JDK8/Java8源码在线阅读
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package java.awt;
import java.awt.RenderingHints.Key;
import java.awt.geom.AffineTransform;
import java.awt.image.ImageObserver;
import java.awt.image.BufferedImageOp;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.awt.image.renderable.RenderableImage;
import java.awt.font.GlyphVector;
import java.awt.font.FontRenderContext;
import java.awt.font.TextAttribute;
import java.text.AttributedCharacterIterator;
import java.util.Map;
/**
* This <code>Graphics2D</code> class extends the
* {@link 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.
* <p>
* <h2>Coordinate Spaces</h2>
* All coordinates passed to a <code>Graphics2D</code> object are specified
* in a device-independent coordinate system called User Space, which is
* used by applications. The <code>Graphics2D</code> object contains
* an {@link AffineTransform} object as part of its rendering state
* that defines how to convert coordinates from user space to
* device-dependent coordinates in Device Space.
* <p>
* Coordinates in device space usually refer to individual device pixels
* and are aligned on the infinitely thin gaps between these pixels.
* Some <code>Graphics2D</code> 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 <code>Graphics2D</code> <code>Transform</code> 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.
* <p>
* Some of the operations performed by the rendering attribute objects
* occur in the device space, but all <code>Graphics2D</code> methods take
* user space coordinates.
* <p>
* Every <code>Graphics2D</code> object is associated with a target that
* defines where rendering takes place. A
* {@link 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
* <code>Graphics2D</code> object.
* <p>
* When creating a <code>Graphics2D</code> object, the
* <code>GraphicsConfiguration</code>
* specifies the <a name="deftransform">default transform</a> for
* the target of the <code>Graphics2D</code> (a
* {@link Component} or {@link 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
* <code>Identity</code> transform.
*
* <h2>Rendering Process</h2>
* The Rendering Process can be broken down into four phases that are
* controlled by the <code>Graphics2D</code> 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.
* <p>
* The steps in the rendering process are:
* <ol>
* <li>
* Determine what to render.
* <li>
* Constrain the rendering operation to the current <code>Clip</code>.
* The <code>Clip</code> is specified by a {@link Shape} in user
* space and is controlled by the program using the various clip
* manipulation methods of <code>Graphics</code> and
* <code>Graphics2D</code>. This <i>user clip</i>
* is transformed into device space by the current
* <code>Transform</code> and combined with the
* <i>device clip</i>, which is defined by the visibility of windows and
* device extents. The combination of the user clip and device clip
* defines the <i>composite clip</i>, which determines the final clipping
* region. The user clip is not modified by the rendering
* system to reflect the resulting composite clip.
* <li>
* Determine what colors to render.
* <li>
* Apply the colors to the destination drawing surface using the current
* {@link Composite} attribute in the <code>Graphics2D</code> context.
* </ol>
* <br>
* The three types of rendering operations, along with details of each
* of their particular rendering processes are:
* <ol>
* <li>
* <b><a name="rendershape"><code>Shape</code> operations</a></b>
* <ol>
* <li>
* If the operation is a <code>draw(Shape)</code> operation, then
* the {@link Stroke#createStrokedShape(Shape) createStrokedShape}
* method on the current {@link Stroke} attribute in the
* <code>Graphics2D</code> context is used to construct a new
* <code>Shape</code> object that contains the outline of the specified
* <code>Shape</code>.
* <li>
* The <code>Shape</code> is transformed from user space to device space
* using the current <code>Transform</code>
* in the <code>Graphics2D</code> context.
* <li>
* The outline of the <code>Shape</code> is extracted using the
* {@link Shape#getPathIterator(AffineTransform) getPathIterator} method of
* <code>Shape</code>, which returns a
* {@link java.awt.geom.PathIterator PathIterator}
* object that iterates along the boundary of the <code>Shape</code>.
* <li>
* If the <code>Graphics2D</code> object cannot handle the curved segments
* that the <code>PathIterator</code> object returns then it can call the
* alternate
* {@link Shape#getPathIterator(AffineTransform, double) getPathIterator}
* method of <code>Shape</code>, which flattens the <code>Shape</code>.
* <li>
* The current {@link Paint} in the <code>Graphics2D</code> context
* is queried for a {@link PaintContext}, which specifies the
* colors to render in device space.
