Java Wiki en:swing

en:swing:antialiasing

2012-10-09T15:29:48+02:00

Java - AWT/Swing java.awt.Graphics2D java.awt.RenderingHints The code-example draws a line and a string almost without stairs effect: public void paint(Graphics g) { Graphics2D g2 = (Graphics2D)g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g2.drawLine(0, 0, 100, 100); g2.drawString("Test", 0, 20); }

en:swing:anwendung_beenden_beim_schliessen_eines_jframe

2012-09-29T09:01:49+02:00

Java - AWT/Swing Normally, by activating the „x“-button of the frame, the application is only hidden but not closed. But you can change this by means of the following instruction: JFrame frame = new ... frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

en:swing:application-icon

2012-09-29T09:01:04+02:00

Java - AWT/Swing java.awt.Toolkit The class JFrame disposes of the method setIconImage, over which the application-icon can be set. Image img = Toolkit.getDefaultToolkit().getImage("images/tdg.png"); setIconImage(img);

en:swing:beep

2020-01-22T21:00:37+02:00

Java - AWT/Swing A simple beep, which is used for error messages, can be produced like this: java.awt.Toolkit.getDefaultToolkit().beep();

en:swing:display-html

2012-10-07T16:36:18+02:00

Java - AWT/Swing The class JEditorPane makes it possible to display HTML on a very simple way. JEditorPane editor = new JEditorPane(); editor.setContentType("text/html"); editor.setEditable(false); editor.setText("

Hallo World!

");

en:swing:fontmetrics

2012-10-07T16:11:33+02:00

Java - AWT/Swing java.awt.FontMetrics java.awt.Graphics This class comes up with information to a font. The example hands out the total width of a string: public void paint(Graphics g) { String str = "Test"; FontMetrics fm = g.getFontMetrics(g.getFont()); System.out.println("width of 'Test': "+fm.stringWidth(str)); }

en:swing:gridbaglayout

2012-10-07T16:35:51+02:00

Java - AWT/Swing Again and again you hear that the GridBagLayout is so complicated. It is really very extensive, but as a general rule you only need a few methods. The GridBagLayout works fundamentally with a thought grid. Each array in this grid can be addressed by its position (x,y). To define the size of the grid, you can outline the desired layout on a piece of paper. With the class GridBagConstraints, the qualities of a single element are determined. Example The desired dialogue…

en:swing:htmldocument

2012-10-07T16:37:02+02:00

Java - AWT/Swing In the example, an HTML-document is converted to pure text (well, merely the
-tag is taken into consideration): package com.sowas.javawiki.snippets; import java.io.Reader; import java.io.StringReader; import javax.swing.text.EditorKit; import javax.swing.text.MutableAttributeSet; import javax.swing.text.html.HTML; import javax.swing.text.html.HTMLDocument; import javax.swing.text.html.HTMLEditorKit; public class HtmlToText { public static String getText(St…

en:swing:htmleditorkit-getstylesheet

2012-10-07T16:36:29+02:00

Java - AWT/Swing If HTML-code shall be depicted in JEditorPane, so the basis-character set can be modified with the following code: StyleSheet css = ((HTMLEditorKit)jmEditorPane.getEditorKit()).getStyleSheet(); css.addRule("P { margin: 0; font-family: Arial, sans-serif; font-size: 11px; font-style: normal; }");

en:swing:hyperlinklistener

2012-10-07T16:37:22+02:00

Java - AWT/Swing javax.swing.event.HyperlinkListener JTextPane tp = ... tp.setText("JavaWiki"); tpBody.addHyperlinkListener(new HyperlinkListener() { public void hyperlinkUpdate(HyperlinkEvent e) { if (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED) System.out.prinln("You have clicked on this link: " + e.getDescription()); } });

en:swing:image-bufferedimageicon

2012-10-07T16:37:34+02:00

Java - AWT/Swing JLabel dummyObserver = new JLabel(); Image image = Toolkit.getDefaultToolkit().getImage("myimage.jpg"); int width = image.getWidth(dummyObserver); int height = image.getHeight(dummyObserver); BufferedImage bImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); bImage.getGraphics().drawImage(image, 0, 0, dummyObserver);

en:swing:invokelater-invokeandwait

2012-09-29T09:01:20+02:00

Java - AWT/Swing com.javax.SwingUtilities At Swing the same thread is responsible for drawing the surface new and working off the events. This is especially unpleasant, if a rake-intensive operation is activated by pressing a button. This results in that the button seems to be pressed as long as the operation continues. The GUI seems to be freezed up until the operation is finished. Here, the SwingUtilities offer two methods: invokeLater and invokeAndWait. invokeLater works out of s…

