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.
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Constrain the rendering operation to the current
Clip. TheClipis specified by aShapein user space and is controlled by the program using the various clip manipulation methods ofGraphicsandGraphics2D. This user clip is transformed into device space by the currentTransformand 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.
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Apply the colors to the destination drawing surface using the current
Compositeattribute in theGraphics2Dcontext.
The three types of rendering operations, along with details of each of their particular rendering processes are:
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Shapeoperations-
If the operation is a
draw(Shape)operation, then thecreateStrokedShapemethod on the currentStrokeattribute in theGraphics2Dcontext is used to construct a newShapeobject that contains the outline of the specifiedShape. -
The
Shapeis transformed from user space to device space using the currentTransformin theGraphics2Dcontext. -
The outline of the
Shapeis extracted using thegetPathIteratormethod ofShape, which returns aPathIteratorobject that iterates along the boundary of theShape. -
If the
Graphics2Dobject cannot handle the curved segments that thePathIteratorobject returns then it can call the alternategetPathIteratormethod ofShape, which flattens theShape. -
The current
Paintin theGraphics2Dcontext is queried for aPaintContext, which specifies the colors to render in device space.
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If the operation is a
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Text operations
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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 currentFontin theGraphics2Dcontext is asked to convert the Unicode characters in theStringinto 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 aTextLayoutusing its embedded font attributes. TheTextLayoutimplements 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 theGlyphVectorobject already contains the appropriate font-specific glyph codes with explicit coordinates for the position of each glyph.
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If the argument is a
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The current
Fontis 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
Shapeoperations. -
The current
Paintis queried for aPaintContext, which specifies the colors to render in device space.
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The following steps are used to determine the set of glyphs required
to render the indicated
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ImageOperations-
The region of interest is defined by the bounding box of the source
Image. This bounding box is specified in Image Space, which is theImageobject's local coordinate system. -
If an
AffineTransformis passed todrawImage(Image, AffineTransform, ImageObserver), theAffineTransformis used to transform the bounding box from image space to user space. If noAffineTransformis supplied, the bounding box is treated as if it is already in user space. -
The bounding box of the source
Imageis 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
Imageobject determines what colors to render, sampled according to the source to destination coordinate mapping specified by the currentTransformand the optional image transform.
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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
Fontof theComponent. Stroke- A square pen with a linewidth of 1, no dashing, miter segment joins and square end caps.
Transform- The
getDefaultTransformfor theGraphicsConfigurationof theComponent. Composite- The
AlphaComposite.SRC_OVERrule. 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
BasicStrokeobject 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_CONTROLhint. 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:
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For
filloperations, includingfillRect,fillRoundRect,fillOval,fillArc,fillPolygon, andclearRect,fillcan 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,drawcan now be called with the desiredShape. For example, when drawing a rectangle:draw(new Rectangle(x, y, w, h));
is called. -
The
draw3DRectandfill3DRectmethods were implemented in terms of thedrawLineandfillRectmethods in theGraphicsclass which would predicate their behavior upon the currentStrokeandPaintobjects in aGraphics2Dcontext. This class overrides those implementations with versions that use the currentColorexclusively, overriding the currentPaintand which usesfillRectto 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.
