First off I would like to say that I understand I am asking a lot so any help would be appreciated and I thank you for your time. I am extremely grateful.
Anyway I am creating a game for my A2 coursework, most commonly known as Checkers. I have completed my code and everything works as I had planned except that the CheckerBoard itself as well as the checkerpieces do not appear to be showing.
The section of were my board should be present is just a black space. Although my board does not appear to be displaying, all of the actions I perform on it such as clicking certain section produces the planned response, and although I've checked through my code I cannot work out what I've done wrong.
Anyway if anyone could possibly spot my mistake or perhaps give me some advice I would be extremely grateful. Thank you
public class CheckerBoard extends JPanel implements ActionListener, MouseListener {
// Main routine that opens an Applet that shows a CheckerBoard
public static void main(String[] args) {
JFrame application = new JFrame("Checkers"); // Sets the title at the top of the application as 'Checkers'
JMenuBar bar = new JMenuBar(); // Adds the Menu Bar
JMenu fileMenu = new JMenu("File"); // Adds a File Tab to the Menu Bar
JMenu helpMenu = new JMenu("Help"); // Adds a Help Tab to the Menu Bar
JMenuItem exit = new JMenuItem("Exit"); // Adds the Exit sub-tab as an Item of the JMenu
JMenuItem mainMenu = new JMenuItem("Main Menu"); // Adds the Main Menu sub-tab as an Item of the JMenu
final JMenuItem Rules = new JMenuItem("Rules"); // Adds the Rules of Checkers sub-tab as an Item of the JMenu
helpMenu.add(Rules); // Adds the Rules of Checkers tab into the Help tab
fileMenu.add(mainMenu);// Adds the Main Menu sub-tab into the File tab
fileMenu.addSeparator(); // Adds a line in between the Main Menu sub-tab and the Exit sub-tab
fileMenu.add(exit); // Adds the Exit sub-tab into the Menu tab
bar.add(fileMenu); // Adds the Menu tab to the Menu bar
bar.add(helpMenu); // Adds the Help tab to the Menu Bar
application.setJMenuBar(bar); // Adds the Menu Bar to the application window
Rules.addActionListener(new ActionListener() // Adds a new ActionListener to the Rules sub-tab
{
public void actionPerformed(ActionEvent ev)
{
JOptionPane.showMessageDialog(Rules,
"- Pieces must always move diagonally\n" +
"- Single pieces are limited to forward moves\n" +
"- Kings may move both forward and backward\n" +
"- When a piece is captured, it is removed from the board\n" +
"- If a player is able to make a capture, there is no option, the jump must be made\n" +
"- When a piece reaches the opponents end of the board, it is crowned and becomes a King",
"Rules for Checkers",
JOptionPane.PLAIN_MESSAGE);
}
}); //This has added a JOptionPane action when my Rules sub-tab is clicked, this displays the message dialog of the JOptionPane which can be seen
exit.addActionListener(new ActionListener() // Adds an ActionListener to the Exit Sub-tab
{
public void actionPerformed(ActionEvent ev)
{
System.exit(0); // This means that when the Exit sub-tab is clicked, it will exit the application
}
});
CheckerBoard content = new CheckerBoard(); // Sets the CheckerBoard values into the content to be used in the next line
application.setContentPane(content); // Container holds the values together, Content pane of the CheckerBoard
application.pack(); // Use preferred size of content to set size of application.
