Class Graphics2D
- java.lang.Object
-
- java.awt.Graphics
-
- java.awt.Graphics2D
public abstract class Graphics2D extends Graphics
This Graphics2D
class extends the Graphics
class to provide more sophisticated control over geometry, coordinate transformations, color management, and text layout. This is the fundamental class for rendering 2-dimensional shapes, text and images on the Java(tm) platform.
Coordinate Spaces
All coordinates passed to aGraphics2D
object are specified in a device-independent coordinate system called User Space, which is used by applications. The Graphics2D
object contains an AffineTransform
object as part of its rendering state that defines how to convert coordinates from user space to device-dependent coordinates in Device Space.
Coordinates in device space usually refer to individual device pixels and are aligned on the infinitely thin gaps between these pixels. Some Graphics2D
objects can be used to capture rendering operations for storage into a graphics metafile for playback on a concrete device of unknown physical resolution at a later time. Since the resolution might not be known when the rendering operations are captured, the Graphics2D Transform
is set up to transform user coordinates to a virtual device space that approximates the expected resolution of the target device. Further transformations might need to be applied at playback time if the estimate is incorrect.
Some of the operations performed by the rendering attribute objects occur in the device space, but all Graphics2D
methods take user space coordinates.
Every Graphics2D
object is associated with a target that defines where rendering takes place. A GraphicsConfiguration
object defines the characteristics of the rendering target, such as pixel format and resolution. The same rendering target is used throughout the life of a Graphics2D
object.
When creating a Graphics2D
object, the GraphicsConfiguration
specifies the default transform for the target of the Graphics2D
(a Component
or Image
). This default transform maps the user space coordinate system to screen and printer device coordinates such that the origin maps to the upper left hand corner of the target region of the device with increasing X coordinates extending to the right and increasing Y coordinates extending downward. The scaling of the default transform is set to identity for those devices that are close to 72 dpi, such as screen devices. The scaling of the default transform is set to approximately 72 user space coordinates per square inch for high resolution devices, such as printers. For image buffers, the default transform is the Identity
transform.
Rendering Process
The Rendering Process can be broken down into four phases that are controlled by theGraphics2D
rendering attributes. The renderer can optimize many of these steps, either by caching the results for future calls, by collapsing multiple virtual steps into a single operation, or by recognizing various attributes as common simple cases that can be eliminated by modifying other parts of the operation. The steps in the rendering process are:
- Determine what to render.
- Constrain the rendering operation to the current
Clip
. TheClip
is specified by aShape
in user space and is controlled by the program using the various clip manipulation methods ofGraphics
andGraphics2D
. This user clip is transformed into device space by the currentTransform
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 is not modified by the rendering system to reflect the resulting composite clip. - Determine what colors to render.
- Apply the colors to the destination drawing surface using the current
Composite
attribute in theGraphics2D
context.
The three types of rendering operations, along with details of each of their particular rendering processes are:
-
Shape
operations- If the operation is a
draw(Shape)
operation, then thecreateStrokedShape
method on the currentStroke
attribute in theGraphics2D
context is used to construct a newShape
object that contains the outline of the specifiedShape
. - The
Shape
is transformed from user space to device space using the currentTransform
in theGraphics2D
context. - The outline of the
Shape
is extracted using thegetPathIterator
method ofShape
, which returns aPathIterator
object that iterates along the boundary of theShape
. - If the
Graphics2D
object cannot handle the curved segments that thePathIterator
object returns then it can call the alternategetPathIterator
method ofShape
, which flattens theShape
. - The current
Paint
in theGraphics2D
context is queried for aPaintContext
, which specifies the colors to render in device space.
- If the operation is a
- Text operations
- The following steps are used to determine the set of glyphs required to render the indicated
String
:- If the argument is a
String
, then the currentFont
in theGraphics2D
context is asked to convert the Unicode characters in theString
into a set of glyphs for presentation with whatever basic layout and shaping algorithms the font implements. - If the argument is an
AttributedCharacterIterator
, the iterator is asked to convert itself to aTextLayout
using its embedded font attributes. TheTextLayout
implements more sophisticated glyph layout algorithms that perform Unicode bi-directional layout adjustments automatically for multiple fonts of differing writing directions. - If the argument is a
GlyphVector
, then theGlyphVector
object already contains the appropriate font-specific glyph codes with explicit coordinates for the position of each glyph.
- If the argument is a
- The current
Font
is queried to obtain outlines for the indicated glyphs. These outlines are treated as shapes in user space relative to the position of each glyph that was determined in step 1. - The character outlines are filled as indicated above under
Shape
operations. - The current
Paint
is queried for aPaintContext
, which specifies the colors to render in device space.
