JButton在更新JTextArea之后更改位置

Question

我目前正在從事一個項目，該項目應該創建一個包含電子組件（如電阻器，LED和電容器）的電路板。

我有一個主JFrame，其中包含所有小的JPanel：Centerpanel-包含板Rightpanel-包含有關所選組件的信息

我如何想象它的工作原理如下：

1. 您從JComboBox中選擇一個組件

   1.1。 組件是通過ComponentFactory創建的

2. 您單擊中央面板上的某處以將新組件添加到板上

之后，當您單擊該組件時，信息應顯示在JTextArea的右側面板中。

我的問題是：一切都按計划進行，直到我第二次單擊該組件以獲取有關該組件的信息（如右面板所示）。 然后，將JButton調整為較小的尺寸，並移至左上角。

當我添加代碼時發生了這種情況：

String strBuilder = "Type: " + e.getComponent().getName() + "\n" + 
"ID: " + ((Components) e.getComponent()).getCompID() + "\n";
infoContainer.append(strBuilder);

完整的代碼：

public class Framework extends JFrame{
// Declaring variables for the frame
private ComponentFactory cf = new ComponentFactory();
private JToolBar menuToolbar;
private String[] menuItemsString = new String[]{ "newFile", "loadFile", "saveFile" };
private JButton[] menuItems = new JButton[menuItemsString.length];

private JPanel menuPane, centerPane, innerCenter;
private JPanel rightPane;
private JTextArea infoContainer;

private JComboBox<String> componentList;
private final String NOT_SELECTABLE_OPTION = " - Select a component - ";
private String[] componentListStrings = new String[] {"Resistor","LED","Capacitor","Inductor"};
private Components newComponent, selectedComponent;
private boolean componentSelected = false;

private ArrayList<Components> compList = new ArrayList<Components>();

/**
 * Creates a new dispatcher that will listen for keyboard actions on all the selected elements.
 * @author Zovsaman
 */
private class MyDispatcher implements KeyEventDispatcher {
    @Override
    public boolean dispatchKeyEvent(KeyEvent e) {
        if(e.getID() == KeyEvent.KEY_PRESSED){
            if(componentSelected){
                if(e.getKeyCode() == 27){
                    componentSelected = false;
                }

            }
        }
        return false;
    }
}

public Framework(){
    setLayout(new BorderLayout());
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    setSize((int)screenSize.getWidth()/2, (int)screenSize.getHeight()/2);

    // Initiating all the JPanels and stuff
    menuToolbar = new JToolBar(null);
    componentList = new JComboBox<String>();
    centerPane = new JPanel();
    innerCenter = new JPanel();
    rightPane = new JPanel();
    infoContainer = new JTextArea(5, 20);

    // Setting settings and adding buttons to JToolBar at the top of the program
    menuToolbar.setFloatable(false);
    for(int i = 0; i < menuItemsString.length; i++){
        menuItems[i] = new JButton();
        menuItems[i].setName(menuItemsString[i]);
        addIcon(menuItems[i]);
        menuToolbar.add(menuItems[i]);
        if(i < menuItemsString.length){
            // Add spacing to the button menu
            menuToolbar.addSeparator(new Dimension(4, 0));
        }
    }

    // Changing settings on the JComboBox that holds all the different kinds of components
    // Changing the ComboBox to a fixed Size
    componentList.setMaximumSize(new Dimension(200, 24));

    // Adding all the items to JComboBox
    componentList.addItem(NOT_SELECTABLE_OPTION);
    for(int i = 0; i < componentListStrings.length; i++){
        componentList.addItem(componentListStrings[i]);
    }
    // Setting actionListener to listen after changing the JComboBox
    componentList.addActionListener(new ActionListener(){
        @Override
        public void actionPerformed(ActionEvent e) {
            componentSelected = true;
            newComponent = cf.createComponent((String)componentList.getSelectedItem());
        }
    });

    menuToolbar.add(componentList);

    add(menuToolbar, BorderLayout.NORTH);

    KeyboardFocusManager manager = KeyboardFocusManager.getCurrentKeyboardFocusManager();
    manager.addKeyEventDispatcher(new MyDispatcher());



    // Creating the center piece
    innerCenter.setLayout(new BoxLayout(innerCenter, EXIT_ON_CLOSE));

    innerCenter.setPreferredSize(new Dimension(700, 400));
    innerCenter.setBackground(Color.LIGHT_GRAY);

    innerCenter.addMouseListener(new MouseAdapter(){
        public void mousePressed(MouseEvent e){ 
            if(newComponent != null){
                Dimension size = newComponent.getPreferredSize();

                newComponent.setBounds(e.getX() - (size.width/2), e.getY() - (size.height/2), size.width, size.height);
                newComponent.setLocation(e.getPoint());

                newComponent.addMouseListener(new MouseAdapter(){
                    public void mousePressed(MouseEvent e){
                        // TODO Update infopanel with info about marked component....
                        String strBuilder = "Type: " + e.getComponent().getName() + "\n" +
                                            "ID: " + ((Components) e.getComponent()).getCompID() + "\n";
                        infoContainer.append(strBuilder);
                    }
                });

                innerCenter.add(newComponent);
                innerCenter.repaint();

                componentSelected = false;
                newComponent = null;
            }
        }
    });
    centerPane.add(innerCenter);
    centerPane.setVisible(true);
    add(centerPane, BorderLayout.CENTER);

    JPanel tempPane = new JPanel();
    tempPane.setLayout(new BoxLayout(tempPane, BoxLayout.PAGE_AXIS));

    // Right pane, info panel
    // rightPane = new JPanel();
    // infoContainer = new JTextArea();
    infoContainer.setBackground(Color.LIGHT_GRAY);
    infoContainer.setVisible(true);

    JLabel tempLabel = new JLabel("Information about component:");
    tempPane.add(tempLabel);
    tempPane.add(infoContainer);
    rightPane.add(tempPane);

    add(rightPane, BorderLayout.EAST);

    setVisible(true);
    pack();
    setDefaultCloseOperation(EXIT_ON_CLOSE);
}

和描述我的意思更好的圖像（第一個圖像：將組件放在onclick板上，第二個圖像：再次單擊該組件以從中獲取數據以顯示在右側面板中）

添加組件：

再次單擊它：

Answer 1

您在混淆Swing布局。 您正在使用layoutmanager設置面板：

innerCenter.setLayout(new BoxLayout(innerCenter, EXIT_ON_CLOSE));

但是隨后，您嘗試在其上設置組件的邊界，就像您手動放置它一樣：

newComponent.setBounds(e.getX() - (size.width/2), e.getY() - (size.height/2), size.width, size.height);
newComponent.setLocation(e.getPoint());

如果要手動放置，則需要從面板中刪除布局管理器：

innerCenter.setLayout(null);

這樣您就可以告訴Swing您將手動設置所有子項的邊界和位置。 否則，每當您添加/刪除/重新驗證/包裝容器時，布局管理器都將嘗試重新布局所有內容。