AWT Component Class


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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
1

protected Component()

This creates a new Component.

Class methods

S.N.Method & Description
1

boolean action(Event evt, Object what)

Deprecated. As of JDK version 1.1, should register this component as ActionListener on component which fires action events.

2

void add(PopupMenu popup)

Adds the specified popup menu to the component.

3

void addComponentListener(ComponentListener l)

Adds the specified component listener to receive component events from this component.

4

void addFocusListener(FocusListener l)

Adds the specified focus listener to receive focus events from this component when this component gains input focus.

5

void 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.

6

void 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.

7

void addInputMethodListener(InputMethodListener l)

Adds the specified input method listener to receive input method events from this component.

8

void addKeyListener(KeyListener l)

Adds the specified key listener to receive key events from this component.

9

void addMouseListener(MouseListener l)

Adds the specified mouse listener to receive mouse events from this component.

10

void addMouseMotionListener(MouseMotionListener l)

Adds the specified mouse motion listener to receive mouse motion events from this component.

11

void addMouseWheelListener(MouseWheelListener l)

Adds the specified mouse wheel listener to receive mouse wheel events from this component.

12

void addNotify()

Makes this Component displayable by connecting it to a native screen resource.

13

void addPropertyChangeListener(PropertyChangeListener listener)

Adds a PropertyChangeListener to the listener list.

14

void addProperty ChangeListener(String propertyName, Property ChangeListener listener)

Adds a PropertyChangeListener to the listener list for a specific property.

15

void applyComponentOrientation(ComponentOrientation orientation)

Sets the ComponentOrientation property of this component and all components contained within it.

16

boolean areFocusTraversalKeysSet(int id)

Returns whether the Set of focus traversal keys for the given focus traversal operation has been explicitly defined for this Component.

17

int checkImage(Image image, ImageObserver observer)

Returns the status of the construction of a screen representation of the specified image.

18

int checkImage(Image image,int width,int height, ImageObserver observer)

Returns the status of the construction of a screen representation of the specified image.

19

boolean 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.

20

boolean 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.

21

Image createImage(ImageProducer producer)

Creates an image from the specified image producer.

22

Image createImage(int width,int height)

Creates an off-screen drawable image to be used for double buffering.

23

VolatileImage createVolatileImage(int width,int height)

Creates a volatile off-screen drawable image to be used for double buffering.

24

VolatileImage createVolatileImage(int width,int height, ImageCapabilities caps)

Creates a volatile off-screen drawable image, with the given capabilities.

25

void deliverEvent(Event e)

Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent e).

26

void disable()

Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).

27

protected void disableEvents(long eventsToDisable)

Disables the events defined by the specified event mask parameter from being delivered to this component.

28

void dispatchEvent(AWTEvent e)

Dispatches an event to this component or one of its sub components.

29

void doLayout()

Prompts the layout manager to lay out this component.

30

void enable()

Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).

31

void enable(boolean b)

Deprecated. As of JDK version 1.1, replaced by setEnabled(boolean).

32

protected void enableEvents(long eventsToEnable)

Enables the events defined by the specified event mask parameter to be delivered to this component.

33

void enableInputMethods(boolean enable)

Enables or disables input method support for this component.

34

protected void firePropertyChange(String propertyName, boolean oldValue, boolean newValue)

Support for reporting bound property changes for boolean properties.

35

void firePropertyChange(String propertyName, byte oldValue, byte newValue)

Reports a bound property change.

36

void firePropertyChange(String propertyName, char oldValue, char newValue)

Reports a bound property change.

37

void firePropertyChange(String propertyName, double oldValue, double newValue)

Reports a bound property change.

38

void firePropertyChange(String propertyName, float oldValue, float newValue)

Reports a bound property change.

39

void firePropertyChange(String propertyName, long oldValue, long newValue)

Reports a bound property change.

40

protected void firePropertyChange(String propertyName, Object oldValue, Object newValue)

Support for reporting bound property changes for Object properties.

