Java examples for Swing:JLabel
Create a Scrollable label
import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.border.*; import java.awt.*; import javax.swing.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.border.*; /* ScrollablePicture.java is used by ScrollDemo.java. */ class ScrollablePicture extends JLabel implements Scrollable, MouseMotionListener {/*w w w . ja v a 2 s .com*/ private int maxUnitIncrement = 1; private boolean missingPicture = false; public ScrollablePicture(ImageIcon i, int m) { super(i); if (i == null) { missingPicture = true; setText("No picture found."); setHorizontalAlignment(CENTER); setOpaque(true); setBackground(Color.white); } maxUnitIncrement = m; //Let the user scroll by dragging to outside the window. setAutoscrolls(true); //enable synthetic drag events addMouseMotionListener(this); //handle mouse drags } //Methods required by the MouseMotionListener interface: public void mouseMoved(MouseEvent e) { } public void mouseDragged(MouseEvent e) { //The user is dragging us, so scroll! Rectangle r = new Rectangle(e.getX(), e.getY(), 1, 1); scrollRectToVisible(r); } public Dimension getPreferredSize() { if (missingPicture) { return new Dimension(320, 480); } else { return super.getPreferredSize(); } } public Dimension getPreferredScrollableViewportSize() { return getPreferredSize(); } public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) { //Get the current position. int currentPosition = 0; if (orientation == SwingConstants.HORIZONTAL) { currentPosition = visibleRect.x; } else { currentPosition = visibleRect.y; } //Return the number of pixels between currentPosition //and the nearest tick mark in the indicated direction. if (direction < 0) { int newPosition = currentPosition - (currentPosition / maxUnitIncrement) * maxUnitIncrement; return (newPosition == 0) ? maxUnitIncrement : newPosition; } else { return ((currentPosition / maxUnitIncrement) + 1) * maxUnitIncrement - currentPosition; } } public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) { if (orientation == SwingConstants.HORIZONTAL) { return visibleRect.width - maxUnitIncrement; } else { return visibleRect.height - maxUnitIncrement; } } public boolean getScrollableTracksViewportWidth() { return false; } public boolean getScrollableTracksViewportHeight() { return false; } public void setMaxUnitIncrement(int pixels) { maxUnitIncrement = pixels; } } /* Corner.java is used by ScrollDemo.java. */ class Corner extends JComponent { protected void paintComponent(Graphics g) { // Fill me with dirty brown/orange. g.setColor(new Color(230, 163, 4)); g.fillRect(0, 0, getWidth(), getHeight()); } } class Rule extends JComponent { public static final int INCH = Toolkit.getDefaultToolkit() .getScreenResolution(); public static final int HORIZONTAL = 0; public static final int VERTICAL = 1; public static final int SIZE = 35; public int orientation; public boolean isMetric; private int increment; private int units; public Rule(int o, boolean m) { orientation = o; isMetric = m; setIncrementAndUnits(); } public void setIsMetric(boolean isMetric) { this.isMetric = isMetric; setIncrementAndUnits(); repaint(); } private void setIncrementAndUnits() { if (isMetric) { units = (int) ((double) INCH / (double) 2.54); // dots per centimeter increment = units; } else { units = INCH; increment = units / 2; } } public boolean isMetric() { return this.isMetric; } public int getIncrement() { return increment; } public void setPreferredHeight(int ph) { setPreferredSize(new Dimension(SIZE, ph)); } public void setPreferredWidth(int pw) { setPreferredSize(new Dimension(pw, SIZE)); } protected void paintComponent(Graphics g) { Rectangle drawHere = g.getClipBounds(); // Fill clipping area with dirty brown/orange. g.setColor(new Color(230, 163, 4)); g.fillRect(drawHere.x, drawHere.y, drawHere.width, drawHere.height); // Do the ruler labels in a small font that's black. g.setFont(new Font("SansSerif", Font.PLAIN, 10)); g.setColor(Color.black); // Some vars we need. int end = 0; int start = 0; int tickLength = 0; String text = null; // Use clipping bounds to calculate first and last tick locations. if (orientation == HORIZONTAL) { start = (drawHere.x / increment) * increment; end = (((drawHere.x + drawHere.width) / increment) + 1) * increment; } else { start = (drawHere.y / increment) * increment; end = (((drawHere.y + drawHere.height) / increment) + 1) * increment; } // Make a special case of 0 to display the number // within the rule and draw a units label. if (start == 0) { text = Integer.toString(0) + (isMetric ? " cm" : " in"); tickLength = 10; if (orientation == HORIZONTAL) { g.drawLine(0, SIZE - 1, 0, SIZE - tickLength - 1); g.drawString(text, 2, 21); } else { g.drawLine(SIZE - 1, 0, SIZE - tickLength - 1, 0); g.drawString(text, 9, 10); } text = null; start = increment; } // ticks and labels for (int i = start; i < end; i += increment) { if (i % units == 0) { tickLength = 10; text = Integer.toString(i / units); } else { tickLength = 7; text = null; } if (tickLength != 0) { if (orientation == HORIZONTAL) { g.drawLine(i, SIZE - 1, i, SIZE - tickLength - 1); if (text != null) g.drawString(text, i - 3, 21); } else { g.drawLine(SIZE - 1, i, SIZE - tickLength - 1, i); if (text != null) g.drawString(text, 9, i + 3); } } } } } /* * ScrollDemo.java requires these files: * Rule.java * Corner.java * ScrollablePicture.java * images/flyingBee.jpg */ public class ScrollDemo extends JPanel implements ItemListener { private Rule columnView; private Rule rowView; private JToggleButton isMetric; private ScrollablePicture picture; public ScrollDemo() { setLayout(new BoxLayout(this, BoxLayout.LINE_AXIS)); //Get the image to use. ImageIcon bee = createImageIcon("images/flyingBee.jpg"); //Create the row and column headers. columnView = new Rule(Rule.HORIZONTAL, true); rowView = new Rule(Rule.VERTICAL, true); if (bee != null) { columnView.setPreferredWidth(bee.getIconWidth()); rowView.setPreferredHeight(bee.getIconHeight()); } else { columnView.setPreferredWidth(320); rowView.setPreferredHeight(480); } //Create the corners. JPanel buttonCorner = new JPanel(); //use FlowLayout isMetric = new JToggleButton("cm", true); isMetric.setFont(new Font("SansSerif", Font.PLAIN, 11)); isMetric.setMargin(new Insets(2, 2, 2, 2)); isMetric.addItemListener(this); buttonCorner.add(isMetric); //Set up the scroll pane. picture = new ScrollablePicture(bee, columnView.getIncrement()); JScrollPane pictureScrollPane = new JScrollPane(picture); pictureScrollPane.setPreferredSize(new Dimension(300, 250)); pictureScrollPane.setViewportBorder(BorderFactory .createLineBorder(Color.black)); pictureScrollPane.setColumnHeaderView(columnView); pictureScrollPane.setRowHeaderView(rowView); //Set the corners. //In theory, to support internationalization you would change //UPPER_LEFT_CORNER to UPPER_LEADING_CORNER, //LOWER_LEFT_CORNER to LOWER_LEADING_CORNER, and //UPPER_RIGHT_CORNER to UPPER_TRAILING_CORNER. In practice, //bug #4467063 makes that impossible (in 1.4, at least). pictureScrollPane.setCorner(JScrollPane.UPPER_LEFT_CORNER, buttonCorner); pictureScrollPane.setCorner(JScrollPane.LOWER_LEFT_CORNER, new Corner()); pictureScrollPane.setCorner(JScrollPane.UPPER_RIGHT_CORNER, new Corner()); //Put it in this panel. add(pictureScrollPane); setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20)); } public void itemStateChanged(ItemEvent e) { if (e.getStateChange() == ItemEvent.SELECTED) { //Turn it to metric. rowView.setIsMetric(true); columnView.setIsMetric(true); } else { //Turn it to inches. rowView.setIsMetric(false); columnView.setIsMetric(false); } picture.setMaxUnitIncrement(rowView.getIncrement()); } /** Returns an ImageIcon, or null if the path was invalid. */ protected static ImageIcon createImageIcon(String path) { java.net.URL imgURL = ScrollDemo.class.getResource(path); if (imgURL != null) { return new ImageIcon(imgURL); } else { System.err.println("Couldn't find file: " + path); return null; } } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window. JFrame frame = new JFrame("ScrollDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. JComponent newContentPane = new ScrollDemo(); newContentPane.setOpaque(true); //content panes must be opaque frame.setContentPane(newContentPane); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } } /* * Copyright (c) 1995, 2011, Oracle and/or its affiliates. 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IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */