(MouseEvent e) {
// Component component = getComponentAt(e.getPoint());
// selectedCell = null;
// if (component != null) {
// selectedCell = component.getBounds();
// }
// repaint();
// }
// });
}
public void highlight(Rectangle bounds) {
selectedCell = bounds;
repaint();
}
#Override
public void paint(Graphics g) {
super.paint(g);
if (selectedCell != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(new Color(0, 0, 255, 128));
g2d.fill(selectedCell);
g2d.dispose();
}
}
}
}
}

The GUI itself has a set size and is not resizable
So the issue here is that you are forcing the "board" panel to have an arbitrary size.
this.setSize(600, 600);
The actual size of the panel should be 8 * 64 = 512. So extra space is being added to each grid.
Don't hardcode size values.
It is the job of the layout manager to determine the preferred size of each component.
So instead of using setSize(...) you should pack() the frame before making it visible:
this.pack();
this.setVisible(true);
When you do this you will see that the maze fits completely in the frame.
If you want extra space around the maze then you need to add a "border" to your board:
setBorder( new EmptyBorder(88, 88, 88, 88) );
GridLayout layout = new GridLayout(m.getNumRows(),m.getNumCols(), 0, 0);
Turns out I should have been using GridBagLayout!
There is no need to change layout managers, only use the layout managers more effectively.
If you really for some reason need to specify a fixed frame size then you can make the following change:
//this.add(scroller, BorderLayout.CENTER);
JPanel wrapper = new JPanel( new GridBagLayout() );
wrapper.add(scroller, new GridBagConstraints());
this.add(wrapper, BorderLayout.CENTER);
This will allow the "board" panel to be displayed at its preferred size and the "board" panel will be centered in its parent container.
Using these tips will help you effectively create more complicated layouts.

Get click position in grid. Java Swing

I got this code witch creates a clickable grid that shows the mouse position, altough i am not able to get the position in the grid in where the mouse is clicked, trying to be both X and Y position. Any ideas? This is how the grid looks:
Code:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.Border;
import javax.swing.border.MatteBorder;
public class TestGrid02 {
public TestGrid02() {
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 static final int ROWS = 20;
private static final int COLUMNS = 20;
private static GridBagConstraints gbc;
public TestPane() {
setLayout(new GridBagLayout());
gbc = new GridBagConstraints();
for (int row = 0; row < ROWS; row++) {
for (int col = 0; col < COLUMNS; col++) {
gbc.gridx = col;
gbc.gridy = row;
CellPane cellPane = new CellPane();
Border border = null;
if (row < ROWS-1) {
if (col < COLUMNS-1) {
border = new MatteBorder(1, 1, 0, 0, Color.GRAY);
} else {
border = new MatteBorder(1, 1, 0, 1, Color.GRAY);
}
} else {
border = new MatteBorder(1, 1, 1, 0, Color.GRAY);
}
cellPane.setBorder(border);
add(cellPane, gbc);
}
}
}
}
public class CellPane extends JPanel {
private Color defaultBackground;
public CellPane() {
addMouseListener(new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent e) {
defaultBackground = getBackground();
setBackground(Color.RED);
}
#Override
public void mouseExited(MouseEvent e) {
setBackground(defaultBackground);
}
#Override
public void mouseClicked(MouseEvent e){
//Here is where it is supposed to be
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(30, 30);
}
}
}
In the CellPane class, witch is intended to be the one that listens to the mouse it is supposed to be the function that i need, at the mouseClicked listener, however i have tried with e.getX() or e.getLocationOnScreen() and these values were changing everytime i click in the same grid.

Well, that looks familiar 🤣
So, the basic idea would be to pass in the cell it's coordinates (ie, row/column) value via the constructor, for example...
public class CellPane extends JPanel {
private Color defaultBackground;
private Point cellCoordinate;
public CellPane(Point cellCoordinate) {
this.cellCoordinate = cellCoordinate;
addMouseListener(new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent e) {
defaultBackground = getBackground();
setBackground(Color.RED);
}
#Override
public void mouseExited(MouseEvent e) {
setBackground(defaultBackground);
}
#Override
public void mouseClicked(MouseEvent e) {
//Here is where it is supposed to be
System.out.println("Did click cell # " + getCellCoordinate().x + "x" + getCellCoordinate().y);
}
});
}
public Point getCellCoordinate() {
return cellCoordinate;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(30, 30);
}
}
The cell itself doesn't really care, not does it have any reasonable information available to it to determine how it's been laid out, so your best bet is to "tell" it the information you want it to represent.
For me, I'd just pass in the GridBagLayout row/col information, for example...
gbc.gridx = col;
gbc.gridy = row;
CellPane cellPane = new CellPane(new Point(col, row));
This way you remove all concept (and the issues associated with it) of how the cell is laid out