41

void firePropertyChange(String propertyName, short oldValue, short newValue)

Reports a bound property change.

42

AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this Component.

43

float getAlignmentX()

Returns the alignment along the x axis.

44

float getAlignmentY()

Returns the alignment along the y axis.

45

Color getBackground()

Gets the background color of this component.

46

int getBaseline(int width,int height)

Returns the baseline.

47

Component.BaselineResizeBehavior getBaselineResizeBehavior()

Returns an enum indicating how the baseline of the component changes as the size changes.

48

Rectangle getBounds()

Gets the bounds of this component in the form of a Rectangle object.

49

Rectangle getBounds(Rectangle rv)

Stores the bounds of this component into return value rv and return rv.

50

ColorModel getColorModel()

Gets the instance of ColorModel used to display the component on the output device.

51

Component 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.

52

Component getComponentAt(Point p)

Returns the component or subcomponent that contains the specified point.

53

ComponentListener[] getComponentListeners()

Returns an array of all the component listeners registered on this component.

54

ComponentOrientation getComponentOrientation()

Retrieves the language-sensitive orientation that is to be used to order the elements or text within this component.

55

Cursor getCursor()

Gets the cursor set in the component.

56

DropTarget getDropTarget()

Gets the DropTarget associated with this Component.

57

Container getFocusCycleRootAncestor()

Returns the Container which is the focus cycle root of this Component's focus traversal cycle.

58

FocusListener[] getFocusListeners()

Returns an array of all the focus listeners registered on this component.

59

Set<AWTKeyStroke> getFocusTraversalKeys(int id)

Returns the Set of focus traversal keys for a given traversal operation for this Component.

60

boolean getFocusTraversalKeysEnabled()

Returns whether focus traversal keys are enabled for this Component.

61

Font getFont()

Gets the font of this component.

62

FontMetrics getFontMetrics(Font font)

Gets the font metrics for the specified font.

63

Color getForeground()

Gets the foreground color of this component.

64

Graphics getGraphics()

Creates a graphics context for this component.

65

GraphicsConfiguration getGraphicsConfiguration()

Gets the GraphicsConfiguration associated with this Component.

66

int getHeight()

Returns the current height of this component.

67

HierarchyBoundsListener[] getHierarchyBoundsListeners()

Returns an array of all the hierarchy bounds listeners registered on this component.

68

HierarchyListener[] getHierarchyListeners()

Returns an array of all the hierarchy listeners registered on this component.

69

boolean getIgnoreRepaint()

70

InputContext getInputContext()

Gets the input context used by this component for handling the communication with input methods when text is entered in this component.

71

InputMethodListener[] getInputMethodListeners()
Returns an array of all the input method listeners registered on this component.

72

InputMethodRequests getInputMethodRequests()

Gets the input method request handler which supports requests from input methods for this component.

73

KeyListener[] 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.

75

Locale getLocale()

Gets the locale of this component.

76

Point getLocation()

Gets the location of this component in the form of a point specifying the component's top-left corner.

77

Point getLocation(Point rv)

Stores the x,y origin of this component into return value rv and return rv.

78

Point 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.

79

Dimension getMaximumSize()

Gets the maximum size of this component.

80

Dimension getMinimumSize()

Gets the mininimum size of this component.

81

MouseListener[] getMouseListeners()

Returns an array of all the mouse listeners registered on this component.

82

MouseMotionListener[] getMouseMotionListeners()

Returns an array of all the mouse motion listeners registered on this component.

83

Point 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.
85

String getName()

Gets the name of the component.

86

Container getParent()

Gets the parent of this component.

87

java.awt.peer.ComponentPeer getPeer() Deprecated. As of JDK version 1.1, programs should not directly manipulate peers; replaced by boolean isDisplayable().

88

Dimension getPreferredSize()

Gets the preferred size of this component.

89

PropertyChangeListener[] getPropertyChangeListeners()

Returns an array of all the property change listeners registered on this component.

