Very simple Java AWT Frame resize question

In the following code, I create an awt Frame. Unfortunately, when I run the resulting Java application (on Windows) and use the mouse to resize the window, none of the Frame's resize/setSize methods get called. Can anyone explain why this is?
Thanks
Greg
import java.awt.* ;
public class Junk extends Frame {
public static void main (String args[])
Junk j = new Junk ();
j.show ();
public void resize(Dimension arg0)
super.resize(arg0);
public void resize(int arg0, int arg1)
super.resize(arg0, arg1);
public void setSize(Dimension arg0)
super.setSize(arg0);
public void setSize(int arg0, int arg1)
super.setSize(arg0, arg1);
}

When the user resizes the frame with the mouse, the resizing action probably happens entirely on the Frame's peer, without the java.awt.Frame getting involved at all. setSize() and [deprecated] resize() allow an application to programmatically change the size of a Frame, but the Frame just passes the new size to its peer.
If you want to detect when your Frame has been resized, use addComponentListener to register a component listener on the Frame, and then put your code in the componentResized method of the listener.

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I searched for litterature, but only found the Programmer Reference Manual (http://www.ni.com/pdf/manuals/323643a.pdf). The litterature you suggest seems very relevant, I'll take a look at it. Thanks.

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lduren wrote:
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Read my postsI do. Quite often.
Contrast that versus the vast majority of kaze0's posts, which are clearly meant for wasting people's
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Hi all,
I have to draw a custom created image in a scroll pane. As the image is very large I want to display it in a scroll pane. As parts of the image may change within seconds, and drawing the whole image is very time consuming (several seconds) I want to draw only the part of the image that is currently visible to the user.
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package graphics;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.ScrollPane;
import java.awt.event.AdjustmentEvent;
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 private final Component m_Target;
 /** Default constructor.
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 public void adjustmentValueChanged(AdjustmentEvent e) { m_Target.paint(m_Target.getGraphics()); }
 public CMyComponent() {
 // Ensure that the component repaints upon changing of the scroll bars
 ScrollBarAdjustmentListener sbal = new ScrollBarAdjustmentListener(this);
 getHAdjustable().addAdjustmentListener(sbal);
 getVAdjustable().addAdjustmentListener(sbal);
 public void paint(Graphics g) {
 setBackground(Color.BLUE);
 g.setColor(Color.RED);
 g.fillRect(getScrollPosition().x, getScrollPosition().y, getViewportSize().width, getViewportSize().height);
 public final static void main(String[] args) {
 java.awt.Frame f = new java.awt.Frame();
 f.add(new CMyComponent());
 f.pack();
 f.setVisible(true);
}

