AWT Component Class

Advertisements


Introduction

The class Component is the abstract base class for the non menu user-interface controls of AWT. Component represents an object with graphical representation.

Class declaration

Following is the declaration for java.awt.Component class:

public abstract class Component
   extends Object
      implements ImageObserver, MenuContainer, Serializable

Field

Following are the fields for java.awt.Component class:

  • static float BOTTOM_ALIGNMENT -- Ease-of-use constant for getAlignmentY.

  • static float CENTER_ALIGNMENT -- Ease-of-use constant for getAlignmentY and getAlignmentX.

  • static float LEFT_ALIGNMENT -- Ease-of-use constant for getAlignmentX.

  • static float RIGHT_ALIGNMENT -- Ease-of-use constant for getAlignmentX.

  • static float TOP_ALIGNMENT -- Ease-of-use constant for getAlignmentY().

Class constructors

S.N.Constructor & Description
1protected Component()
This creates a new Component.

Class methods

S.N.Method & Description
1boolean action(Event evt, Object what)
Deprecated. As of JDK version 1.1, should register this component as ActionListener on component which fires action events.
2void add(PopupMenu popup)
Adds the specified popup menu to the component.
3void addComponentListener(ComponentListener l)
Adds the specified component listener to receive component events from this component.
4void addFocusListener(FocusListener l)
Adds the specified focus listener to receive focus events from this component when this component gains input focus.
5void addHierarchyBoundsListener(HierarchyBoundsListener l)
Adds the specified hierarchy bounds listener to receive hierarchy bounds events from this component when the hierarchy to which this container belongs changes.
6void addHierarchyListener(HierarchyListener l)
Adds the specified hierarchy listener to receive hierarchy changed events from this component when the hierarchy to which this container belongs changes.
7void addInputMethodListener(InputMethodListener l)
Adds the specified input method listener to receive input method events from this component.
8void addKeyListener(KeyListener l)
Adds the specified key listener to receive key events from this component.
9void addMouseListener(MouseListener l)
Adds the specified mouse listener to receive mouse events from this component.
10void addMouseMotionListener(MouseMotionListener l)
Adds the specified mouse motion listener to receive mouse motion events from this component.
11void addMouseWheelListener(MouseWheelListener l)
Adds the specified mouse wheel listener to receive mouse wheel events from this component.
12void addNotify()
Makes this Component displayable by connecting it to a native screen resource.
13void addPropertyChangeListener(PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list.
14void addPropertyChangeListener(String propertyName, PropertyChangeListener listener)
Adds a PropertyChangeListener to the listener list for a specific property.
15void applyComponentOrientation(ComponentOrientation orientation)
Sets the ComponentOrientation property of this component and all components contained within it.
16boolean areFocusTraversalKeysSet(int id)
Returns whether the Set of focus traversal keys for the given focus traversal operation has been explicitly defined for this Component.
17int checkImage(Image image, ImageObserver observer)
Returns the status of the construction of a screen representation of the specified image.
18int checkImage(Image image,int width,int height, ImageObserver observer)
Returns the status of the construction of a screen representation of the specified image.
19boolean contains(int x,int y)
Checks whether this component "contains" the specified point, where x and y are defined to be relative to the coordinate system of this component.
20boolean contains(Point p)
Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component.
21Image createImage(ImageProducer producer)
Creates an image from the specified image producer.
22Image createImage(int width,int height)
Creates an off-screen drawable image to be used for double buffering.
23VolatileImage createVolatileImage(int width,int height)
Creates a volatile off-screen drawable image to be used for double buffering.
24VolatileImage createVolatileImage(int width,int height, ImageCapabilities caps)
Creates a volatile off-screen drawable image, with the given capabilities.
25void deliverEvent(Event e)
Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent e).
26void disable()
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).
27protected void disableEvents(long eventsToDisable)
Disables the events defined by the specified event mask parameter from being delivered to this component.
28void dispatchEvent(AWTEvent e)
Dispatches an event to this component or one of its sub components.
29void doLayout()
Prompts the layout manager to lay out this component.
30void enable()
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).
31void enable(boolean b)
Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).
