Chapter 9: Objects and Classes

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3 (Swing) AWTEvent Font LayoutManager 1 Classes in the javax.swing package Heavyweight FontMetrics Object Color Panel Applet JApplet Graphics Component Container Window Frame JFrame * Dialog JDialog JComponent Swing Components in the javax.swing package Lightweight

4 JComponent JCheckBoxMenuItem JMenuItem JMenu AbstractButton JButton.JRadioButtonMenuItem.JToggleButton JCheckBox JComponent.JEditorPane JRadioButton.JTextComponent.JTextField.JPasswordField.JTextArea.JLabel.JList.JComboBox.JMenuBar.JPanel.JOptionPane.JScrollBar.JScrollPane.JFileChooser.JPopupMenu.JSeparator.JSlider.JTabbedPane.JRootPane.JPane.JProgressBar.JToolBar.JSplitPane.JTable.JTree.JColorChooser.JInternalFrame.JToolTip.JLayeredPane.JTableHeader

5 AWT (Optional) AWTEvent Container Panel Applet Font Button Window Frame FontMetrics Label TextField Dialog FileDialog Object Color TextComponent Graphics List TextArea Component Choice CheckBox LayoutManager CheckBoxGroup Canvas MenuComponent MenuItem Menu Scrollbar MenuBar

6 applet Frame Pull-down Menus Applet Pull-down Menus Panel Panel Panel User Interface Components (UI) User Interface Components User Interface Components Panel Panel Panel Panel Panel Panel User Interface Components User Interface Components UI UI UI panel

7 Creating Frames import javax.swing.*; public class MyFrame { public static void main(string[] args) { JFrame frame = new JFrame("Test Frame"); frame.setsize(400, 300); frame.setvisible(true); // frame.setdefaultcloseoperation( JFrame.EXIT_ON_CLOSE); } } Run

8 JFrame setlocation(x, y). (x, y).

9 Screen (x, y) Frame frameheight screenh screenwidth screenwidth CenterFrame Run

10 Adding Components into a Frame // Add a button into the frame frame.getcontentpane().add( new JButton("OK")); MyFrameWithComponents Run

11 Layout Managers Java s layout managers provide a level of abstraction to automatically map your user interface on all windowing systems. The UI components are placed in containers. Each container has a layout manager to arrange the UI components within the container.

12 Kinds of Layout Managers FlowLayout GridLayout BorderLayout CardLayout GridBagLayout

13 Example 8.1 Testing the FlowLayout Manager The components are arranged in the container from left to right in the order in which they were added. When one row becomes filled, a new row is started. ShowFlowLayout Run

14 FlowLayout Constructors public FlowLayout(int align, int hgap, int vgap) Constructs a new FlowLayout with a specified alignment, horizontal gap, and vertical gap. The gaps are the distances in pixel between components. public FlowLayout(int alignment) Constructs a new FlowLayout with a specified alignment and a default gap of five pixels for both horizontal and vertical. public FlowLayout() Constructs a new FlowLayout with a default center alignment and a default gap of five pixels for both horizontal and vertical.

15 Example 8.2 Testing the GridLayout Manager The GridLayout manager arranges components in a grid (matrix) formation with the number of rows and columns defined by the constructor. The components are placed in the grid from left to right starting with the first row, then the second, and so on. ShowGridLayout Run

16 GridLayout Constructors public GridLayout(int rows, int columns) Constructs a new GridLayout with the specified number of rows and columns. public GridLayout(int rows, int columns, int hgap, int vgap) Constructs a new GridLayout with the specified number of rows and columns, along with specified horizontal and vertical gaps between components.

17 Example 8.3 Testing the BorderLayout Manager The BorderLayout manager divides the window into five areas: East, South, West, North, and Center. Components are added to a BorderLayout by using ShowBorderLayout add(component, constraint), where constraint is BorderLayout.East, BorderLayout.South, BorderLayout.West", BorderLayout.North", or BorderLayout.Center. Run

18 Using Panels as Containers Panels act as smaller containers for grouping user interface components. It is recommended that you place the user interface components in panels and place the panels in a frame. You can also place panels in a panel.