90

Property ChangeListener[] getProperty ChangeListeners (String propertyName)

Returns an array of all the listeners which have been associated with the named property.

91

Dimension getSize()

Returns the size of this component in the form of a Dimension object.

92

Dimension getSize(Dimension rv)Stores the width/height of this component into return value rv and return rv.

93

Toolkit getToolkit()

Gets the toolkit of this component.

94

Object getTreeLock()

Gets this component's locking object (the object that owns the thread sychronization monitor)

for AWT component-tree and layout operations.

95

int getWidth()

Returns the current width of this component.

96

int getX()

Returns the current x coordinate of the components origin.

97

int getY()

Returns the current y coordinate of the components origin.

98

boolean gotFocus(Event evt, Object what)

Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent)

99

boolean handleEvent(Event evt)

Deprecated. As of JDK version 1.1 replaced by processEvent(AWTEvent).

100

boolean hasFocus()

Returns true if this Component is the focus owner.

101

void hide()

Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).

102

boolean imageUpdate(Image img,int infoflags,int x,int y,int w,int h)

Repaints the component when the image has changed.

103

boolean inside(int x,int y)

Deprecated. As of JDK version 1.1, replaced by contains(int, int).

104

void invalidate()

Invalidates this component.

105

boolean isBackgroundSet()

Returns whether the background color has been explicitly set for this Component.

106

boolean isCursorSet()

Returns whether the cursor has been explicitly set for this Component.

107

boolean isDisplayable()

Determines whether this component is displayable.

108

boolean isDoubleBuffered()

Returns true if this component is painted to an offscreen image (buffer)

that's copied to the screen later.

109

boolean isEnabled()

Determines whether this component is enabled.

110

boolean isFocusable()

Returns whether this Component can be focused.

111

boolean isFocusCycleRoot(Container container)

Returns whether the specified Container is the focus cycle root of this Component's focus traversal cycle.

112

boolean isFocusOwner()

Returns true if this Component is the focus owner.

113

boolean isFocusTraversable()

Deprecated. As of 1.4, replaced by isFocusable().

114

boolean isFontSet()

Returns whether the font has been explicitly set for this Component.

115

boolean isForegroundSet()

Returns whether the foreground color has been explicitly set for this Component.

116

boolean isLightweight()

A lightweight component doesn't have a native toolkit peer.

117

boolean isMaximumSizeSet()

Returns true if the maximum size has been set to a non-null value otherwise returns false.

118

boolean isMinimumSizeSet()

Returns whether or not setMinimumSize has been invoked with a non-null value.

119

boolean isOpaque()

Returns true if this component is completely opaque, returns false by default.

120

boolean isPreferredSizeSet()

Returns true if the preferred size has been set to a non-null value otherwise returns false.

121

boolean isShowing()

Determines whether this component is showing on screen.

122

boolean isValid()

Determines whether this component is valid.

123

boolean isVisible()

Determines whether this component should be visible when its parent is visible.

124

boolean keyDown(Event evt,int key)

Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).

125

boolean keyUp(Event evt,int key)

Deprecated. As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).

126

void layout()

Deprecated. As of JDK version 1.1, replaced by doLayout().

127

void list()

Prints a listing of this component to the standard system output stream System.out.

128

void list(PrintStream out)

Prints a listing of this component to the specified output stream.

129

void list(PrintStream out,int indent)

Prints out a list, starting at the specified indentation, to the specified print stream.

130

void list(PrintWriter out)

Prints a listing to the specified print writer.

131

void list(PrintWriter out,int indent)

Prints out a list, starting at the specified indentation, to the specified print writer.

132

Component locate(int x,int y)

Deprecated. As of JDK version 1.1, replaced by getComponentAt(int, int).

133

Point location()

Deprecated. As of JDK version 1.1, replaced by getLocation().

134

boolean lostFocus(Event evt, Object what)

Deprecated. As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).

135

boolean mouseDown(Event evt,int x,int y)

Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).

136

boolean mouseDrag(Event evt,int x,int y)

Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).