* </ol>
* <li>
* <b><a name=rendertext>Text operations</a></b>
* <ol>
* <li>
* The following steps are used to determine the set of glyphs required
* to render the indicated <code>String</code>:
* <ol>
* <li>
* If the argument is a <code>String</code>, then the current
* <code>Font</code> in the <code>Graphics2D</code> context is asked to
* convert the Unicode characters in the <code>String</code> into a set of
* glyphs for presentation with whatever basic layout and shaping
* algorithms the font implements.
* <li>
* If the argument is an
* {@link AttributedCharacterIterator},
* the iterator is asked to convert itself to a
* {@link java.awt.font.TextLayout TextLayout}
* using its embedded font attributes. The <code>TextLayout</code>
* implements more sophisticated glyph layout algorithms that
* perform Unicode bi-directional layout adjustments automatically
* for multiple fonts of differing writing directions.
* <li>
* If the argument is a
* {@link GlyphVector}, then the
* <code>GlyphVector</code> object already contains the appropriate
* font-specific glyph codes with explicit coordinates for the position of
* each glyph.
* </ol>
* <li>
* The current <code>Font</code> 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.
* <li>
* The character outlines are filled as indicated above
* under <a href="#rendershape"><code>Shape</code> operations</a>.
* <li>
* The current <code>Paint</code> is queried for a
* <code>PaintContext</code>, which specifies
* the colors to render in device space.
* </ol>
* <li>
* <b><a name= renderingimage><code>Image</code> Operations</a></b>
* <ol>
* <li>
* The region of interest is defined by the bounding box of the source
* <code>Image</code>.
* This bounding box is specified in Image Space, which is the
* <code>Image</code> object's local coordinate system.
* <li>
* If an <code>AffineTransform</code> is passed to
* {@link #drawImage(java.awt.Image, java.awt.geom.AffineTransform, java.awt.image.ImageObserver) drawImage(Image, AffineTransform, ImageObserver)},
* the <code>AffineTransform</code> is used to transform the bounding
* box from image space to user space. If no <code>AffineTransform</code>
* is supplied, the bounding box is treated as if it is already in user space.
* <li>
* The bounding box of the source <code>Image</code> is transformed from user
* space into device space using the current <code>Transform</code>.
* Note that the result of transforming the bounding box does not
* necessarily result in a rectangular region in device space.
* <li>
* The <code>Image</code> object determines what colors to render,
* sampled according to the source to destination
* coordinate mapping specified by the current <code>Transform</code> and the
* optional image transform.
* </ol>
* </ol>
*
* <h2>Default Rendering Attributes</h2>
* The default values for the <code>Graphics2D</code> rendering attributes are:
* <dl compact>
* <dt><i><code>Paint</code></i>
* <dd>The color of the <code>Component</code>.
* <dt><i><code>Font</code></i>
* <dd>The <code>Font</code> of the <code>Component</code>.
* <dt><i><code>Stroke</code></i>
* <dd>A square pen with a linewidth of 1, no dashing, miter segment joins
* and square end caps.
* <dt><i><code>Transform</code></i>
* <dd>The
* {@link GraphicsConfiguration#getDefaultTransform() getDefaultTransform}
* for the <code>GraphicsConfiguration</code> of the <code>Component</code>.
* <dt><i><code>Composite</code></i>
* <dd>The {@link AlphaComposite#SRC_OVER} rule.
* <dt><i><code>Clip</code></i>
* <dd>No rendering <code>Clip</code>, the output is clipped to the
* <code>Component</code>.
* </dl>
*
* <h2>Rendering Compatibility Issues</h2>
* 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.
* <p>
* 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
* {@link RenderingHints#KEY_ANTIALIASING KEY_ANTIALIASING} hint key
* to the
* {@link RenderingHints#VALUE_ANTIALIAS_OFF 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
* {@link RenderingHints#KEY_ANTIALIASING KEY_ANTIALIASING} hint
* key to
* {@link RenderingHints#VALUE_ANTIALIAS_ON 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.
* <p>
* 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 <code>draw</code> and
* <code>fill</code> methods are defined, which clearly indicates
* how <code>Graphics2D</code> extends <code>Graphics</code> based
* on settings of <code>Stroke</code> and <code>Transform</code>
* attributes and rendering hints. The definition
* performs identically under default attribute settings.