19 Example 8.4 Testing Panel TestPanels Run

20 Drawing on Panels JPanel. JPanel, JPanel paintcomponent.

21 The Color Class Color c = new Color(r, g, b); r, g, and b specify a color by its red, green, and blue components. Example: Color c = new Color(128, 100, 100);

22 Setting Colors You can use the following methods to set the component s background and foreground colors: setbackground(color c) setforeground(color c) Example: setbackground(color.yellow); setforeground(color.red);

23 The Font Class Font myfont = Font(name, style, size); Example: Font myfont = new Font("SansSerif ", Font.BOLD, 16); Font myfont = new Font("Serif", Font.BOLD+Font.ITALIC, 12);

24 Setting Fonts public void paint(graphics g) { Font myfont = new Font("Times", Font.BOLD, 16); g.setfont(myfont); g.drawstring("welcome to Java", 20, 40); } //set a new font g.setfont(new Font("Courier", Font.BOLD+Font.ITALIC, 12)); g.drawstring("welcome to Java", 20, 70);

25 The FontMetrics Class Leading seline Height By Ascent Descent

26 Get FontMetrics g.getfontmetrics(font f); or g.getfontmetrics(); public int getascent() public int getdescent() public int getleading() public int getheight() public int stringwidth(string str)

27 Example 8.5 Using FontMetrics Objective: Display Welcome to Java in SansSerif 20-point bold, centered in the frame. (0,0) x (120, 0) y TestFontMetrics (0, 100) (120, 100) Run

28 Drawing Geometric Figures Drawing Lines Drawing Rectangles Drawing Ovals Drawing Arcs Drawing Polygons

29 Drawing Lines drawline(x1, y1, x2, y2); (x 1, y 1 ) (x 2, y 2 )

30 Drawing Rectangles drawrect(x, y, w, h); fillrect(x, y, w, h); (x, y) h w

31 Drawing Rounded Rectangles drawroundrect(x, y, w, h, aw, ah); fillroundrect(x, y, w, h, aw, ah); (x, y) ah aw h w

32 Drawing Ovals drawoval(x, y, w, h); filloval(x, y, w, h); (x, y) h w

33 Drawing Arcs drawarc(x, y, w, h, angle1, angle2); fillarc(x, y, w, h, angle1, angle2); (x, y) angle2 angle1 h w

34 Drawing Polygons int x[] = {40, 70, 60, 45, 20}; int y[] = {20, 40, 80, 45, 60}; g.drawpolygon(x, y, x.length); g.fillpolygon(x, y, x.length); (x[0], y[0]) (x[3], y[3]) (x[1], y[1]) (x[4], y[4]) (x[2], y[2])

35 6 Example 8.6 Drawing a Clock Objective: Use drawing and trigonometric methods to draw a clock showing the specified hour, minute, and second in a frame. 12 (xend,yend) 9 3 (xcenter,ycenter) handlength DrawClock DisplayClock Run

36 Java,

37 ( event ) java.util.eventobject

38 ActionEvent ContainerEvent AdjustmentEvent FocusEvent MouseEvent EventObject AWTEvent ComponentEvent InputEvent ItemEvent PaintEvent KeyEvent TextEvent WindowEvent ListSelectionEvent

39 Selected User Actions JButton ActionEvent JTextComponent TextEvent JTextField ActionEvent JComboBox ItemEvent,ActionEvent JList javax.swing.event.listselectionevent JCheckBox ItemEvent,ActionEvent JRadioButton ItemEvent,ActionEvent JMenuItem ActionEvent JScrollBar AdjustmentEvent Window WindowEvent Container ContainerEvent Component ComponentEvent Component FocusEvent Component KeyEvent Component MouseEvent

41 Example 8.7 Ok Canel TestActionEvent Run ActionEvent TestActionEvent JFrame TestActionEvent Actionlistener jbtok.addactionlistener(this); jbtcancel.addactionlistener(this); this(testactionevent) ActionEvent.

42 Example 8.8 Objective: Window. TestWindowEvent Run JFrame Window WindowEvent WindowListener

43 java AWT UI Swing

44 8.6

Chapter 9: Objects and Classes

Chapter 9: Objects and Classes What is a JavaBean? JavaBean Java JavaBean Java JavaBean JComponent tooltiptext font background foreground doublebuffered border preferredsize minimumsize maximumsize JButton. Swing JButton JButton() JButton(String