- The following steps are used to determine the set of glyphs required to render the indicated
-
Image
Operations- The region of interest is defined by the bounding box of the source
Image
. This bounding box is specified in Image Space, which is theImage
object's local coordinate system. - If an
AffineTransform
is passed todrawImage(Image, AffineTransform, ImageObserver)
, theAffineTransform
is used to transform the bounding box from image space to user space. If noAffineTransform
is supplied, the bounding box is treated as if it is already in user space. - The bounding box of the source
Image
is transformed from user space into device space using the currentTransform
. Note that the result of transforming the bounding box does not necessarily result in a rectangular region in device space. - The
Image
object determines what colors to render, sampled according to the source to destination coordinate mapping specified by the currentTransform
and the optional image transform.
- The region of interest is defined by the bounding box of the source
Default Rendering Attributes
The default values for theGraphics2D
rendering attributes are: -
Paint
- The color of the
Component
. -
Font
- The
Font
of theComponent
. -
Stroke
- A square pen with a linewidth of 1, no dashing, miter segment joins and square end caps.
-
Transform
- The
getDefaultTransform
for theGraphicsConfiguration
of theComponent
. -
Composite
- The
AlphaComposite.SRC_OVER
rule. -
Clip
- No rendering
Clip
, the output is clipped to theComponent
.
Rendering Compatibility Issues
The JDK(tm) 1.1 rendering model is based on a pixelization model that specifies that coordinates are infinitely thin, lying between the pixels. Drawing operations are performed using a one-pixel wide pen that fills the pixel below and to the right of the anchor point on the path. The JDK 1.1 rendering model is consistent with the capabilities of most of the existing class of platform renderers that need to resolve integer coordinates to a discrete pen that must fall completely on a specified number of pixels. The Java 2D(tm) (Java(tm) 2 platform) API supports antialiasing renderers. A pen with a width of one pixel does not need to fall completely on pixel N as opposed to pixel N+1. The pen can fall partially on both pixels. It is not necessary to choose a bias direction for a wide pen since the blending that occurs along the pen traversal edges makes the sub-pixel position of the pen visible to the user. On the other hand, when antialiasing is turned off by setting the KEY_ANTIALIASING
hint key to the VALUE_ANTIALIAS_OFF
hint value, the renderer might need to apply a bias to determine which pixel to modify when the pen is straddling a pixel boundary, such as when it is drawn along an integer coordinate in device space. While the capabilities of an antialiasing renderer make it no longer necessary for the rendering model to specify a bias for the pen, it is desirable for the antialiasing and non-antialiasing renderers to perform similarly for the common cases of drawing one-pixel wide horizontal and vertical lines on the screen. To ensure that turning on antialiasing by setting the KEY_ANTIALIASING
hint key to VALUE_ANTIALIAS_ON
does not cause such lines to suddenly become twice as wide and half as opaque, it is desirable to have the model specify a path for such lines so that they completely cover a particular set of pixels to help increase their crispness.
Java 2D API maintains compatibility with JDK 1.1 rendering behavior, such that legacy operations and existing renderer behavior is unchanged under Java 2D API. Legacy methods that map onto general draw
and fill
methods are defined, which clearly indicates how Graphics2D
extends Graphics
based on settings of Stroke
and Transform
attributes and rendering hints. The definition performs identically under default attribute settings. For example, the default Stroke
is a BasicStroke
with a width of 1 and no dashing and the default Transform for screen drawing is an Identity transform.
The following two rules provide predictable rendering behavior whether aliasing or antialiasing is being used.
- Device coordinates are defined to be between device pixels which avoids any inconsistent results between aliased and antialiased rendering. If coordinates were defined to be at a pixel's center, some of the pixels covered by a shape, such as a rectangle, would only be half covered. With aliased rendering, the half covered pixels would either be rendered inside the shape or outside the shape. With anti-aliased rendering, the pixels on the entire edge of the shape would be half covered. On the other hand, since coordinates are defined to be between pixels, a shape like a rectangle would have no half covered pixels, whether or not it is rendered using antialiasing.
- Lines and paths stroked using the
BasicStroke
object may be "normalized" to provide consistent rendering of the outlines when positioned at various points on the drawable and whether drawn with aliased or antialiased rendering. This normalization process is controlled by theKEY_STROKE_CONTROL
hint. The exact normalization algorithm is not specified, but the goals of this normalization are to ensure that lines are rendered with consistent visual appearance regardless of how they fall on the pixel grid and to promote more solid horizontal and vertical lines in antialiased mode so that they resemble their non-antialiased counterparts more closely. A typical normalization step might promote antialiased line endpoints to pixel centers to reduce the amount of blending or adjust the subpixel positioning of non-antialiased lines so that the floating point line widths round to even or odd pixel counts with equal likelihood. This process can move endpoints by up to half a pixel (usually towards positive infinity along both axes) to promote these consistent results.
