public abstract class Graphics extends Object
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)
Modifier | Constructor and Description |
---|---|
protected |
Graphics()
Constructs a new
Graphics object. |
Modifier and Type | Method and Description |
---|---|
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)
Renders the text of the specified iterator applying its attributes
in accordance with the specification of the
TextAttribute class. |
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.
|
protected Graphics()
Graphics
object.
This constructor is the default constructor 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()
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 fontgetFont()
,
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.NullPointerException
- if str
is null
.drawBytes(byte[], int, int, int, int)
,
drawChars(char[], int, int, int, int)
public abstract void drawString(AttributedCharacterIterator iterator, int x, int y)
TextAttribute
class.
The baseline of the leftmost character is at position (x, y) in this graphics context's coordinate system.
iterator
- the iterator whose text is to be drawnx
- the x coordinate.y
- the y coordinate.NullPointerException
- if iterator
is
null
.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 textNullPointerException
- if data
is null
.IndexOutOfBoundsException
- if offset
or
length
is less than zero, or
offset+length
is greater than the length of the
data
array.drawBytes(byte[], int, int, int, int)
,
drawString(java.lang.String, int, int)
public void drawBytes(byte[] data, int offset, int length, int x, int y)
Use of this method is not recommended as each byte is interpreted as a Unicode code point in the range 0 to 255, and so can only be used to draw Latin characters in that range.
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 textNullPointerException
- if data
is null
.IndexOutOfBoundsException
- if offset
or
length
is less than zero, or offset+length
is greater than the length of the data
array.drawChars(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 completely loaded and its pixels are
no longer being changed, then
drawImage
returns true
.
Otherwise, drawImage
returns false
and as more of
the image becomes available
or it is time to draw another frame of animation,
the process that loads the image notifies
the specified image observer.
img
- the specified image to be drawn. This method does
nothing if img
is null.x
- the x coordinate.y
- the y coordinate.observer
- object to be notified as more of
the image is converted.false
if the image pixels are still changing;
true
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 loads 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. This method does
nothing if img
is null.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.false
if the image pixels are still changing;
true
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 completely loaded and its pixels are
no longer being changed, then
drawImage
returns true
.
Otherwise, drawImage
returns false
and as more of
the image becomes available
or it is time to draw another frame of animation,
the process that loads the image notifies
the specified image observer.
img
- the specified image to be drawn. This method does
nothing if img
is null.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.false
if the image pixels are still changing;
true
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 loads 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. This method does
nothing if img
is null.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.false
if the image pixels are still changing;
true
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 loads 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 drawn. This method does
nothing if img
is null.dx1
- 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.false
if the image pixels are still changing;
true
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 loads 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 drawn. This method does
nothing if img
is null.dx1
- 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.false
if the image pixels are still changing;
true
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.
public void finalize()
public String toString()
String
object representing this
Graphics
object's value.@Deprecated 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 cliptrue
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. Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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