Dimension screensize = Toolkit.getDefaultToolkit().getScreenSize();
application.setLocation( (screensize.width - application.getWidth())/2,
(screensize.height - application.getHeight())/2 );
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); // Sets so that the application can be exited when the application is closed
application.setResizable(false); // This makes it so that the user can't change the application's size.
application.setVisible(true); // Sets it so that the application can actually be seen
}
private JButton NewGameButton; // Button for starting a new game.
private JButton ResignButton; // Button that a player can use to end the game by resigning
private JLabel MessageDisplay; // Label for displaying messages to the user.
public CheckerBoard() {
// This is going to be a constructor, this constructor will set the layout manager for the panel to be null, it will then add components to the panel
// and it will set their bounds.
setLayout(null); // So that it will match my requirement specification, I will do the layout myself
setBackground(new Color(0,120,0)); // Dark Green Background colour.
setPreferredSize(new Dimension(350,250)); // The size of the Panel
BoardComplete checkerboardData = new BoardComplete();
add(checkerboardData); // This will create the components and add them to the content pane
add(NewGameButton);
add(ResignButton);
add(MessageDisplay);
// I will now have to produce a method to set the position and size of each component by calling its setBounds() method
checkerboardData.setBounds(20,20,164,164); // Sets the board dimensions
NewGameButton.setBounds(210, 60, 120, 30);
ResignButton.setBounds(210, 120, 120, 30);
MessageDisplay.setBounds(20, 200, 350, 30);
}
public class BoardComplete extends JPanel implements ActionListener, MouseListener {
DataForCheckers checkerboardData; // This is where the data for the checkerboard is going to be kept, this board will be responsible for the
// generating of the lists of the legal moves then I will define at a later stage.
boolean CheckerMatchInProgress; // In some of the actions I will be creating, I will have to check whether a game is in progress
// therefore this is a boolean value as it is either true or false, only two possible outcomes.
// The next three variables as seen below will only be valid when the game is in progress
int ChosenRow, ChosenColumn; // If the current player has selected a piece to
// move, these give the row and column
// containing that piece. If no piece is
// yet selected, then ChosenRow is -1.
int ChosenPlayer; // This will check which user turn it is, there will be two possible values which will include DataForCheckers.RED and Checkers.Data.BLACK
DataForMoves[] LegalMoves; // An array containing the legal moves for the
// current player.
// The constructor will create the buttons and the labels. It will
// listen for mouse clicks and for clicks on the buttons. It will create
// the board and start the first game.
BoardComplete() {
setBackground(Color.BLACK);
addMouseListener(this);
ResignButton = new JButton("Resign");
ResignButton.addActionListener(this);
NewGameButton = new JButton("New Game");
NewGameButton.addActionListener(this);
MessageDisplay = new JLabel("",JLabel.CENTER);
MessageDisplay.setFont(new Font("Serif", Font.BOLD, 14));
MessageDisplay.setForeground(Color.green);
checkerboardData = new DataForCheckers();
}
// Now I will have to draw the checkerboard pattern in Gray and LightGray
// Just like with my CheckerBoard Class, this will draw the checkers, and if
// a game is in progress, it will highlight the legal moves that the user can make.
public void PaintCheckerBoard(Graphics g) {
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// This will draw a two-pixel black border around the edges of the canvas.
g.setColor(Color.black);
g.drawRect(0,0,getSize().width-1,getSize().height-1);
g.drawRect(1,1,getSize().width-3,getSize().height-3);
// Draw the squares of the checkerboard and the checkers.
for (int row = 0; row < 8; row++) {
for (int col = 0; col < 8; col++) {
if ( row % 2 == col % 2 )
g.setColor(Color.LIGHT_GRAY);
else
g.setColor(Color.GRAY);
g.fillRect(2 + col*20, 2 + row*20, 20, 20);
switch (checkerboardData.PieceLocation(row,col)) {
case DataForCheckers.RED:
g.setColor(Color.RED);
g.fillOval(4 + col*20, 4 + row*20, 15, 15);
break;
case DataForCheckers.BLACK:
g.setColor(Color.BLACK);
g.fillOval(4 + col*20, 4 + row*20, 15, 15);
break;
case DataForCheckers.RED_KING:
g.setColor(Color.RED);
g.fillOval(4 + col*20, 4 + row*20, 15, 15);
g.setColor(Color.WHITE);
g.drawString("K", 7 + col*20, 16 + row*20);
break;
case DataForCheckers.BLACK_KING:
g.setColor(Color.BLACK);
g.fillOval(4 + col*20, 4 + row*20, 15, 15);
g.setColor(Color.WHITE);
g.drawString("K", 7 + col*20, 16 + row*20);
break;
}
}
}
} // end PaintCheckerBoard()
I understand that this is a lot to ask but any help would be greatly appreciate and I would be extremely grateful. Thank you so much
Basically, nothing calls your PaintCheckerBoard method.