This approach (using buttons and action listeners) is better IMO. It uses the getButtonRowCol method to return a string indicating the button's location in an array (the buttonArray).
Use b.setBorderPainted(false); (uncomment that code line) to get rid of the borders around each button. Look to the values passed to the constructor of the GridLayout to remove the space between buttons.
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
public class GameGridLayout {
int size = 40;
int iconSize = 10;
JButton[][] buttonArray = new JButton[size][size];
ActionListener actionListener;
JLabel output = new JLabel("Click somewhere on the GUI");
GameGridLayout() {
JPanel gui = new JPanel(new BorderLayout(2,2));
gui.setBorder(new EmptyBorder(4,4,4,4));
gui.add(output,BorderLayout.PAGE_END);
JPanel gameContainer = new JPanel(new GridLayout(0,size,2,2));
gui.add(gameContainer);
actionListener = e -> output.setText(getButtonRowCol((JButton)e.getSource()));
for (int ii=0; ii<size*size; ii++) {
JButton b = getButton();
gameContainer.add(b);
buttonArray[ii%size][ii/size] = b;
}
JFrame f = new JFrame("GameGridLayout");
f.add(gui);
f.pack();
f.setMinimumSize(f.getSize());
f.setLocationByPlatform(true);
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setVisible(true);
}
private String getButtonRowCol(JButton button) {
StringBuilder sb = new StringBuilder();
for (int xx=0; xx<size; xx++) {
for (int yy=0; yy<size; yy++) {
if (button.equals(buttonArray[xx][yy])) {
sb.append("User selected button at: ");
sb.append(xx+1);
sb.append(",");
sb.append(yy+1);
break;
}
}
}
return sb.toString();
}
private JButton getButton() {
JButton b = new JButton();
b.setIcon(new ImageIcon(
new BufferedImage(iconSize,iconSize,BufferedImage.TYPE_INT_ARGB)));
b.setRolloverIcon(new ImageIcon(
new BufferedImage(iconSize,iconSize,BufferedImage.TYPE_INT_RGB)));
b.setMargin(new Insets(0,0,0,0));
//b.setBorderPainted(false);
b.setContentAreaFilled(false);
b.addActionListener(actionListener);
return b;
}
public static void main(String[] args) {
Runnable r = () -> new GameGridLayout();
SwingUtilities.invokeLater(r);
}
}

How can I set a Java Component to set its location in free space?

I'm trying to add a JButton to a JPanel programatically on click. I am able to add it in the panel, but I would like to add the succeeding buttons NOT ON TOP of the button but on the available space not occupied.
addButton.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent arg0) {
JButton button = new JButton("Button");
button.setBounds(50,20, 90,20);
internalFrame.getContentPane().add(button);
button.addMouseListener(drag);
button.addMouseMotionListener(drag);
repaint();
System.out.println("Button added.");
}
});