32protected void enableEvents(long eventsToEnable)
Enables the events defined by the specified event mask parameter to be delivered to this component.
33void enableInputMethods(boolean enable)
Enables or disables input method support for this component.
34protected void firePropertyChange(String propertyName, boolean oldValue, boolean newValue)
Support for reporting bound property changes for boolean properties.
35void firePropertyChange(String propertyName, byte oldValue, byte newValue)
Reports a bound property change.
36void firePropertyChange(String propertyName, char oldValue, char newValue)
Reports a bound property change.
37void firePropertyChange(String propertyName, double oldValue, double newValue)
Reports a bound property change.
38void firePropertyChange(String propertyName, float oldValue, float newValue)
Reports a bound property change.
39void firePropertyChange(String propertyName, long oldValue, long newValue)
Reports a bound property change.
40protected void firePropertyChange(String propertyName, Object oldValue, Object newValue)
Support for reporting bound property changes for Object properties.
41void firePropertyChange(String propertyName, short oldValue, short newValue)
Reports a bound property change.
42AccessibleContext getAccessibleContext()
Gets the AccessibleContext associated with this Component.
43float getAlignmentX()
Returns the alignment along the x axis.
44float getAlignmentY()
Returns the alignment along the y axis.
45Color getBackground()
Gets the background color of this component.
46int getBaseline(int width,int height)
Returns the baseline.
47Component.BaselineResizeBehavior getBaselineResizeBehavior()
Returns an enum indicating how the baseline of the component changes as the size changes.
48Rectangle getBounds()
Gets the bounds of this component in the form of a Rectangle object.
49Rectangle getBounds(Rectangle rv)
Stores the bounds of this component into return value rv and return rv.
50ColorModel getColorModel()
Gets the instance of ColorModel used to display the component on the output device.
51Component getComponentAt(int x,int y)
Determines if this component or one of its immediate subcomponents contains the (x, y) location, and if so, returns the containing component.
52Component getComponentAt(Point p)
Returns the component or subcomponent that contains the specified point.
53ComponentListener[] getComponentListeners()
Returns an array of all the component listeners registered on this component.
54ComponentOrientation getComponentOrientation()
Retrieves the language-sensitive orientation that is to be used to order the elements or text within this component.
55Cursor getCursor()
Gets the cursor set in the component.
56DropTarget getDropTarget()
Gets the DropTarget associated with this Component.
57Container getFocusCycleRootAncestor()
Returns the Container which is the focus cycle root of this Component's focus traversal cycle.
58FocusListener[] getFocusListeners()
Returns an array of all the focus listeners registered on this component.
59Set<AWTKeyStroke> getFocusTraversalKeys(int id)
Returns the Set of focus traversal keys for a given traversal operation for this Component.
60boolean getFocusTraversalKeysEnabled()
Returns whether focus traversal keys are enabled for this Component.
61Font getFont()
Gets the font of this component.
62FontMetrics getFontMetrics(Font font)
Gets the font metrics for the specified font.
63Color getForeground()
Gets the foreground color of this component.
64Graphics getGraphics()
Creates a graphics context for this component.
65GraphicsConfiguration getGraphicsConfiguration()
Gets the GraphicsConfiguration associated with this Component.
66int getHeight()
Returns the current height of this component.
67HierarchyBoundsListener[] getHierarchyBoundsListeners()
Returns an array of all the hierarchy bounds listeners registered on this component.
68HierarchyListener[] getHierarchyListeners()
Returns an array of all the hierarchy listeners registered on this component.
69boolean getIgnoreRepaint()
70InputContext getInputContext()
Gets the input context used by this component for handling the communication with input methods when text is entered in this component.
71InputMethodListener[] getInputMethodListeners()
Returns an array of all the input method listeners registered on this component.
72InputMethodRequests getInputMethodRequests()
Gets the input method request handler which supports requests from input methods for this component.
73KeyListener[] getKeyListeners()
Returns an array of all the key listeners registered on this component.
74<T extends EventListener> T[] getListeners(Class<T> listenerType)
Returns an array of all the objects currently registered as FooListeners upon this Component.
75Locale getLocale()
Gets the locale of this component.
76Point getLocation()
Gets the location of this component in the form of a point specifying the component's top-left corner.
77Point getLocation(Point rv)
Stores the x,y origin of this component into return value rv and return rv.
78Point getLocationOnScreen()
Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.
79Dimension getMaximumSize()
Gets the maximum size of this component.
80Dimension getMinimumSize()
Gets the mininimum size of this component.
81MouseListener[] getMouseListeners()
Returns an array of all the mouse listeners registered on this component.
82MouseMotionListener[] getMouseMotionListeners()
Returns an array of all the mouse motion listeners registered on this component.
83Point getMousePosition()
Returns the position of the mouse pointer in this Component's coordinate space if the Component is directly under the mouse pointer, otherwise returns null.
84MouseWheelListener[] getMouseWheelListeners()
Returns an array of all the mouse wheel listeners registered on this component.
85String getName()
Gets the name of the component.
86Container getParent()
Gets the parent of this component.
87java.awt.peer.ComponentPeer getPeer() Deprecated. As of JDK version 1.1, programs should not directly manipulate peers; replaced by boolean isDisplayable().
88Dimension getPreferredSize()
Gets the preferred size of this component.
89PropertyChangeListener[] getPropertyChangeListeners()
Returns an array of all the property change listeners registered on this component.
90PropertyChangeListener[] getPropertyChangeListeners(String propertyName)
Returns an array of all the listeners which have been associated with the named property.
91Dimension getSize()
Returns the size of this component in the form of a Dimension object.
92Dimension getSize(Dimension rv)Stores the width/height of this component into return value rv and return rv.
93Toolkit getToolkit()
Gets the toolkit of this component.
94Object getTreeLock()
Gets this component's locking object (the object that owns the thread sychronization monitor)
for AWT component-tree and layout operations.
95int getWidth()
Returns the current width of this component.
96int getX()
Returns the current x coordinate of the components origin.
97int getY()
Returns the current y coordinate of the components origin.
98boolean gotFocus(Event evt, Object what)
Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent)
.
99boolean handleEvent(Event evt)
Deprecated. As of JDK version 1.1 replaced by processEvent(AWTEvent).
100boolean hasFocus()
Returns true if this Component is the focus owner.
101void hide()
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).
102boolean imageUpdate(Image img,int infoflags,int x,int y,int w,int h)
Repaints the component when the image has changed.
103boolean inside(int x,int y)
Deprecated. As of JDK version 1.1, replaced by contains(int, int).
104void invalidate()
Invalidates this component.
105boolean isBackgroundSet()
Returns whether the background color has been explicitly set for this Component.
106boolean isCursorSet()
Returns whether the cursor has been explicitly set for this Component.
107boolean isDisplayable()
Determines whether this component is displayable.
108boolean isDoubleBuffered()
Returns true if this component is painted to an offscreen image (buffer)
that's copied to the screen later.
109boolean isEnabled()
Determines whether this component is enabled.
110boolean isFocusable()
Returns whether this Component can be focused.
111boolean isFocusCycleRoot(Container container)
Returns whether the specified Container is the focus cycle root of this Component's focus traversal cycle.
112boolean isFocusOwner()
Returns true if this Component is the focus owner.
113boolean isFocusTraversable()
Deprecated. As of 1.4, replaced by isFocusable().
114boolean isFontSet()
Returns whether the font has been explicitly set for this Component.
115boolean isForegroundSet()
Returns whether the foreground color has been explicitly set for this Component.
116boolean isLightweight()
A lightweight component doesn't have a native toolkit peer.
117boolean isMaximumSizeSet()
Returns true if the maximum size has been set to a non-null value otherwise returns false.
118boolean isMinimumSizeSet()
Returns whether or not setMinimumSize has been invoked with a non-null value.
119boolean isOpaque()
Returns true if this component is completely opaque, returns false by default.
120boolean isPreferredSizeSet()
Returns true if the preferred size has been set to a non-null value otherwise returns false.
121boolean isShowing()
Determines whether this component is showing on screen.
122boolean isValid()
Determines whether this component is valid.
123boolean isVisible()
Determines whether this component should be visible when its parent is visible.
124boolean keyDown(Event evt,int key)
Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
125boolean keyUp(Event evt,int key)
Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
126void layout()
Deprecated. As of JDK version 1.1, replaced by doLayout().
127void list()
Prints a listing of this component to the standard system output stream System.out.
128void list(PrintStream out)
Prints a listing of this component to the specified output stream.
129void list(PrintStream out,int indent)
Prints out a list, starting at the specified indentation, to the specified print stream.