en:swing:jbutton-icon

2012-10-07T16:37:48+02:00

Java - AWT/Swing URL url = getClass().getResource("images/close-4x4.png"); Button myButton = new JButton(new ImageIcon(url)); // Oder: // myButton.setIcon(new ImageIcon(url));

en:swing:jcombobox-layout

2012-10-07T16:38:00+02:00

Java - AWT/Swing The layout with a JComboBox can be a bit complicated under circumstances. The PreferredSize of a JComboBox is by long text entries the width of the longest entry. This quality can lead into the destruction of the whole layout. A simple remedy is the setting of PreferredSize:

en:swing:jfilechooser

2012-10-07T16:38:12+02:00

Java - AWT/Swing javax.swing.JFileChooser JFileChooser fc = new JFileChooser(); fc.setFileSelectionMode(JFileChooser.FILES_ONLY); fc.setMultiSelctionEnabled(false); fc.setCurrentDirectory(new File(System.getProperty("user.home"))); if (fc.showDialog(this, "open file") == JFileChooser.APPROVE_OPTION) { System.out.println(fc.getSelectedFile().getAbsoluteFile()); }

en:swing:jframe-find

2012-10-07T16:38:28+02:00

Java - AWT/Swing Component frame = SwingUtilities.getRoot(myComponent);

en:swing:jlabel-hyperlink

2012-10-07T16:38:40+02:00

Java - AWT/Swing Each label can contain a hyperlink with little code: JLabel label = new JLabel("http://javawiki.sowas.com"); label.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR)); label.addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { if (e.getClickCount() > 0) { // browsercall (for Windows): Runtime.getRuntime().exec("cmd.exe /c start h…

en:swing:jpanel-transparent

2012-10-07T16:38:50+02:00

Java - AWT/Swing JPanel panel = new JPanel(); panel.setOpaque(false);

en:swing:jprogressbar

2012-10-07T16:39:02+02:00

Java - AWT/Swing int MAX = 10; JProgressBar progressBar; progressBar = new JProgressBar(0, MAX); progressBar.setValue(0); progressBar.setMaximum(MAX); for (int i=0; i <= MAX; i++) { try { Thread.sleep(100); } catch { e.printStackTrace(); } progressBar.setValue(i); }

en:swing:jradiobutton

2012-10-07T16:39:17+02:00

Java - AWT/Swing The example-code produces two radiobuttons which are part of a group: // produce two RadioButtons: JRadioButton rb1 = new JRadioButton("Button 1", false); JRadioButton rb2 = new JRadioButton("Button 2", false); // assign both RadioButtons to a ButtonGroup, with that only one radiobuttons can be chosen at time: ButtonGroup bg = new ButtonGroup(); bg.add(rb1); bg.add(rb2);

en:swing:jtabbedpane

2012-10-07T16:39:28+02:00

Java - AWT/Swing create tabs: JTabbedPane tp = new JTabbedPane(); tp.addTab("Tab 1", new JPanel()); tp.addTab("Tab 2", new JPanel()); react to the tab-change: JTabbedPane tp = new JTabbedPane(); //... (add tabs) tp.addChangeListener(new ChangeListener() { stateChanged(ChangeEvent e) { JTabbedPane tp = (JTabbedPane)e.getSource(); int indx = tp.getSelectedIndex(); // indx identifys the selected tab. }

en:swing:jtable-column-width

2012-10-07T16:41:04+02:00

Java - AWT/Swing javax.swing.table.JTable JTable table = new JTable(10, 20); // turn off autoresizing, or else all columns are equal wide: table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF); // set first column on 100 pixel width: final int INDEX_COLUMN1 = 0; TableColumn col = table.getColumnModel().getColumn(INDEX_COLUMN1); col.setPreferredWidth(100);

en:swing:jtable-dnd

2012-10-07T16:39:42+02:00

Java - AWT/Swing If the drag and drop does not function by an empty table, then you should try it with the following code: table.setFillsViewportHeight(true);

en:swing:jtable-row-height

2012-10-07T16:41:25+02:00

Java - AWT/Swing JTable offers a simple order to set the height of the line: JTable table = new JTable(... table.setRowHeight(24); By the way, the font stays unrevised with it. If this is to be changed, a TableCellRenderer must be insert.