The following definitions of general legacy methods perform identically to previously specified behavior under default attribute settings:
- For
fill
operations, includingfillRect
,fillRoundRect
,fillOval
,fillArc
,fillPolygon
, andclearRect
,fill
can now be called with the desiredShape
. For example, when filling a rectangle:fill(new Rectangle(x, y, w, h));
is called. - Similarly, for draw operations, including
drawLine
,drawRect
,drawRoundRect
,drawOval
,drawArc
,drawPolyline
, anddrawPolygon
,draw
can now be called with the desiredShape
. For example, when drawing a rectangle:draw(new Rectangle(x, y, w, h));
is called. - The
draw3DRect
andfill3DRect
methods were implemented in terms of thedrawLine
andfillRect
methods in theGraphics
class which would predicate their behavior upon the currentStroke
andPaint
objects in aGraphics2D
context. This class overrides those implementations with versions that use the currentColor
exclusively, overriding the currentPaint
and which usesfillRect
to describe the exact same behavior as the preexisting methods regardless of the setting of the currentStroke
.
Graphics
class defines only the setColor
method to control the color to be painted. Since the Java 2D API extends the Color
object to implement the new Paint
interface, the existing setColor
method is now a convenience method for setting the current Paint
attribute to a Color
object. setColor(c)
is equivalent to setPaint(c)
. The Graphics
class defines two methods for controlling how colors are applied to the destination.
- The
setPaintMode
method is implemented as a convenience method to set the defaultComposite
, equivalent tosetComposite(new AlphaComposite.SrcOver)
. - The
setXORMode(Color xorcolor)
method is implemented as a convenience method to set a specialComposite
object that ignores theAlpha
components of source colors and sets the destination color to the value:dstpixel = (PixelOf(srccolor) ^ PixelOf(xorcolor) ^ dstpixel);
- See Also:
RenderingHints
Constructor Summary
Modifier | Constructor | Description |
---|---|---|
protected | Graphics2D() | Constructs a new |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
abstract void | addRenderingHints(Map<?,?> hints) | Sets the values of an arbitrary number of preferences for the rendering algorithms. |
abstract void | clip(Shape s) | Intersects the current |
abstract void | draw(Shape s) | Strokes the outline of a |
void | draw3DRect(int x,
int y,
int width,
int height,
boolean raised) | Draws a 3-D highlighted outline of the specified rectangle. |
abstract void | drawGlyphVector(GlyphVector g,
float x,
float y) | Renders the text of the specified |
abstract void | drawImage(BufferedImage img,
BufferedImageOp op,
int x,
int y) | Renders a |
abstract boolean | drawImage(Image img,
AffineTransform xform,
ImageObserver obs) | Renders an image, applying a transform from image space into user space before drawing. |
abstract void | drawRenderableImage(RenderableImage img,
AffineTransform xform) | Renders a |
abstract void | drawRenderedImage(RenderedImage img,
AffineTransform xform) | Renders a |
abstract void | drawString(String str,
float x,
float y) | Renders the text specified by the specified |
abstract void | drawString(String str,
int x,
int y) | Renders the text of the specified |
abstract void | drawString(AttributedCharacterIterator iterator,
float x,
float y) | Renders the text of the specified iterator applying its attributes in accordance with the specification of the |
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 |
abstract void | fill(Shape s) | Fills the interior of a |
void | fill3DRect(int x,
int y,
int width,
int height,
boolean raised) | Paints a 3-D highlighted rectangle filled with the current color. |
abstract Color | getBackground() | Returns the background color used for clearing a region. |
abstract Composite | getComposite() | Returns the current |
abstract GraphicsConfiguration | getDeviceConfiguration() | Returns the device configuration associated with this |
abstract FontRenderContext | getFontRenderContext() | Get the rendering context of the |
abstract Paint | getPaint() | Returns the current |
abstract Object | getRenderingHint(RenderingHints.Key hintKey) | Returns the value of a single preference for the rendering algorithms. |
abstract RenderingHints | getRenderingHints() | Gets the preferences for the rendering algorithms. |
abstract Stroke | getStroke() | Returns the current |
abstract AffineTransform | getTransform() | Returns a copy of the current |
abstract boolean | hit(Rectangle rect,
Shape s,
boolean onStroke) | Checks whether or not the specified |
abstract void | rotate(double theta) | Concatenates the current |
abstract void | rotate(double theta,
double x,
double y) | Concatenates the current |
abstract void | scale(double sx,
double sy) | Concatenates the current |
abstract void | setBackground(Color color) | Sets the background color for the |
abstract void | setComposite(Composite comp) | Sets the |
abstract void | setPaint(Paint paint) | Sets the |
abstract void | setRenderingHint(RenderingHints.Key hintKey,
Object hintValue) | Sets the value of a single preference for the rendering algorithms. |
abstract void | setRenderingHints(Map<?,?> hints) | Replaces the values of all preferences for the rendering algorithms with the specified |
abstract void | setStroke(Stroke s) | Sets the |
abstract void | setTransform(AffineTransform Tx) | Overwrites the Transform in the |
abstract void | shear(double shx,
double shy) | Concatenates the current |
abstract void | transform(AffineTransform Tx) | Composes an |
abstract void | translate(double tx,
double ty) | Concatenates the current |
abstract void | translate(int x,
int y) | Translates the origin of the |
Methods declared in class java.awt.Graphics
clearRect, clipRect, copyArea, create, create, dispose, drawArc, drawBytes, drawChars, drawImage, drawImage, drawImage, drawImage, drawImage, drawImage, drawLine, drawOval, drawPolygon, drawPolygon, drawPolyline, drawRect, drawRoundRect, fillArc, fillOval, fillPolygon, fillPolygon, fillRect, fillRoundRect, finalize, getClip, getClipBounds, getClipBounds, getClipRect, getColor, getFont, getFontMetrics, getFontMetrics, hitClip, setClip, setClip, setColor, setFont, setPaintMode, setXORMode, toString
Methods declared in class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
Constructor Detail
Graphics2D
protected Graphics2D()
Constructs a new Graphics2D
object. Since Graphics2D
is an abstract class, and since it must be customized by subclasses for different output devices, Graphics2D
objects cannot be created directly. Instead, Graphics2D
objects must be obtained from another Graphics2D
object, created by a Component
, or obtained from images such as BufferedImage
objects.
