《Java焦点技术 卷I》用户界面AWT变乱继承层次

AWT变乱继承层次

EventObject类有一个子类AWTEvent，它是所有AWT变乱类的父类。
Swing组件会天生更多其他变乱对象，都直接拓展自EventObject而不是AWTEvent。
AWT将变乱分为底层(low-level)变乱和语义变乱。
语义变乱：表示用户的动作变乱，例如点击按钮，调节滚动条。
底层变乱：使得语义变乱得以发生的变乱，例如按下鼠标，移动鼠标等。
AWT变乱类的继承关系图

java.awt.event包中最常用的语义变乱类：

• ActionEvent(对应按钮点击，菜单选择，选择列表，文本域中按回车)
  
• AdjustmentEvent(用户调用滚动条)
  
• ItemEvent(用户从复选框或列表框中选择一项)
  

最常用的5个底层变乱类是：

• KeyEvent(一个键按下或释放)
  
• MouseEvent(鼠标键按下、释放、移动、拖动)
  
• MouseWheelEvent(鼠标滚轮转动)
  
• FocusEvent(某个组件获得焦点或失去焦点)
  
• WindowEvent(窗口状态改变)
  

最重要的AWT监听器接口、变乱和变乱源

接口	方法	参数/访问方法	变乱源
ActionListener	actionPerformed	ActionEvent       getActionCommand getModifiers	AbstractButton JComboBox JTextField Timer
AdjustmentListener	adjustmentValueChanged	AdjustmentEvent       getAdjustable getAdjustmentType getValue	JScrollbar
ItemListener	itemStateChanged	ItemEvent       getItem getItemSelectable getStateChange	AbstractButton JComboxBox
FocusListener	focusGained focusLost	FocusEvent       isTemporary	Component
KeyListener	keyPressed keyReleased keyTyped	KeyEvent       getKeyChar getKeyCode getKeyModifiersText getKeyText isActionKey	Component
MouseListener	mousePressed mouseReleased mouseEntered mouseExited mouseClicked	MouseEvent       getClickCount getX getY getPoint translatePoint	Component
MouseMotionListener	mouseDragged mouseMoved	MouseEvent	Component
MouseWheelListener	mouseWheelMoved	MouseWheelEvent       getWheelRotation getScrollAmount	Component
WindowListener	windowClosing windowOpened windowIconfied windowDeiconified windowClosed windowActivated windowDeactivated	WindowEvent       getWindow	Window
WindowFocusListener	windowGainedFocus windowLostFocus	WindowEvent       getOppositeWindow	Window
WindowStateListener	windowStateChanged	WindowEvent       getOldState getNewState	Window