en:swing:jtable-rowheader

2012-10-07T16:40:42+02:00

Java - AWT/Swing Sometimes you want to have a lettering for the lines of a table, as it is usual by table calculationsn. This can be achieved through a further list at the left, next to the table. package com.sowas.javawiki.rowheadertable; import java.awt.BorderLayout; import java.awt.Component; import javax.swing.AbstractListModel; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JList; import javax.swing.JScrollPane; import javax.swing.JTable; import jav…

en:swing:jtable-setselection

2012-10-07T16:40:53+02:00

Java - AWT/Swing To set the selection/marking in a JTable, you must use the SelectionModel: JTable table = new JTable(... table.getSelectionModel().setSelectionInterval(1, 3); // marks the lines 1-3

en:swing:jtable-tablecellrenderer

2012-10-07T16:41:15+02:00

Java - AWT/Swing JTable offers the possibility to change the depiction of a table by means of a TableCellRenderer: public class MyRenderer extends JLabel implements TableCellRenderer { public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) { TableModel model = table.getModel(); setBackground(row%2==0 ? Color.WHITE : Color.YELLOW); setForegro…

en:swing:jtextfield-numeric

2020-01-22T21:00:38+02:00

Java - AWT/Swing In the following code-example only numeric entries are accepted: To that, an own document „NumberDocument“ is defined. package com.sowas.snippets.jtextfield; import javax.swing.text.BadLocationException; import javax.swing.text.PlainDocument; import javax.swing.text.AttributeSet; import java.math.BigDecimal; import javax.swing.*; import java.awt.*; import java.awt.event.*; public class NumberDocument extends PlainDocument { @Override public void insertStri…

en:swing:jtextfield-size

2020-01-22T21:00:37+02:00

Java - AWT/Swing In the following code example the maximal number of symbols is rationed to 10: To that, an own document „MaxSizeDocument“ is defined. package com.sowas.snippets.jtextfield; import java.awt.BorderLayout; import java.awt.Toolkit; import javax.swing.JFrame; import javax.swing.JTextField; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.PlainDocument; public class MaxSizeDocument extends PlainDocument { …

en:swing:jtooltip-images

2020-01-22T21:00:37+02:00

Java - AWT/Swing javax.swing.JToolTip There is a simple possibility to provide a tooltip with a picture: String imageName = "file:image.gif"; component.setToolTipText("Bild: ");

en:swing:jtree-icons

2020-01-22T21:00:38+02:00

Java - AWT/Swing JTree myTree = new JTree(); DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer)myTree.getCellRenderer(); renderer.setClosedIcon(iconClosed); // Icon for snap knot shut renderer.setOpenIcon(iconOpen); // Icon for opened knot renderer.setLeafIcon(iconLeaf); // Icon for a page

en:swing:jtree-transparent

2020-01-22T21:00:38+02:00

AWT/Swing javax.swing.JTree javax.swing.tree.DefaultTreeCellRenderer To get a JTree totally transparent, an own CellRenderer must be implemented: DefaultTreeCellRenderer renderer = new DefaultTreeCellRenderer() { public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus) { setOpaque(false); return super.getTreeCellRendererComponent(tree, value,…

en:swing:jtree-treenode

2020-01-22T21:00:37+02:00

Java - AWT/Swing An often put question is how to modify the text of a TreeNodes belated. But it is very easy: treeModel.nodeChanged(modifiedNode);

en:swing:jtree

2020-01-22T21:00:37+02:00

Java - AWT/Swing An easy example for a JTree: package com.sowas.javawiki.jtree; import java.awt.BorderLayout; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; public class JTreeDemo extends JFrame { public JTreeDemo() { setLayout(new BorderLayout()); DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root"); DefaultMutableTreeNode node = new DefaultMutableTreeNo…

en:swing:keylistener-keyevent

2020-01-22T21:00:38+02:00

Java - AWT/Swing java.awt.event.KeyEvent java.awt.event.KeyAdapter In the example the keys „Ctrl +“ and „Ctrl -“ shall be discerned: myControl.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e){ if (e.isControlDown()){ // Ctrl if (e.getKeyCode()==KeyEvent.VK_PLUS) { // + System.out.println("Strg +"); }else{ if (e.getKeyCode()==KeyEvent.VK_MINUS) { // - System.out.println("Strg -"); } …

en:swing:modifyfont

2012-10-07T16:10:48+02:00

Java - AWT/Swing java.awt.Font If you want to modify an existing font, it is the easiest way to use the following code: Label label = new Label("Test"); label.setFont(label.getFont().deriveFont(Font.BOLD)); // set Font style on BOLD label.setFont(label.getFont().deriveFont(12.0)); // set Font size on 12

en:swing:resize-listener

2012-10-09T15:36:30+02:00

Java - AWT/Swing java.awt.event.ComponentListener import java.awt.*; import java.awt.event.*; Frame frame = new Frame(); frame.addComponentListener(new ComponentListener() { public void componentHidden(ComponentEvent e) { } public void componentMoved(ComponentEvent e) { } public void componentResized(ComponentEvent e) { System.out.println("Resized"); } public void componentShown(ComponentEvent e) { } });