* For example, the default <code>Stroke</code> is a
* <code>BasicStroke</code> with a width of 1 and no dashing and the
* default Transform for screen drawing is an Identity transform.
* <p>
* The following two rules provide predictable rendering behavior whether
* aliasing or antialiasing is being used.
* <ul>
* <li> 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.
* <li> Lines and paths stroked using the <code>BasicStroke</code>
* 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 the
* {@link RenderingHints#KEY_STROKE_CONTROL KEY_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.
* </ul>
* <p>
* The following definitions of general legacy methods
* perform identically to previously specified behavior under default
* attribute settings:
* <ul>
* <li>
* For <code>fill</code> operations, including <code>fillRect</code>,
* <code>fillRoundRect</code>, <code>fillOval</code>,
* <code>fillArc</code>, <code>fillPolygon</code>, and
* <code>clearRect</code>, {@link #fill(Shape) fill} can now be called
* with the desired <code>Shape</code>. For example, when filling a
* rectangle:
* <pre>
* fill(new Rectangle(x, y, w, h));
* </pre>
* is called.
* <p>
* <li>
* Similarly, for draw operations, including <code>drawLine</code>,
* <code>drawRect</code>, <code>drawRoundRect</code>,
* <code>drawOval</code>, <code>drawArc</code>, <code>drawPolyline</code>,
* and <code>drawPolygon</code>, {@link #draw(Shape) draw} can now be
* called with the desired <code>Shape</code>. For example, when drawing a
* rectangle:
* <pre>
* draw(new Rectangle(x, y, w, h));
* </pre>
* is called.
* <p>
* <li>
* The <code>draw3DRect</code> and <code>fill3DRect</code> methods were
* implemented in terms of the <code>drawLine</code> and
* <code>fillRect</code> methods in the <code>Graphics</code> class which
* would predicate their behavior upon the current <code>Stroke</code>
* and <code>Paint</code> objects in a <code>Graphics2D</code> context.
* This class overrides those implementations with versions that use
* the current <code>Color</code> exclusively, overriding the current
* <code>Paint</code> and which uses <code>fillRect</code> to describe
* the exact same behavior as the preexisting methods regardless of the
* setting of the current <code>Stroke</code>.
* </ul>
* The <code>Graphics</code> class defines only the <code>setColor</code>
* method to control the color to be painted. Since the Java 2D API extends
* the <code>Color</code> object to implement the new <code>Paint</code>
* interface, the existing
* <code>setColor</code> method is now a convenience method for setting the
* current <code>Paint</code> attribute to a <code>Color</code> object.
* <code>setColor(c)</code> is equivalent to <code>setPaint(c)</code>.
* <p>
* The <code>Graphics</code> class defines two methods for controlling
* how colors are applied to the destination.
* <ol>
* <li>
* The <code>setPaintMode</code> method is implemented as a convenience
* method to set the default <code>Composite</code>, equivalent to
* <code>setComposite(new AlphaComposite.SrcOver)</code>.
* <li>
* The <code>setXORMode(Color xorcolor)</code> method is implemented
* as a convenience method to set a special <code>Composite</code> object that
* ignores the <code>Alpha</code> components of source colors and sets the
* destination color to the value:
* <pre>
* dstpixel = (PixelOf(srccolor) ^ PixelOf(xorcolor) ^ dstpixel);
* </pre>
* </ol>
*
* @author Jim Graham
* @see java.awt.RenderingHints
*/
public abstract class Graphics2D extends Graphics {
/**
* Constructs a new <code>Graphics2D</code> object. Since
* <code>Graphics2D</code> is an abstract class, and since it must be
* customized by subclasses for different output devices,
* <code>Graphics2D</code> objects cannot be created directly.
* Instead, <code>Graphics2D</code> objects must be obtained from another
* <code>Graphics2D</code> object, created by a
* <code>Component</code>, or obtained from images such as
* {@link BufferedImage} objects.
* @see java.awt.Component#getGraphics
* @see java.awt.Graphics#create
*/
protected Graphics2D() {
}
/**
* 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.
* <p>
* The colors used for the highlighting effect are determined
* based on the current color.
* The resulting rectangle covers an area that is
* <code>width + 1</code> pixels wide
* by <code>height + 1</code> pixels tall. This method
* uses the current <code>Color</code> exclusively and ignores
* the current <code>Paint</code>.
