java.awt.Graphics
is new.
java.lang.Object
public abstract class Graphics
The Graphics class is the abstract base class for all graphics contexts that allow an application to draw onto components that are realized on various devices, as well as onto off-screen images.
A Graphics object encapsulates state information needed for the basic rendering operations that Java supports. This state information includes the following properties:
Coordinates are infinitely thin and lie between the pixels of the output device. Operations that draw the outline of a figure operate by traversing an infinitely thin path between pixels with a pixel-sized pen that hangs down and to the right of the anchor point on the path. Operations that fill a figure operate by filling the interior of that infinitely thin path. Operations that render horizontal text render the ascending portion of character glyphs entirely above the baseline coordinate.
The graphics pen hangs down and to the right from the path it traverses. This has the following implications:
All coordinates that appear as arguments to the methods of this Graphics object are considered relative to the translation origin of this Graphics object prior to the invocation of the method.
All rendering operations modify only pixels which lie within the area bounded by the current clip, which is specified by a Shape in user space and is controlled by the program using the Graphics object. This user clip is transformed into device space and combined with the device clip , which is defined by the visibility of windows and device extents. The combination of the user clip and device clip defines the composite clip , which determines the final clipping region. The user clip cannot be modified by the rendering system to reflect the resulting composite clip. The user clip can only be changed through the setClip or clipRect methods. All drawing or writing is done in the current color, using the current paint mode, and in the current font.
| Constructor Summary | |
|---|---|
| protected |
Graphics
() Constructs a new Graphics object. |
| Method Summary | |
|---|---|
| abstract void |
clearRect
(int x, int y, int width, int height) Clears the specified rectangle by filling it with the background color of the current drawing surface. |
| abstract void |
clipRect
(int x, int y, int width, int height) Intersects the current clip with the specified rectangle. |
| abstract void |
copyArea
(int x, int y, int width, int height, int dx, int dy) Copies an area of the component by a distance specified by dx and dy. |
| abstract Graphics |
create
() Creates a new Graphics object that is a copy of this Graphics object. |
| Graphics |
create
(int x, int y, int width, int height) Creates a new Graphics object based on this Graphics object, but with a new translation and clip area. |
| abstract void |
dispose
() Disposes of this graphics context and releases any system resources that it is using. |
| void |
draw3DRect
(int x, int y, int width, int height, boolean raised) Draws a 3-D highlighted outline of the specified rectangle. |
| abstract void |
drawArc
(int x, int y, int width, int height, int startAngle, int arcAngle) Draws the outline of a circular or elliptical arc covering the specified rectangle. |
| void |
drawBytes
(byte[] data, int offset, int length, int x, int y) Draws the text given by the specified byte array, using this graphics context's current font and color. |
| void |
drawChars
(char[] data, int offset, int length, int x, int y) Draws the text given by the specified character array, using this graphics context's current font and color. |
| abstract boolean |
drawImage
(
Image
img, int x, int y,
Color
bgcolor,
ImageObserver
observer) Draws as much of the specified image as is currently available. |
| abstract boolean |
drawImage
(
Image
img, int x, int y,
ImageObserver
observer) Draws as much of the specified image as is currently available. |
| abstract boolean |
drawImage
(
Image
img, int x, int y, int width, int height,
Color
bgcolor,
ImageObserver
observer) Draws as much of the specified image as has already been scaled to fit inside the specified rectangle. |
| abstract boolean |
drawImage
(
Image
img, int x, int y, int width, int height,
ImageObserver
observer) Draws as much of the specified image as has already been scaled to fit inside the specified rectangle. |
| abstract boolean |
drawImage
(
Image
img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2,
Color
bgcolor,
ImageObserver
observer) Draws as much of the specified area of the specified image as is currently available, scaling it on the fly to fit inside the specified area of the destination drawable surface. |
| abstract boolean |
drawImage
(
Image
img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2,
ImageObserver
observer) Draws as much of the specified area of the specified image as is currently available, scaling it on the fly to fit inside the specified area of the destination drawable surface. |
| abstract void |
drawLine
