JComponentBounds
Die Klasse "JComponentBounds" erlaubt es, JComponents zu verschieben und in der Grösse zu verändern. Die Klasse "PictureDemo" weiter unten zeigt ein Anwendungsbeispiel. <code=java> /*
* JComponentBounds.java * * This class aims at making any JComponent resizable * simply by putting it inside a JInternalFrame. * The wrapped JComponent is made moveable * by means of a MouseInputAdapter. * The class includes a "snap to grid" option. * * author: Andre Uhres * update April 15, 2010 at 6:00 * update December 21, 2010 at 15:00 */
import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; import javax.swing.plaf.basic.*;
public class JComponentBounds extends JInternalFrame {
public static final int FOCUS_GAINED = 97531; private JComponent componentsContainer; private boolean focused; private JComponent comp; private static final Color TRANSPARENT = new Color(0.0f, 0.0f, 0.0f, 0.0f); public static final int MARGIN = 5; private KeyAdapter kl; private MouseInputAdapter ml; private ComponentAdapter cl; private boolean snapToGrid;
public JComponentBounds() { this(new JLabel("jComponentBounds")); }
public JComponentBounds(final JComponent comp) { this(comp, 0, 0, false); }
public JComponentBounds(final JComponent comp, final boolean focused) { this(comp, 0, 0, focused); }
public JComponentBounds(final JComponent comp, final int x, final int y, final boolean focused) { super(); this.comp = comp; this.focused = focused; setBounds(x, y, comp.getPreferredSize().width, comp.getPreferredSize().height); setResizable(true); setVisible(true); setOpaque(false); setBackground(TRANSPARENT); ((BasicInternalFrameUI) getUI()).setNorthPane(null); setBorder(BorderFactory.createEmptyBorder( MARGIN, MARGIN, MARGIN, MARGIN)); comp.setFocusable(true); add(comp); ml = new MouseInputAdapter() {
private Point p1;
@Override public void mousePressed(final MouseEvent e) { p1 = e.getPoint(); componentsContainer = (JComponent) getParent(); e.setSource(JComponentBounds.this); //componentsContainer might use the mousePressed event //to take hidden components to the top: componentsContainer.dispatchEvent(e); }
@Override public void mouseReleased(final MouseEvent e) { componentsContainer = (JComponent) getParent(); e.setSource(JComponentBounds.this); //componentsContainer might use the mouseReleased event //to take hidden components to the top: componentsContainer.dispatchEvent(e); }
@Override public void mouseDragged(final MouseEvent e) { if (!JComponentBounds.this.isFocused()) { return; } //drag operation: Point p2 = e.getPoint(); Point loc = getLocation(); loc.translate(p2.x - p1.x, p2.y - p1.y); setLocation(loc); componentsContainer = (JComponent) getParent(); //auto scroll: componentsContainer.scrollRectToVisible( new Rectangle(loc.x, loc.y, getWidth(), getHeight())); //componentsContainer might use the focusGained event //to keep the dragged component in front: componentsContainer.getFocusListeners()[0].focusGained( new FocusEvent(JComponentBounds.this, JComponentBounds.FOCUS_GAINED)); } }; kl = new KeyAdapter() {
@Override public void keyPressed(final KeyEvent e) { componentsContainer = (JComponent) getParent(); //componentsContainer might use the keyPressed event //to delete the component: componentsContainer.dispatchEvent(e); } }; cl = new ComponentAdapter() {
@Override public void componentResized(final ComponentEvent e) { ((JComponent) e.getSource()).revalidate(); componentsContainer = (JComponent) getParent(); //componentsContainer might use the componentResized event //to transfer focus to the resizing component: componentsContainer.dispatchEvent(e); }
@Override public void componentMoved(final ComponentEvent e) { ((JComponent) e.getSource()).revalidate(); } }; addAllListeners(); }
/* Move and resize this component. * This method has been overridden to implement the "snap to grid" option. */ @Override public void reshape(final int x, final int y, final int width, final int height) { if (snapToGrid) { //convert all parameters to multiples of MARGIN: int gridx = x / MARGIN * MARGIN; int gridy = y / MARGIN * MARGIN; int gridwidth = width / MARGIN * MARGIN; int gridheight = height / MARGIN * MARGIN; //if not horizontally on the grid, round up the grid width: if (gridx != x && gridwidth != width) { gridwidth += MARGIN; } //if not vertically on the grid, round up the grid height: if (gridy != y && gridheight != height) { gridheight += MARGIN; } //snap to the grid: super.reshape(gridx, gridy, gridwidth, gridheight); } else { super.reshape(x, y, width, height); } }