Here is a demonstration of adding components with a mouse click, as well as basic dragging. Please note the comments:
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import java.awt.Point;
import java.awt.event.MouseEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import javax.swing.border.BevelBorder;
import javax.swing.border.TitledBorder;
import javax.swing.event.MouseInputAdapter;
public class DragDemo extends JFrame {
private static int NAX_COMP_COUNT = 3;
public DragDemo() {
setTitle("Drag Demo");
setLayout(new GridLayout(1,3));
//demonstrates adding components to a null layout panel, with a button click
JPanel panelA = new CustomPanel("Add components,Null layout");
add(panelA);
//adds drsg support to the above
JPanel panelB = new CustomPanel("Add components,Null layout, Drag", true);
add(panelB);
//demonstrates adding components to a flow layout panel, with a button click
//you can add drag support, but components will be auto-layout when repainted
JPanel panelC = new CustomPanel("Add components, Flow layout", new FlowLayout());
add(panelC);
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
public static void main(String[] args) { new DragDemo(); }
private class CustomPanel extends JPanel {
private final BevelBorder border = new BevelBorder(BevelBorder.RAISED);
private final int W =250, H = 200, GAP = 5;
private int originX =10, originY = 10;
private int compCounter = 0;
private JPanel centerPane ;
private LayoutManager layoutManager;
private boolean isDragSupport = false;
CustomPanel(String title) { this(title, null, false); }
CustomPanel(String title, boolean isDragSupport ) {
this(title,null, isDragSupport);
}
CustomPanel(String title, LayoutManager layoutManager) {
this(title,layoutManager, false);
}
CustomPanel(String title, LayoutManager layoutManager, boolean isDragSupport) {
this.layoutManager = layoutManager;
this.isDragSupport = isDragSupport;
TitledBorder tBorder = new TitledBorder(border, title);
setBorder(tBorder);
setLayout(new BorderLayout(GAP,GAP));
JButton button = new JButton("Add Label");
button.addActionListener( e-> addComponenet());
add(button, BorderLayout.SOUTH);
centerPane = new JPanel();
centerPane.setPreferredSize(new Dimension(W, H));
centerPane.setLayout(layoutManager);
add(centerPane, BorderLayout.CENTER);
}
private void addComponenet() {
if( ++ compCounter <= NAX_COMP_COUNT) {
centerPane.add(getComponent());
centerPane.getParent().revalidate();
centerPane.repaint();
}
}
private Component getComponent() {
JLabel label = new JLabel(""+ compCounter, SwingConstants.CENTER);
label.setBorder(border);
if(isDragSupport) {
DragListener drag = new DragListener();
label.addMouseListener( drag );
label.addMouseMotionListener( drag );
}
if(layoutManager == null) {//if no layout manger set bounds
label.setBounds(originX, originY, W/5, H/5);
originX +=W/5; originY += H/5; //update origin of next component
}else {
label.setPreferredSize(new Dimension(W/5, H/5));
}
return label;
}
}
//source: https://tips4java.wordpress.com/2009/06/14/moving-windows/
private class DragListener extends MouseInputAdapter {
Point location;
MouseEvent pressed;
#Override
public void mousePressed(MouseEvent me) { pressed = me; }
#Override
public void mouseDragged(MouseEvent me) {
Component component = me.getComponent();
location = component.getLocation(location);
int x = (location.x - pressed.getX()) + me.getX();
int y = (location.y - pressed.getY()) + me.getY();
component.setLocation(x, y);
}
}
}
For more control and auto-layout you may want to consider DragLayout.
Feel free to ask for any clarifications needed.

setPreferredSize not working on panels when frame maximized on Windows XP?