Check Painting in AWT and Swing and Performing Custom Painting for more details about how painting works in Swing.
Essentially, you need to override the BoardComplete's paintComponent and perform you custom painting from within it
Having said that, it would probably be easier to achieve with a GridLayout
Avoid using null layouts, pixel perfect layouts are an illusion within modern ui design. There are too many factors which affect the individual size of components, none of which you can control. Swing was designed to work with layout managers at the core, discarding these will lead to no end of issues and problems that you will spend more and more time trying to rectify
Related
I'm learning java through university and I've been taught the basics of making a java program and designing GUIs. Maximizing a window after running my program makes all the JFrame components stay in place while grey fills the rest of the space. Here's an example of how it looks like:
JFrame window normally, Maximized window before "fix".
After failing to find a solution I came up with a band-aid solution which is to get the component locations and just move them with hard-coded values when the jframe is maximized. This was not an elegant solution and every jframe in my java course project increased in the number of elements on screen. Is there any piece of code to make my components move and resize automatically and dynamically?
Here's what I've tried so far:
First I obtained the positions of components through 2D points:
Point managementLoginBtnLocation, empLogLocation, logoLocation, customerBtnLocation, welcomeLblLocation, contactBtnLocation, aboutBtnLocation, mainMenuBtnLocation;
//Constructor and rest of code...
public final void getOriginalComponentLocations()
{
managementLoginBtnLocation = managementLoginBtn.getLocation();
empLogLocation = empLoginBtn.getLocation();
logoLocation = shopLogo.getLocation();
customerBtnLocation = customerBtn.getLocation();
welcomeLblLocation = welcomeLbl.getLocation();
contactBtnLocation = contactBtn.getLocation();
aboutBtnLocation = aboutBtn.getLocation();
mainMenuBtnLocation = mainMenuBtn.getLocation();
}
//This method is called within the constructor.
I implemented the ComponentListener Interface and added a component listener to my jframe. Then I made it so when the jframe's size changes, it changes the size of the jlabel used for background art. And if the label's width is greater than 800 (the default I used while designing) it moves the components and doubles their size and font size. When the jframe is minimized the label will go back to the default size so I made a method to revert the font sizes, because I found the component sizes and locations reset automatically.
public void componentResized(ComponentEvent e)
{
//Resizing the background label and setting its icon to a resized version of its current icon.