Dear all,
I used the last days and tried several things. I think now I have a quite good working solution (just one bug remains) and it is very performant. To give others a chance to see what I have done I post the source code of the main class (a canvas drawing and implementing scrolling) here. As soon as the sourceforge project is accepted, I will publish the whole sources at there. Enjoy. And if you have some idea for my last bug in getElementAtPixel(Point), then please tell me.
package internetrail.graphics.hexgrid;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.Polygon;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.geom.Area;
import java.awt.image.BufferedImage;
import java.util.WeakHashMap;
import java.util.Map;
/** Hex grid view.
* Visualizes a {@link IHexGridModel}.
* @version 0.1, 03.06.2006
* @author Bjoern Wuest, Germany
public final class CHexGridView extends Canvas implements ComponentListener, IHexGridElementListener {
 /** Serial version unique identifier. */
 private static final long serialVersionUID = -965902826101261530L;
 /** Instance-constant parameter for the width of a hex grid element. */
 public final int CONST_Width;
 /** Instance-constant parameter for 1/4 of the width of a hex grid element. */
 public final int CONST_Width1fourth;
 /** Instance-constant parameter for 3/4 of the width of a hex grid element. */
 public final int CONST_Width3fourth;
 /** Instance-constant parameter for 1.5 times of the width of a hex grid element. */
 public final int CONST_Width1dot5;
 /** Instance-constant parameter for 4 times of the width of a hex grid element. */
 public final int CONST_Widthquad;
 /** Instance-constant parameter for the height of a hex grid element. */
 public final int CONST_Height;
 /** Instance-constant parameter for 1/2 of the height of a hex grid element. */
 public final int CONST_Heighthalf;
 /** Instance-constant parameter for the double height of a hex grid element. */
 public final int CONST_Heightdouble;
 /** The steepness of a side of the hex grid element (calculated for the upper left arc). */
 public final double CONST_Steepness;
 /** The model of this hex grid */
 private final IHexGridModel m_Model;
 /** A cache for already created images of the hex map. */
 private final Map<Point, Image> m_Cache = new WeakHashMap<Point, Image>();
 /** The graphical area to draw the selection ring around a hex element. */
 private final Area m_SelectionRing;
 /** The image of the selection ring around a hex element. */
 private final BufferedImage m_SelectionRingImage;
 /** The current position of the hex grid in pixels (top left visible corner). */
 private Point m_ScrollPosition = new Point(0, 0);
 /** Flag to define if a grid is shown ({@code true}) or not ({@code false}). */
 private boolean m_ShowGrid = true;
 /** Flag to define if the selected hex grid element should be highlighted ({@code true}) or not ({@code false}). */
 private boolean m_ShowSelected = true;
 /** The offset of hex grid elements shown on the screen, measured in hex grid elements. */
 private Point m_CurrentOffset = new Point(0, 0);
 /** The offset of the image shown on the screen, measured in pixels. */
 private Point m_PixelOffset = new Point(0, 0);
 /** The index of the currently selected hex grid element. */
 private Point m_CurrentSelected = new Point(0, 0);
 /** The width of a buffered pre-calculated image in pixel. */
 private int m_ImageWidth;
 /** The height of a buffered pre-calculated image in pixel. */
 private int m_ImageHeight;
 /** The maximum number of columns of hex grid elements to be shown at once on the screen. */
 private int m_MaxColumn;
 /** The maximum number of rows of hex grid elements to be shown at once on the screen. */
 private int m_MaxRow;
 /** Create a new hex grid view.
 * The hex grid view is bound to a {@link IHexGridModel} and registers at
 * that model to listen for {@link IHexGridElement} updates.
 * @param Model The model backing this view.
 public CHexGridView(IHexGridModel Model) {
 // Set the model
 m_Model = Model;
 CONST_Width = m_Model.getElementsWidth();
 CONST_Height = m_Model.getElementsHeight();
 CONST_Width1fourth = CONST_Width/4;
 CONST_Width3fourth = CONST_Width*3/4;
 CONST_Width1dot5 = CONST_Width*3/2;
 CONST_Heighthalf = CONST_Height/2;
 CONST_Widthquad = CONST_Width*4;
 CONST_Heightdouble = CONST_Height*2;
 CONST_Steepness = (double)CONST_Heighthalf / CONST_Width1fourth;
 m_ImageWidth = getSize().width+CONST_Widthquad;
 m_ImageHeight = getSize().height+CONST_Heightdouble;
 m_MaxColumn = m_ImageWidth / CONST_Width3fourth;
 m_MaxRow = m_ImageHeight / CONST_Height;
 // Register this canvas for various notifications
 m_Model.addElementListener(this);
 addComponentListener(this);
 // Create the selection ring to highlight hex grid elements
 m_SelectionRing = new Area(new Polygon(new int[]{-1, CONST_Width1fourth-1, CONST_Width3fourth+1, CONST_Width+1, CONST_Width3fourth+1, CONST_Width1fourth-1}, new int[]{CONST_Heighthalf, -1, -1, CONST_Heighthalf, CONST_Height+1, CONST_Height+1}, 6));
 m_SelectionRing.subtract(new Area(new Polygon(new int[]{2, CONST_Width1fourth+2, CONST_Width3fourth-2, CONST_Width-2, CONST_Width3fourth-2, CONST_Width1fourth+2}, new int[]{CONST_Heighthalf, 2, 2, CONST_Heighthalf, CONST_Height-2, CONST_Height-2}, 6)));