(int x1, int y1, int x2, int y2) Draws a line, using the current color, between the points (x1, y1) and (x2, y2) in this graphics context's coordinate system. |
| abstract void |
drawOval
(int x, int y, int width, int height) Draws the outline of an oval. |
| abstract void |
drawPolygon
(int[] xPoints, int[] yPoints, int nPoints) Draws a closed polygon defined by arrays of x and y coordinates. |
| void |
drawPolygon
(
Polygon
p) Draws the outline of a polygon defined by the specified Polygon object. |
| abstract void |
drawPolyline
(int[] xPoints, int[] yPoints, int nPoints) Draws a sequence of connected lines defined by arrays of x and y coordinates. |
| void |
drawRect
(int x, int y, int width, int height) Draws the outline of the specified rectangle. |
| abstract void |
drawRoundRect
(int x, int y, int width, int height, int arcWidth, int arcHeight) Draws an outlined round-cornered rectangle using this graphics context's current color. |
| abstract void |
drawString
(
AttributedCharacterIterator
Renders the text of the specified iterator applying its attributes in accordance with the specification of the
TextAttribute
|
| abstract void |
drawString
(
String
str, int x, int y) Draws the text given by the specified string, using this graphics context's current font and color. |
| void |
fill3DRect
(int x, int y, int width, int height, boolean raised) Paints a 3-D highlighted rectangle filled with the current color. |
| abstract void |
fillArc
(int x, int y, int width, int height, int startAngle, int arcAngle) Fills a circular or elliptical arc covering the specified rectangle. |
| abstract void |
fillOval
(int x, int y, int width, int height) Fills an oval bounded by the specified rectangle with the current color. |
| abstract void |
fillPolygon
(int[] xPoints, int[] yPoints, int nPoints) Fills a closed polygon defined by arrays of x and y coordinates. |
| void |
fillPolygon
(
Polygon
p) Fills the polygon defined by the specified Polygon object with the graphics context's current color. |
| abstract void |
fillRect
(int x, int y, int width, int height) Fills the specified rectangle. |
| abstract void |
fillRoundRect
(int x, int y, int width, int height, int arcWidth, int arcHeight) Fills the specified rounded corner rectangle with the current color. |
| void |
finalize
() Disposes of this graphics context once it is no longer referenced. |
| abstract Shape |
getClip
() Gets the current clipping area. |
| abstract Rectangle |
getClipBounds
() Returns the bounding rectangle of the current clipping area. |
| Rectangle |
getClipBounds
(
Rectangle
r) Returns the bounding rectangle of the current clipping area. |
| Rectangle |
getClipRect
() Deprecated. As of JDK version 1.1, replaced by getClipBounds(). |
| abstract Color |
getColor
() Gets this graphics context's current color. |
| abstract Font |
getFont
() Gets the current font. |
| FontMetrics |
getFontMetrics
() Gets the font metrics of the current font. |
| abstract FontMetrics |
getFontMetrics
(
Font
f) Gets the font metrics for the specified font. |
| boolean |
hitClip
(int x, int y, int width, int height) Returns true if the specified rectangular area might intersect the current clipping area. |
| abstract void |
setClip
(int x, int y, int width, int height) Sets the current clip to the rectangle specified by the given coordinates. |
| abstract void |
setClip
(
Shape
clip) Sets the current clipping area to an arbitrary clip shape. |
| abstract void |
setColor
(
Color
c) Sets this graphics context's current color to the specified color. |
| abstract void |
setFont
(
Font
font) Sets this graphics context's font to the specified font. |
| abstract void |
setPaintMode
() Sets the paint mode of this graphics context to overwrite the destination with this graphics context's current color. |
| abstract void |
setXORMode
(
Color
c1) Sets the paint mode of this graphics context to alternate between this graphics context's current color and the new specified color. |
| String |
toString
() Returns a String object representing this Graphics object's value. |
| abstract void |
translate
(int x, int y) Translates the origin of the graphics context to the point ( x , y ) in the current coordinate system. |
| Methods inherited from class java.lang. Object |
|---|
| clone , equals , getClass , hashCode , notify , notifyAll , wait , wait , wait |
| Constructor Detail |
|---|
protected Graphics()
Since Graphics is an abstract class, applications cannot call this constructor directly. Graphics contexts are obtained from other graphics contexts or are created by calling getGraphics on a component.
| Method Detail |
|---|
public abstract Graphics create()
public Graphics create(int x,
int y,
int width,
int height)
public abstract void translate(int x,
int y)
public abstract Color getColor()
public abstract void setColor(Color c)
public abstract void setPaintMode()
public abstract void setXORMode(Color c1)
When drawing operations are performed, pixels which are the current color are changed to the specified color, and vice versa.