backgroundMainArt.setSize(this.getWidth() - 16, this.getHeight() - 21);
ImageIcon icon = new ImageIcon("C:\\Program Files\\OMOClothingStore\\Resources\\Main menu\\main menu background art.jpg");
Image img = icon.getImage();
Image newImage = img.getScaledInstance(backgroundMainArt.getWidth(), backgroundMainArt.getHeight(), Image.SCALE_FAST);
icon = new ImageIcon(newImage);
backgroundMainArt.setIcon(icon);
if(backgroundMainArt.getWidth() > 800) //When the size of the label is greater than default
{
//I move the components, enlarge the buttons and zoom the font size
moveComponents();
enlargeBtns();
zoomBtnsFontSize();
}
else //When the label is back to its original size
{
//I revert the font sizes as button sizes and positions reset automatically
revertBtnsFontSize();
setLogoIconAndBackgroundArtAndWelcomeLbl();
}
}
public void moveComponents()
{
moveLogo();
moveManagementLoginBtn();
moveEmployeeLoginBtn();
moveCustomerBtn();
moveWelcomeLbl();
moveContactInfoBtn();
moveAboutBtn();
moveMainMenuBtn();
}
public void moveLogo()
{
ImageIcon logoIcon = new ImageIcon("C:\\Program Files\\OMOClothingStore\\Resources\\Shared resources\\OMO Clothing Store logo.png");
Image logoImg = logoIcon.getImage();
Image newLogoImage = logoImg.getScaledInstance(250, 250, Image.SCALE_DEFAULT);
logoIcon = new ImageIcon(newLogoImage);
shopLogo.setIcon(logoIcon);
Point newLogoLocation = new Point();
newLogoLocation.x = (logoLocation.x * 2) + 200;
newLogoLocation.y = (logoLocation.y * 2) + 30;
shopLogo.setLocation(newLogoLocation);
}
//The rest of the "moveX" methods follow the same pattern as moveLogo()
public void enlargeBtns()
{
managementLoginBtn.setSize(410, 94);
empLoginBtn.setSize(410, 94);
customerBtn.setSize(410, 94);
}
public void zoomBtnsFontSize()
{
customerBtn.setFont(sizeBtn.getFont());
//sizeBtn is a JButton that has a font size of 24. I found that just creating a new Font object with bigger size here made the font way larger for some reason.
empLoginBtn.setFont(sizeBtn.getFont());
managementLoginBtn.setFont(sizeBtn.getFont());
}
public void revertBtnsFontSize()
{
empLoginBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
managementLoginBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
customerBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
}
I split the moving of the components into many methods inside other methods because I found it easier to keep up with.
This worked. Here's how it looks like when running the JFrame: Maximized window after "fix". But moving on to other JFrames, they are more intricate and have many more components - extra buttons, panels with other components in them, menu bars, etc.
Is there a better approach to fixing this? Or do I just remove the ability to resize and move on?
So im writing a small test program for fun replicating a inventory from games like minecraft and runescape. Basically a frame with another one inside it, and pictures of your items in it, and a scroll bar to scroll down through all the stuff you have in your inventory. The "Stuff" i would have in my inventory would be buttons added later on with their own functionality, so you can scroll through vertically and see all the "stuff." Right now i have some test buttons being added to deomsntrate the error. Basically i want the buttons to be 100,100 and for them to be in a row of 4, and go onto the next column. I though GridLayout would be the best choice, but it seems to add more rows after being added into a scrollpane. Well heres the code skimmed down:
public class inventory extends JFrame{
public static void main(String[] args){
new inventory();
}
JPanel mainInv = new JPanel();
JScrollPane sp;
public inventory(){
setSize(500,500);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Toolkit tk = this.getToolkit();
setLocation(tk.getScreenSize().width/2-getWidth()/2, tk.getScreenSize().height/2-getHeight()/2);
setLayout(null);
mainInv.setSize(getWidth()-10, 1000);
mainInv.setBackground(Color.blue);
mainInv.setLayout(new GridLayout(8,4));
sp = new JScrollPane(mainInv, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
sp.setMaximumSize(new Dimension(400,400));
sp.setBounds(5, 5, 500-10, 500-130);
JButton[] testButs = new JButton[100];
for(int i = 0; i < 50; i++){
testButs[i] = new JButton("Test Button " + i);
testButs[i].setSize(100,100);
mainInv.add(testButs[i]);
}
add(sp);
setVisible(true);
}
}
With GridLayout the number of rows is the dominating factor.
If you have 8 rows and 4 columns that can only fit 48 buttons, if you try to add a 49th button it will create a 5th column not a 9th row.
You can solve your problem by setting up the GridLayout with more rows.
I am a little new to swing. In order to learn to use the API correctly, I am designing the following project:
The project is a solving block puzzle solver sliding block puzzle similar to the rush-hour puzzles common in toy stores - https://en.wikipedia.org/wiki/Rush_Hour_(board_game) except there is no escape for a special car.