 m_SelectionRingImage = new BufferedImage(CONST_Width, CONST_Height, BufferedImage.TYPE_INT_ARGB);
 Graphics2D g = m_SelectionRingImage.createGraphics();
 g.setColor(Color.WHITE);
 g.fill(m_SelectionRing);
 @Override public synchronized void paint(Graphics g2) {
 // Caculate the offset of indexes to show
 int offsetX = 2 * (m_ScrollPosition.x / CONST_Width1dot5) - 2;
 int offsetY = (int)(Math.ceil(m_ScrollPosition.y / CONST_Height) - 1);
 m_CurrentOffset = new Point(offsetX, offsetY);
 // Check if the image is in the cache
 Image drawing = m_Cache.get(m_CurrentOffset);
 if (drawing == null) {
 // The image is not cached, so draw it
 drawing = new BufferedImage(m_ImageWidth, m_ImageHeight, BufferedImage.TYPE_INT_ARGB);
 Graphics2D g = ((BufferedImage)drawing).createGraphics();
 // Draw background
 g.setColor(Color.BLACK);
 g.fillRect(0, 0, m_ImageWidth, m_ImageHeight);
 // Draw the hex grid
 for (int column = 0; column <= m_MaxColumn; column += 2) {
 for (int row = 0; row <= m_MaxRow; row++) {
 // Draw even column
 IHexGridElement element = m_Model.getElementAt(offsetX + column, offsetY + row);
 if (element != null) { g.drawImage(element.getImage(m_ShowGrid), (int)(column*(CONST_Width3fourth-0.5)), CONST_Height*row, null); }
 // Draw odd column
 element = m_Model.getElementAt(offsetX + column+1, offsetY + row);
 if (element!= null) { g.drawImage(element.getImage(m_ShowGrid), (int)(column*(CONST_Width3fourth-0.5)+CONST_Width3fourth), CONST_Heighthalf*(row*2+1), null); }
 // Put the image into the cache
 m_Cache.put(m_CurrentOffset, drawing);
 // Calculate the position of the image to show
 offsetX = CONST_Width1dot5 + (m_ScrollPosition.x % CONST_Width1dot5);
 offsetY = CONST_Height + (m_ScrollPosition.y % CONST_Height);
 m_PixelOffset = new Point(offsetX, offsetY);
 g2.drawImage(drawing, -offsetX, -offsetY, null);
 // If the selected element should he highlighted, then do so
 if (m_ShowSelected) {
 // Check if the selected element is on screen
 if (isElementOnScreen(m_CurrentSelected)) {
 // Correct vertical offset for odd columns
 if ((m_CurrentSelected.x % 2 == 1)) { offsetY -= CONST_Heighthalf; }
 // Draw the selection circle
 g2.drawImage(m_SelectionRingImage, (m_CurrentSelected.x - m_CurrentOffset.x) * CONST_Width3fourth - offsetX - ((m_CurrentSelected.x + 1) / 2), (m_CurrentSelected.y - m_CurrentOffset.y) * CONST_Height - offsetY, null);
 @Override public synchronized void update(Graphics g) { paint(g); }
 public synchronized void componentResized(ComponentEvent e) {
 // Upon resizing of the component, adjust several pre-calculated values
 m_ImageWidth = getSize().width+CONST_Widthquad;
 m_ImageHeight = getSize().height+CONST_Heightdouble;
 m_MaxColumn = m_ImageWidth / CONST_Width3fourth;
 m_MaxRow = m_ImageHeight / CONST_Height;
 // And flush the cache
 m_Cache.clear();
 public void componentMoved(ComponentEvent e) { /* do nothing */ }
 public void componentShown(ComponentEvent e) { /* do nothing */ }
 public void componentHidden(ComponentEvent e) { /* do nothing */ }
 public synchronized void elementUpdated(IHexGridElement Element) {
 // Clear cache where the element may be contained at
 for (Point p : m_Cache.keySet()) { if (isElementInScope(Element.getIndex(), p, new Point(p.x + m_MaxColumn, p.y + m_MaxRow))) { m_Cache.remove(p); } }
 // Update the currently shown image if the update element is shown, too
 if (isElementOnScreen(Element.getIndex())) { repaint(); }
 /** Returns the model visualized by this grid view.
 * @return The model visualized by this grid view.
 public IHexGridModel getModel() { return m_Model; }
 /** Returns the current selected hex grid element.
 * @return The current selected hex grid element.
 public IHexGridElement getSelected() { return m_Model.getElementAt(m_CurrentSelected.x, m_CurrentSelected.y); }
 /** Sets the current selected hex grid element by its index.
 * If the selected hex grid element should be highlighted and is currently
 * shown on the screen, then this method will {@link #repaint() redraw} this
 * component automatically.
 * @param Index The index of the hex grid element to become the selected one.
 * @throws IllegalArgumentException If the index refers to a non-existing hex
 * grid element.
 public synchronized void setSelected(Point Index) throws IllegalArgumentException {
 // Check that the index is valid
 if ((Index.x < 0) || (Index.y < 0) || (Index.x > m_Model.getXElements()) || (Index.y > m_Model.getYElements())) { throw new IllegalArgumentException("There is no hex grid element with such index."); }
 m_CurrentSelected = Index;
 // If the element is on screen and should be highlighted, then repaint
 if (m_ShowSelected && isElementOnScreen(m_CurrentSelected)) { repaint(); }
 /** Moves the visible elements to the left by the number of pixels.
 * To move the visible elements to the left by one hex grid element, pass
 * {@link #CONST_Width3fourth} as the parameter. The component will
 * automatically {@link #repaint()}.
 * @param Pixels The number of pixels to move to the left.
 * @return The number of pixels moved to the left. This is always between 0
 * and {@code abs(Pixels)}.
 public synchronized int moveLeft(int Pixels) {
 int delta = m_ScrollPosition.x - Math.max(0, m_ScrollPosition.x - Math.max(0, Pixels));
 if (delta != 0) {
 m_ScrollPosition.x -= delta;