130void list(PrintWriter out)
Prints a listing to the specified print writer.
131void list(PrintWriter out,int indent)
Prints out a list, starting at the specified indentation, to the specified print writer.
132Component locate(int x,int y)
Deprecated. As of JDK version 1.1, replaced by getComponentAt(int, int).
133Point location()
Deprecated. As of JDK version 1.1, replaced by getLocation().
134boolean lostFocus(Event evt, Object what)
Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
135boolean mouseDown(Event evt,int x,int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
136boolean mouseDrag(Event evt,int x,int y)
Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
137boolean mouseEnter(Event evt,int x,int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
138boolean mouseExit(Event evt,int x,int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent)..
139boolean mouseMove(Event evt,int x,int y)
Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent)..
140boolean mouseUp(Event evt,int x,int y)
Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
141void move(int x,int y)
Deprecated. As of JDK version 1.1, replaced by setLocation(int, int).
142void nextFocus()
Deprecated. As of JDK version 1.1, replaced by transferFocus().
143void paint(Graphics g)
Paints this component.
144void paintAll(Graphics g)
Paints this component and all of its subcomponents.
145boolean postEvent(Event e)
Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).
146boolean prepareImage(Image image,int width,int height, ImageObserver observer)
Prepares an image for rendering on this component at the specified width and height.
147void print(Graphics g)
Prints this component.
148void printAll(Graphics g)
Prints this component and all of its subcomponents.
149protectedvoid processComponentEvent(ComponentEvent e)
Processes component events occurring on this component by dispatching them to any registered ComponentListener objects.
150protected void processEvent(AWTEvent e)
Processes events occurring on this component.
151protected void processFocusEvent(FocusEvent e)
Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.
152protected void processHierarchyBoundsEvent(HierarchyEvent e)
Processes hierarchy bounds events occurring on this component by dispatching them to any registered HierarchyBoundsListener objects.
153protected void processHierarchyEvent(HierarchyEvent e)
Processes hierarchy events occurring on this component by dispatching them to any registered HierarchyListener objects.
154protectedvoid processInputMethodEvent(InputMethodEvent e)
Processes input method events occurring on this component by dispatching them to any registered InputMethodListener objects.
155protected void processKeyEvent(KeyEvent e)
Processes key events occurring on this component by dispatching them to any registered KeyListener objects.
156protected void processMouseEvent(MouseEvent e)
Processes mouse events occurring on this component by dispatching them to any registered MouseListener objects.
157protected void processMouseMotionEvent(MouseEvent e)
Processes mouse motion events occurring on this component by dispatching them to any registered MouseMotionListener objects.
158protected void processMouseWheelEvent(MouseWheelEvent e)
Processes mouse wheel events occurring on this component by dispatching them to any registered MouseWheelListener objects.
159void remove(MenuComponent popup)
Removes the specified popup menu from the component.
160void removeComponentListener(ComponentListener l)
Removes the specified component listener so that it no longer receives component events from this component.
161void removeFocusListener(FocusListener l)
Removes the specified focus listener so that it no longer receives focus events from this component.
162void removeHierarchyBoundsListener(HierarchyBoundsListener l)
Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component.
163void removeHierarchyListener(HierarchyListener l)
Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component.
164void removeInputMethodListener(InputMethodListener l)
Removes the specified input method listener so that it no longer receives input method events from this component.
165void removeKeyListener(KeyListener l)
Removes the specified key listener so that it no longer receives key events from this component.
166void removeMouseListener(MouseListener l)
Removes the specified mouse listener so that it no longer receives mouse events from this component.
167void removeMouseMotionListener(MouseMotionListener l)
Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.
168void removeMouseWheelListener(MouseWheelListener l)
Removes the specified mouse wheel listener so that it no longer receives mouse wheel events from this component.
169void removeNotify()
Makes this Component undisplayable by destroying it native screen resource.
170void removePropertyChangeListener(PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list.
171void removePropertyChangeListener(String propertyName, PropertyChangeListener listener)