By dragging the blocks from an off board area to the board, the user specifies the starting configuration of the puzzle. The user, in the same way, specifies an ending goal configuration which dictates where some (or all) of the blocks the user specified initially must be at the end of the puzzle - the ending configuration can be specified using only SOME of the blocks, making multiple legal ending configurations.
The algorithm for solving the puzzle is already complete - I just need to design the interface and I am getting stuck. For designing the tray, I used a grid layout. Since blocks need to be entered at certain positions, I need to be able to place blocks in specific cells in the grid and move them around.
A 'block' object has four attributes - its height, width, its top row, and its left most column (ie - each block is addressed by its top left corner).
I used the suggestion here ( https://stackoverflow.com/questions/2510159/can-i-add-a-component-to-a-specific-grid-cell-when-a-gridlayout-is-used ) for the grid layout.
Right now I have only programmed to the point where java reads the puzzle from a .txt file and is supposed to display it on the screen ( I have not designed any user interactablity yet ).
First, here is the code I have written so far.
public class SolverPuzzleGUI extends JFrame {
//Specs from the puzzle.
Board initBoard;
ArrayList<Block> goalBlocks;
LinkedList<Move> moveList;
JLayeredPane layeredpane;
JPanel Board;
Dimension boardsize = new Dimension(400, 500);
JPanel[][] panelHolder = new JPanel[5][4];
public SolverPuzzleGUI(Board startBoard, ArrayList<Block> startGoalBlocks,
LinkedList<Move> startMoveList) {
this.initBoard = startBoard;
this.goalBlocks = startGoalBlocks;
this.moveList = startMoveList;
} // end constructor.
//gives the actual simulation
public void runSimulation() {
// Initalizing the main window.
setSize(500, 600);
setName("Solution");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setMinimumSize(getMinimumSize());
//Using layered pane
layeredpane = new JLayeredPane();
add(layeredpane);
layeredpane.setPreferredSize(boardsize);
layeredpane.setBackground(Color.YELLOW);
layeredpane.setVisible(true);
// adding the game tray
Board = new JPanel();
layeredpane.add(Board, JLayeredPane.DEFAULT_LAYER);
Board.setLayout(new GridLayout(5, 4));
// centering the game tray.
Board.setPreferredSize(boardsize);
Board.setMinimumSize(boardsize);
Board.setMaximumSize(boardsize);
Box box = new Box(BoxLayout.Y_AXIS);
box.add(Box.createVerticalGlue());
box.add(Board);
box.add(Box.createVerticalGlue());
add(box);
//Adding placeholders to the board for creating blocks
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 4; j++) {
panelHolder[i][j] = new JPanel();
panelHolder[i][j].setBackground(Color.DARK_GRAY);
Board.add(panelHolder[i][j]);
layeredpane.setLayer(panelHolder[i][j], JLayeredPane.DEFAULT_LAYER);
panelHolder[i][j].setVisible(false);
} // end 'j' for
} // end 'i' for
ArrayList<Block> initBlocks = initBoard.getBlocks();
//int count = 0; //DEBUG
for (Block block : initBlocks) {
this.drawBlock(block);
//count++;
//if(count > 4) { break; }
} // end 'for'
Board.setBackground(Color.DARK_GRAY);
Board.setVisible(true);
setVisible(true);
} // end 'run'
private void drawBlock(Block block) {
Dimension blockSize = new Dimension(block.getWidth()*100, block.getHeight()*100);
System.out.println(blockSize.width);
System.out.println(blockSize.height);
JPanel screenBlock = new JPanel();
screenBlock.setPreferredSize(blockSize);
screenBlock.setMinimumSize(blockSize);
screenBlock.setMaximumSize(blockSize);
screenBlock.setSize(blockSize);
screenBlock.setBackground(Color.BLUE);
screenBlock.setBorder(BorderFactory.createLineBorder(Color.BLACK));
layeredpane.setLayer(screenBlock, JLayeredPane.MODAL_LAYER);
int leftRow = block.getRow();
int leftCol = block.getColumn();
panelHolder[leftRow][leftCol].setSize(blockSize);
panelHolder[leftRow][leftCol].setVisible(true);
panelHolder[leftRow][leftCol].add(screenBlock);
layeredpane.setLayer(panelHolder[leftRow][leftCol], JLayeredPane.MODAL_LAYER);
screenBlock.setVisible(true);
}// end 'drawBlock'
public static void main(String[] args) {
String file = "C:\\Users\\Tim\\Desktop\\init.from.handout.txt";
String goal = "C:\\Users\\Tim\\Desktop\\goal.2.from.handout.txt";
/*
A SolverPuzzle object is the object which actually solves the algorithm -
when the class is constructed, it takes the file path of the inital
configuration as an input, as well as the file path of the goal
configuration. It has the following fields:
A 'board' object which specifies the inital configuration of the board.
It contains an ArrayList of Block objects(Remember block objects store
the height and width of the block, as well as the address of the
top left corner of block) which specify the starting
blocks, an ArrayList of EmptySpace objects which specify the empty
spaces on the board, an ArrayList of Move objects, which contain
the legal moves of the configuration, and the height and width of
the tray (in this application, the tray will always be 5 x 4).
An ArrayList of Block objects which specify the ending configuration.
A LinkedList of Move objects which specify the shortest possible
list of Moves which brings the configuration to a position which
satisfies the goal position. A Move object has three fields -
The block object being moved, and the row and column of the
top left corner of the block in the new position.
*/
SolverPuzzle test;
try { test = new SolverPuzzle(file, goal); }
catch (IOException ex) {
System.out.println("IOException");
return;
}
Board testBoard = test.getStartBoard();
ArrayList<Block> testGoalBlocks = test.getGoalBlocks();
LinkedList<Move> testMoveSolution = test.getMoveList();
// testing the gui
SolverPuzzleGUI testGUI = new SolverPuzzleGUI(testBoard, testGoalBlocks,
testMoveSolution);
testGUI.runSimulation();
}
} // end class 'SolverPuzzleGUI'
Here's the current output vs desired output.
http://imgur.com/a/ykXXP
So specifically, I have two questions:
1 - Why is the image only showing the top left corners of the blocks instead of the whole block?
2 - Is it better to continue using the GridLayout or switch to GridBagLayout?
Thanks
GridBagLayout would definitely be suitable for want you want to do. For example, you can expand components to envelop more than one column or row - just like what you want to do. Check out the java tutorials for how to use them.
A key point to remember when using GridBagLayoutis that you need to reset the Constraints after each component, assuming that they're unique to that particular component.
Also - I can't discern what you mean by only showing the top-left - it looks likes its showing the whole thing to me...
I have a JFrame extended class that implements a multi-tab chat. Every tab is a chat with someone or with a group of people. What I have implemented works fine, except when I assign a ToolTipText to the label of a tab. In this case I can't click anymore (and select) the tab that has a ToolTipText assigned. The others work fine.
Graphical example:
As you can see the tabs are properly being added, and the first two tabs ("Gruppo prova" and "Gruppo test") have a ToolTipText, the other two don't. I can switch between the last two, but I can't do the same with the first two. I thought that the icon next to the label could be a problem, but I removed it and still doesn't work. However I can still click all the 'X' (close) buttons (working properly).
This is a piece of the code I used to add a tab:
// Some stuff...
