问题描述
想在图像上绘制文字。在第一次鼠标单击一个矩形区域显示时，一旦输入文本，文本应该用矩形shap绘制，矩形应该自动调整大小，文本显示在附加图像中。
want to draw text over image. on first mouse click a rectangle region show, as soon as enter text, text should be drawn with in rectangle shap and rectangle should be auto resize with text as displayed in attached image.
推荐答案
基本概念就像任何普通的Swing形式一样。你只需要添加一些额外的工作就可以把它们全部拉到一起。
The basic concept is like any normal Swing form. You just need to add a little extra work to pull it all together.
你需要决定的第一件事是你想要多线支持吗？
The first thing you need to decide is do you want multi line support or not?
以下示例simple使用 JLayeredPane 来提供免费布局，以及自定义 JTextArea 提供可编辑的字段。
The example below simple uses a JLayeredPane, to supply the free layout, and a custom JTextArea to supply the editable fields.
关于这个问题很简单，重新调整大多是照顾你的，可重新编辑性也是如此。 ，只需点击文字，你就会明白我的意思。
The neat thing about this, is the resizing is mostly taken care for you, as is the "re-editability", simply click back on the text and you'll see what I mean.
我会留下重新定位给你;）
I'll leave repositioning up to you ;)
public class TextOverImage {
public static void main(String[] args) {
new TextOverImage();
}
public TextOverImage() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new ImagePane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ImagePane extends JLayeredPane {
private BufferedImage background;
public ImagePane() {
setFocusable(true);
try {
background = ImageIO.read(new File("Your/image/here"));
} catch (Exception e) {
e.printStackTrace();
}
addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
Component focusOwner = FocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
if (!(focusOwner instanceof OverlayEditor)) {
OverlayEditor field = new OverlayEditor();
field.setLocation(e.getPoint());
add(field);
invalidate();
repaint();
field.requestFocusInWindow();
} else {
requestFocusInWindow();
}
}
});
InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
ActionMap am = getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), "cancel");
am.put("cancel", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
Component focusOwner = FocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
if (focusOwner instanceof OverlayEditor) {
remove(focusOwner);
invalidate();
repaint();
}
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (background != null) {
int x = (getWidth() - background.getWidth());
int y = (getHeight() - background.getHeight());
g.drawImage(background, x, y, this);
}
}
}
public class OverlayEditor extends JTextArea {
public OverlayEditor() {
super(1, 10);
setBorder(null);
setForeground(Color.WHITE);
setOpaque(false);
setSize(getPreferredSize());
getDocument().addDocumentListener(new DocumentListener() {
public void update() {
setSize(getPreferredSize());
}
@Override
public void insertUpdate(DocumentEvent e) {
update();
}
@Override
public void removeUpdate(DocumentEvent e) {
update();
}
@Override
public void changedUpdate(DocumentEvent e) {
update();
}
});
addFocusListener(new FocusListener() {
@Override
public void focusGained(FocusEvent e) {
setBorder(new LineBorder(Color.WHITE));
repaint();
}
@Override
public void focusLost(FocusEvent e) {
setBorder(null);
repaint();
}
});
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
if (hasFocus()) {
g2d.setColor(new Color(0, 0, 0, 32));
g2d.fill(new Rectangle(getWidth(), getHeight()));
}
g2d.dispose();
}
}
}
这篇关于如何在JPanel中显示的矩形区域内的图像上书写文本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！