java.lang.Object
java.awt.Graphics
The Graphics
class is the abstract base class for all
graphics contexts that allow an application to draw onto components
that are realized on various devices, as well as onto off-screen
images.
A Graphics
object encapsulates state information
needed for the basic rendering operations that Java supports. This
state information includes the following properties:
Component
object on which to draw. setXORMode(java.awt.Color)
).
Coordinates are infinitely thin and lie between the pixels of the output device. Operations that draw the outline of a figure operate by traversing an infinitely thin path between pixels with a pixel-sized pen that hangs down and to the right of the anchor point on the path. Operations that fill a figure operate by filling the interior of that infinitely thin path. Operations that render horizontal text render the ascending portion of character glyphs entirely above the baseline coordinate.
The graphics pen hangs down and to the right from the path it traverses. This has the following implications:
All coordinates that appear as arguments to the methods of this Graphics
object are considered relative to the translation origin of this Graphics
object prior to the invocation of the method.
All rendering operations modify only pixels which lie within the
area bounded by the current clip, which is specified by a Shape
in user space and
is controlled by the program using the Graphics
object.
This user clip is transformed into device space and combined
with the device clip, which is defined by the visibility of
windows and device extents. The combination of the user clip and device
clip defines the composite clip, which determines the final
clipping region. The user clip cannot be modified by the rendering
system to reflect the resulting composite clip. The user clip can only
be changed through the setClip
or clipRect
methods. All drawing or writing is done in the current color, using the
current paint mode, and in the current font.
Component
, clipRect(int,
int,
int, int)
, setColor(java.awt.Color)
,
setPaintMode()
,
setXORMode(java.awt.Color)
,
setFont(java.awt.Font)
Constructor Summary | |
protected
|
Graphics()
Constructs a new Graphics object. |
Method Summary | |
abstract
void |
clearRect(int x,
int y,
int width, int height) Clears the specified rectangle by filling it with the background color of the current drawing surface. |
abstract
void |
clipRect(int x,
int y,
int width, int height) Intersects the current clip with the specified rectangle. |
abstract
void |
copyArea(int x,
int y,
int width, int height, int dx, int dy) Copies an area of the component by a distance specified by dx and dy . |
abstract
Graphics |
create()
Creates a new Graphics object that is a copy of this Graphics
object. |
Graphics |
create(int x,
int y,
int width, int height) Creates a new Graphics object based on this Graphics
object, but with a new translation and clip area. |
abstract
void |
dispose()
Disposes of this graphics context and releases any system resources that it is using. |
void |
draw3DRect(int x,
int y,
int width, int height, boolean raised) Draws a 3-D highlighted outline of the specified rectangle. |
abstract
void |
drawArc(int x,
int y,
int width, int height, int startAngle,
int arcAngle) Draws the outline of a circular or elliptical arc covering the specified rectangle. |
void |
drawBytes(byte[] data,
int offset,
int length, int x, int y) Draws the text given by the specified byte array, using this graphics context's current font and color. |
void |
drawChars(char[] data,
int offset,
int length, int x, int y) Draws the text given by the specified character array, using this graphics context's current font and color. |
abstract
boolean |
drawImage(Image img, int x, int y, Color bgcolor, ImageObserver observer)
Draws as much of the specified image as is currently available. |
abstract
boolean |
drawImage(Image img, int x, int y, ImageObserver observer)
Draws as much of the specified image as is currently available. |
abstract
boolean |
drawImage(Image img, int x, int y,
int width, int height, Color bgcolor, ImageObserver observer)
Draws as much of the specified image as has already been scaled to fit inside the specified rectangle. |
abstract
boolean |
drawImage(Image img, int x, int y,
int width, int height, ImageObserver observer)
Draws as much of the specified image as has already been scaled to fit inside the specified rectangle. |
abstract
boolean |
drawImage(Image img, int dx1,
int dy1, int dx2, int dy2, int sx1, int sy1,
int sx2, int sy2, Color bgcolor, ImageObserver observer)
Draws as much of the specified area of the specified image as is currently available, scaling it on the fly to fit inside the specified area of the destination drawable surface. |
