Java Drawing - ComboBox, Font family, Font size

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		Language
	ComboBox	H. Jyounishi, Tokyo Japan
Frame (Index), No frame version:0.3(latest)

Summary: This page describes the way to creates a combo box object.

Relevant major classes of Java SE: java.awt.*, java.awt.event.*, javax.swing.*

Classes on this page:ComboBox, ComboBoxAction

1. Class ComboBox 戻る=>page top
public class ComboBox extends JComboBox

Field	Description
action	ComboBoxAction action ComboBoxAction object.

Method	Description
Constructor	public ComboBox(String commandName, String[] items, String tip) Parameters: commandName - The command name. items - The array of the JComboBox items. tip - The text to be displayed in a tool tip. Processing: Calls the following methods. this.setActionCommand(commandName); this.addActionListener(this.action); this.setName(commandName); this.setToolTipText(tip);
activateListener	public void activateListener(boolean activate) If the activate is true, then adds the ComboBoxAction to this object as an ActionListener, otherwise removes the ComboBoxAction from this object. : If the setSelectedItem or setSelectedIndex method of the JComboBox is called, the action occurs and the actionPerformed method is called to execute a command. This behavior may be inconvenient in some situation. This method provides the function to restrain the occurrence of the action by adding or removing the ActionListener. =>FontStyle.setFontStyleToMenu
isActionListener	private boolean isActionListener(ActionListener listener) Return true if the ComboBoxAction is added to this object.
createFontFamily ComboBox (static)	public static JComboBox createFontFamilyComboBox(String name) Parameters: name - The command name Processing: Create a new ComboBox object for selecting a font family. ComboBox for font families
createFontSizeComboBox (static)	public static JComboBox createFontSizeComboBox(String name) Parameters: name - The command name Processing: Create a new ComboBox object for selecting a font size. ComboBox for font sizes

2. ComboBoxAction 戻る=>page top
class ComboBoxAction extends AbstractAction

Method

Description

actionPerformed

public void actionPerformed(ActionEvent e)
∙ The action command

The action command can be got by the following line.
String commandName=e.getActionCommand();

∙ Generates the command

The commandId can be got by the getCommandId method with the parameter of the commandName. The command parameter can be got by the getSelectedItem method of the JComboBox.
Then generates a Command object using the commandId and the command paremter, and calls the exec method of the ExecCommand.