I have overridden validate() in my JFrame so that I can manually control the size of a couple of nested JPanels (they're used in scrolling content onto the screen and no layout manager I know of lets you lay out components outside of the bounds of the parent container). This works fine when dragging the window to resize it, but when clicking the Maximize button, validate() gets called, the setPreferredSize()s get called, but the panel sizes don't update. Problem seen on XP, not seen in OSX.
public void validate() {
super.validate();
LOGGER.debug("Validate called on Frame. Resizing panel");
if (inited == true) {
Dimension size = panelLeft.getSize();
int referenceHeight = size.height;
LOGGER.info("referenceHeight is " + referenceHeight);
size = lower.getSize();
size.height = referenceHeight;
lower.setPreferredSize(size);
lower.setMinimumSize(size);
size.height = size.height * 2;
movingPanel.setPreferredSize(size);
movingPanel.setMinimumSize(size);
LOGGER.info("sizes now: panel: " + lower.getSize().height + ", scrollpane: "
+ movingPanel.getSize().height);
if (panelSlideController != null) {
panelSlideController.redraw();
LOGGER.debug("redrawing panel slide controller");
}
}
}
panelLeft is a panel which is auto-resized by its layout manager to be the full height of the frame. So its height is used as a reference.
The relevant panels are arranged:
----------------------------------
|scrollPane |
| -------------------------------- |
||movingPanel ||
|| ------------------------------ ||
|||upper |||
||| |||
||| |||
||| |||
|| ------------------------------ ||
|| ------------------------------ ||
|||lower |||
||| |||
||| |||
||| |||
|| ------------------------------ ||
| -------------------------------- |
----------------------------------
The user only sees the top half of this layout.
The movingPanel JPanel is in the viewport of a JScrollPane. The goal is to keep the upper panel taking up all the visible vertical space, so is roughly the same height as the enclosing JFrame. The lower panel is ready to scroll on and is kept with the same height as upper panel. By keeping lower.height == panelLeft.height and movingPanel.height == panelLeft.heightx2, it means half of movingPanel is showing, and upper ends at the bottom of the Frame.
Like I said, works fine. When dragging the window, some example output is:
2013-06-20 23:15:41,298 [WT-EventQueue-0] DEBUG s.billing.ui.Form - Validate called on Frame. Resizing panel
2013-06-20 23:15:41,298 [WT-EventQueue-0] INFO s.billing.ui.Form - newheight is 617
2013-06-20 23:15:41,298 [WT-EventQueue-0] INFO s.billing.ui.Form - sizes now: panel: 607, scrollpane: 1214
2013-06-20 23:15:41,538 [WT-EventQueue-0] DEBUG s.billing.ui.Form - Validate called on Frame. Resizing panel
2013-06-20 23:15:41,538 [WT-EventQueue-0] INFO s.billing.ui.Form - newheight is 640
2013-06-20 23:15:41,538 [WT-EventQueue-0] INFO s.billing.ui.Form - sizes now: panel: 636, scrollpane: 1272
When maximizing the window, output is like:
2013-06-20 22:08:21,234 [WT-EventQueue-0] DEBUG s.billing.ui.Form - Validate called on Frame. Resizing panel
2013-06-20 22:08:21,234 [WT-EventQueue-0] INFO s.billing.ui.Form - newheight is 783
2013-06-20 22:08:21,234 [WT-EventQueue-0] INFO s.billing.ui.Form - sizes now: panel: 543, scrollpane: 1086
I added the setMinimumSize in there to try to be more persuasive but it didn't help.
Any thoughts very welcome
EDIT:
Added SSCCE
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JViewport;
import javax.swing.ScrollPaneConstants;
import javax.swing.Timer;
import javax.swing.UIManager;
class Frame extends JFrame {
private JPanel panelLeft;
private JScrollPane scrollPane;
private JPanel movingPanel;
private JPanel upper;
private JPanel lower;
private boolean inited;
private JLabel labelUpper;
private JLabel labelLower;
private JButton scrollBtn;
private Frame.PanelSlideController panelSlideController;
private JButton resizeBtn;
private boolean lowerShowing = false;
public Frame() {
getContentPane().setLayout(new BorderLayout());
panelLeft = new JPanel();
panelLeft.setBackground(Color.CYAN);
panelLeft.setPreferredSize(new Dimension(300, 400));
getContentPane().add(panelLeft, BorderLayout.WEST);
labelUpper = new JLabel("upper");
panelLeft.add(labelUpper);
labelLower = new JLabel("lower");
panelLeft.add(labelLower);
resizeBtn = new JButton("resize");
resizeBtn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
doResize();
}
});
panelLeft.add(resizeBtn);
scrollBtn = new JButton("Scroll");
scrollBtn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
doScroll();
}
});
panelLeft.add(scrollBtn);
scrollPane = new JScrollPane();
scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER);
movingPanel = new JPanel(new GridLayout(2, 1));
movingPanel.setOpaque(false);
movingPanel.setPreferredSize(new Dimension(300, 400));
upper = new JPanel();
upper.setBackground(Color.YELLOW);
movingPanel.add(upper);
lower = new JPanel();
lower.setBackground(Color.RED);
movingPanel.add(lower);
scrollPane.setViewportView(movingPanel);
getContentPane().add(scrollPane, BorderLayout.EAST);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
inited = true;
}
/**
* This is a manual step instead of overriding validate()
*/
protected void doResize() {
// Get the height we want
int referenceHeight = panelLeft.getSize().height;
// Update the height of the lower panel to equal this
Dimension size = lower.getSize();
size.height = referenceHeight;
lower.setPreferredSize(size);
lower.setMinimumSize(size);
// Update the height of the surrounding panel
size = scrollPane.getSize();
size.height = referenceHeight * 2;
movingPanel.setPreferredSize(size);
movingPanel.setMinimumSize(size);
if (panelSlideController != null) {
panelSlideController.redraw();
System.out.println("redrawing panel slide controller");
}
upper.invalidate();
lower.invalidate();
scrollPane.revalidate();
}
protected void doScroll() {
panelSlideController = new PanelSlideController(scrollPane, 20);
int scrollDirection = lowerShowing ? -1 : 1;
panelSlideController.scrollY(panelLeft.getHeight() * scrollDirection);
lowerShowing = !lowerShowing;
}
#Override
public void validate() {
super.validate();
System.out.println("Validating");
if (inited) {
labelUpper.setText("upper: " + upper.getSize().height);
labelLower.setText("lower: " + lower.getSize().height);
}
}
class PanelSlideController implements ActionListener {
private final JScrollPane scrollPane;
private final int speed;
private Timer timer;
private int endPos;
private boolean scrollingPositive;
public PanelSlideController(JScrollPane scrollPane, int speed) {
this.scrollPane = scrollPane;
this.speed = speed;
}
public void scrollY(int scrollDistance) {
endPos = scrollPane.getViewport().getViewPosition().y + scrollDistance;
scrollingPositive = scrollDistance > 0;
timer = new Timer(speed, this);
timer.start();
}
public void redraw() {
JViewport viewport = scrollPane.getViewport();
Point position = viewport.getViewPosition();
if (scrollingPositive) {
position.y = endPos;
}
else {
position.y = 0;
}
viewport.setViewPosition(position);
}
#Override
public void actionPerformed(ActionEvent e) {
JViewport viewport = scrollPane.getViewport();
Point position = viewport.getViewPosition();
int offset = scrollingPositive ? 10 : -10;
position.y += offset;
viewport.setViewPosition(position);
if ((scrollingPositive && position.y >= endPos)
|| (!scrollingPositive && (position.y <= endPos || position.y <= 0))) {
timer.stop();
}
}
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Exception e) {
e.printStackTrace();
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Frame().setVisible(true);
}
});
}
}
Right, so the above is runnable. panelLeft (cyan) is used as the reference height. I moved the code out of validate() and instead it's run by clicking resize button.
So you can se the red panel (lower) should not be visible until scroll is clicked, at which point yellow scrolls up while red scroll into view. And then back again in the opposite direction. To do this, I need the yellow panel taking up all the vertical height and if I can do this with a layout manager then yay.
I've updated the original snippet and the 'diagram' to mirror the names used in here.
Thanks