abstract
boolean |
drawImage(Image img, int dx1,
int dy1, int dx2, int dy2, int sx1, int sy1,
int sx2, int sy2, ImageObserver observer)
Draws as much of the specified area of the specified image as is currently available, scaling it on the fly to fit inside the specified area of the destination drawable surface. |
abstract
void |
drawLine(int x1,
int y1,
int x2, int y2) Draws a line, using the current color, between the points (x1, y1)
and (x2, y2) in this graphics context's coordinate
system. |
abstract
void |
drawOval(int x,
int y,
int width, int height) Draws the outline of an oval. |
abstract
void |
drawPolygon(int[] xPoints,
int[] yPoints,
int nPoints) Draws a closed polygon defined by arrays of x and y coordinates. |
void |
drawPolygon(Polygon p) Draws the outline of a polygon defined by the specified Polygon
object. |
abstract
void |
drawPolyline(int[] xPoints,
int[] yPoints,
int nPoints) Draws a sequence of connected lines defined by arrays of x and y coordinates. |
void |
drawRect(int x,
int y,
int width, int height) Draws the outline of the specified rectangle. |
abstract
void |
drawRoundRect(int x,
int y,
int width, int height, int arcWidth,
int arcHeight) Draws an outlined round-cornered rectangle using this graphics context's current color. |
abstract
void |
drawString(AttributedCharacterIterator iterator,
int x,
int y) Draws the text given by the specified iterator, using this graphics context's current color. |
abstract
void |
drawString(String str, int x, int y)
Draws the text given by the specified string, using this graphics context's current font and color. |
void |
fill3DRect(int x,
int y,
int width, int height, boolean raised) Paints a 3-D highlighted rectangle filled with the current color. |
abstract
void |
fillArc(int x,
int y,
int width, int height, int startAngle,
int arcAngle) Fills a circular or elliptical arc covering the specified rectangle. |
abstract
void |
fillOval(int x,
int y,
int width, int height) Fills an oval bounded by the specified rectangle with the current color. |
abstract
void |
fillPolygon(int[] xPoints,
int[] yPoints,
int nPoints) Fills a closed polygon defined by arrays of x and y coordinates. |
void |
fillPolygon(Polygon p) Fills the polygon defined by the specified Polygon object with the graphics context's current color. |
abstract
void |
fillRect(int x,
int y,
int width, int height) Fills the specified rectangle. |
abstract
void |
fillRoundRect(int x,
int y,
int width, int height, int arcWidth,
int arcHeight) Fills the specified rounded corner rectangle with the current color. |
void |
finalize()
Disposes of this graphics context once it is no longer referenced. |
abstract
Shape |
getClip()
Gets the current clipping area. |
abstract
Rectangle |
getClipBounds()
Returns the bounding rectangle of the current clipping area. |
Rectangle |
getClipBounds(Rectangle r) Returns the bounding rectangle of the current clipping area. |
Rectangle |
getClipRect()
Deprecated. As of JDK version 1.1, replaced by getClipBounds() . |
abstract
Color |
getColor()
Gets this graphics context's current color. |
abstract
Font |
getFont()
Gets the current font. |
FontMetrics |
getFontMetrics()
Gets the font metrics of the current font. |
abstract
FontMetrics |
getFontMetrics(Font f) Gets the font metrics for the specified font. |
boolean |
hitClip(int x,
int y,
int width, int height) Returns true if the specified rectangular area might intersect the current clipping area. |
abstract
void |
setClip(int x,
int y,
int width, int height) Sets the current clip to the rectangle specified by the given coordinates. |
abstract
void |
setClip(Shape clip) Sets the current clipping area to an arbitrary clip shape. |
abstract
void |
setColor(Color c) Sets this graphics context's current color to the specified color. |
abstract
void |
setFont(Font font) Sets this graphics context's font to the specified font. |
abstract
void |
setPaintMode()
Sets the paint mode of this graphics context to overwrite the destination with this graphics context's current color. |
abstract
void |
setXORMode(Color c1) Sets the paint mode of this graphics context to alternate between this graphics context's current color and the new specified color. |
String |
toString()
Returns a String
object representing this Graphics object's value. |
abstract
void |
translate(int x,
int y) Translates the origin of the graphics context to the point (x, y) in the current coordinate system. |
Methods inherited from class java.lang.Object |
clone,
equals,
getClass,
hashCode,
notify,
notifyAll,
wait,
wait,
wait |
Constructor Detail |
protected Graphics()
Graphics
object. This constructor
is the default contructor for a graphics context.