- See Also:
-
Component.getGraphics()
,Graphics.create()
Method Detail
draw3DRect
public void draw3DRect(int x, int y, int width, int height, boolean raised)
Draws a 3-D highlighted outline of the specified rectangle. The edges of the rectangle are highlighted so that they appear to be beveled and lit from the upper left corner.
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. This method uses the current Color
exclusively and ignores the current Paint
.
- Overrides:
-
draw3DRect
in classGraphics
- Parameters:
-
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. - See Also:
Graphics.fill3DRect(int, int, int, int, boolean)
fill3DRect
public void fill3DRect(int x, int y, int width, int height, boolean raised)
Paints a 3-D highlighted rectangle filled with the current color. The edges of the rectangle are highlighted so that it appears as if the edges were beveled and lit from the upper left corner. The colors used for the highlighting effect and for filling are determined from the current Color
. This method uses the current Color
exclusively and ignores the current Paint
.
- Overrides:
-
fill3DRect
in classGraphics
- Parameters:
-
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. - See Also:
Graphics.draw3DRect(int, int, int, int, boolean)
draw
public abstract void draw(Shape s)
Strokes the outline of a Shape
using the settings of the current Graphics2D
context. The rendering attributes applied include the Clip
, Transform
, Paint
, Composite
and Stroke
attributes.
- Parameters:
-
s
- theShape
to be rendered - See Also:
-
setStroke(java.awt.Stroke)
,setPaint(java.awt.Paint)
,Graphics.setColor(java.awt.Color)
,transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
,clip(java.awt.Shape)
,Graphics.setClip(int, int, int, int)
,setComposite(java.awt.Composite)
drawImage
public abstract boolean drawImage(Image img, AffineTransform xform, ImageObserver obs)
Renders an image, applying a transform from image space into user space before drawing. The transformation from user space into device space is done with the current Transform
in the Graphics2D
. The specified transformation is applied to the image before the transform attribute in the Graphics2D
context is applied. The rendering attributes applied include the Clip
, Transform
, and Composite
attributes. Note that no rendering is done if the specified transform is noninvertible.
- Parameters:
-
img
- the specified image to be rendered. This method does nothing ifimg
is null. -
xform
- the transformation from image space into user space -
obs
- theImageObserver
to be notified as more of theImage
is converted - Returns:
-
true
if theImage
is fully loaded and completely rendered, or if it's null;false
if theImage
is still being loaded. - See Also:
-
transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,clip(java.awt.Shape)
,Graphics.setClip(int, int, int, int)
drawImage
public abstract void drawImage(BufferedImage img, BufferedImageOp op, int x, int y)
Renders a BufferedImage
that is filtered with a BufferedImageOp
. The rendering attributes applied include the Clip
, Transform
and Composite
attributes. This is equivalent to:
img1 = op.filter(img, null); drawImage(img1, new AffineTransform(1f,0f,0f,1f,x,y), null);
- Parameters:
-
op
- the filter to be applied to the image before rendering -
img
- the specifiedBufferedImage
to be rendered. This method does nothing ifimg
is null. -
x
- the x coordinate of the location in user space where the upper left corner of the image is rendered -
y
- the y coordinate of the location in user space where the upper left corner of the image is rendered - See Also:
-
transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,clip(java.awt.Shape)
,Graphics.setClip(int, int, int, int)
drawRenderedImage
public abstract void drawRenderedImage(RenderedImage img, AffineTransform xform)
Renders a RenderedImage
, applying a transform from image space into user space before drawing. The transformation from user space into device space is done with the current Transform
in the Graphics2D
. The specified transformation is applied to the image before the transform attribute in the Graphics2D
context is applied. The rendering attributes applied include the Clip
, Transform
, and Composite
attributes. Note that no rendering is done if the specified transform is noninvertible.