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The
setPaintModemethod 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 specialCompositeobject that ignores theAlphacomponents of source colors and sets the destination color to the value:dstpixel = (PixelOf(srccolor) ^ PixelOf(xorcolor) ^ dstpixel);
- See Also:
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionabstract voidaddRenderingHints(Map<?, ?> hints) Sets the values of an arbitrary number of preferences for the rendering algorithms.abstract voidIntersects the currentClipwith the interior of the specifiedShapeand sets theClipto the resulting intersection.abstract voidStrokes the outline of aShapeusing the settings of the currentGraphics2Dcontext.voiddraw3DRect(int x, int y, int width, int height, boolean raised) Draws a 3-D highlighted outline of the specified rectangle.abstract voiddrawGlyphVector(GlyphVector g, float x, float y) Renders the text of the specifiedGlyphVectorusing theGraphics2Dcontext's rendering attributes.abstract voiddrawImage(BufferedImage img, BufferedImageOp op, int x, int y) Renders aBufferedImagethat is filtered with aBufferedImageOp.abstract booleandrawImage(Image img, AffineTransform xform, ImageObserver obs) Renders an image, applying a transform from image space into user space before drawing.abstract voiddrawRenderableImage(RenderableImage img, AffineTransform xform) Renders aRenderableImage, applying a transform from image space into user space before drawing.abstract voiddrawRenderedImage(RenderedImage img, AffineTransform xform) Renders aRenderedImage, applying a transform from image space into user space before drawing.abstract voiddrawString(String str, float x, float y) Renders the text specified by the specifiedString, using the current text attribute state in theGraphics2Dcontext.abstract voiddrawString(String str, int x, int y) Renders the text of the specifiedString, using the current text attribute state in theGraphics2Dcontext.abstract voiddrawString(AttributedCharacterIterator iterator, float x, float y) Renders the text of the specified iterator applying its attributes in accordance with the specification of theTextAttributeclass.abstract voiddrawString(AttributedCharacterIterator iterator, int x, int y) Renders the text of the specified iterator applying its attributes in accordance with the specification of theTextAttributeclass.abstract voidFills the interior of aShapeusing the settings of theGraphics2Dcontext.voidfill3DRect(int x, int y, int width, int height, boolean raised) Paints a 3-D highlighted rectangle filled with the current color.abstract ColorReturns the background color used for clearing a region.abstract CompositeReturns the currentCompositein theGraphics2Dcontext.abstract GraphicsConfigurationReturns the device configuration associated with thisGraphics2D.abstract FontRenderContextGet the rendering context of theFontwithin thisGraphics2Dcontext.abstract PaintgetPaint()Returns the currentPaintof theGraphics2Dcontext.abstract ObjectgetRenderingHint(RenderingHints.Key hintKey) Returns the value of a single preference for the rendering algorithms.abstract RenderingHintsGets the preferences for the rendering algorithms.abstract StrokeReturns the currentStrokein theGraphics2Dcontext.abstract AffineTransformReturns a copy of the currentTransformin theGraphics2Dcontext.abstract booleanChecks whether or not the specifiedShapeintersects the specifiedRectangle, which is in device space.abstract voidrotate(double theta) Concatenates the currentGraphics2DTransformwith a rotation transform.abstract voidrotate(double theta, double x, double y) Concatenates the currentGraphics2DTransformwith a translated rotation transform.abstract voidscale(double sx, double sy) Concatenates the currentGraphics2DTransformwith a scaling transformation Subsequent rendering is resized according to the specified scaling factors relative to the previous scaling.abstract voidsetBackground(Color color) Sets the background color for theGraphics2Dcontext.abstract voidsetComposite(Composite comp) Sets theCompositefor theGraphics2Dcontext.abstract voidSets thePaintattribute for theGraphics2Dcontext.abstract voidsetRenderingHint(RenderingHints.Key hintKey, Object hintValue) Sets the value of a single preference for the rendering algorithms.abstract voidsetRenderingHints(Map<?, ?> hints) Replaces the values of all preferences for the rendering algorithms with the specifiedhints.abstract voidSets theStrokefor theGraphics2Dcontext.abstract voidOverwrites the Transform in theGraphics2Dcontext.abstract voidshear(double shx, double shy) Concatenates the currentGraphics2DTransformwith a shearing transform.abstract voidComposes anAffineTransformobject with theTransformin thisGraphics2Daccording to the rule last-specified-first-applied.abstract voidtranslate(double tx, double ty) Concatenates the currentGraphics2D Transformwith a translation transform.abstract voidtranslate(int x, int y) Translates the origin of theGraphics2Dcontext to the point (x, y) in the current coordinate system.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
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Constructor Details
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Graphics2D
protected Graphics2D()Constructs a newGraphics2Dobject. SinceGraphics2Dis an abstract class, and since it must be customized by subclasses for different output devices,Graphics2Dobjects cannot be created directly. Instead,Graphics2Dobjects must be obtained from anotherGraphics2Dobject, created by aComponent, or obtained from images such asBufferedImageobjects.- See Also:
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Method Details
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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 + 1pixels wide byheight + 1pixels tall. This method uses the currentColorexclusively and ignores the currentPaint.- Overrides:
draw3DRectin 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:
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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 currentColor. This method uses the currentColorexclusively and ignores the currentPaint.- Overrides:
fill3DRectin 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:
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draw
Strokes the outline of aShapeusing the settings of the currentGraphics2Dcontext. The rendering attributes applied include theClip,Transform,Paint,CompositeandStrokeattributes.- Parameters:
s- theShapeto be rendered- See Also:
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drawImage
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 currentTransformin theGraphics2D. The specified transformation is applied to the image before the transform attribute in theGraphics2Dcontext is applied. The rendering attributes applied include theClip,Transform, andCompositeattributes. Note that no rendering is done if the specified transform is noninvertible.- Parameters:
img- the specified image to be rendered. This method does nothing ifimgis null.xform- the transformation from image space into user spaceobs- theImageObserverto be notified as more of theImageis converted- Returns:
trueif theImageis fully loaded and completely rendered, or if it's null;falseif theImageis still being loaded.- See Also:
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drawImage
Renders aBufferedImagethat is filtered with aBufferedImageOp. The rendering attributes applied include theClip,TransformandCompositeattributes. 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 renderingimg- the specifiedBufferedImageto be rendered. This method does nothing ifimgis null.x- the x coordinate of the location in user space where the upper left corner of the image is renderedy- the y coordinate of the location in user space where the upper left corner of the image is rendered- See Also:
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drawRenderedImage
Renders aRenderedImage, applying a transform from image space into user space before drawing. The transformation from user space into device space is done with the currentTransformin theGraphics2D. The specified transformation is applied to the image before the transform attribute in theGraphics2Dcontext is applied. The rendering attributes applied include theClip,Transform, andCompositeattributes. Note that no rendering is done if the specified transform is noninvertible.- Parameters:
img- the image to be rendered. This method does nothing ifimgis null.xform- the transformation from image space into user space- See Also:
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drawRenderableImage
Renders aRenderableImage, applying a transform from image space into user space before drawing. The transformation from user space into device space is done with the currentTransformin theGraphics2D. The specified transformation is applied to the image before the transform attribute in theGraphics2Dcontext is applied. The rendering attributes applied include theClip,Transform, andCompositeattributes. Note that no rendering is done if the specified transform is noninvertible.Rendering hints set on the
Graphics2Dobject might be used in rendering theRenderableImage. If explicit control is required over specific hints recognized by a specificRenderableImage, or if knowledge of which hints are used is required, then aRenderedImageshould be obtained directly from theRenderableImageand rendered usingdrawRenderedImage.- Parameters:
img- the image to be rendered. This method does nothing ifimgis null.xform- the transformation from image space into user space- See Also:
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drawString
Renders the text of the specifiedString, using the current text attribute state in theGraphics2Dcontext. The baseline of the first character is at position (x, y) in the User Space. The rendering attributes applied include theClip,Transform,Paint,FontandCompositeattributes. 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:
drawStringin classGraphics- Parameters:
str- the string to be renderedx- the x coordinate of the location where theStringshould be renderedy- the y coordinate of the location where theStringshould be rendered- Throws:
NullPointerException- ifstrisnull- Since:
- 1.0
- See Also:
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drawString
Renders the text specified by the specifiedString, using the current text attribute state in theGraphics2Dcontext. The baseline of the first character is at position (x, y) in the User Space. The rendering attributes applied include theClip,Transform,Paint,FontandCompositeattributes. 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- theStringto be renderedx- the x coordinate of the location where theStringshould be renderedy- the y coordinate of the location where theStringshould be rendered- Throws:
NullPointerException- ifstrisnull- See Also:
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drawString
Renders the text of the specified iterator applying its attributes in accordance with the specification of theTextAttributeclass.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:
drawStringin classGraphics- Parameters:
iterator- the iterator whose text is to be renderedx- the x coordinate where the iterator's text is to be renderedy- the y coordinate where the iterator's text is to be rendered- Throws:
NullPointerException- ifiteratorisnull- See Also:
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drawString
Renders the text of the specified iterator applying its attributes in accordance with the specification of theTextAttributeclass.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 renderedx- the x coordinate where the iterator's text is to be renderedy- the y coordinate where the iterator's text is to be rendered- Throws:
NullPointerException- ifiteratorisnull- See Also:
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drawGlyphVector
Renders the text of the specifiedGlyphVectorusing theGraphics2Dcontext's rendering attributes. The rendering attributes applied include theClip,Transform,Paint, andCompositeattributes. TheGlyphVectorspecifies individual glyphs from aFont. TheGlyphVectorcan also contain the glyph positions. This is the fastest way to render a set of characters to the screen.- Parameters:
g- theGlyphVectorto be renderedx- the x position in User Space where the glyphs should be renderedy- the y position in User Space where the glyphs should be rendered- Throws:
NullPointerException- ifgisnull.- See Also:
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fill
Fills the interior of aShapeusing the settings of theGraphics2Dcontext. The rendering attributes applied include theClip,Transform,Paint, andComposite. -
hit
Checks whether or not the specifiedShapeintersects the specifiedRectangle, which is in device space. IfonStrokeis false, this method checks whether or not the interior of the specifiedShapeintersects the specifiedRectangle. IfonStrokeistrue, this method checks whether or not theStrokeof the specifiedShapeoutline intersects the specifiedRectangle. The rendering attributes taken into account include theClip,Transform, andStrokeattributes.- Parameters:
rect- the area in device space to check for a hits- theShapeto check for a hitonStroke- flag used to choose between testing the stroked or the filled shape. If the flag istrue, theStrokeoutline is tested. If the flag isfalse, the filledShapeis tested.- Returns:
trueif there is a hit;falseotherwise.- See Also:
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getDeviceConfiguration
Returns the device configuration associated with thisGraphics2D.- Returns:
- the device configuration of this
Graphics2D.
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setComposite
Sets theCompositefor theGraphics2Dcontext. TheCompositeis used in all drawing methods such asdrawImage,drawString,draw, andfill. It specifies how new pixels are to be combined with the existing pixels on the graphics device during the rendering process.If this
Graphics2Dcontext is drawing to aComponenton the display screen and theCompositeis a custom object rather than an instance of theAlphaCompositeclass, and if there is a security manager, itscheckPermissionmethod is called with anAWTPermission("readDisplayPixels")permission.- Parameters:
comp- theCompositeobject to be used for rendering- Throws:
SecurityException- if a customCompositeobject is being used to render to the screen and a security manager is set and itscheckPermissionmethod does not allow the operation.- See Also:
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setPaint
Sets thePaintattribute for theGraphics2Dcontext. Calling this method with anull Paintobject does not have any effect on the currentPaintattribute of thisGraphics2D.- Parameters:
paint- thePaintobject to be used to generate color during the rendering process, ornull- See Also:
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setStroke
Sets theStrokefor theGraphics2Dcontext.- Parameters:
s- theStrokeobject to be used to stroke aShapeduring the rendering process- See Also:
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setRenderingHint
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 theRenderingHintsclass 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:
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getRenderingHint
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 theRenderingHintsclass 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
RenderingHintsclass. - See Also:
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setRenderingHints
Replaces the values of all preferences for the rendering algorithms with the specifiedhints. The existing values for all rendering hints are discarded and the new set of known hints and values are initialized from the specifiedMapobject. Hint categories include controls for rendering quality and overall time/quality trade-off in the rendering process. Refer to theRenderingHintsclass for definitions of some common keys and values.- Parameters:
hints- the rendering hints to be set- See Also:
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addRenderingHints
Sets the values of an arbitrary number of preferences for the rendering algorithms. Only values for the rendering hints that are present in the specifiedMapobject 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 theRenderingHintsclass for definitions of some common keys and values.- Parameters:
hints- the rendering hints to be set- See Also:
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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 theRenderingHintsclass for definitions of some common keys and values.- Returns:
- a reference to an instance of
RenderingHintsthat contains the current preferences. - See Also:
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translate
public abstract void translate(int x, int y) Translates the origin of theGraphics2Dcontext to the point (x, y) in the current coordinate system. Modifies theGraphics2Dcontext so that its new origin corresponds to the point (x, y) in theGraphics2Dcontext's former coordinate system. All coordinates used in subsequent rendering operations on this graphics context are relative to this new origin. -
translate
public abstract void translate(double tx, double ty) Concatenates the currentGraphics2D Transformwith 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 anAffineTransformrepresented by the following matrix:[ 1 0 tx ] [ 0 1 ty ] [ 0 0 1 ]- Parameters:
tx- the distance to translate along the x-axisty- the distance to translate along the y-axis
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rotate
public abstract void rotate(double theta) Concatenates the currentGraphics2DTransformwith a rotation transform. Subsequent rendering is rotated by the specified radians relative to the previous origin. This is equivalent to callingtransform(R), where R is anAffineTransformrepresented 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
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rotate
public abstract void rotate(double theta, double x, double y) Concatenates the currentGraphics2DTransformwith 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 radiansx- the x coordinate of the origin of the rotationy- the y coordinate of the origin of the rotation
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scale
public abstract void scale(double sx, double sy) Concatenates the currentGraphics2DTransformwith a scaling transformation Subsequent rendering is resized according to the specified scaling factors relative to the previous scaling. This is equivalent to callingtransform(S), where S is anAffineTransformrepresented 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.