* @param x the x coordinate of the rectangle to be drawn.
* @param y the y coordinate of the rectangle to be drawn.
* @param width the width of the rectangle to be drawn.
* @param height the height of the rectangle to be drawn.
* @param raised a boolean that determines whether the rectangle
* appears to be raised above the surface
* or sunk into the surface.
* @see java.awt.Graphics#fill3DRect
*/
public void draw3DRect(int x, int y, int width, int height,
boolean raised) {
Paint p = getPaint();
Color c = getColor();
Color brighter = c.brighter();
Color darker = c.darker();
setColor(raised ? brighter : darker);
//drawLine(x, y, x, y + height);
fillRect(x, y, 1, height + 1);
//drawLine(x + 1, y, x + width - 1, y);
fillRect(x + 1, y, width - 1, 1);
setColor(raised ? darker : brighter);
//drawLine(x + 1, y + height, x + width, y + height);
fillRect(x + 1, y + height, width, 1);
//drawLine(x + width, y, x + width, y + height - 1);
fillRect(x + width, y, 1, height);
setPaint(p);
}
/**
* 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 <code>Color</code>. This method uses
* the current <code>Color</code> exclusively and ignores the current
* <code>Paint</code>.
* @param x the x coordinate of the rectangle to be filled.
* @param y the y coordinate of the rectangle to be filled.
* @param width the width of the rectangle to be filled.
* @param height the height of the rectangle to be filled.
* @param raised a boolean value that determines whether the
* rectangle appears to be raised above the surface
* or etched into the surface.
* @see java.awt.Graphics#draw3DRect
*/
public void fill3DRect(int x, int y, int width, int height,
boolean raised) {
Paint p = getPaint();
Color c = getColor();
Color brighter = c.brighter();
Color darker = c.darker();
if (!raised) {
setColor(darker);
} else if (p != c) {
setColor(c);
}
fillRect(x+1, y+1, width-2, height-2);
setColor(raised ? brighter : darker);
//drawLine(x, y, x, y + height - 1);
fillRect(x, y, 1, height);
//drawLine(x + 1, y, x + width - 2, y);
fillRect(x + 1, y, width - 2, 1);
setColor(raised ? darker : brighter);
//drawLine(x + 1, y + height - 1, x + width - 1, y + height - 1);
fillRect(x + 1, y + height - 1, width - 1, 1);
//drawLine(x + width - 1, y, x + width - 1, y + height - 2);
fillRect(x + width - 1, y, 1, height - 1);
setPaint(p);
}
/**
* Strokes the outline of a <code>Shape</code> using the settings of the
* current <code>Graphics2D</code> context. The rendering attributes
* applied include the <code>Clip</code>, <code>Transform</code>,
* <code>Paint</code>, <code>Composite</code> and
* <code>Stroke</code> attributes.
* @param s the <code>Shape</code> to be rendered
* @see #setStroke
* @see #setPaint
* @see java.awt.Graphics#setColor
* @see #transform
* @see #setTransform
* @see #clip
* @see #setClip
* @see #setComposite
*/
public abstract void draw(Shape s);
/**
* 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 <code>Transform</code> in the <code>Graphics2D</code>.
* The specified transformation is applied to the image before the
* transform attribute in the <code>Graphics2D</code> context is applied.
* The rendering attributes applied include the <code>Clip</code>,
* <code>Transform</code>, and <code>Composite</code> attributes.
* Note that no rendering is done if the specified transform is
* noninvertible.
* @param img the specified image to be rendered.
* This method does nothing if <code>img</code> is null.
* @param xform the transformation from image space into user space
* @param obs the {@link ImageObserver}
* to be notified as more of the <code>Image</code>
* is converted
* @return <code>true</code> if the <code>Image</code> is
* fully loaded and completely rendered, or if it's null;
* <code>false</code> if the <code>Image</code> is still being loaded.
* @see #transform
* @see #setTransform
* @see #setComposite
* @see #clip
* @see #setClip
*/
public abstract boolean drawImage(Image img,
AffineTransform xform,
ImageObserver obs);
/**
* Renders a <code>BufferedImage</code> that is
* filtered with a
* {@link BufferedImageOp}.