- Parameters:
-
img
- the image to be rendered. This method does nothing ifimg
is null. -
xform
- the transformation from image space into user space - See Also:
-
transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,clip(java.awt.Shape)
,Graphics.setClip(int, int, int, int)
drawRenderableImage
public abstract void drawRenderableImage(RenderableImage img, AffineTransform xform)
Renders a RenderableImage
, applying a transform from image space into user space before drawing. The transformation from user space into device space is done with the current Transform
in the Graphics2D
. The specified transformation is applied to the image before the transform attribute in the Graphics2D
context is applied. The rendering attributes applied include the Clip
, Transform
, and Composite
attributes. Note that no rendering is done if the specified transform is noninvertible.
Rendering hints set on the Graphics2D
object might be used in rendering the RenderableImage
. If explicit control is required over specific hints recognized by a specific RenderableImage
, or if knowledge of which hints are used is required, then a RenderedImage
should be obtained directly from the RenderableImage
and rendered using drawRenderedImage
.
- Parameters:
-
img
- the image to be rendered. This method does nothing ifimg
is null. -
xform
- the transformation from image space into user space - See Also:
-
transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,clip(java.awt.Shape)
,Graphics.setClip(int, int, int, int)
,drawRenderedImage(java.awt.image.RenderedImage, java.awt.geom.AffineTransform)
drawString
public abstract void drawString(String str, int x, int y)
Renders the text of the specified String
, using the current text attribute state in the Graphics2D
context. The baseline of the first character is at position (x, y) in the User Space. The rendering attributes applied include the Clip
, Transform
, Paint
, Font
and Composite
attributes. For characters in script systems such as Hebrew and Arabic, the glyphs can be rendered from right to left, in which case the coordinate supplied is the location of the leftmost character on the baseline.
- Specified by:
-
drawString
in classGraphics
- Parameters:
-
str
- the string to be rendered -
x
- the x coordinate of the location where theString
should be rendered -
y
- the y coordinate of the location where theString
should be rendered - Throws:
-
NullPointerException
- ifstr
isnull
- Since:
- 1.0
- See Also:
-
Graphics.drawBytes(byte[], int, int, int, int)
,Graphics.drawChars(char[], int, int, int, int)
drawString
public abstract void drawString(String str, float x, float y)
Renders the text specified by the specified String
, using the current text attribute state in the Graphics2D
context. The baseline of the first character is at position (x, y) in the User Space. The rendering attributes applied include the Clip
, Transform
, Paint
, Font
and Composite
attributes. For characters in script systems such as Hebrew and Arabic, the glyphs can be rendered from right to left, in which case the coordinate supplied is the location of the leftmost character on the baseline.
- Parameters:
-
str
- theString
to be rendered -
x
- the x coordinate of the location where theString
should be rendered -
y
- the y coordinate of the location where theString
should be rendered - Throws:
-
NullPointerException
- ifstr
isnull
- See Also:
-
setPaint(java.awt.Paint)
,Graphics.setColor(java.awt.Color)
,Graphics.setFont(java.awt.Font)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,Graphics.setClip(int, int, int, int)
drawString
public 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.
The baseline of the first character is at position (x, y) in User Space. For characters in script systems such as Hebrew and Arabic, the glyphs can be rendered from right to left, in which case the coordinate supplied is the location of the leftmost character on the baseline.
- Specified by:
-
drawString
in classGraphics
- Parameters:
-
iterator
- the iterator whose text is to be rendered -
x
- the x coordinate where the iterator's text is to be rendered -
y
- the y coordinate where the iterator's text is to be rendered - Throws:
-
NullPointerException
- ifiterator
isnull
- See Also:
-
setPaint(java.awt.Paint)
,Graphics.setColor(java.awt.Color)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,Graphics.setClip(int, int, int, int)
drawString
public abstract void drawString(AttributedCharacterIterator iterator, float x, float y)
Renders the text of the specified iterator applying its attributes in accordance with the specification of the TextAttribute
class.
The baseline of the first character is at position (x, y) in User Space. For characters in script systems such as Hebrew and Arabic, the glyphs can be rendered from right to left, in which case the coordinate supplied is the location of the leftmost character on the baseline.
- Parameters:
-
iterator
- the iterator whose text is to be rendered -
x
- the x coordinate where the iterator's text is to be rendered -
y
- the y coordinate where the iterator's text is to be rendered - Throws:
-
NullPointerException
- ifiterator
isnull
- See Also:
-
setPaint(java.awt.Paint)
,Graphics.setColor(java.awt.Color)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,Graphics.setClip(int, int, int, int)
drawGlyphVector
public abstract void drawGlyphVector(GlyphVector g, float x, float y)
Renders the text of the specified GlyphVector
using the Graphics2D
context's rendering attributes. The rendering attributes applied include the Clip
, Transform
, Paint
, and Composite
attributes. The GlyphVector
specifies individual glyphs from a Font
. The GlyphVector
can also contain the glyph positions. This is the fastest way to render a set of characters to the screen.