public boolean isSnapToGrid() { return snapToGrid; }
public void setSnapToGrid(final boolean snapToGrid) { this.snapToGrid = snapToGrid; }
private void addAllListeners() { comp.addMouseListener(ml); comp.addMouseMotionListener(ml); comp.addKeyListener(kl); addComponentListener(cl); }
public void removeAllListeners() { comp.removeMouseListener(ml); comp.removeMouseMotionListener(ml); comp.removeKeyListener(kl); removeComponentListener(cl); }
public void setComponent(final JComponent comp) { //remove old component: removeAllListeners(); remove(this.comp); //add new component: this.comp = comp; comp.setFocusable(true); add(comp); addAllListeners(); }
public void setFocused(final boolean focused) { this.focused = focused; repaint(); }
public boolean isFocused() { return focused; }
public Rectangle getComponentRect() { Insets insets = getInsets(); Rectangle rect = getBounds(); rect.x += insets.left; rect.y += insets.top; rect.width -= (insets.right + insets.left); rect.height -= (insets.top + insets.bottom); return rect; }
} </code=java> <code=java> /*
* PictureDemo.java */
import container.JComponentBounds; import java.awt.*; import java.awt.event.*; import java.awt.image.*; import java.io.*; import java.util.*; import javax.imageio.*; import javax.swing.*;
class GUI extends JFrame implements Observer {
private PictureDemo demo; private JComponent picture; private JComponentBounds pictureBounds; private GUI frame; private Image image;
public GUI(final PictureDemo demo) { super(); this.demo = demo; this.init(); }
private void init() { frame = this; setTitle("Demo: click to load picture"); setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); setSize(800, 600); setLocationRelativeTo(null); addMouseListener(new MouseAdapter() {
@Override public void mousePressed(final MouseEvent e) { FileDialog fileDialog = new FileDialog(frame); fileDialog.setVisible(true); String dir = fileDialog.getDirectory(); String file = fileDialog.getFile(); if (dir != null && file != null) { demo.loadPicture(dir + file); } } }); //configure picture: setLayout(null); picture = new JLabel() {
@Override protected void paintComponent(final Graphics g) { super.paintComponent(g);
// g.drawImage(image, 0, 0, this);
g.drawImage(image, 0, 0, pictureBounds.getWidth(), pictureBounds.getHeight(), this); } }; picture.setPreferredSize(new Dimension(100, 100)); pictureBounds = new JComponentBounds(picture, 10, 10, true); pictureBounds.setMinimumSize(new Dimension(40, 20));
// pictureBounds.setSnapToGrid(true);
add(pictureBounds); }
public void update(final Observable observable, final Object arg) { image = (Image) arg; if (image == null) { JOptionPane.showMessageDialog(this, "Picture not found"); } else { pictureBounds.setSize(image.getWidth(null), image.getHeight(null)); picture.setOpaque(true); picture.setBackground(Color.LIGHT_GRAY); picture.repaint(); } }
}
class PictureStorage extends Observable {
private BufferedImage data;
public PictureStorage() { }
public void loadPicture(final String filename) { System.out.println("loading " + filename); SwingWorker<BufferedImage, Void> loadPicture = new SwingWorker<BufferedImage, Void>() {
@Override protected BufferedImage doInBackground() throws Exception { try { data = ImageIO.read(new File(filename)); } catch (IOException ex) { System.out.println(ex); } return data; }
@Override protected void done() { setChanged(); notifyObservers(data); //sends change notification to the view } }; loadPicture.execute(); }
}
public class PictureDemo {
private PictureStorage model;
public PictureDemo() { model = new PictureStorage(); GUI gui = new GUI(this); model.addObserver(gui); gui.setVisible(true); }
public void loadPicture(final String file) { model.loadPicture(file); }
public static void main(final String[] args) { Runnable gui = new Runnable() {
@Override public void run() { PictureDemo pictureDemo = new PictureDemo(); } }; //GUI must start on EventDispatchThread: SwingUtilities.invokeLater(gui); }
} </code=java>