Since Graphics
is an abstract class, applications
cannot call this constructor directly. Graphics contexts are obtained
from other graphics contexts or are created by calling getGraphics
on a component.
create()
,
Component.getGraphics()
Method Detail |
public abstract Graphics create()
Graphics
object that is a copy of
this Graphics
object.
public Graphics create(int x,
int y,
int width,
int height)
Graphics
object based on this Graphics
object, but with a new translation and clip area. The new Graphics
object has its origin translated to the specified point (x, y).
Its
clip area is determined by the intersection of the original clip
area with the specified rectangle. The arguments are all interpreted in
the coordinate system of the original Graphics
object.
The new graphics context is identical to the original, except in two
respects:
0
, 0
) in the
new graphics context is the same as (x, y) in the
original graphics context. 0
, 0
), and its
size is specified by the width
and height
arguments. x
- the x coordinate.y
- the y coordinate.width
- the width of the clipping rectangle.height
- the height of the clipping rectangle. translate(int,
int)
, clipRect(int,
int,
int, int)
public abstract void translate(int x,
int y)
x
- the x coordinate.y
- the y coordinate.public abstract Color getColor()
Color
, setColor(Color)
public abstract void setColor(Color c)
c
- the new rendering color.Color
, getColor()
public abstract void setPaintMode()
public abstract void setXORMode(Color c1)
When drawing operations are performed, pixels which are the current color are changed to the specified color, and vice versa.
Pixels that are of colors other than those two colors are changed in an unpredictable but reversible manner; if the same figure is drawn twice, then all pixels are restored to their original values.
c1
- the XOR alternation colorpublic abstract Font getFont()
Font
, setFont(Font)
public abstract void setFont(Font font)
font
- the font.getFont()
,
drawString(java.lang.String,
int,
int)
, drawBytes(byte[],
int,
int, int, int)
, drawChars(char[],
int,
int, int, int)
public FontMetrics getFontMetrics()
getFont()
,
FontMetrics
, getFontMetrics(Font)
public abstract FontMetrics getFontMetrics(Font f)
f
- the specified font getFont()
,
FontMetrics
, getFontMetrics()
public abstract Rectangle getClipBounds()
setClip(null)
,
this
method returns null
. The coordinates in the
rectangle are relative to the coordinate system origin of this graphics
context.
null
if no clip is set.getClip()
,
clipRect(int,
int,
int, int)
, setClip(int,
int,
int, int)
, setClip(Shape)
public abstract void clipRect(int x,
int y,
int width,
int height)
setClip(null)
, the specified rectangle
becomes the new clip. This method sets the user clip, which is
independent of the clipping associated with device bounds and window
visibility. This method can only be used to make the current clip
smaller. To set the current clip larger, use any of the setClip
methods. Rendering operations have no effect outside of the clipping
area.
x
- the x coordinate of the rectangle to
intersect the clip withy
- the y coordinate of the rectangle to
intersect the clip withwidth
- the width of the rectangle to intersect
the clip withheight
- the height of the rectangle to
intersect the clip withsetClip(int,
int,
int, int)
, setClip(Shape)
public abstract void setClip(int x,
int y,
int width,
int height)
x
- the x coordinate of the new clip
rectangle.y
- the y coordinate of the new clip
rectangle.width
- the width of the new clip rectangle.height
- the height of the new clip rectangle.clipRect(int,
int,
int, int)
, setClip(Shape)
,
getClip()
public abstract Shape getClip()
setClip(null)
, this
method returns null
.