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shear
public abstract void shear(double shx, double shy) Concatenates the currentGraphics2DTransformwith a shearing transform. Subsequent renderings are sheared by the specified multiplier relative to the previous position. This is equivalent to callingtransform(SH), where SH is anAffineTransformrepresented 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 coordinateshy- the multiplier by which coordinates are shifted in the positive Y axis direction as a function of their X coordinate
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transform
Composes anAffineTransformobject with theTransformin thisGraphics2Daccording to the rule last-specified-first-applied. If the currentTransformis Cx, the result of composition with Tx is a newTransformCx'. Cx' becomes the currentTransformfor thisGraphics2D. Transforming a point p by the updatedTransformCx' is equivalent to first transforming p by Tx and then transforming the result by the originalTransformCx. 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- theAffineTransformobject to be composed with the currentTransform- See Also:
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setTransform
Overwrites the Transform in theGraphics2Dcontext. WARNING: This method should never be used to apply a new coordinate transform on top of an existing transform because theGraphics2Dmight 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, orshearmethods. ThesetTransformmethod is intended only for restoring the originalGraphics2Dtransform 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- theAffineTransformthat was retrieved from thegetTransformmethod- See Also:
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getTransform
Returns a copy of the currentTransformin theGraphics2Dcontext.- Returns:
- the current
AffineTransformin theGraphics2Dcontext. - See Also:
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getPaint
Returns the currentPaintof theGraphics2Dcontext.- Returns:
- the current
Graphics2D Paint, which defines a color or pattern. - See Also:
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getComposite
Returns the currentCompositein theGraphics2Dcontext.- Returns:
- the current
Graphics2D Composite, which defines a compositing style. - See Also:
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setBackground
Sets the background color for theGraphics2Dcontext. The background color is used for clearing a region. When aGraphics2Dis constructed for aComponent, the background color is inherited from theComponent. Setting the background color in theGraphics2Dcontext only affects the subsequentclearRectcalls and not the background color of theComponent. To change the background of theComponent, use appropriate methods of theComponent.- Parameters:
color- the background color that is used in subsequent calls toclearRect- See Also:
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getBackground
Returns the background color used for clearing a region.- Returns:
- the current
Graphics2D Color, which defines the background color. - See Also:
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getStroke
Returns the currentStrokein theGraphics2Dcontext.- Returns:
- the current
Graphics2D Stroke, which defines the line style. - See Also:
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clip
Intersects the currentClipwith the interior of the specifiedShapeand sets theClipto the resulting intersection. The specifiedShapeis transformed with the currentGraphics2DTransformbefore being intersected with the currentClip. This method is used to make the currentClipsmaller. To make theCliplarger, usesetClip.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
setClipwith anullargument, the specifiedShapebecomes the new user clip.Since this method intersects the specified shape with the current clip, it will throw
NullPointerExceptionfor anullshape unless the user clip is alsonull. So calling this method with anullargument is not recommended.- Parameters:
s- theShapeto be intersected with the currentClip. This method updates the currentClip.- Throws:
NullPointerException- ifsisnulland a user clip is currently set.
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getFontRenderContext
Get the rendering context of theFontwithin thisGraphics2Dcontext. TheFontRenderContextencapsulates 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 asFontandTextLayout. 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
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