en:swing:return-enter

2012-10-09T15:43:39+02:00

AWT/Swing Both return-/enter-keys deliver the KeyCode VK_ENTER (10). The distinction is only possible on the basis of the position: if (e.getKeyCode() == KeyEvent.VK_ENTER) { if(e.getKeyLocation() == KeyEvent.KEY_LOCATION_STANDARD) System.out.println("Return"); else if (e.getKeyLocation() == KeyEvent.KEY_LOCATION_NUMPAD) System.out.println("Enter"); }

en:swing:simple-input-dialog

2012-10-09T16:11:59+02:00

Java - AWT/Swing javax.swing.JOptionPane.showInputDialog(..) For a simple input there is already a prefabricated dialogue: String result = JOptionPane.showInputDialog(zero, "entry please:", "entry-heading", JOptionPane.QUESTION_MESSAGE);

en:swing:splashscreen

2020-01-22T21:00:37+02:00

Java - AWT/Swing A Splashscreen is mostly showed at the gun of a program. It is about a normal JFrame, whose decorations are just turned off. package com.sowas.javawiki.splashscreen; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Label; import javax.swing.JFrame; public class SplashScreenDemo extends JFrame { public SplashScreenDemo(){ setLayout(new BorderLayout()); setLocation(400, 300); setPreferredSize(n…

en:swing:strong-lines

2012-10-09T15:31:43+02:00

Java - AWT/Swing java.awt.Graphics2D java.awt.Stroke The code-example draws a line with a thickness of three pixel: public void paint(Graphics g) { Graphics2D g2 = (Graphics2D)g; g2.setStroke(new BasicStroke(3)); g2.drawLine(0, 0, 100, 100); }

en:swing:stylesheet

2020-01-22T21:00:38+02:00

Java - AWT/Swing javax.swing.JTextPane javax.swing.text.html.StyleSheet JTextPane textPane; StyleSheet css = new StyleSheet(); css.addRule("p {margin: 0; font-family: Arial, sans-serif; font-size: 12px; }"); ((HTMLEditorKit)textPane.getEditorKit()).setStyleSheet(css);

en:swing:swing-messagebox

2020-01-22T21:00:37+02:00

Java - AWT/Swing At the easiest case, a MessageBox under Swing can be realized as follows: JOptionPane.showMessageDialog(null, "My message!");

en:swing:swing

2014-08-19T14:57:18+02:00

* beep * carry out actions after GUI-update * center window * convert image to BufferedImage * determine JFrame of a component * display HTML, JEditorPane * distinguish Return/Enter * edge smoothing * evaluate keystrokes * FontMetrics * GridBagLayout * HTML, modify font * parse HTMLDocument * HyperlinkListener

en:swing:systemcolors

2020-01-22T21:00:37+02:00

Java - AWT/Swing java.awt.SystemColor SystemColor Which colour responds to thatdesktop colour of desktop backgroundactiveCaption backgroundcolour for text in the window frameactiveCaptionText colour for text in the window frameactiveCaptionBorder frame colour for active window frameinactiveCaption backgroundcolour for inactive text in the window frameinactiveCaptionText colour for inactive text in the window frameinactiveCaptionBorder frame colour for inactive window framewindow backg…

en:swing:tooltip-delay

2020-01-22T21:00:36+02:00

Java - AWT/Swing ToolTipManager.sharedInstance().setInitialDelay(1000); // value in ms

en:swing:treepath

2020-01-22T21:00:37+02:00

Java - AWT/Swing public TreePath getPath(TreeNode treeNode){ List list = new ArrayList(); while (treeNode != null) { list.add(treeNode); treeNode = treeNode.getParent(); } Collections.reverse(list); return new TreePath(list.toArray()); }

en:swing:window-center

2012-10-07T16:10:31+02:00

Java - AWT/Swing java.awt.Window In Java, you can center a window (JFrame, JDialog, ...) with the method setLocationRelativeTo(Component c). With it, the parameter indicates c, to what paramount window it shall be centered. The parameter c can also be zero. In this case, it is centered on the screen:

en:swing:window-maximize

2012-09-29T09:00:21+02:00

Java - AWT/Swing How it is to maximize the application window in Java shows the following code: package com.sowas.javawiki; import java.awt.*; import javax.swing.*; public class MaxFrame extends JFrame { public MaxFrame() { setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setExtendedState(JFrame.MAXIMIZED_BOTH); // Here, the window is maximized } public static void main(final String[] args) { new MaxFrame().setVisible(true); } }