Shape
object representing the current
clipping area, or null
if no clip is set.getClipBounds()
,
clipRect(int,
int,
int, int)
, setClip(int,
int,
int, int)
, setClip(Shape)
public abstract void setClip(Shape clip)
Shape
interface can be
used to set the clip. The only Shape
objects that are
guaranteed to be supported are Shape
objects that are
obtained via the getClip
method and via Rectangle
objects. This method sets the user clip, which is independent of the
clipping associated with device bounds and window visibility.
clip
- the Shape
to use to set the
clipgetClip()
,
clipRect(int,
int,
int, int)
, setClip(int,
int,
int, int)
public abstract void copyArea(int x,
int y,
int width,
int height,
int dx,
int dy)
dx
and dy
. From the point specified by x
and y
,
this
method copies downwards and to the right. To copy an area of the
component to the left or upwards, specify a negative value for dx
or dy
. If a portion of the source rectangle lies outside
the bounds of the component, or is obscured by another window or
component, copyArea
will be unable to copy the associated
pixels. The area that is omitted can be refreshed by calling the
component's paint
method.
x
- the x coordinate of the source
rectangle.y
- the y coordinate of the source
rectangle.width
- the width of the source rectangle.height
- the height of the source rectangle.dx
- the horizontal distance to copy the pixels.dy
- the vertical distance to copy the pixels.public abstract void drawLine(int x1,
int y1,
int x2,
int y2)
(x1, y1)
and (x2, y2)
in this graphics context's coordinate
system.
x1
- the first point's x coordinate.y1
- the first point's y coordinate.x2
- the second point's x coordinate.y2
- the second point's y coordinate.public abstract void fillRect(int x,
int y,
int width,
int height)
x
and x + width - 1
.
The
top and bottom edges are at y
and y + height - 1
.
The
resulting rectangle covers an area width
pixels wide
by height
pixels tall. The rectangle is filled using the
graphics context's current color.
x
- the x coordinate of the rectangle to
be filled.y
- the y coordinate of the rectangle to
be filled.width
- the width of the rectangle to be filled.height
- the height of the rectangle to be
filled.clearRect(int,
int,
int, int)
, drawRect(int,
int,
int, int)
public void drawRect(int x,
int y,
int width,
int height)
x
and x + width
.
The
top and bottom edges are at y
and y + height
.
The
rectangle is drawn using the graphics context's current color.
x
- the x coordinate of the rectangle to
be drawn.y
- the y coordinate of the rectangle to
be drawn.width
- the width of the rectangle to be drawn.height
- the height of the rectangle to be drawn.fillRect(int,
int,
int, int)
, clearRect(int,
int,
int, int)
public abstract void clearRect(int x,
int y,
int width,
int height)
Beginning with Java 1.1, the background color of offscreen
images may be system dependent. Applications should use setColor
followed by fillRect
to ensure that an offscreen image is
cleared to a specific color.
x
- the x coordinate of the rectangle to
clear.y
- the y coordinate of the rectangle to
clear.width
- the width of the rectangle to clear.height
- the height of the rectangle to clear.fillRect(int,
int,
int, int)
, drawRect(int,
int,
int, int)
, setColor(java.awt.Color)
,
setPaintMode()
,
setXORMode(java.awt.Color)
public abstract void drawRoundRect(int x,
int y,
int width,
int height,
int arcWidth,
int arcHeight)
x
and x + width
, respectively.
The top and bottom edges of the rectangle are at y
and y + height
.
x
- the x coordinate of the rectangle to
be drawn.y
- the y coordinate of the rectangle to
be drawn.width
- the width of the rectangle to be drawn.height
- the height of the rectangle to be drawn.arcWidth
- the horizontal diameter of the arc at
the four corners.arcHeight
- the vertical diameter of the arc at
the four corners.fillRoundRect(int,
int,
int, int, int, int)
public abstract void fillRoundRect(int x,
int y,
int width,
int height,
int arcWidth,
int arcHeight)
x
and x + width - 1
, respectively. The
top and bottom edges of the rectangle are at y
and y + height - 1
.