 repaint();
 return delta;
 /** Moves the visible elements up by the number of pixels.
 * To move the visible elements up by one hex grid element, pass {@link
 * #CONST_Height} as the parameter. The component will automatically {@link
 * #repaint()}.
 * @param Pixels The number of pixels to move up.
 * @return The number of pixels moved up. This is always between 0 and {@code
 * abs(Pixels)}.
 public synchronized int moveUp(int Pixels) {
 int delta = m_ScrollPosition.y - Math.max(0, m_ScrollPosition.y - Math.max(0, Pixels));
 if (delta != 0) {
 m_ScrollPosition.y -= delta;
 repaint();
 return delta;
 /** Moves the visible elements to the right by the number of pixels.
 * To move the visible elements to the right by one hex grid element, pass
 * {@link #CONST_Width3fourth} as the parameter. The component will
 * automatically {@link #repaint()}.
 * @param Pixels The number of pixels to move to the right.
 * @return The number of pixels moved to the right. This is always between 0
 * and {@code abs(Pixels)}.
 public synchronized int moveRight(int Pixels) {
 int delta = Math.min(m_Model.getXElements() * CONST_Width3fourth + CONST_Width1fourth - getSize().width, m_ScrollPosition.x + Math.max(0, Pixels)) - m_ScrollPosition.x;
 if (delta != 0) {
 m_ScrollPosition.x += delta;
 repaint();
 return delta;
 /** Moves the visible elements down by the number of pixels.
 * To move the visible elements down by one hex grid element, pass {@link
 * #CONST_Height} as the parameter. The component will automatically {@link
 * #repaint()}.
 * @param Pixels The number of pixels to move down.
 * @return The number of pixels moved down. This is always between 0 and
 * {@code abs(Pixels)}.
 public synchronized int moveDown(int Pixels) {
 int delta = Math.min(m_Model.getYElements() * CONST_Height + CONST_Heighthalf - getSize().height, m_ScrollPosition.y + Math.max(0, Pixels)) - m_ScrollPosition.y;
 if (delta != 0) {
 m_ScrollPosition.y += delta;
 repaint();
 return delta;
 /** Checks if the hex grid element of the given index is currently
 * displayed on the screen (even just one pixel).
 * The intention of this method is to check if a {@link #repaint()} is
 * necessary or not.
 * @param ElementIndex The index of the element to check.
 * @return {@code true} if the hex grid element of the given index is
 * displayed on the screen, {@code false} if not.
 public synchronized boolean isElementOnScreen(Point ElementIndex) { return isElementInScope(ElementIndex, m_CurrentOffset, new Point(m_CurrentOffset.x + m_MaxColumn, m_CurrentOffset.y + m_MaxRow)); }
 /** Checks if the hex grid element of the given index is within the given
 * indexes.
 * The intention of this method is to check if a {@link #repaint()} is
 * necessary or not.
 * @param ElementIndex The index of the element to check.
 * @param ReferenceIndexLeftTop The left top index of the area to check.
 * @param ReferenceIndexRightBottom The right bottom index of the area to check.
 * @return {@code true} if the hex grid element of the given index is within
 * the given area, {@code false} if not.
 public synchronized boolean isElementInScope(Point ElementIndex, Point ReferenceIndexLeftTop, Point ReferenceIndexRightBottom) { if ((ElementIndex.x >= ReferenceIndexLeftTop.x) && (ElementIndex.x <= ReferenceIndexRightBottom.x) && (ElementIndex.y >= ReferenceIndexLeftTop.y) && (ElementIndex.y <= (ReferenceIndexRightBottom.y))) { return true; } else { return false; } }
 /** Return the {@link IHexGridElement hex grid element} shown at the given
 * pixel on the screen.
 * Remark: There seems to be a bug in retrieving the proper element,
 * propably caused by rounding errors and unprecise pixel calculations.
 * @param P The pixel on the screen.
 * @return The {@link IHexGridElement hex grid element} shown at the pixel.
 public synchronized IHexGridElement getElementAtPixel(Point P) {
 // @FIXME Here seems to be some bugs remaining
 int dummy = 0; // Variable for warning to indicate that there is something to do :)
 // Calculate the pixel on the image, not on the screen
 int px = P.x + m_PixelOffset.x;
 int py = P.y + m_PixelOffset.y;
 // Determine the x-index of the column (is maybe decreased by one)
 int x = px / CONST_Width3fourth + m_CurrentOffset.x;
 // If the column is odd, then shift the y-pixel by half element height
 if ((x % 2) == 1) { py -= CONST_Heighthalf; }
 // Determine the y-index of the row (is maybe decreased by one)
 int y = py / CONST_Height + m_CurrentOffset.y;
 // Normative coordinates to a single element
 px -= (x - m_CurrentOffset.x) * CONST_Width3fourth;
 py -= (y - m_CurrentOffset.y) * CONST_Height;
 // Check if the normative pixel is in the first quarter of a column
 if (px < CONST_Width1fourth) {
 // Adjustments to the index may be necessary
 if (py < CONST_Heighthalf) {
 // We are in the upper half of a hex-element
 double ty = CONST_Heighthalf - CONST_Steepness * px;
 if (py < ty) { x--; }
 } else {
 // We are in the lower half of a hex-element
 double ty = CONST_Heighthalf + CONST_Steepness * px;
 if (py > ty) {
 x--;
 y++;
 return m_Model.getElementAt(x, y);
}Ah, just to give you some idea: I use this component to visualize a hex grid map with more than 1 million grid elements. And it works, really fast, and requires less than 10 MByte of memory.