* The rendering attributes applied include the <code>Clip</code>,
* <code>Transform</code>
* and <code>Composite</code> attributes. This is equivalent to:
* <pre>
* img1 = op.filter(img, null);
* drawImage(img1, new AffineTransform(1f,0f,0f,1f,x,y), null);
* </pre>
* @param op the filter to be applied to the image before rendering
* @param img the specified <code>BufferedImage</code> to be rendered.
* This method does nothing if <code>img</code> is null.
* @param x the x coordinate of the location in user space where
* the upper left corner of the image is rendered
* @param y the y coordinate of the location in user space where
* the upper left corner of the image is rendered
*
* @see #transform
* @see #setTransform
* @see #setComposite
* @see #clip
* @see #setClip
*/
public abstract void drawImage(BufferedImage img,
BufferedImageOp op,
int x,
int y);
/**
* Renders a {@link 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 <code>Transform</code> in the <code>Graphics2D</code>.
* The specified transformation is applied to the image before the
* transform attribute in the <code>Graphics2D</code> context is applied.
* The rendering attributes applied include the <code>Clip</code>,
* <code>Transform</code>, and <code>Composite</code> attributes. Note
* that no rendering is done if the specified transform is
* noninvertible.
* @param img the image to be rendered. This method does
* nothing if <code>img</code> is null.
* @param xform the transformation from image space into user space
* @see #transform
* @see #setTransform
* @see #setComposite
* @see #clip
* @see #setClip
*/
public abstract void drawRenderedImage(RenderedImage img,
AffineTransform xform);
/**
* Renders a
* {@link 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 <code>Transform</code> in the <code>Graphics2D</code>.
* The specified transformation is applied to the image before the
* transform attribute in the <code>Graphics2D</code> context is applied.
* The rendering attributes applied include the <code>Clip</code>,
* <code>Transform</code>, and <code>Composite</code> attributes. Note
* that no rendering is done if the specified transform is
* noninvertible.
*<p>
* Rendering hints set on the <code>Graphics2D</code> object might
* be used in rendering the <code>RenderableImage</code>.
* If explicit control is required over specific hints recognized by a
* specific <code>RenderableImage</code>, or if knowledge of which hints
* are used is required, then a <code>RenderedImage</code> should be
* obtained directly from the <code>RenderableImage</code>
* and rendered using
*{@link #drawRenderedImage(RenderedImage, AffineTransform) drawRenderedImage}.
* @param img the image to be rendered. This method does
* nothing if <code>img</code> is null.
* @param xform the transformation from image space into user space
* @see #transform
* @see #setTransform
* @see #setComposite
* @see #clip
* @see #setClip
* @see #drawRenderedImage
*/
public abstract void drawRenderableImage(RenderableImage img,
AffineTransform xform);
/**
* Renders the text of the specified <code>String</code>, using the
* current text attribute state in the <code>Graphics2D</code> context.
* The baseline of the
* first character is at position (<i>x</i>, <i>y</i>) in
* the User Space.
* The rendering attributes applied include the <code>Clip</code>,
* <code>Transform</code>, <code>Paint</code>, <code>Font</code> and
* <code>Composite</code> 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.
* @param str the string to be rendered
* @param x the x coordinate of the location where the
* <code>String</code> should be rendered
* @param y the y coordinate of the location where the
* <code>String</code> should be rendered
* @throws NullPointerException if <code>str</code> is
* <code>null</code>
* @see java.awt.Graphics#drawBytes
* @see java.awt.Graphics#drawChars
* @since JDK1.0
*/
public abstract void drawString(String str, int x, int y);
/**
* Renders the text specified by the specified <code>String</code>,
* using the current text attribute state in the <code>Graphics2D</code> context.
* The baseline of the first character is at position
* (<i>x</i>, <i>y</i>) in the User Space.
* The rendering attributes applied include the <code>Clip</code>,
* <code>Transform</code>, <code>Paint</code>, <code>Font</code> and
* <code>Composite</code> 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.
* @param str the <code>String</code> to be rendered
* @param x the x coordinate of the location where the
* <code>String</code> should be rendered
* @param y the y coordinate of the location where the
* <code>String</code> should be rendered
* @throws NullPointerException if <code>str</code> is
* <code>null</code>
* @see #setPaint
* @see java.awt.Graphics#setColor
* @see java.awt.Graphics#setFont
* @see #setTransform
* @see #setComposite
* @see #setClip
*/
public abstract void drawString(String str, float x, float y);
/**
* Renders the text of the specified iterator applying its attributes
* in accordance with the specification of the {@link TextAttribute} class.