x
- the x coordinate of the rectangle to
be filled.y
- the y coordinate of the rectangle to
be filled.width
- the width of the rectangle to be filled.height
- the height of the rectangle to be
filled.arcWidth
- the horizontal diameter of the arc at
the four corners.arcHeight
- the vertical diameter of the arc at
the four corners.drawRoundRect(int,
int,
int, int, int, int)
public void draw3DRect(int x,
int y,
int width,
int height,
boolean raised)
The colors used for the highlighting effect are determined
based on the current color. The resulting rectangle covers an area that
is width + 1
pixels wide by height + 1
pixels tall.
x
- the x coordinate of the rectangle to
be drawn.y
- the y coordinate of the rectangle to
be drawn.width
- the width of the rectangle to be drawn.height
- the height of the rectangle to be drawn.raised
- a boolean that determines whether the
rectangle appears to be raised above the surface or sunk into the
surface.fill3DRect(int,
int,
int, int, boolean)
public void fill3DRect(int x,
int y,
int width,
int height,
boolean raised)
x
- the x coordinate of the rectangle to
be filled.y
- the y coordinate of the rectangle to
be filled.width
- the width of the rectangle to be filled.height
- the height of the rectangle to be
filled.raised
- a boolean value that determines whether
the rectangle appears to be raised above the surface or etched into the
surface.draw3DRect(int,
int,
int, int, boolean)
public abstract void drawOval(int x,
int y,
int width,
int height)
x
, y
,
width
, and height
arguments.
The oval covers an area that is width + 1
pixels wide and height + 1
pixels tall.
x
- the x coordinate of the upper left
corner of the oval to be drawn.y
- the y coordinate of the upper left
corner of the oval to be drawn.width
- the width of the oval to be drawn.height
- the height of the oval to be drawn.fillOval(int,
int,
int, int)
public abstract void fillOval(int x,
int y,
int width,
int height)
x
- the x coordinate of the upper left
corner of the oval to be filled.y
- the y coordinate of the upper left
corner of the oval to be filled.width
- the width of the oval to be filled.height
- the height of the oval to be filled.drawOval(int,
int,
int, int)
public abstract void drawArc(int x,
int y,
int width,
int height,
int startAngle,
int arcAngle)
The resulting arc begins at startAngle
and
extends for arcAngle
degrees, using the current color.
Angles are interpreted such that 0 degrees is at the
3 o'clock position. A positive value indicates a counter-clockwise
rotation while a negative value indicates a clockwise rotation.
The center of the arc is the center of the rectangle whose
origin is (x, y) and whose size is specified by the width
and height
arguments.
The resulting arc covers an area width + 1
pixels wide by height + 1
pixels tall.
The angles are specified relative to the non-square extents of the bounding rectangle such that 45 degrees always falls on the line from the center of the ellipse to the upper right corner of the bounding rectangle. As a result, if the bounding rectangle is noticeably longer in one axis than the other, the angles to the start and end of the arc segment will be skewed farther along the longer axis of the bounds.
x
- the x coordinate of the upper-left
corner of the arc to be drawn.y
- the y coordinate of the upper-left
corner of the arc to be drawn.width
- the width of the arc to be drawn.height
- the height of the arc to be drawn.startAngle
- the beginning angle.arcAngle
- the angular extent of the arc,
relative to the start angle.fillArc(int,
int,
int, int, int, int)
public abstract void fillArc(int x,
int y,
int width,
int height,
int startAngle,
int arcAngle)
The resulting arc begins at startAngle
and
extends for arcAngle
degrees. Angles are interpreted such
that 0 degrees is at the 3 o'clock position. A positive value
indicates a counter-clockwise rotation while a negative value indicates
a clockwise rotation.
The center of the arc is the center of the rectangle whose
origin is (x, y) and whose size is specified by the width
and height
arguments.
The resulting arc covers an area width + 1
pixels wide by height + 1
pixels tall.