How to restrict the maximum size of a java.awt.ScrollPane

Dear all,
I would like to implement a scroll pane which is resizable, but not to a size exceeding the maximum size of the java.awt.Canvas that it contains.
I've sort of managed to do this by writing a subclass of java.awt.ScrollPane which implements java.awt.event.ComponentListener and has a componentResized method that checks whether the ScrollPane's viewport width (height) exceeds the content's preferred size, and if so, resizes the pane appropriately (see code below).
It seems to me, however, that there ought to be a simpler way to achieve this.
One slightly weird thing is that when the downsizing of the pane happens, the content can once be moved to the left by sliding the horizontal scrollbar, but not by clicking on the arrows. This causes one column of gray pixels to disappear and the rightmost column of the content to appear; subsequent actions on the scrollbar does not have any further effect. Likewise, the vertical scrollbar can also be moved up once.
Also, I would like a java.awt.Frame containing such a restrictedly resizable scrollpane, such that the Frame cannot be resized by the user such that its inside is larger than the maximum size of the scrollpane. The difficulty I encountered with that is that setSize on a Frame appears to set the size of the window including the decorations provided by the window manager (fvwm2, if that matters), and I haven't been able to find anything similar to getViewportSize, which would let me find out the size of the area inside the Frame which is available for the scrollpane which the frame contains.
Thanks in advance for hints and advice.
Here's the code of the componentResized method:
public void componentResized(java.awt.event.ComponentEvent e)
 java.awt.Dimension contentSize = this.content.getPreferredSize();
 this.content.setSize(contentSize);
 java.awt.Dimension viewportSize = getViewportSize();
 System.err.println("MaxSizeScrollPane: contentSize = " + contentSize);
 System.err.println("MaxSizeScrollPane: viewportSize = " + viewportSize);
 int dx = Math.max(0, (int) (viewportSize.getWidth() - contentSize.getWidth()));
 int dy = Math.max(0, (int) (viewportSize.getHeight() - contentSize.getHeight()));
 System.err.println("MaxSizeScrollPane: dx = " + dx + ", dy = " + dy);
 if ((dx > 0) || (dy > 0))
 java.awt.Dimension currentSize = getSize();
 System.err.println("MaxSizeScrollPane: currentSize = " + currentSize);
 setSize(new java.awt.Dimension(((int) currentSize.getWidth()) - dx, ((int) currentSize.getHeight()) - dy));
 System.err.println();
}Best regards, Jan

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
public class ScrollPaneTest
 GraphicCanvas canvas;
 CustomScrollPane scrollPane;
 private Panel getScrollPanel()
 canvas = new GraphicCanvas();
 scrollPane = new CustomScrollPane();
 scrollPane.add(canvas);
 // GridBagLayout allows scrollPane to remain at
 // its preferred size during resizing activity
 Panel panel = new Panel(new GridBagLayout());
 GridBagConstraints gbc = new GridBagConstraints();
 panel.add(scrollPane, gbc);
 return panel;
 private WindowListener closer = new WindowAdapter()
 public void windowClosing(WindowEvent e)
 System.exit(0);
 private Panel getUIPanel()
 int w = canvas.width;
 int h = canvas.height;
 int visible = 100;
 int minimum = 200;
 int maximum = 500;
 final Scrollbar
 width = new Scrollbar(Scrollbar.HORIZONTAL, w,
 visible, minimum, maximum),
 height = new Scrollbar(Scrollbar.HORIZONTAL, h,
 visible, minimum, maximum);
 AdjustmentListener l = new AdjustmentListener()
 public void adjustmentValueChanged(AdjustmentEvent e)
 Scrollbar scrollbar = (Scrollbar)e.getSource();
 int value = scrollbar.getValue();
 if(scrollbar == width)
 canvas.setWidth(value);
 if(scrollbar == height)
 canvas.setHeight(value);
 canvas.invalidate();
 scrollPane.validate();
 width.addAdjustmentListener(l);
 height.addAdjustmentListener(l);
 Panel panel = new Panel(new GridBagLayout());
 GridBagConstraints gbc = new GridBagConstraints();
 gbc.insets = new Insets(2,2,2,2);
 gbc.weightx = 1.0;
 addComponents(new Label("width"), width, panel, gbc);
 addComponents(new Label("height"), height, panel, gbc);
 gbc.anchor = GridBagConstraints.CENTER;
 return panel;
 private void addComponents(Component c1, Component c2, Container c,
 GridBagConstraints gbc)
 gbc.anchor = GridBagConstraints.EAST;
 c.add(c1, gbc);
 gbc.anchor = GridBagConstraints.WEST;
 c.add(c2, gbc);
 public static void main(String[] args)
 ScrollPaneTest test = new ScrollPaneTest();
 Frame f = new Frame();
 f.addWindowListener(test.closer);
 f.add(test.getScrollPanel());
 f.add(test.getUIPanel(), "South");
 f.pack();
 f.setLocation(200,200);
 f.setVisible(true);
 f.addComponentListener(new FrameSizer(f));
class GraphicCanvas extends Canvas
 int width, height;
 public GraphicCanvas()
 width = 300;
 height = 300;
 public void paint(Graphics g)
 super.paint(g);
 Graphics2D g2 = (Graphics2D)g;
 g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
 RenderingHints.VALUE_ANTIALIAS_ON);
 int dia = Math.min(width, height)*7/8;
 g2.setPaint(Color.blue);
 g2.draw(new Rectangle2D.Double(width/16, height/16, width*7/8, height*7/8));
 g2.setPaint(Color.green.darker());
 g2.draw(new Ellipse2D.Double(width/2 - dia/2, height/2 - dia/2, dia-1, dia-1));
 g2.setPaint(Color.red);
 g2.draw(new Line2D.Double(width/16, height*15/16-1, width*15/16-1, height/16));
 public Dimension getPreferredSize()
 return new Dimension(width, height);
 public Dimension getMaximumSize()
 return getPreferredSize();
 public void setWidth(int w)
 width = w;
 repaint();
 public void setHeight(int h)
 height = h;
 repaint();
class CustomScrollPane extends ScrollPane
 Dimension minimumSize;
 public Dimension getPreferredSize()
 Component child = getComponent(0);
 if(child != null)
 Dimension d = child.getPreferredSize();
 if(minimumSize == null)
 minimumSize = (Dimension)d.clone();
 Insets insets = getInsets();
 d.width += insets.left + insets.right;
 d.height += insets.top + insets.bottom;
 return d;
 return null;
 public Dimension getMinimumSize()
 return minimumSize;
 public Dimension getMaximumSize()
 Component child = getComponent(0);
 if(child != null)
 return child.getMaximumSize();
 return null;
class FrameSizer extends ComponentAdapter
 Frame f;
 public FrameSizer(Frame f)
 this.f = f;
 public void componentResized(ComponentEvent e)
 Dimension needed = getSizeForViewport();
 Dimension size = f.getSize();
 if(size.width > needed.width || size.height > needed.height)
 f.setSize(needed);
 f.pack();
 * returns the minimum required frame size that will allow
 * the scrollPane to be displayed at its preferred size
 private Dimension getSizeForViewport()
 ScrollPane scrollPane = getScrollPane(f);
 Insets insets = f.getInsets();
 int w = scrollPane.getWidth() + insets.left + insets.right;
 int h = getHeightOfChildren() + insets.top + insets.bottom;
 return new Dimension(w, h);
 private ScrollPane getScrollPane(Container cont)
 Component[] c = cont.getComponents();
 for(int j = 0; j < c.length; j++)
 if(c[j] instanceof ScrollPane)
 return (ScrollPane)c[j];
 if(((Container)c[j]).getComponentCount() > 0)
 return getScrollPane((Container)c[j]);
 return null;
 private int getHeightOfChildren()
 Component[] c = f.getComponents();
 int extraHeight = 0;
 for(int j = 0; j < c.length; j++)
 int height;
 if(((Container)c[j]).getComponent(0) instanceof ScrollPane)
 height = ((Container)c[j]).getComponent(0).getHeight();
 else
 height = c[j].getHeight();
 extraHeight += height;
 return extraHeight;
}