OK, thanks to the prompts to use a LayoutManager, I did some digging in that direction. Turns out that JScrollPanes use JViewports which in turn use ViewportLayout implemenation of a LayoutManager. These have control over their delegated 'View' component. As can be seen in the modified code below, I override the layoutContainer method in here now to double the height of my 'movingPanel' in relation to the viewport and this works visibly better than before and when maximised in XP.
Thanks
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JViewport;
import javax.swing.ScrollPaneConstants;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.ViewportLayout;
class Frame extends JFrame {
private JPanel panelLeft;
private JScrollPane scrollPane;
private JPanel movingPanel;
private JPanel upper;
private JPanel lower;
private boolean inited;
private JLabel labelUpper;
private JLabel labelLower;
private JButton scrollBtn;
private Frame.PanelSlideController panelSlideController;
private JButton resizeBtn;
private boolean lowerShowing = false;
public Frame() {
getContentPane().setLayout(new BorderLayout());
panelLeft = new JPanel();
panelLeft.setBackground(Color.CYAN);
panelLeft.setPreferredSize(new Dimension(300, 400));
getContentPane().add(panelLeft, BorderLayout.WEST);
labelUpper = new JLabel("upper");
panelLeft.add(labelUpper);
labelLower = new JLabel("lower");
panelLeft.add(labelLower);
scrollBtn = new JButton("Scroll");
scrollBtn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
doScroll();
}
});
panelLeft.add(scrollBtn);
scrollPane = new JScrollPane();
scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER);
movingPanel = new JPanel(new GridLayout(2, 1));
movingPanel.setOpaque(false);
movingPanel.setPreferredSize(new Dimension(300, 400));
upper = new JPanel();
upper.setBackground(Color.YELLOW);
movingPanel.add(upper);
lower = new JPanel();
lower.setBackground(Color.RED);
movingPanel.add(lower);
// ------------------------------
// This is the key bit
// ------------------------------
JViewport viewport = new JViewport() {
#Override
protected LayoutManager createLayoutManager() {
return new ViewportLayout() {
#Override
public void layoutContainer(Container parent) {
JViewport vp = (JViewport) parent;
Component view = vp.getView();
Dimension viewPrefSize = view.getPreferredSize();
Dimension vpSize = vp.getSize();
Dimension viewSize = new Dimension(viewPrefSize);
viewSize.width = vpSize.width;
viewSize.height = vpSize.height * 2;
vp.setViewSize(viewSize);
}
};
}
};
scrollPane.setViewport(viewport);
viewport.setView(movingPanel);
// ------------------------------
// End of key bit
// ------------------------------
getContentPane().add(scrollPane, BorderLayout.EAST);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
inited = true;
}
protected void doScroll() {
panelSlideController = new PanelSlideController(scrollPane, 20);
int scrollDirection = lowerShowing ? -1 : 1;
panelSlideController.scrollY(panelLeft.getHeight() * scrollDirection);
lowerShowing = !lowerShowing;
}
#Override
public void validate() {
super.validate();
System.out.println("Validating");
if (inited) {
labelUpper.setText("upper: " + upper.getSize().height);
labelLower.setText("lower: " + lower.getSize().height);
}
}
class PanelSlideController implements ActionListener {
private final JScrollPane scrollPane;
private final int speed;
private Timer timer;
private int endPos;
private boolean scrollingPositive;
public PanelSlideController(JScrollPane scrollPane, int speed) {
this.scrollPane = scrollPane;
this.speed = speed;
}
public void scrollY(int scrollDistance) {
endPos = scrollPane.getViewport().getViewPosition().y + scrollDistance;
scrollingPositive = scrollDistance > 0;
timer = new Timer(speed, this);
timer.start();
}
public void redraw() {
JViewport viewport = scrollPane.getViewport();
Point position = viewport.getViewPosition();
if (scrollingPositive) {
position.y = endPos;
}
else {
position.y = 0;
}
viewport.setViewPosition(position);
}
#Override
public void actionPerformed(ActionEvent e) {
JViewport viewport = scrollPane.getViewport();
Point position = viewport.getViewPosition();
int offset = scrollingPositive ? 10 : -10;
position.y += offset;
viewport.setViewPosition(position);
if ((scrollingPositive && position.y >= endPos)
|| (!scrollingPositive && (position.y <= endPos || position.y <= 0))) {
timer.stop();
}
}
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Exception e) {
e.printStackTrace();
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Frame().setVisible(true);
}
});
}
}
Note: I had a subsequent question open before deleting it, and am including the title here for SEO purposes: How to use Swing Layout Managers to contain objects out of frame?