The angles are specified relative to the non-square extents of the bounding rectangle such that 45 degrees always falls on the line from the center of the ellipse to the upper right corner of the bounding rectangle. As a result, if the bounding rectangle is noticeably longer in one axis than the other, the angles to the start and end of the arc segment will be skewed farther along the longer axis of the bounds.
x
- the x coordinate of the upper-left
corner of the arc to be filled.y
- the y coordinate of the upper-left
corner of the arc to be filled.width
- the width of the arc to be filled.height
- the height of the arc to be filled.startAngle
- the beginning angle.arcAngle
- the angular extent of the arc,
relative to the start angle.drawArc(int,
int,
int, int, int, int)
public abstract void drawPolyline(int[] xPoints,
int[] yPoints,
int nPoints)
xPoints
- an array of x pointsyPoints
- an array of y pointsnPoints
- the total number of pointsdrawPolygon(int[],
int[],
int)
public abstract void drawPolygon(int[] xPoints,
int[] yPoints,
int nPoints)
This method draws the polygon defined by nPoint
line segments, where the first nPoint - 1
line
segments are line segments from (xPoints[i - 1], yPoints[i - 1])
to (xPoints[i], yPoints[i])
, for 1 ≤ i ≤ nPoints
.
The
figure is automatically closed by drawing a line connecting the
final point to the first point, if those points are different.
xPoints
- a an array of x
coordinates.yPoints
- a an array of y
coordinates.nPoints
- a the total number of points.fillPolygon(int[],
int[],
int)
, drawPolyline(int[],
int[],
int)
public void drawPolygon(Polygon p)
Polygon
object.
p
- the polygon to draw.fillPolygon(int[],
int[],
int)
, drawPolyline(int[],
int[],
int)
public abstract void fillPolygon(int[] xPoints,
int[] yPoints,
int nPoints)
This method draws the polygon defined by nPoint
line segments, where the first nPoint - 1
line
segments are line segments from (xPoints[i - 1], yPoints[i - 1])
to (xPoints[i], yPoints[i])
, for 1 ≤ i ≤ nPoints
.
The
figure is automatically closed by drawing a line connecting the
final point to the first point, if those points are different.
The area inside the polygon is defined using an even-odd fill rule, also known as the alternating rule.
xPoints
- a an array of x
coordinates.yPoints
- a an array of y
coordinates.nPoints
- a the total number of points.drawPolygon(int[],
int[],
int)
public void fillPolygon(Polygon p)
The area inside the polygon is defined using an even-odd fill rule, also known as the alternating rule.
p
- the polygon to fill.drawPolygon(int[],
int[],
int)
public abstract void drawString(String str,
int x,
int y)
str
- the string to be drawn.x
- the x coordinate.y
- the y coordinate.drawBytes(byte[],
int,
int, int, int)
, drawChars(char[],
int,
int, int, int)
public abstract void drawString(AttributedCharacterIterator iterator,
int x,
int y)
iterator
- the iterator whose text is to be drawnx
- the x coordinate.y
- the y coordinate.drawBytes(byte[],
int,
int, int, int)
, drawChars(char[],
int,
int, int, int)
public void drawChars(char[] data,
int offset,
int length,
int x,
int y)
data
- the array of characters to be drawnoffset
- the start offset in the datalength
- the number of characters to be drawnx
- the x coordinate of the baseline of
the texty
- the y coordinate of the baseline of
the textdrawBytes(byte[],
int,
int, int, int)
, drawString(java.lang.String,
int,
int)
public void drawBytes(byte[] data,
int offset,
int length,
int x,
int y)
data
- the data to be drawnoffset
- the start offset in the datalength
- the number of bytes that are drawnx
- the x coordinate of the baseline of
the texty
- the y coordinate of the baseline of
the textdrawChars(char[],
int,
int, int, int)
, drawString(java.lang.String,
int,
int)
public abstract boolean drawImage(Image img,
int x,
int y,
ImageObserver observer)
This method returns immediately in all cases, even if the complete image has not yet been loaded, and it has not been dithered and converted for the current output device.
If the image has not yet been completely loaded, then drawImage
returns false
. As more of the image becomes available,
the process that draws the image notifies the specified image observer.
img
- the specified image to be drawn.x
- the x coordinate.y
- the y coordinate.observer
- object to be notified as more of the
image is converted. true
if the image is completely loaded; false
otherwise.Image
, ImageObserver
, ImageObserver.imageUpdate(java.awt.Image,
int,
int, int, int, int)
public abstract boolean drawImage(Image img,
int x,
int y,
int width,
int height,
ImageObserver observer)
The image is drawn inside the specified rectangle of this graphics context's coordinate space, and is scaled if necessary. Transparent pixels do not affect whatever pixels are already there.