Problem with Horizontal Scroll on java.awt.List

I use the same code for a General Application as a CDC Application.
I have no problem at all with the General Application but on the CDC I can't scroll to the right (horizontal).
Why do I get this problem on the CDC application and not on a regular application?
I use the PP-1.0 Profile for the CDC application. Does it not support horizontal scroll on java.awt.List?
This is the code:
* Main.java
* Created on den 22 augusti 2007, 10:52
package cdcapplication6;
* @author Erik Rothman
public class Main extends java.awt.Frame {
 /** Creates new form Main */
 public Main() {
 initComponents();
 for (int i = 0; i < 10; i++) {
 list1.add("Short text");
 list1.add("Some very long text indeed. Some very long text indeed.");
 /** This method is called from within the constructor to
 * initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is
 * always regenerated by the Form Editor.
 // <editor-fold defaultstate="collapsed" desc=" Generated Code ">
 private void initComponents() {
 list1 = new java.awt.List();
 addWindowListener(new java.awt.event.WindowAdapter() {
 public void windowClosing(java.awt.event.WindowEvent evt) {
 exitForm(evt);
 add(list1, java.awt.BorderLayout.CENTER);
 pack();
 }// </editor-fold>
 /** Exit the Application */
 private void exitForm(java.awt.event.WindowEvent evt) {
 System.exit(0);
 * @param args the command line arguments
 public static void main(String args[]) {
 java.awt.EventQueue.invokeLater(new Runnable() {
 public void run() {
 new Main().setVisible(true);
 // Variables declaration - do not modify
 private java.awt.List list1;
 // End of variables declaration
}

