AllComponentspublic class AllComponents extends Frame implements ActionListener| A program that uses all the standard AWT components |
| Fields Summary |
|---|
| TextArea | textarea |
| Constructors Summary |
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public AllComponents(String title)Create the whole GUI, and set up event listeners
super(title); // set frame title.
// Arrange to detect window close events
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) { System.exit(0); }
});
// Set a default font
this.setFont(new Font("SansSerif", Font.PLAIN, 12));
// Create the menubar. Tell the frame about it.
MenuBar menubar = new MenuBar();
this.setMenuBar(menubar);
// Create the file menu. Add to menubar.
Menu file = new Menu("File");
menubar.add(file);
// Create two items for the file menu, setting their label, shortcut,
// action command and listener. Add them to File menu.
// Note that we use the frame itself as the action listener
MenuItem open = new MenuItem("Open", new MenuShortcut(KeyEvent.VK_O));
open.setActionCommand("open");
open.addActionListener(this);
file.add(open);
MenuItem quit = new MenuItem("Quit", new MenuShortcut(KeyEvent.VK_Q));
quit.setActionCommand("quit");
quit.addActionListener(this);
file.add(quit);
// Create Help menu; add an item; add to menubar
// Display the help menu in a special reserved place.
Menu help = new Menu("Help");
menubar.add(help);
menubar.setHelpMenu(help);
// Create and add an item to the Help menu
MenuItem about = new MenuItem("About", new MenuShortcut(KeyEvent.VK_A));
about.setActionCommand("about");
about.addActionListener(this);
help.add(about);
// Now that we've done the menu, we can begin work on the contents of
// the frame. Assign a BorderLayout manager with margins for this frame.
this.setLayout(new BorderLayout(10, 10));
// Create two panels to contain two columns of components. Use our custom
// ColumnLayout layout manager for each. Add them on the west and
// center of the frame's border layout
Panel column1 = new Panel();
column1.setLayout(new ColumnLayout(5, 10, 2, ColumnLayout.LEFT));
this.add(column1, "West");
Panel column2 = new Panel();
column2.setLayout(new ColumnLayout(5, 10, 2, ColumnLayout.LEFT));
this.add(column2, "Center");
// Create a panel to contain the buttons at the bottom of the window
// Give it a FlowLayout layout manager, and add it along the south border
Panel buttonbox = new Panel();
buttonbox.setLayout(new FlowLayout(FlowLayout.CENTER, 100, 10));
this.add(buttonbox, "South");
// Create pushbuttons and add them to the buttonbox
Button okay = new Button("Okay");
Button cancel = new Button("Cancel");
buttonbox.add(okay);
buttonbox.add(cancel);
// Handle events on the buttons
ActionListener buttonlistener = new ActionListener() {
public void actionPerformed(ActionEvent e) {
textarea.append("You clicked: " +
((Button)e.getSource()).getLabel() + "\n");
}
};
okay.addActionListener(buttonlistener);
cancel.addActionListener(buttonlistener);
// Now start filling the left column.
// Create a 1-line text field and add to left column, with a label
TextField textfield = new TextField(15);
column1.add(new Label("Name:"));
column1.add(textfield);
// Handle events on the TextField
textfield.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
textarea.append("Your name is: " +
((TextField)e.getSource()).getText() + "\n");
}
});
textfield.addTextListener(new TextListener() {
public void textValueChanged(TextEvent e) {
textarea.append("You have typed: " +
((TextField)e.getSource()).getText() + "\n");
}
});
// Create a dropdown list or option menu of choices
Choice choice = new Choice();
choice.addItem("red");
choice.addItem("green");
choice.addItem("blue");
column1.add(new Label("Favorite color:"));
column1.add(choice);
// Handle events on this choice
choice.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
textarea.append("Your favorite color is: " + e.getItem() + "\n");
}
});
// Create checkboxes, and group them in a CheckboxGroup to give them
// "radio button" behavior.
CheckboxGroup checkbox_group = new CheckboxGroup();
Checkbox[] checkboxes = new Checkbox[3];
checkboxes[0] = new Checkbox("vanilla", checkbox_group, false);
checkboxes[1] = new Checkbox("chocolate", checkbox_group, true);
checkboxes[2] = new Checkbox("strawberry", checkbox_group, false);
column1.add(new Label("Favorite flavor:"));
for(int i = 0; i < checkboxes.length; i++) column1.add(checkboxes[i]);
// Handle events on the checkboxes
ItemListener checkbox_listener = new ItemListener() {
public void itemStateChanged(ItemEvent e) {
textarea.append("Your favorite flavor is: " +
((Checkbox)e.getItemSelectable()).getLabel() + "\n");
}
};
for(int i = 0; i < checkboxes.length; i++)
checkboxes[i].addItemListener(checkbox_listener);
// Create a list of choices.
List list = new List(4, true);
list.addItem("Java"); list.addItem("C"); list.addItem("C++");
list.addItem("Smalltalk"); list.addItem("Lisp");
list.addItem("Modula-3"); list.addItem("Forth");
column1.add(new Label("Favorite languages:"));
column1.add(list);
// Handle events on this list
list.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
textarea.append("Your favorite languages are: ");
String[] languages = ((List)e.getItemSelectable()).getSelectedItems();
for(int i = 0; i < languages.length; i++) {
if (i > 0) textarea.append(",");
textarea.append(languages[i]);
}
textarea.append("\n");
}
});
// Create a multi-line text area in column 2
textarea = new TextArea(6, 40);
textarea.setEditable(false);
column2.add(new Label("Messages"));
column2.add(textarea);
// Create a scrollpane that displays portions of a larger component
ScrollPane scrollpane = new ScrollPane();
scrollpane.setSize(300, 150);
column2.add(new Label("Scrolling Window"));
column2.add(scrollpane);
// Create a custom MultiLineLabel with a really big font and make it
// a child of the ScrollPane container
String message =
"/*************************************************\n" +
" * AllComponents.java *\n" +
" * Written by David Flanagan *\n" +
" * Copyright (c) 1997 by O'Reilly & Associates *\n" +
" * *\n" +
" *************************************************/\n";
MultiLineLabel biglabel = new MultiLineLabel(message);
biglabel.setFont(new Font("Monospaced", Font.BOLD + Font.ITALIC, 24));
scrollpane.add(biglabel);
|
| Methods Summary |
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| public void | actionPerformed(java.awt.event.ActionEvent e)This is the action listener method that the menu items invoke
String command = e.getActionCommand();
if (command.equals("quit")) {
YesNoDialog d = new YesNoDialog(this, "Really Quit?",
"Are you sure you want to quit?",
"Yes", "No", null);
d.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("yes")) System.exit(0);
else textarea.append("Quit not confirmed\n");
}
});
d.show();
}
else if (command.equals("open")) {
FileDialog d = new FileDialog(this, "Open File", FileDialog.LOAD);
d.show(); // display the dialog and block until answered
textarea.append("You selected file: " + d.getFile() + "\n");
d.dispose();
}
else if (command.equals("about")) {
InfoDialog d = new InfoDialog(this, "About",
"This demo was written by David Flanagan\n" +
"Copyright (c) 1997 O'Reilly & Associates");
d.show();
}
| | public static void | main(java.lang.String[] args)
Frame f = new AllComponents("AWT Demo");
f.pack();
f.show();
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