This method returns immediately in all cases, even if the
entire image has not yet been scaled, dithered, and converted for the
current output device. If the current output representation is not yet
complete, then drawImage
returns false
. As
more of the image becomes available, the process that draws the image
notifies the image observer by calling its imageUpdate
method.
A scaled version of an image will not necessarily be available immediately just because an unscaled version of the image has been constructed for this output device. Each size of the image may be cached separately and generated from the original data in a separate image production sequence.
img
- the specified image to be drawn.x
- the x coordinate.y
- the y coordinate.width
- the width of the rectangle.height
- the height of the rectangle.observer
- object to be notified as more of the
image is converted. true
if the current output representation is
complete; false
otherwise.Image
, ImageObserver
, ImageObserver.imageUpdate(java.awt.Image,
int,
int, int, int, int)
public abstract boolean drawImage(Image img,
int x,
int y,
Color bgcolor,
ImageObserver observer)
This operation is equivalent to filling a rectangle of the width and height of the specified image with the given color and then drawing the image on top of it, but possibly more efficient.
This method returns immediately in all cases, even if the complete image has not yet been loaded, and it has not been dithered and converted for the current output device.
If the image has not yet been completely loaded, then drawImage
returns false
. As more of the image becomes available,
the process that draws the image notifies the specified image observer.
img
- the specified image to be drawn.x
- the x coordinate.y
- the y coordinate.bgcolor
- the background color to paint under
the non-opaque portions of the image.observer
- object to be notified as more of the
image is converted. true
if the image is completely loaded; false
otherwise.Image
, ImageObserver
, ImageObserver.imageUpdate(java.awt.Image,
int,
int, int, int, int)
public abstract boolean drawImage(Image img,
int x,
int y,
int width,
int height,
Color bgcolor,
ImageObserver observer)
The image is drawn inside the specified rectangle of this graphics context's coordinate space, and is scaled if necessary. Transparent pixels are drawn in the specified background color. This operation is equivalent to filling a rectangle of the width and height of the specified image with the given color and then drawing the image on top of it, but possibly more efficient.
This method returns immediately in all cases, even if the
entire image has not yet been scaled, dithered, and converted for the
current output device. If the current output representation is not yet
complete then drawImage
returns false
. As
more of the image becomes available, the process that draws the image
notifies the specified image observer.
A scaled version of an image will not necessarily be available immediately just because an unscaled version of the image has been constructed for this output device. Each size of the image may be cached separately and generated from the original data in a separate image production sequence.
img
- the specified image to be drawn.x
- the x coordinate.y
- the y coordinate.width
- the width of the rectangle.height
- the height of the rectangle.bgcolor
- the background color to paint under
the non-opaque portions of the image.observer
- object to be notified as more of the
image is converted. true
if the current output representation is
complete; false
otherwise.Image
, ImageObserver
, ImageObserver.imageUpdate(java.awt.Image,
int,
int, int, int, int)
public abstract boolean drawImage(Image img,
int dx1,
int dy1,
int dx2,
int dy2,
int sx1,
int sy1,
int sx2,
int sy2,
ImageObserver observer)
This method returns immediately in all cases, even if the image
area to be drawn has not yet been scaled, dithered, and converted for
the current output device. If the current output representation is not
yet complete then drawImage
returns false
.
As more of the image becomes available, the process that draws the
image notifies the specified image observer.
