CODEWITHSUNDEEP
javaswinglocationmouseeventjlist
g0dzax
g0dzax

Reputation: 131

MouseEvents inside JList objects

I am a bit confused regarding a situation I have. I created a ListModel extending DefaultListModel and ListRenderer implementing ListCellRenderer for displaying a custom cell in a JList. The cells are some objects created from a class extending JPanel, that contain a JLabel and a JButton.

My issue is related to the mouse events: I want to trigger a certain event when clicking on the JButton inside a cell of the JList, yet I can not figure out how to match the mouse source point to that of the JButton from the respective index. More exactly, I added a mouse listener to the list, but I want it to trigger something if the mouse point is located inside the bounds of the JButton, and another action if it's on the data item. I added some prints to find out the cause of this, but before that some code to highlight the structure:

 public WifiGuiHandler(JButton reference) {
    btnReference = reference;
    wifiListener = new WifiListener();
    wifiPopupContainer = new JScrollPopupMenu("Connections.");
    wifiPopupContainer.setMaximumVisibleRows(7);
    connectionsHolder = new ArrayList<>();
    listOfConnections = new JList();
    listOfConnectionsModel = new ListModel(connectionsHolder);
    listOfConnectionsRenderer = new ListRenderer();
    listOfConnections.setModel(listOfConnectionsModel);
    listOfConnections.setCellRenderer(listOfConnectionsRenderer);
    wifiPopupContainer.add(listOfConnections);
    wifiPopupContainer.pack();
    initializeTestVariables();
    initializeListeners();
}

Here, the constructor for the class that takes a JButton and adds a mouse listener to it, that triggers the appearance of a JPopupMenu, which has only one component, the JList that hold the entire data. Also, links the ArrayList with the data items to the ListModel.

public void initializeTestVariables() {
    for (int i = 0; i <= 10; i++) {
        WifiItem item = new WifiItem("Connection number " + i + ".", i);
        connectionsHolder.add(item);
    }
}

Setting up the data items.

public void initializeListeners() {

    listOfConnections.addMouseListener(new MouseAdapter() {
        public void mouseClicked(MouseEvent e) {
            int index = listOfConnections.locationToIndex(e.getPoint());
            if (index >= 0) {
                WifiItem item = (WifiItem) ((ListModel) listOfConnections.getModel()).getElementAt(index);
                System.out.println("Button of " + item.getConnectionName() + " is at location :" + item.getButton().getLocation());
                System.out.println("Button has the bounds : " + item.getButton().getBounds());
                System.out.println("MouseEvent detected on : " + e.getPoint().getLocation());
                if (item.getButton().getBounds().contains(e.getPoint())) {
                    item.connectHere();
                }
                if (item.getButton().isVisible()) {
                    System.out.println("Set expanded on : " + item.getConnectionName());
                    item.setExpandedState(false);
                    listOfConnectionsModel.fireContentsChanged(item, index, index);
                    updateGui(false);
                } else {
                    System.out.println("Set expanded on : " + item.getConnectionName());
                    listOfConnectionsModel.fireContentsChanged(item, index, index);
                    item.setExpandedState(true);
                    updateGui(false);
                }
            }
        }

    });
    btnReference.addMouseListener(new MouseAdapter() {
        public void mouseClicked(MouseEvent e) {
            updateGui(true);
        }
    });

}

And this is where the confusion arises. I correctly get the data item( WifiItem) from the mouse event location/point, but when I click on the JButton of the WifiItem, it doesn't trigger that method, like it doesn't seem to detect that the JButton actually is there. I also set up the prints, and what is strange, the Point for the JButton is always the same, even though it actually is different, and this seems to be the problem. More exactly, from the output of the program:

Button of Connection number 2. is at location :java.awt.Point[x=137,y=33]

Button has the bounds : java.awt.Rectangle[x=137,y=33,width=90,height=26]

MouseEvent detected on : java.awt.Point[x=172,y=125]

Button of Connection number 3. is at location :java.awt.Point[x=137,y=33]

Button has the bounds : java.awt.Rectangle[x=137,y=33,width=90,height=26]

MouseEvent detected on : java.awt.Point[x=172,y=125]

The above mouse events points were actually located on the JButton itself, only it didn't get that. As another strange fact, only if I click the JButton of the FIRST element of the list does it trigger the required mouse action.

Another print revealed that all the JButtons have the same Point and Rectangle, and I don't get it. There are 10 items in the JList, each displayed properly, how can all their JButtons have the same location? I must be missing some key element here. I looked at other posts and tried other recommendations: converting the point with SwingUtilities, removing all the mouse listeners from the JList and adding them to the data items.

To sum it up,the issue is that the list triggers the events for the correct data item in it(meaning, I do get the correct index for the item located there), but if the mouse event happens on the JButton of any data item inside the list, it doesn't trigger the required effect (the point is not withing the bounds of the button, even though it should be).

Upvotes: 0

Views: 999

Answers (1)

camickr
camickr

Reputation: 324207

More exactly, I added a mouse listener for the list, but I want it to trigger something if the mouse point is located inside the bounds of the JButton, and another action if it's on the data item.

An easier solution would be to use a JTable. The data is separated into columns and the JTable has an API to let you know which row/column was selected.

You can use the Table Button Column as your renderer/editor for the button.

Edit:

only if I click the JButton of the FIRST element of the list does it trigger the required mouse action

Sounds like your conversion of the mouse point is off.

, how can all their JButtons have the same location?

Again, the button location is releative to the renderer panel. The panel itself is relative to the row in the JList. So I would guess you need to need the row index and add the height of each of the previous rows to your calculation.

Upvotes: 0

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