* <p>
* The baseline of the first character is at position
* (<i>x</i>, <i>y</i>) 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.
* @param iterator the iterator whose text is to be rendered
* @param x the x coordinate where the iterator's text is to be
* rendered
* @param y the y coordinate where the iterator's text is to be
* rendered
* @throws NullPointerException if <code>iterator</code> is
* <code>null</code>
* @see #setPaint
* @see java.awt.Graphics#setColor
* @see #setTransform
* @see #setComposite
* @see #setClip
*/
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 {@link TextAttribute} class.
* <p>
* The baseline of the first character is at position
* (<i>x</i>, <i>y</i>) 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.
* @param iterator the iterator whose text is to be rendered
* @param x the x coordinate where the iterator's text is to be
* rendered
* @param y the y coordinate where the iterator's text is to be
* rendered
* @throws NullPointerException if <code>iterator</code> is
* <code>null</code>
* @see #setPaint
* @see java.awt.Graphics#setColor
* @see #setTransform
* @see #setComposite
* @see #setClip
*/
public abstract void drawString(AttributedCharacterIterator iterator,
float x, float y);
/**
* Renders the text of the specified
* {@link GlyphVector} using
* the <code>Graphics2D</code> context's rendering attributes.
* The rendering attributes applied include the <code>Clip</code>,
* <code>Transform</code>, <code>Paint</code>, and
* <code>Composite</code> attributes. The <code>GlyphVector</code>
* specifies individual glyphs from a {@link Font}.
* The <code>GlyphVector</code> can also contain the glyph positions.
* This is the fastest way to render a set of characters to the
* screen.
* @param g the <code>GlyphVector</code> to be rendered
* @param x the x position in User Space where the glyphs should
* be rendered
* @param y the y position in User Space where the glyphs should
* be rendered
* @throws NullPointerException if <code>g</code> is <code>null</code>.
*
* @see java.awt.Font#createGlyphVector
* @see java.awt.font.GlyphVector
* @see #setPaint
* @see java.awt.Graphics#setColor
* @see #setTransform
* @see #setComposite
* @see #setClip
*/
public abstract void drawGlyphVector(GlyphVector g, float x, float y);
/**
* Fills the interior of a <code>Shape</code> using the settings of the
* <code>Graphics2D</code> context. The rendering attributes applied
* include the <code>Clip</code>, <code>Transform</code>,
* <code>Paint</code>, and <code>Composite</code>.
* @param s the <code>Shape</code> to be filled
* @see #setPaint
* @see java.awt.Graphics#setColor
* @see #transform
* @see #setTransform
* @see #setComposite
* @see #clip
* @see #setClip
*/
public abstract void fill(Shape s);
/**
* Checks whether or not the specified <code>Shape</code> intersects
* the specified {@link Rectangle}, which is in device
* space. If <code>onStroke</code> is false, this method checks
* whether or not the interior of the specified <code>Shape</code>
* intersects the specified <code>Rectangle</code>. If
* <code>onStroke</code> is <code>true</code>, this method checks
* whether or not the <code>Stroke</code> of the specified
* <code>Shape</code> outline intersects the specified
* <code>Rectangle</code>.
* The rendering attributes taken into account include the
* <code>Clip</code>, <code>Transform</code>, and <code>Stroke</code>
* attributes.
* @param rect the area in device space to check for a hit
* @param s the <code>Shape</code> to check for a hit
* @param onStroke flag used to choose between testing the
* stroked or the filled shape. If the flag is <code>true</code>, the
* <code>Stroke</code> outline is tested. If the flag is
* <code>false</code>, the filled <code>Shape</code> is tested.
* @return <code>true</code> if there is a hit; <code>false</code>
* otherwise.
* @see #setStroke
* @see #fill
* @see #draw
* @see #transform
* @see #setTransform
* @see #clip
* @see #setClip
*/
public abstract boolean hit(Rectangle rect,
Shape s,
boolean onStroke);
/**
* Returns the device configuration associated with this
* <code>Graphics2D</code>.