This method always uses the unscaled version of the image to render the scaled rectangle and performs the required scaling on the fly. It does not use a cached, scaled version of the image for this operation. Scaling of the image from source to destination is performed such that the first coordinate of the source rectangle is mapped to the first coordinate of the destination rectangle, and the second source coordinate is mapped to the second destination coordinate. The subimage is scaled and flipped as needed to preserve those mappings.
img
- the specified image to be drawndx1
- the x coordinate of the first
corner of the destination rectangle.dy1
- the y coordinate of the first
corner of the destination rectangle.dx2
- the x coordinate of the second
corner of the destination rectangle.dy2
- the y coordinate of the second
corner of the destination rectangle.sx1
- the x coordinate of the first
corner of the source rectangle.sy1
- the y coordinate of the first
corner of the source rectangle.sx2
- the x coordinate of the second
corner of the source rectangle.sy2
- the y coordinate of the second
corner of the source rectangle.observer
- object to be notified as more of the
image is scaled and converted. true
if the current output representation is
complete; false
otherwise.Image
, ImageObserver
, ImageObserver.imageUpdate(java.awt.Image,
int,
int, int, int, int)
public abstract boolean drawImage(Image img,
int dx1,
int dy1,
int dx2,
int dy2,
int sx1,
int sy1,
int sx2,
int sy2,
Color bgcolor,
ImageObserver observer)
Transparent pixels are drawn in the specified background color. This operation is equivalent to filling a rectangle of the width and height of the specified image with the given color and then drawing the image on top of it, but possibly more efficient.
This method returns immediately in all cases, even if the image
area to be drawn has not yet been scaled, dithered, and converted for
the current output device. If the current output representation is not
yet complete then drawImage
returns false
.
As more of the image becomes available, the process that draws the
image notifies the specified image observer.
This method always uses the unscaled version of the image to render the scaled rectangle and performs the required scaling on the fly. It does not use a cached, scaled version of the image for this operation. Scaling of the image from source to destination is performed such that the first coordinate of the source rectangle is mapped to the first coordinate of the destination rectangle, and the second source coordinate is mapped to the second destination coordinate. The subimage is scaled and flipped as needed to preserve those mappings.
img
- the specified image to be drawndx1
- the x coordinate of the first
corner of the destination rectangle.dy1
- the y coordinate of the first
corner of the destination rectangle.dx2
- the x coordinate of the second
corner of the destination rectangle.dy2
- the y coordinate of the second
corner of the destination rectangle.sx1
- the x coordinate of the first
corner of the source rectangle.sy1
- the y coordinate of the first
corner of the source rectangle.sx2
- the x coordinate of the second
corner of the source rectangle.sy2
- the y coordinate of the second
corner of the source rectangle.bgcolor
- the background color to paint under
the non-opaque portions of the image.observer
- object to be notified as more of the
image is scaled and converted. true
if the current output representation is
complete; false
otherwise.Image
, ImageObserver
, ImageObserver.imageUpdate(java.awt.Image,
int,
int, int, int, int)
public abstract void dispose()
Graphics
object cannot be
used after dispose
has been called.
When a Java program runs, a large number of Graphics
objects can be created within a short time frame. Although the
finalization process of the garbage collector also disposes of the same
system resources, it is preferable to manually free the associated
resources by calling this method rather than to rely on a finalization
process which may not run to completion for a long period of time.
Graphics objects which are provided as arguments to the paint
and update
methods of components are automatically
released by the system when those methods return. For efficiency,
programmers should call dispose
when finished using a Graphics
object only if it was created directly from a component or another Graphics
object.
finalize()
,
Component.paint(java.awt.Graphics)
,
Component.update(java.awt.Graphics)
,
Component.getGraphics()
,
create()
public void finalize()
finalize
in class Object
dispose()
public String toString()
String
object representing this Graphics
object's value.
toString
in class Object
public Rectangle getClipRect()
getClipBounds()
.
null
if no clip is set.public boolean hitClip(int x,
int y,
int width,
int height)
x
- the x coordinate of the rectangle to test
against the clipy
- the y coordinate of the rectangle to test
against the clipwidth
- the width of the rectangle to test
against the clipheight
- the height of the rectangle to test
against the clip true
if the specified rectangle intersects the
bounds of the current clip; false
otherwise.public Rectangle getClipBounds(Rectangle r)
getClipBounds
in that an existing rectangle is used instead of allocating a new one.
This method refers to the user clip, which is independent of the
clipping associated with device bounds and window visibility. If no
clip has previously been set, or if the clip has been cleared using setClip(null)
,
this
method returns the specified Rectangle
.
r
- the rectangle where the current clipping
area is copied to. Any current values in this rectangle are
overwritten.