137

boolean mouseEnter(Event evt,int x,int y)

Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).

138

boolean mouseExit(Event evt,int x,int y)

Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent)..

139

boolean mouseMove(Event evt,int x,int y)

Deprecated. As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent)..

140

boolean mouseUp(Event evt,int x,int y)

Deprecated. As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).

141

void move(int x,int y)

Deprecated. As of JDK version 1.1, replaced by setLocation(int, int).

142

void nextFocus()

Deprecated. As of JDK version 1.1, replaced by transferFocus().

143

void paint(Graphics g)

Paints this component.

144

void paintAll(Graphics g)

Paints this component and all of its subcomponents.

145

boolean postEvent(Event e)

Deprecated. As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).

146

boolean prepareImage(Image image,int width,int height, ImageObserver observer)

Prepares an image for rendering on this component at the specified width and height.

147

void print(Graphics g)

Prints this component.

148

void printAll(Graphics g)

Prints this component and all of its subcomponents.

149

protectedvoid processComponentEvent(ComponentEvent e)

Processes component events occurring on this component by dispatching them to any registered ComponentListener objects.

150

protected void processEvent(AWTEvent e)

Processes events occurring on this component.

151

protected void processFocusEvent(FocusEvent e)

Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.

152

protected void processHierarchyBoundsEvent(HierarchyEvent e)

Processes hierarchy bounds events occurring on this component by dispatching them to any registered HierarchyBoundsListener objects.

153

protected void processHierarchyEvent(HierarchyEvent e)

Processes hierarchy events occurring on this component by dispatching them to any registered HierarchyListener objects.

154

protectedvoid processInputMethodEvent(InputMethodEvent e)

Processes input method events occurring on this component by dispatching them to any registered InputMethodListener objects.

155

protected void processKeyEvent(KeyEvent e)

Processes key events occurring on this component by dispatching them to any registered KeyListener objects.

156

protected void processMouseEvent(MouseEvent e)

Processes mouse events occurring on this component by dispatching them to any registered MouseListener objects.

157

protected void processMouseMotionEvent(MouseEvent e)

Processes mouse motion events occurring on this component by dispatching them to any registered MouseMotionListener objects.

158

protected void processMouseWheelEvent(MouseWheelEvent e)

Processes mouse wheel events occurring on this component by dispatching them to any registered MouseWheelListener objects.

159

void remove(MenuComponent popup)

Removes the specified popup menu from the component.

160

void removeComponentListener(ComponentListener l)

Removes the specified component listener so that it no longer receives component events from this component.

161

void removeFocusListener(FocusListener l)

Removes the specified focus listener so that it no longer receives focus events from this component.

162

void removeHierarchyBoundsListener(HierarchyBoundsListener l)

Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component.

163

void removeHierarchyListener(HierarchyListener l)

Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component.

164

void removeInputMethodListener(InputMethodListener l)

Removes the specified input method listener so that it no longer receives input method events from this component.

165

void removeKeyListener(KeyListener l)

Removes the specified key listener so that it no longer receives key events from this component.

166

void removeMouseListener(MouseListener l)

Removes the specified mouse listener so that it no longer receives mouse events from this component.

167

void removeMouseMotionListener(MouseMotionListener l)

Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.

168

void removeMouseWheelListener(MouseWheelListener l)

Removes the specified mouse wheel listener so that it no longer receives mouse wheel events from this component.

169

void removeNotify()

Makes this Component undisplayable by destroying it native screen resource.

170

void removePropertyChangeListener(PropertyChangeListener listener)

Removes a PropertyChangeListener from the listener list.

171

void remove Property ChangeListener(String propertyName, PropertyChange Listener listener)

Removes a PropertyChangeListener from the listener list for a specific property.

172

void repaint()

Repaints this component.

173

void repaint(int x,int y,int width,int height)

Repaints the specified rectangle of this component.

174

void repaint(long tm)

Repaints the component.

175

void repaint(long tm,int x,int y,int width,int height)

Repaints the specified rectangle of this component within tm milliseconds.

