Transcript Chapter 10 Getting Started with Graphics Programming

GUI Basics: Introduction
Creating GUI Objects
// Create a button with text OK
JButton jbtOK = new JButton("OK");
// Create a label with text "Enter your name: "
JLabel jlblName = new JLabel("Enter your name: ");
Label
Text
field
Check
Box
Button
// Create a text field with text "Type Name Here"
JTextField jtfName = new JTextField("Type Name Here");
// Create a check box with text bold
JCheckBox jchkBold = new JCheckBox("Bold");
// Create a radio button with text red
JRadioButton jrbRed = new JRadioButton("Red");
// Create a combo box with choices red, green, and blue
JComboBox jcboColor = new JComboBox(new String[]{"Red",
"Green", "Blue"});
Combo
Box
Radio
Button
Swing vs. AWT
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The biggest difference between the AWT components
and Swing components are:
Swing components are implemented with absolutely no
native code. Native code is methods implemented in
another programming language such as C .
Swing features are present on every platform.
Swing can have more functionality than AWT components.
Swing can be shipped as an add-on to JDK 1.1, in addition
to being part of the Java 2 Platform.
Swing vs. AWT
Swing components have capabilities far beyond what the AWT
components offer:
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Swing buttons and labels can display images instead of, or in
addition to, text.
You can easily add or change the borders drawn around most
Swing components. For example, it's easy to put a box around the
outside of a container or label.
You can easily change the behavior or appearance of a Swing
component by either invoking methods on it or creating a subclass
of it.
Swing components don't have to be rectangular. Buttons, for
example, can be round.
GUI Class Hierarchy (Swing)
Dimension
Font
Classes in the java.awt
package
LayoutManager
1
Heavyweight
FontMetrics
Object
Color
Panel
Applet
JApplet
Window
Frame
JFrame
Dialog
JDialog
Graphics
Component
Container
*
Swing Components
in the javax.swing package
JComponent
Lightweight
Container Classes
Dimension
Classes in the java.awt
package
LayoutManager
Font
1
Heavyweight
FontMetrics
Object
Color
Panel
Applet
JApplet
Window
Frame
JFrame
Dialog
JDialog
Graphics
Component
Container
*
Container classes can
contain other GUI
components.
JComponent
Lightweight
JPanel
Swing Components
in the javax.swing package
GUI Helper Classes
Dimension
Font
Classes in the java.awt
package
LayoutManager
1
Heavyweight
FontMetrics
Object
Color
Panel
Applet
JApplet
Window
Frame
JFrame
Dialog
JDialog
Graphics
Component
Container
*
The helper classes are not subclasses
of Component. They are used to
describe the properties of GUI
components such as graphics context,
colors, fonts, and dimension.
JComponent
Lightweight
JPanel
Swing Components
in the javax.swing package
Swing GUI Components
JCheckBoxMenuItem
AbstractButton
JComponent
JMenuItem
JMenu
JButton
JRadioButtonMenuItem
JToggleButton
JCheckBox
JRadioButton
JEditorPane
JTextComponent
JTextField
JPasswordField
JTextArea
JLabel
JTabbedPane
JToolBar
JTree
JComboBox
JList
JSplitPane
JMenuBar
JTable
JPanel
JLayeredPane
JPopupMenu
JTableHeader
JOptionPane
JSeparator
JFileChooser
JInternalFrame
JScrollBar
JSlider
JScrollPane
JRootPane
JColorChooser
JProgressBar
JToolTip
JSpinner
Components Covered in the Core Version
JCheckBoxMenuItem
AbstractButton
JComponent
JMenuItem
JMenu
JButton
JRadioButtonMenuItem
JToggleButton
JCheckBox
JRadioButton
JEditorPane
JTextComponent
JTextField
JPasswordField
JTextArea
JLabel
JTabbedPane
JToolBar
JTree
JComboBox
JList
JSplitPane
JMenuBar
JTable
JPanel
JLayeredPane
JPopupMenu
JTableHeader
JOptionPane
JSeparator
JFileChooser
JInternalFrame
JScrollBar
JSlider
JScrollPane
JRootPane
JColorChooser
JProgressBar
JToolTip
JSpinner
Components Covered in the Comprehensive Version
JCheckBoxMenuItem
AbstractButton
JComponent
JMenuItem
JMenu
JButton
JRadioButtonMenuItem
JToggleButton
JCheckBox
JRadioButton
JEditorPane
JTextComponent
JTextField
JPasswordField
JTextArea
JLabel
JTabbedPane
JToolBar
JTree
JComboBox
JList
JSplitPane
JMenuBar
JTable
JPanel
JLayeredPane
JPopupMenu
JTableHeader
JOptionPane
JSeparator
JFileChooser
JInternalFrame
JScrollBar
JSlider
JScrollPane
JRootPane
JColorChooser
JProgressBar
JToolTip
JSpinner
AWT (Optional)
AWTEvent
Font
FontMetrics
Object
Color
Graphics
Component
Container
Panel
Applet
Button
Window
Frame
Label
TextField
Dialog
TextComponent
List
TextArea
Choice
CheckBox
LayoutManager
CheckBoxGroup
Canvas
MenuComponent
Scrollbar
MenuItem
MenuBar
Menu
FileDialog
Frames
 Frame
is a window that is not contained inside
another window. Frame is the basis to contain
other user interface components in Java GUI
applications.
 The
JFrame class can be used to create
windows.
 For
Swing GUI programs, use JFrame class to
create widows.
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);
}
}
Adding Components into a Frame
Title bar
// Add a button into the frame
frame.getContentPane().add(
new JButton("OK"));
Content pane
import javax.swing.*;
public class MyFrameWithComponents {
public static void main(String[] args) {
JFrame frame = new JFrame("MyFrameWithComponents"); // Add a button into the frame JButton
jbtOK = new JButton("OK");
frame.add(jbtOK);
frame.setSize(400, 300);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null); // New since JDK 1.4
}
}
Content Pane Delegation in JDK 1.5
Title bar
Content pane
// Add a button into the frame
frame.getContentPane().add(
new JButton("OK"));
// Add a button into the frame
frame.add(
new JButton("OK"));
JFrame Class
javax.swing.JFrame
+JFrame()
Creates a default frame with no title.
+JFrame(title: String)
Creates a frame with the specified title.
+getSize(width: int, height: int): void
Specifies the size of the frame.
+setLocation(x: int, y: int): void
Specifies the upper-left corner location of the frame.
+setVisible(visible: boolean): void
Sets true to display the frame.
+setDefaultCloseOperation(mode: int): void
Specifies the operation when the frame is closed.
+setLocationRelativeTo (c: Component):
void
Sets the location of the frame relative to the specified component.
If the component is null, the frame is centered on the screen.
Layout Managers

Java’s layout managers provide a level of abstraction to
automatically map your user interface on all window
systems.

The UI components are placed in containers. Each
container has a layout manager to arrange the UI
components within the container.

Layout managers are set in containers using the
setLayout(LayoutManager) method in a container.
Kinds of Layout Managers
 FlowLayout
 GridLayout
 BorderLayout