JChat chat = new JChat(gui.chatClient, email, name, group);
jTabbedPane.add(email, chat); // I instantiated this before
int index = jTabbedPane.indexOfTab(email);
JPanel pnlTab = new JPanel(new GridBagLayout());
pnlTab.setOpaque(false);
// Core function
JLabel lblTitle;
if (group == 1) {
// If it's a group and not a single chat I assign a name, an icon and a ToolTipText to the tab
lblTitle = new JLabel(name, icon, JLabel.LEFT);
lblTitle.setToolTipText(membersList.toString());
} else {
// otherwise I only assign a name to the tab
lblTitle = new JLabel(name);
}
jTabbedPane.setTabComponentAt(index, pnlTab);
// This applies the 'X' (close) button next to the tab name
CloseButton btnClose = new CloseButton(this, jTabbedPane, tabs, email);
lblTitle.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 5));
pnlTab.add(lblTitle);
pnlTab.add(btnClose);
Is this a Swing bug or am I doing something wrong?
you can use :
void setToolTipTextAt(int, String) to set tool-tip text to specific tab.
void setIconAt(int index, Icon icon) to set the icon to specific tab.
No need to use JLabel for setting tool-tip text or icon.
The above solution, however doesn't however answer your question:
except when I assign a ToolTipText to the label of a tab. In this
case I can't click anymore (and select) the tab that has a ToolTipText
assigned
The only reason i am suspecting:
JLabel doesn't register to any mouse listener by default. When no mouse listener is set to JLabel any mouse clicked event will go through to the UI objects underneath: in this case the JTabbedPane. But when we are setting tool-tip text using setToolTipText(text), the ToolTipManger adds a mouse listener to this JLabel, which will continue to consume the mouse click event.
Check the following code snippets demonstrating the issue and providing a work around setSelectedIndex function:
JLabel label = new JLabel("a Label");
System.out.println(label.getMouseListeners().length); // length is printed as 0
label.setToolTipText("Danger: setting tool tip will consume mouse event");
System.out.println(label.getMouseListeners().length); // length is printed as 1
jTabbedPane1.setTabComponentAt(0, label);
label.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
int index = jTabbedPane1.indexOfTabComponent((Component)e.getSource());
jTabbedPane1.setSelectedIndex(index);
}
});
I have 5 JLabels inside a JPanel which is inside a JFrame. I am adding the JLabels using a for loop which iterates through an array of Colors:
private JLabel target;
// This is the origin of the first label added.
Point origin = new Point(10, 20);
// This is the offset for computing the origin for the next label.
int offset = 200;
for (int i = 0; i < layerColors.length; i++) {
target = createColoredLabel(layerColors[i], origin, targetIcon);
layeredPane.add(target, new Integer(i));
origin.x += offset;
}
// Create and set up a colored label with icon image.
private JLabel createColoredLabel(Color color, Point origin, ImageIcon icon) {
JLabel label = new JLabel(icon);
label.setVerticalAlignment(JLabel.TOP);
label.setHorizontalAlignment(JLabel.CENTER);
label.setOpaque(true);
label.setBackground(color);
label.setBorder(BorderFactory.createLineBorder(Color.black));
label.setBounds(origin.x, origin.y, 175, 263);
label.addMouseListener(this);
return label;
}
This creates 5 JLabels, with the same ImageIcon assigned to each, spread horizontally across the JPanel. Each one has a MouseListener added to it but only the last label to be added triggers the event.
#Override
public void mouseClicked(MouseEvent e) {
if (e.getSource().equals(target)) {
Toolkit.getDefaultToolkit().beep();
}
}
I have a secondary issue involving a label containing an ImageIcon trailing my cursor which stops when I mouse over any of the 5 labels. I imagine it's a layer indexing issue but can't solve it.
Any help with these is much appreciated thanks!
Your mouseClicked(MouseEvent evt) method only checks to see if the event source was a single component (target) which, as Geoffrey points out, is that last label you added. Try adding this as the first line in your mouseClicked method.
System.out.println("Color: " + ((JLabel)evt.getSource()).getBackground());
Note: Untested. Hopefully Color has a nice toString() implementation.
Note 2: You may get a ClassCastException if you added the class as a mouse listener to any other component.