modifying addMouseListener()

This is my button Code onclick i want my program to wait for the user to click one JPanel and as the user clicks the JPanel it should print its name on console.
This button code is not showing the output
JPopupMenu popupMenu_1 = new JPopupMenu();
JMenuItem mntmOneToOne = new JMenuItem("One to One");
mntmOneToOne.setIcon(new ImageIcon("C:\\Users\\Ashad\\Desktop\\oneToone.png"));
popupMenu_1.add(mntmOneToOne);
OneToOne.addMouseListener(new MouseAdapter()
{
#Override
public void mouseClicked(MouseEvent arg0)
{
MouseListener Listen= new MouseAdapter()
{
public void mousePressed(MouseEvent me)
{
String name=new String();
JPanel panel = (JPanel) me.getSource();
// name = panel.getName();
System.out.println(panel.getName());
}
};
}
});

for better help sooner post an SSCCE, short,
runnable, compilable,
because works in my SSCCE, and the answer to
This is my button Code onclick i want my program to wait for the user
to click one JPanel and as the user clicks the JPanel it should print
its name on console.
issue must be in rest of your code,
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
public class MyGridLayout {
public MyGridLayout() {
JPanel bPanel = new JPanel();
bPanel.setLayout(new GridLayout(10, 10, 2, 2));
for (int row = 0; row < 10; row++) {
for (int col = 0; col < 10; col++) {
JPanel b = new JPanel() {
private static final long serialVersionUID = 1L;
#Override
public Dimension getPreferredSize() {
return new Dimension(20, 20);
}
};
b.putClientProperty("column", row);
b.putClientProperty("row", col);
b.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
JPanel btn = (JPanel) e.getSource();
System.out.println("clicked column " + btn.getClientProperty("column")
+ ", row " + btn.getClientProperty("row"));
}
});
b.setBorder(new LineBorder(Color.blue, 1));
bPanel.add(b);
}
}
JFrame frame = new JFrame("PutClientProperty Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(bPanel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
MyGridLayout myGridLayout = new MyGridLayout();
}
});
}
}

You declared a MouseAdapter in your MouseListener mouseClicked method which just sits there and does exactly nothing because nothing is done with it. If you want to add a MouseListener to a panel do the following:
panel.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent arg0) {
JPanel panel = (JPanel) arg0.getSource();
System.out.println(panel.getName());
}
});