Removes a PropertyChangeListener from the listener list for a specific property.
172void repaint()
Repaints this component.
173void repaint(int x,int y,int width,int height)
Repaints the specified rectangle of this component.
174void repaint(long tm)
Repaints the component.
175void repaint(long tm,int x,int y,int width,int height)
Repaints the specified rectangle of this component within tm milliseconds.
176void requestFocus()
Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.
177protected boolean requestFocus(boolean temporary)
Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.
178boolean requestFocusInWindow()
Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.
179protected boolean requestFocusInWindow(boolean temporary)
Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.
180void reshape(int x,int y,int width,int height)
Deprecated. As of JDK version 1.1, replaced by setBounds(int, int, int, int).
181void resize(Dimension d)
Deprecated. As of JDK version 1.1, replaced by setSize(Dimension).
182void resize(int width,int height)
Deprecated. As of JDK version 1.1, replaced by setSize(int, int).
183void setBackground(Color c)
Sets the background color of this component.
184void setBounds(int x,int y,int width,int height)
Moves and resizes this component.
185void setBounds(Rectangle r)
Moves and resizes this component to conform to the new bounding rectangle r.
186void setComponentOrientation(ComponentOrientation o)
Sets the language-sensitive orientation that is to be used to order the elements or text within this component.
187void setCursor(Cursor cursor)
Sets the cursor image to the specified cursor.
188void setDropTarget(DropTarget dt)
Associate a DropTarget with this component.
189void setEnabled(boolean b)
Enables or disables this component, depending on the value of the parameter b.
190void setFocusable(boolean focusable)
Sets the focusable state of this Component to the specified value.
191void setFocusTraversalKeys(int id, Set<? extends AWTKeyStroke> keystrokes)
Sets the focus traversal keys for a given traversal operation for this Component.
192void setFocusTraversalKeysEnabled(boolean focusTraversalKeysEnabled)
Sets whether focus traversal keys are enabled for this Component.
193void setFont(Font f)
Sets the font of this component.
194void setForeground(Color c)
Sets the foreground color of this component.
195void setIgnoreRepaint(boolean ignoreRepaint)
Sets whether or not paint messages received from the operating system should be ignored.
196void setLocale(Locale l)
Sets the locale of this component.
197void setLocation(int x,int y)
Moves this component to a new location.
198void setLocation(Point p)
Moves this component to a new location.
199void setMaximumSize(Dimension maximumSize)
Sets the maximum size of this component to a constant value.
200void setMinimumSize(Dimension minimumSize)
Sets the minimum size of this component to a constant value.
201void setName(String name)
Sets the name of the component to the specified string.
202void setPreferredSize(Dimension preferredSize)
Sets the preferred size of this component to a constant value.
203void setSize(Dimension d)
Resizes this component so that it has width d.width and height d.height.
204void setSize(int width,int height)
Resizes this component so that it has width width and height height.
205void setVisible(boolean b)
Shows or hides this component depending on the value of parameter b.
206void show()
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).
207void show(boolean b)
Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).
208Dimension size()
Deprecated. As of JDK version 1.1, replaced by getSize().
209String toString()
Returns a string representation of this component and its values.
210void transferFocus()
Transfers the focus to the next component, as though this Component were the focus owner.
211void transferFocusBackward()
Transfers the focus to the previous component, as though this Component were the focus owner.
212void transferFocusUpCycle()
Transfers the focus up one focus traversal cycle.
213void update(Graphics g)
Updates this component.
214void validate()
Ensures that this component has a valid layout.
215Rectangle bounds()
Deprecated. As of JDK version 1.1, replaced by getBounds().
216protected AWTEvent coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)
Potentially coalesce an event being posted with an existing event.
217protected String paramString()
Returns a string representing the state of this component.
218protected void firePropertyChange(String propertyName,int oldValue,int newValue)
Support for reporting bound property changes for integer properties.
219Dimension preferredSize()
Deprecated. As of JDK version 1.1, replaced by getPreferredSize().
220boolean prepareImage(Image image, ImageObserver observer)
Prepares an image for rendering on this component.
221Dimension minimumSize()
Deprecated. As of JDK version 1.1, replaced by getMinimumSize().

Methods inherited

This class inherits methods from the following classes:

  • java.lang.Object



Advertisements
Advertisements