- Parameters:
-
g
- theGlyphVector
to be rendered -
x
- the x position in User Space where the glyphs should be rendered -
y
- the y position in User Space where the glyphs should be rendered - Throws:
-
NullPointerException
- ifg
isnull
. - See Also:
-
Font.createGlyphVector(java.awt.font.FontRenderContext, java.lang.String)
,GlyphVector
,setPaint(java.awt.Paint)
,Graphics.setColor(java.awt.Color)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,Graphics.setClip(int, int, int, int)
fill
public abstract void fill(Shape s)
Fills the interior of a Shape
using the settings of the Graphics2D
context. The rendering attributes applied include the Clip
, Transform
, Paint
, and Composite
.
- Parameters:
-
s
- theShape
to be filled - See Also:
-
setPaint(java.awt.Paint)
,Graphics.setColor(java.awt.Color)
,transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
,setComposite(java.awt.Composite)
,clip(java.awt.Shape)
,Graphics.setClip(int, int, int, int)
hit
public abstract boolean hit(Rectangle rect, Shape s, boolean onStroke)
Checks whether or not the specified Shape
intersects the specified Rectangle
, which is in device space. If onStroke
is false, this method checks whether or not the interior of the specified Shape
intersects the specified Rectangle
. If onStroke
is true
, this method checks whether or not the Stroke
of the specified Shape
outline intersects the specified Rectangle
. The rendering attributes taken into account include the Clip
, Transform
, and Stroke
attributes.
- Parameters:
-
rect
- the area in device space to check for a hit -
s
- theShape
to check for a hit -
onStroke
- flag used to choose between testing the stroked or the filled shape. If the flag istrue
, theStroke
outline is tested. If the flag isfalse
, the filledShape
is tested. - Returns:
-
true
if there is a hit;false
otherwise. - See Also:
-
setStroke(java.awt.Stroke)
,fill(java.awt.Shape)
,draw(java.awt.Shape)
,transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
,clip(java.awt.Shape)
,Graphics.setClip(int, int, int, int)
getDeviceConfiguration
public abstract GraphicsConfiguration getDeviceConfiguration()
Returns the device configuration associated with this Graphics2D
.
- Returns:
- the device configuration of this
Graphics2D
.
setComposite
public abstract void setComposite(Composite comp)
Sets the Composite
for the Graphics2D
context. The Composite
is used in all drawing methods such as drawImage
, drawString
, draw
, and fill
. It specifies how new pixels are to be combined with the existing pixels on the graphics device during the rendering process.
If this Graphics2D
context is drawing to a Component
on the display screen and the Composite
is a custom object rather than an instance of the AlphaComposite
class, and if there is a security manager, its checkPermission
method is called with an AWTPermission("readDisplayPixels")
permission.
- Parameters:
-
comp
- theComposite
object to be used for rendering - Throws:
-
SecurityException
- if a customComposite
object is being used to render to the screen and a security manager is set and itscheckPermission
method does not allow the operation. - See Also:
-
Graphics.setXORMode(java.awt.Color)
,Graphics.setPaintMode()
,getComposite()
,AlphaComposite
,SecurityManager.checkPermission(java.security.Permission)
,AWTPermission
setPaint
public abstract void setPaint(Paint paint)
Sets the Paint
attribute for the Graphics2D
context. Calling this method with a null Paint
object does not have any effect on the current Paint
attribute of this Graphics2D
.
- Parameters:
-
paint
- thePaint
object to be used to generate color during the rendering process, ornull
- See Also:
-
Graphics.setColor(java.awt.Color)
,getPaint()
,GradientPaint
,TexturePaint
setStroke
public abstract void setStroke(Stroke s)
Sets the Stroke
for the Graphics2D
context.
- Parameters:
-
s
- theStroke
object to be used to stroke aShape
during the rendering process - See Also:
-
BasicStroke
,getStroke()
setRenderingHint
public abstract void setRenderingHint(RenderingHints.Key hintKey, Object hintValue)
Sets the value of a single preference for the rendering algorithms. Hint categories include controls for rendering quality and overall time/quality trade-off in the rendering process. Refer to the RenderingHints
class for definitions of some common keys and values.
- Parameters:
-
hintKey
- the key of the hint to be set. -
hintValue
- the value indicating preferences for the specified hint category. - See Also:
-
getRenderingHint(RenderingHints.Key)
,RenderingHints
getRenderingHint
public abstract Object getRenderingHint(RenderingHints.Key hintKey)
Returns the value of a single preference for the rendering algorithms. Hint categories include controls for rendering quality and overall time/quality trade-off in the rendering process. Refer to the RenderingHints
class for definitions of some common keys and values.