I use the same code for a General Application as a CDC Application.
I have no problem at all with the General Application but on the CDC I can't scroll to the right (horizontal).
Why do I get this problem on the CDC application and not on a regular application?
I use the PP-1.0 Profile for the CDC application. Does it not support horizontal scroll on java.awt.List?
This is the code:
* Main.java
* Created on den 22 augusti 2007, 10:52
package cdcapplication6;
* @author Erik Rothman
public class Main extends java.awt.Frame {
 /** Creates new form Main */
 public Main() {
 initComponents();
 for (int i = 0; i < 10; i++) {
 list1.add("Short text");
 list1.add("Some very long text indeed. Some very long text indeed.");
 /** This method is called from within the constructor to
 * initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is
 * always regenerated by the Form Editor.
 // <editor-fold defaultstate="collapsed" desc=" Generated Code ">
 private void initComponents() {
 list1 = new java.awt.List();
 addWindowListener(new java.awt.event.WindowAdapter() {
 public void windowClosing(java.awt.event.WindowEvent evt) {
 exitForm(evt);
 add(list1, java.awt.BorderLayout.CENTER);
 pack();
 }// </editor-fold>
 /** Exit the Application */
 private void exitForm(java.awt.event.WindowEvent evt) {
 System.exit(0);
 * @param args the command line arguments
 public static void main(String args[]) {
 java.awt.EventQueue.invokeLater(new Runnable() {
 public void run() {
 new Main().setVisible(true);
 // Variables declaration - do not modify
 private java.awt.List list1;
 // End of variables declaration
}

How to use java awt in linux

I have few questions about linux. Is there any one who can give me the correct o/p of the following errorecode
Exception in thread "main" java.lang.InternalError: Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:134)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
at java.awt.Window.init(Window.java:231)
at java.awt.Window.<init>(Window.java:275)
at java.awt.Frame.<init>(Frame.java:401)
at java.awt.Frame.<init>(Frame.java:366)
at jxml1.<init>(jxml1.java:14)
at jxml1.main(jxml1.java:78)
$ Exception in thread "main" java.lang.InternalError: Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:134)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
at java.awt.Window.init(Window.java:231)
at java.awt.Window.<init>(Window.java:275)
at java.awt.Frame.<init>(Frame.java:401)
at java.awt.Frame.<init>(Frame.java:366)
at jxml1.<init>(jxml1.java:14)
at jxml1.main(jxml1.java:78)
$
^C$

Hi,
Most often than not this is related to xhost in unix-shell systems.
Try the following
$setenv DISPLAY :0
$xhost +
or simply
$xhost +If you need more security add just your user after xhost + command
Hope this helps
Aviroop

How to remove title bar in awt frame?

how can i remove the title bar of frame and make it fullscreen so as to cover all the desktop?

how can i remove the title bar of frame and make it
fullscreen so as to cover all the desktop?foll should suffice in a simple situation
import java.awt.Window;
import java.awt.Frame;
import java.awt.Toolkit;
public class BigWindow extends Frame
     public BigWindow()
          //get screen size
          int height = (int)Toolkit.getDefaultToolkit().getScreenSize().getHeight();
          int width = (int)Toolkit.getDefaultToolkit().getScreenSize().getWidth();
          //make parent frame invisible
          this.setVisible(false);
          //create a new window without borders and titlebar
          Window window = new Window(this);
          window.setSize(width,height);
          window.setVisible(true);
     public static void main(String args[])
          new BigWindow();
}

Missing Defines Error in Simple Java Stored Procedure

Anyone have any suggestions on what might be causing the unusual behavior described below? Could it be a 10g java configuration issue? I am really stuck so I'm open to just about anything. Thanks in advance.
I am writing a java stored procedure and am getting some SQLException's when executing some basic JDBC code from within the database. I reproduced the problem by writing a very simple java stored procedure which I have included below. The code executes just fine when executed outside of the database (10g). Here is the output from that execution:
java.class.path=C:\Program Files\jEdit42\jedit.jar
java.class.version=48.0
java.home=C:\j2sdk1.4.2_04\jre
java.vendor=Sun Microsystems Inc.
java.version=1.4.2_04
os.arch=x86
os.name=Windows XP
os.version=5.1
In getConnection
Executing outside of the DB
Driver Name = Oracle JDBC driver
Driver Version = 10.1.0.2.0
column count=1
column name=TEST
column type=1
TEST
When I execute it on the database by calling the stored procedure I get:
java.class.path=
java.class.version=46.0
java.home=/space/oracle/javavm/
java.vendor=Oracle Corporation
java.version=1.4.1
os.arch=sparc
os.name=Solaris
os.version=5.8
In getConnection
We are executing inside the database
Driver Name = Oracle JDBC driver
Driver Version = 10.1.0.2.0
column count=1
column name='TEST'
column type=1
MEssage: Missing defines
Error Code: 17021
SQL State: null
java.sql.SQLException: Missing defines
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:158)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:206)
at oracle.jdbc.driver.OracleResultSetImpl.getString(Native Method)
at OracleJSPTest.test(OracleJSPTest:70)
Here is the Java code:
// JDBC classes
import java.sql.*;
import java.util.*;
//Oracle Extensions to JDBC
import oracle.jdbc.*;
import oracle.jdbc.driver.OracleDriver;
public class OracleJSPTest {
private static void printProperties(){
     System.out.println("java.class.path="+System.getProperty("java.class.path"));
     System.out.println("java.class.version="+System.getProperty("java.class.version"));
     System.out.println("java.home="+System.getProperty("java.home"));
     System.out.println("java.vendor="+System.getProperty("java.vendor"));
     System.out.println("java.version="+System.getProperty("java.version"));
     System.out.println("os.arch="+System.getProperty("os.arch"));
     System.out.println("os.name="+System.getProperty("os.name"));
     System.out.println("os.version="+System.getProperty("os.version"));
private static Connection getConnection() throws SQLException {
     System.out.println("In getConnection");
Connection connection = null;
// Get a Default Database Connection using Server Side JDBC Driver.
// Note : This class will be loaded on the Database Server and hence use a
// Server Side JDBC Driver to get default Connection to Database
if(System.getProperty("oracle.jserver.version") != null){
          System.out.println("We are executing inside the database");
          //connection = DriverManager.getConnection("jdbc:default:connection:");
          connection = new OracleDriver().defaultConnection();
}else{
     System.out.println("Executing outside of the DB");
     DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
     connection = DriverManager.getConnection("jdbc:oracle:thin:@XXX.XXX.XXX.XX:XXXX:XXXX","username","password");
DatabaseMetaData dbmeta = connection.getMetaData();
System.out.println("Driver Name = "+ dbmeta.getDriverName());
System.out.println("Driver Version = "+ dbmeta.getDriverVersion());
return connection;
public static void main(String args[]){
     test();
public static void test() {
     printProperties();
Connection connection = null; // Database connection object
try {
     connection = getConnection();
     String sql = "select 'TEST' from dual";
     Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery(sql);
     ResultSetMetaData meta = rs.getMetaData();
     System.out.println("column count="+meta.getColumnCount());
     System.out.println("column name="+meta.getColumnName(1));
     System.out.println("column type="+meta.getColumnType(1));
     if(rs.next()){
          System.out.println(rs.getString(1));
} catch (SQLException ex) { // Trap SQL Errors
     System.out.println("MEssage: " + ex.getMessage());
     System.out.println("Error Code: " + ex.getErrorCode());
     System.out.println("SQL State: " + ex.getSQLState());
     ex.printStackTrace();
} finally {
try{
if (connection != null || !connection.isClosed())
connection.close(); // Close the database connection
} catch(SQLException ex){
ex.printStackTrace();
Message was edited by:
jason_mac