Pixels that are of colors other than those two colors are changed in an unpredictable but reversible manner; if the same figure is drawn twice, then all pixels are restored to their original values.
public abstract Font getFont()
public abstract void setFont(Font font)
public FontMetrics getFontMetrics()
public abstract FontMetrics getFontMetrics(Font f)
public abstract Rectangle getClipBounds()
public abstract void clipRect(int x,
int y,
int width,
int height)
public abstract void setClip(int x,
int y,
int width,
int height)
public abstract Shape getClip()
public abstract void setClip(Shape clip)
public abstract void copyArea(int x,
int y,
int width,
int height,
int dx,
int dy)
public abstract void drawLine(int x1,
int y1,
int x2,
int y2)
public abstract void fillRect(int x,
int y,
int width,
int height)
public void drawRect(int x,
int y,
int width,
int height)
public abstract void clearRect(int x,
int y,
int width,
int height)
Beginning with Java 1.1, the background color of offscreen images may be system dependent. Applications should use setColor followed by fillRect to ensure that an offscreen image is cleared to a specific color.
public abstract void drawRoundRect(int x,
int y,
int width,
int height,
int arcWidth,
int arcHeight)
public abstract void fillRoundRect(int x,
int y,
int width,
int height,
int arcWidth,
int arcHeight)
public void draw3DRect(int x,
int y,
int width,
int height,
boolean raised)
The colors used for the highlighting effect are determined based on the current color. The resulting rectangle covers an area that is width + 1 pixels wide by height + 1 pixels tall.
public void fill3DRect(int x,
int y,
int width,
int height,
boolean raised)
public abstract void drawOval(int x,
int y,
int width,
int height)
The oval covers an area that is width + 1 pixels wide and height + 1 pixels tall.
public abstract void fillOval(int x,
int y,
int width,
int height)
public abstract void drawArc(int x,
int y,
int width,
int height,
int startAngle,
int arcAngle)
The resulting arc begins at startAngle and extends for arcAngle degrees, using the current color. Angles are interpreted such that 0 degrees is at the 3 o'clock position. A positive value indicates a counter-clockwise rotation while a negative value indicates a clockwise rotation.
The center of the arc is the center of the rectangle whose origin is ( x , y ) and whose size is specified by the width and height arguments.
The resulting arc covers an area width + 1 pixels wide by height + 1 pixels tall.
The angles are specified relative to the non-square extents of the bounding rectangle such that 45 degrees always falls on the line from the center of the ellipse to the upper right corner of the bounding rectangle. As a result, if the bounding rectangle is noticeably longer in one axis than the other, the angles to the start and end of the arc segment will be skewed farther along the longer axis of the bounds.
public abstract void fillArc(int x,
int y,
int width,
int height,
int startAngle,
int arcAngle)
The resulting arc begins at startAngle and extends for arcAngle degrees. Angles are interpreted such that 0 degrees is at the 3 o'clock position. A positive value indicates a counter-clockwise rotation while a negative value indicates a clockwise rotation.
The center of the arc is the center of the rectangle whose origin is ( x , y ) and whose size is specified by the width and height arguments.
The resulting arc covers an area width + 1 pixels wide by height + 1 pixels tall.
The angles are specified relative to the non-square extents of the bounding rectangle such that 45 degrees always falls on the line from the center of the ellipse to the upper right corner of the bounding rectangle. As a result, if the bounding rectangle is noticeably longer in one axis than the other, the angles to the start and end of the arc segment will be skewed farther along the longer axis of the bounds.
public abstract void drawPolyline(int[] xPoints,
int[] yPoints,
int nPoints)
public abstract void drawPolygon(int[] xPoints,
int[] yPoints,
int nPoints)
This method draws the polygon defined by nPoint line segments, where the first nPoint - 1 line segments are line segments from (xPoints[i - 1], yPoints[i - 1]) to (xPoints[i], yPoints[i]), for 1 ≤ i ≤ nPoints. The figure is automatically closed by drawing a line connecting the final point to the first point, if those points are different.
public void drawPolygon(Polygon p)
public abstract void fillPolygon(int[] xPoints,
int[] yPoints,
int nPoints)
This method draws the polygon defined by nPoint line segments, where the first nPoint - 1 line segments are line segments from (xPoints[i - 1], yPoints[i - 1]) to (xPoints[i], yPoints[i]), for 1 ≤ i ≤ nPoints. The figure is automatically closed by drawing a line connecting the final point to the first point, if those points are different.
The area inside the polygon is defined using an even-odd fill rule, also known as the alternating rule.
public void fillPolygon(Polygon p)
The area inside the polygon is defined using an even-odd fill rule, also known as the alternating rule.
public abstract void drawString(String str,
int x,
int y)
public abstract void drawString(AttributedCharacterIterator iterator,
int x,
int y)
TextAttribute
The baseline of the leftmost character is at position ( x , y ) in this graphics context's coordinate system.
public void drawChars(char[] data,
int offset,
int length,
int x,
int y)
public void drawBytes(byte[] data,
int offset,
int length,
int x,
int y)
Use of this method is not recommended as each byte is interpreted as a Unicode code point in the range 0 to 255, and so can only be used to draw Latin characters in that range.
public abstract boolean drawImage(Image img,
int x,
int y,
ImageObserver observer)
This method returns immediately in all cases, even if the complete image has not yet been loaded, and it has not been dithered and converted for the current output device.