- Parameters:
-
hintKey
- the key corresponding to the hint to get. - Returns:
- an object representing the value for the specified hint key. Some of the keys and their associated values are defined in the
RenderingHints
class. - See Also:
-
RenderingHints
,setRenderingHint(RenderingHints.Key, Object)
setRenderingHints
public abstract void setRenderingHints(Map<?,?> hints)
Replaces the values of all preferences for the rendering algorithms with the specified hints
. The existing values for all rendering hints are discarded and the new set of known hints and values are initialized from the specified Map
object. Hint categories include controls for rendering quality and overall time/quality trade-off in the rendering process. Refer to the RenderingHints
class for definitions of some common keys and values.
- Parameters:
-
hints
- the rendering hints to be set - See Also:
-
getRenderingHints()
,RenderingHints
addRenderingHints
public abstract void addRenderingHints(Map<?,?> hints)
Sets the values of an arbitrary number of preferences for the rendering algorithms. Only values for the rendering hints that are present in the specified Map
object are modified. All other preferences not present in the specified object are left unmodified. Hint categories include controls for rendering quality and overall time/quality trade-off in the rendering process. Refer to the RenderingHints
class for definitions of some common keys and values.
- Parameters:
-
hints
- the rendering hints to be set - See Also:
RenderingHints
getRenderingHints
public abstract RenderingHints getRenderingHints()
Gets the preferences for the rendering algorithms. Hint categories include controls for rendering quality and overall time/quality trade-off in the rendering process. Returns all of the hint key/value pairs that were ever specified in one operation. Refer to the RenderingHints
class for definitions of some common keys and values.
- Returns:
- a reference to an instance of
RenderingHints
that contains the current preferences. - See Also:
-
RenderingHints
,setRenderingHints(Map)
translate
public abstract void translate(int x, int y)
Translates the origin of the Graphics2D
context to the point (x, y) in the current coordinate system. Modifies the Graphics2D
context so that its new origin corresponds to the point (x, y) in the Graphics2D
context's former coordinate system. All coordinates used in subsequent rendering operations on this graphics context are relative to this new origin.
- Specified by:
-
translate
in classGraphics
- Parameters:
-
x
- the specified x coordinate -
y
- the specified y coordinate - Since:
- 1.0
translate
public abstract void translate(double tx, double ty)
Concatenates the current Graphics2D Transform
with a translation transform. Subsequent rendering is translated by the specified distance relative to the previous position. This is equivalent to calling transform(T), where T is an AffineTransform
represented by the following matrix:
[ 1 0 tx ] [ 0 1 ty ] [ 0 0 1 ]
- Parameters:
-
tx
- the distance to translate along the x-axis -
ty
- the distance to translate along the y-axis
rotate
public abstract void rotate(double theta)
Concatenates the current Graphics2D
Transform
with a rotation transform. Subsequent rendering is rotated by the specified radians relative to the previous origin. This is equivalent to calling transform(R)
, where R is an AffineTransform
represented by the following matrix:
[ cos(theta) -sin(theta) 0 ] [ sin(theta) cos(theta) 0 ] [ 0 0 1 ]Rotating with a positive angle theta rotates points on the positive x axis toward the positive y axis.
- Parameters:
-
theta
- the angle of rotation in radians
rotate
public abstract void rotate(double theta, double x, double y)
Concatenates the current Graphics2D
Transform
with a translated rotation transform. Subsequent rendering is transformed by a transform which is constructed by translating to the specified location, rotating by the specified radians, and translating back by the same amount as the original translation. This is equivalent to the following sequence of calls:
translate(x, y); rotate(theta); translate(-x, -y);Rotating with a positive angle theta rotates points on the positive x axis toward the positive y axis.
- Parameters:
-
theta
- the angle of rotation in radians -
x
- the x coordinate of the origin of the rotation -
y
- the y coordinate of the origin of the rotation
scale
public abstract void scale(double sx, double sy)
Concatenates the current Graphics2D
Transform
with a scaling transformation Subsequent rendering is resized according to the specified scaling factors relative to the previous scaling. This is equivalent to calling transform(S)
, where S is an AffineTransform
represented by the following matrix:
[ sx 0 0 ] [ 0 sy 0 ] [ 0 0 1 ]
- Parameters:
-
sx
- the amount by which X coordinates in subsequent rendering operations are multiplied relative to previous rendering operations. -
sy
- the amount by which Y coordinates in subsequent rendering operations are multiplied relative to previous rendering operations.
shear
public abstract void shear(double shx, double shy)
Concatenates the current Graphics2D
Transform
with a shearing transform. Subsequent renderings are sheared by the specified multiplier relative to the previous position. This is equivalent to calling transform(SH)
, where SH is an AffineTransform
represented by the following matrix:
[ 1 shx 0 ] [ shy 1 0 ] [ 0 0 1 ]
- Parameters:
-
shx
- the multiplier by which coordinates are shifted in the positive X axis direction as a function of their Y coordinate -
shy
- the multiplier by which coordinates are shifted in the positive Y axis direction as a function of their X coordinate
transform
public abstract void transform(AffineTransform Tx)
Composes an AffineTransform
object with the Transform
in this Graphics2D
according to the rule last-specified-first-applied. If the current Transform
is Cx, the result of composition with Tx is a new Transform
Cx'. Cx' becomes the current Transform
for this Graphics2D
. Transforming a point p by the updated Transform
Cx' is equivalent to first transforming p by Tx and then transforming the result by the original Transform
Cx. In other words, Cx'(p) = Cx(Tx(p)). A copy of the Tx is made, if necessary, so further modifications to Tx do not affect rendering.