* @return the device configuration of this <code>Graphics2D</code>.
*/
public abstract GraphicsConfiguration getDeviceConfiguration();
/**
* Sets the <code>Composite</code> for the <code>Graphics2D</code> context.
* The <code>Composite</code> is used in all drawing methods such as
* <code>drawImage</code>, <code>drawString</code>, <code>draw</code>,
* and <code>fill</code>. It specifies how new pixels are to be combined
* with the existing pixels on the graphics device during the rendering
* process.
* <p>If this <code>Graphics2D</code> context is drawing to a
* <code>Component</code> on the display screen and the
* <code>Composite</code> is a custom object rather than an
* instance of the <code>AlphaComposite</code> class, and if
* there is a security manager, its <code>checkPermission</code>
* method is called with an <code>AWTPermission("readDisplayPixels")</code>
* permission.
* @throws SecurityException
* if a custom <code>Composite</code> object is being
* used to render to the screen and a security manager
* is set and its <code>checkPermission</code> method
* does not allow the operation.
* @param comp the <code>Composite</code> object to be used for rendering
* @see java.awt.Graphics#setXORMode
* @see java.awt.Graphics#setPaintMode
* @see #getComposite
* @see AlphaComposite
* @see SecurityManager#checkPermission
* @see java.awt.AWTPermission
*/
public abstract void setComposite(Composite comp);
/**
* Sets the <code>Paint</code> attribute for the
* <code>Graphics2D</code> context. Calling this method
* with a <code>null</code> <code>Paint</code> object does
* not have any effect on the current <code>Paint</code> attribute
* of this <code>Graphics2D</code>.
* @param paint the <code>Paint</code> object to be used to generate
* color during the rendering process, or <code>null</code>
* @see java.awt.Graphics#setColor
* @see #getPaint
* @see GradientPaint
* @see TexturePaint
*/
public abstract void setPaint( Paint paint );
/**
* Sets the <code>Stroke</code> for the <code>Graphics2D</code> context.
* @param s the <code>Stroke</code> object to be used to stroke a
* <code>Shape</code> during the rendering process
* @see BasicStroke
* @see #getStroke
*/
public abstract void setStroke(Stroke s);
/**
* 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
* <code>RenderingHints</code> class for definitions of some common
* keys and values.
* @param hintKey the key of the hint to be set.
* @param hintValue the value indicating preferences for the specified
* hint category.
* @see #getRenderingHint(RenderingHints.Key)
* @see RenderingHints
*/
public abstract void setRenderingHint(Key hintKey, Object hintValue);
/**
* 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
* <code>RenderingHints</code> class for definitions of some common
* keys and values.
* @param hintKey the key corresponding to the hint to get.
* @return an object representing the value for the specified hint key.
* Some of the keys and their associated values are defined in the
* <code>RenderingHints</code> class.
* @see RenderingHints
* @see #setRenderingHint(RenderingHints.Key, Object)
*/
public abstract Object getRenderingHint(Key hintKey);
/**
* Replaces the values of all preferences for the rendering
* algorithms with the specified <code>hints</code>.
* The existing values for all rendering hints are discarded and
* the new set of known hints and values are initialized from the
* specified {@link Map} object.
* Hint categories include controls for rendering quality and
* overall time/quality trade-off in the rendering process.
* Refer to the <code>RenderingHints</code> class for definitions of
* some common keys and values.
* @param hints the rendering hints to be set
* @see #getRenderingHints
* @see RenderingHints
*/
public abstract void setRenderingHints(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 <code>Map</code> 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 <code>RenderingHints</code> class for definitions of
* some common keys and values.
* @param hints the rendering hints to be set
* @see RenderingHints
*/
public abstract void addRenderingHints(Map<?,?> hints);
/**
* 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
* <code>RenderingHints</code> class for definitions of some common
* keys and values.
* @return a reference to an instance of <code>RenderingHints</code>
* that contains the current preferences.
* @see RenderingHints
* @see #setRenderingHints(Map)
*/
public abstract RenderingHints getRenderingHints();
/**
* Translates the origin of the <code>Graphics2D</code> context to the
* point (<i>x</i>, <i>y</i>) in the current coordinate system.