Jason,
Works for me on Oracle 10.1.0.3 running on Red Hat Enterprise Linux AS release 3 (Taroon).
Java code:
import java.sql.*;
* Oracle Java Virtual Machine (OJVM) test class.
public class OjvmTest {
public static void test() throws SQLException {
    Connection conn = DriverManager.getConnection("jdbc:default:connection:");
    PreparedStatement ps = null;
    ResultSet rs = null;
    try {
      ps = conn.prepareStatement("select 'TEST' from SYS.DUAL");
      rs = ps.executeQuery();
      if (rs.next()) {
        System.out.println(rs.getString(1));
    finally {
      if (rs != null) {
        try {
          rs.close();
        catch (SQLException sqlEx) {
          System.err.println("Error ignored. Failed to close result set.");
      if (ps != null) {
        try {
          ps.close();
        catch (SQLException sqlEx) {
          System.err.println("Error ignored. Failed to close statement.");
}And my PL/SQL wrapper:
create or replace procedure P_J_TEST as language java
name 'OjvmTest.test()';And here is how I execute it in a SQL*Plus session:
set serveroutput on
exec dbms_java.set_output(2000)
exec p_j_testGood Luck,
Avi.

Efficiency Question: Simple Java DC vs Used WD Component

Hello guys,
The scenario is - I want to call a function that returns a FileInputStream object so I can process it on my WD view. I can think of two approaches - one is to simply write a simple Java DC that does so and just use it as a used DC so I can call the functionality from there. Or create another WD DC that exposes the value (as binary) via component interface.
I'm leaning on the simple Java DC approach - its easier to create. But I'm just curious on what would be the Pro-side (if there's any) if I use the WD Component interface approach? Is there a plus for the efficiency? (Though I doubt) Or is it just a 'best/recommended practice' approach?
Thanks!
Regards,
Jan

Hi Jan
>one is to simply write a simple Java DC that does so and just use it as a used DC so I can call the functionality from there
Implemented Java API for the purpose mentioned in your question is the right way, I think. The Java API can be even located in the same WebDynpro DC as your WebDynpro components. There is not strongly necessity to put it into separate Java DC.
>Or create another WD DC that exposes the value (as binary) via component interface
You should not do this because in general WD components' purpose is UI, not API. Implementing WD component without any UI, but with some component interface has very-very restricted use cases. Such WD component shall only be a choice in the cases when the API is WebDynpro based and if you have to strongly use WebDynpro Runtime API in order to implement your own API.
If your API does not require WebDynpro Runtime API invocations or anything else related to WebDynpro then your choice is simple Java API.
>But I'm just curious on what would be the Pro-side (if there's any) if I use the WD Component interface approach? Is there a plus for the efficiency?
No. Performance will be better in simple Java API then in WebDynpro component interface. The reason is the API will not pass thought heavy WebDynpro engine.
BR, Siarhei

Very simple Java AWT Frame resize question

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