- Parameters:
-
Tx
- theAffineTransform
object to be composed with the currentTransform
- See Also:
-
setTransform(java.awt.geom.AffineTransform)
,AffineTransform
setTransform
public abstract void setTransform(AffineTransform Tx)
Overwrites the Transform in the Graphics2D
context. WARNING: This method should never be used to apply a new coordinate transform on top of an existing transform because the Graphics2D
might already have a transform that is needed for other purposes, such as rendering Swing components or applying a scaling transformation to adjust for the resolution of a printer.
To add a coordinate transform, use the transform
, rotate
, scale
, or shear
methods. The setTransform
method is intended only for restoring the original Graphics2D
transform after rendering, as shown in this example:
// Get the current transform AffineTransform saveAT = g2.getTransform(); // Perform transformation g2d.transform(...); // Render g2d.draw(...); // Restore original transform g2d.setTransform(saveAT);
- Parameters:
-
Tx
- theAffineTransform
that was retrieved from thegetTransform
method - See Also:
-
transform(java.awt.geom.AffineTransform)
,getTransform()
,AffineTransform
getTransform
public abstract AffineTransform getTransform()
Returns a copy of the current Transform
in the Graphics2D
context.
- Returns:
- the current
AffineTransform
in theGraphics2D
context. - See Also:
-
transform(java.awt.geom.AffineTransform)
,setTransform(java.awt.geom.AffineTransform)
getPaint
public abstract Paint getPaint()
Returns the current Paint
of the Graphics2D
context.
- Returns:
- the current
Graphics2D Paint
, which defines a color or pattern. - See Also:
-
setPaint(java.awt.Paint)
,Graphics.setColor(java.awt.Color)
getComposite
public abstract Composite getComposite()
Returns the current Composite
in the Graphics2D
context.
- Returns:
- the current
Graphics2D Composite
, which defines a compositing style. - See Also:
setComposite(java.awt.Composite)
setBackground
public abstract void setBackground(Color color)
Sets the background color for the Graphics2D
context. The background color is used for clearing a region. When a Graphics2D
is constructed for a Component
, the background color is inherited from the Component
. Setting the background color in the Graphics2D
context only affects the subsequent clearRect
calls and not the background color of the Component
. To change the background of the Component
, use appropriate methods of the Component
.
- Parameters:
-
color
- the background color that is used in subsequent calls toclearRect
- See Also:
-
getBackground()
,Graphics.clearRect(int, int, int, int)
getBackground
public abstract Color getBackground()
Returns the background color used for clearing a region.
- Returns:
- the current
Graphics2D Color
, which defines the background color. - See Also:
setBackground(java.awt.Color)
getStroke
public abstract Stroke getStroke()
Returns the current Stroke
in the Graphics2D
context.
- Returns:
- the current
Graphics2D Stroke
, which defines the line style. - See Also:
setStroke(java.awt.Stroke)
clip
public abstract void clip(Shape s)
Intersects the current Clip
with the interior of the specified Shape
and sets the Clip
to the resulting intersection. The specified Shape
is transformed with the current Graphics2D
Transform
before being intersected with the current Clip
. This method is used to make the current Clip
smaller. To make the Clip
larger, use setClip
. The user clip modified by this method is independent of the clipping associated with device bounds and visibility. If no clip has previously been set, or if the clip has been cleared using setClip
with a null
argument, the specified Shape
becomes the new user clip.
- Parameters:
-
s
- theShape
to be intersected with the currentClip
. Ifs
isnull
, this method clears the currentClip
.
getFontRenderContext
public abstract FontRenderContext getFontRenderContext()
Get the rendering context of the Font
within this Graphics2D
context. The FontRenderContext
encapsulates application hints such as anti-aliasing and fractional metrics, as well as target device specific information such as dots-per-inch. This information should be provided by the application when using objects that perform typographical formatting, such as Font
and TextLayout
. This information should also be provided by applications that perform their own layout and need accurate measurements of various characteristics of glyphs such as advance and line height when various rendering hints have been applied to the text rendering.
- Returns:
- a reference to an instance of FontRenderContext.
- Since:
- 1.2
- See Also:
-
FontRenderContext
,Font.createGlyphVector(java.awt.font.FontRenderContext, java.lang.String)
,TextLayout