* Modifies the <code>Graphics2D</code> context so that its new origin
* corresponds to the point (<i>x</i>, <i>y</i>) in the
* <code>Graphics2D</code> context's former coordinate system. All
* coordinates used in subsequent rendering operations on this graphics
* context are relative to this new origin.
* @param x the specified x coordinate
* @param y the specified y coordinate
* @since JDK1.0
*/
public abstract void translate(int x, int y);
/**
* Concatenates the current
* <code>Graphics2D</code> <code>Transform</code>
* 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
* <code>AffineTransform</code> represented by the following matrix:
* <pre>
* [ 1 0 tx ]
* [ 0 1 ty ]
* [ 0 0 1 ]
* </pre>
* @param tx the distance to translate along the x-axis
* @param ty the distance to translate along the y-axis
*/
public abstract void translate(double tx, double ty);
/**
* Concatenates the current <code>Graphics2D</code>
* <code>Transform</code> with a rotation transform.
* Subsequent rendering is rotated by the specified radians relative
* to the previous origin.
* This is equivalent to calling <code>transform(R)</code>, where R is an
* <code>AffineTransform</code> represented by the following matrix:
* <pre>
* [ cos(theta) -sin(theta) 0 ]
* [ sin(theta) cos(theta) 0 ]
* [ 0 0 1 ]
* </pre>
* Rotating with a positive angle theta rotates points on the positive
* x axis toward the positive y axis.
* @param theta the angle of rotation in radians
*/
public abstract void rotate(double theta);
/**
* Concatenates the current <code>Graphics2D</code>
* <code>Transform</code> 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:
* <pre>
* translate(x, y);
* rotate(theta);
* translate(-x, -y);
* </pre>
* Rotating with a positive angle theta rotates points on the positive
* x axis toward the positive y axis.
* @param theta the angle of rotation in radians
* @param x the x coordinate of the origin of the rotation
* @param y the y coordinate of the origin of the rotation
*/
public abstract void rotate(double theta, double x, double y);
/**
* Concatenates the current <code>Graphics2D</code>
* <code>Transform</code> with a scaling transformation
* Subsequent rendering is resized according to the specified scaling
* factors relative to the previous scaling.
* This is equivalent to calling <code>transform(S)</code>, where S is an
* <code>AffineTransform</code> represented by the following matrix:
* <pre>
* [ sx 0 0 ]
* [ 0 sy 0 ]
* [ 0 0 1 ]
* </pre>
* @param sx the amount by which X coordinates in subsequent
* rendering operations are multiplied relative to previous
* rendering operations.
* @param sy the amount by which Y coordinates in subsequent
* rendering operations are multiplied relative to previous
* rendering operations.
*/
public abstract void scale(double sx, double sy);
/**
* Concatenates the current <code>Graphics2D</code>
* <code>Transform</code> with a shearing transform.
* Subsequent renderings are sheared by the specified
* multiplier relative to the previous position.
* This is equivalent to calling <code>transform(SH)</code>, where SH
* is an <code>AffineTransform</code> represented by the following
* matrix:
* <pre>
* [ 1 shx 0 ]
* [ shy 1 0 ]
* [ 0 0 1 ]
* </pre>
* @param shx the multiplier by which coordinates are shifted in
* the positive X axis direction as a function of their Y coordinate
* @param shy the multiplier by which coordinates are shifted in
* the positive Y axis direction as a function of their X coordinate
*/
public abstract void shear(double shx, double shy);
/**
* Composes an <code>AffineTransform</code> object with the
* <code>Transform</code> in this <code>Graphics2D</code> according
* to the rule last-specified-first-applied. If the current
* <code>Transform</code> is Cx, the result of composition
* with Tx is a new <code>Transform</code> Cx'. Cx' becomes the
* current <code>Transform</code> for this <code>Graphics2D</code>.
* Transforming a point p by the updated <code>Transform</code> Cx' is
* equivalent to first transforming p by Tx and then transforming
* the result by the original <code>Transform</code> 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.
* @param Tx the <code>AffineTransform</code> object to be composed with
* the current <code>Transform</code>
* @see #setTransform
* @see AffineTransform
*/
public abstract void transform(AffineTransform Tx);
/**
* Overwrites the Transform in the <code>Graphics2D</code> context.
* WARNING: This method should <b>never</b> be used to apply a new
* coordinate transform on top of an existing transform because the
* <code>Graphics2D</code> 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
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