176

void requestFocus()

Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.

177

protected boolean requestFocus(boolean temporary)

Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.

178

boolean requestFocusInWindow()

Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.

179

protected boolean requestFocusInWindow(boolean temporary)

Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.

180

void reshape(int x,int y,int width,int height)

Deprecated. As of JDK version 1.1, replaced by setBounds(int, int, int, int).

181

void resize(Dimension d)

Deprecated. As of JDK version 1.1, replaced by setSize(Dimension).

182

void resize(int width,int height)

Deprecated. As of JDK version 1.1, replaced by setSize(int, int).

183

void setBackground(Color c)

Sets the background color of this component.

184

void setBounds(int x,int y,int width,int height)

Moves and resizes this component.

185

void setBounds(Rectangle r)

Moves and resizes this component to conform to the new bounding rectangle r.

186

void setComponentOrientation(ComponentOrientation o)

Sets the language-sensitive orientation that is to be used to order the elements or text within this component.

187

void setCursor(Cursor cursor)

Sets the cursor image to the specified cursor.

188

void setDropTarget(DropTarget dt)

Associate a DropTarget with this component.

189

void setEnabled(boolean b)

Enables or disables this component, depending on the value of the parameter b.

190

void setFocusable(boolean focusable)

Sets the focusable state of this Component to the specified value.

191

void setFocusTraversalKeys(int id, Set<? extends AWTKeyStroke> keystrokes)

Sets the focus traversal keys for a given traversal operation for this Component.

192

void setFocusTraversalKeysEnabled(boolean focusTraversalKeysEnabled)

Sets whether focus traversal keys are enabled for this Component.

193

void setFont(Font f)

Sets the font of this component.

194

void setForeground(Color c)

Sets the foreground color of this component.

195

void setIgnoreRepaint(boolean ignoreRepaint)

Sets whether or not paint messages received from the operating system should be ignored.

196

void setLocale(Locale l)

Sets the locale of this component.

197

void setLocation(int x,int y)

Moves this component to a new location.

198

void setLocation(Point p)

Moves this component to a new location.

199

void setMaximumSize(Dimension maximumSize)

Sets the maximum size of this component to a constant value.

200

void setMinimumSize(Dimension minimumSize)

Sets the minimum size of this component to a constant value.

201

void setName(String name)

Sets the name of the component to the specified string.

202

void setPreferredSize(Dimension preferredSize)

Sets the preferred size of this component to a constant value.

203

void 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.

205

void setVisible(boolean b)

Shows or hides this component depending on the value of parameter b.

206

void show()

Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).

207

void show(boolean b)

Deprecated. As of JDK version 1.1, replaced by setVisible(boolean).

208

Dimension size()

Deprecated. As of JDK version 1.1, replaced by getSize().

209

String toString()

Returns a string representation of this component and its values.

210

void transferFocus()

Transfers the focus to the next component, as though this Component were the focus owner.

211

void transferFocusBackward()

Transfers the focus to the previous component, as though this Component were the focus owner.

212

void transferFocusUpCycle()

Transfers the focus up one focus traversal cycle.

213

void update(Graphics g)

Updates this component.

214

void validate()

Ensures that this component has a valid layout.

215

Rectangle bounds()

Deprecated. As of JDK version 1.1, replaced by getBounds().

216

protected AWTEvent coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)

Potentially coalesce an event being posted with an existing event.

217

protected String paramString()

Returns a string representing the state of this component.

218

protected void firePropertyChange(String propertyName,int oldValue,int newValue)

Support for reporting bound property changes for integer properties.

219

Dimension preferredSize()

Deprecated. As of JDK version 1.1, replaced by getPreferredSize().

220

boolean prepareImage(Image image, ImageObserver observer)

Prepares an image for rendering on this component.

221

Dimension minimumSize()

Deprecated. As of JDK version 1.1, replaced by getMinimumSize().

Methods inherited

This class inherits methods from the following classes:

  • java.lang.Object


awt_controls.htm

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