If the image has completely loaded and its pixels are no longer being changed, then drawImage returns true. Otherwise, drawImage returns false and as more of the image becomes available or it is time to draw another frame of animation, the process that loads the image notifies the specified image observer.
public abstract boolean drawImage(Image img,
int x,
int y,
int width,
int height,
ImageObserver observer)
The image is drawn inside the specified rectangle of this graphics context's coordinate space, and is scaled if necessary. Transparent pixels do not affect whatever pixels are already there.
This method returns immediately in all cases, even if the entire image has not yet been scaled, dithered, and converted for the current output device. If the current output representation is not yet complete, then drawImage returns false. As more of the image becomes available, the process that loads the image notifies the image observer by calling its imageUpdate method.
A scaled version of an image will not necessarily be available immediately just because an unscaled version of the image has been constructed for this output device. Each size of the image may be cached separately and generated from the original data in a separate image production sequence.
public abstract boolean drawImage(Image img,
int x,
int y,
Color bgcolor,
ImageObserver observer)
This operation is equivalent to filling a rectangle of the width and height of the specified image with the given color and then drawing the image on top of it, but possibly more efficient.
This method returns immediately in all cases, even if the complete image has not yet been loaded, and it has not been dithered and converted for the current output device.
If the image has completely loaded and its pixels are no longer being changed, then drawImage returns true. Otherwise, drawImage returns false and as more of the image becomes available or it is time to draw another frame of animation, the process that loads the image notifies the specified image observer.
public abstract boolean drawImage(Image img,
int x,
int y,
int width,
int height,
Color bgcolor,
ImageObserver observer)
The image is drawn inside the specified rectangle of this graphics context's coordinate space, and is scaled if necessary. Transparent pixels are drawn in the specified background color. This operation is equivalent to filling a rectangle of the width and height of the specified image with the given color and then drawing the image on top of it, but possibly more efficient.
This method returns immediately in all cases, even if the entire image has not yet been scaled, dithered, and converted for the current output device. If the current output representation is not yet complete then drawImage returns false. As more of the image becomes available, the process that loads the image notifies the specified image observer.
A scaled version of an image will not necessarily be available immediately just because an unscaled version of the image has been constructed for this output device. Each size of the image may be cached separately and generated from the original data in a separate image production sequence.
public abstract boolean drawImage(Image img,
int dx1,
int dy1,
int dx2,
int dy2,
int sx1,
int sy1,
int sx2,
int sy2,
ImageObserver observer)
This method returns immediately in all cases, even if the image area to be drawn has not yet been scaled, dithered, and converted for the current output device. If the current output representation is not yet complete then drawImage returns false. As more of the image becomes available, the process that loads the image notifies the specified image observer.
This method always uses the unscaled version of the image to render the scaled rectangle and performs the required scaling on the fly. It does not use a cached, scaled version of the image for this operation. Scaling of the image from source to destination is performed such that the first coordinate of the source rectangle is mapped to the first coordinate of the destination rectangle, and the second source coordinate is mapped to the second destination coordinate. The subimage is scaled and flipped as needed to preserve those mappings.
public abstract boolean drawImage(Image img,
int dx1,
int dy1,
int dx2,
int dy2,
int sx1,
int sy1,
int sx2,
int sy2,
Color bgcolor,
ImageObserver observer)
Transparent pixels are drawn in the specified background color. This operation is equivalent to filling a rectangle of the width and height of the specified image with the given color and then drawing the image on top of it, but possibly more efficient.
This method returns immediately in all cases, even if the image area to be drawn has not yet been scaled, dithered, and converted for the current output device. If the current output representation is not yet complete then drawImage returns false. As more of the image becomes available, the process that loads the image notifies the specified image observer.
This method always uses the unscaled version of the image to render the scaled rectangle and performs the required scaling on the fly. It does not use a cached, scaled version of the image for this operation. Scaling of the image from source to destination is performed such that the first coordinate of the source rectangle is mapped to the first coordinate of the destination rectangle, and the second source coordinate is mapped to the second destination coordinate. The subimage is scaled and flipped as needed to preserve those mappings.
public abstract void dispose()
When a Java program runs, a large number of Graphics objects can be created within a short time frame. Although the finalization process of the garbage collector also disposes of the same system resources, it is preferable to manually free the associated resources by calling this method rather than to rely on a finalization process which may not run to completion for a long period of time.
Graphics objects which are provided as arguments to the paint and update methods of components are automatically released by the system when those methods return. For efficiency, programmers should call dispose when finished using a Graphics object only if it was created directly from a component or another Graphics object.
public void finalize()
public String toString()
@Deprecated public Rectangle getClipRect()
public boolean hitClip(int x,
int y,
int width,
int height)
public Rectangle getClipBounds(Rectangle r)