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| Package java.awt |
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public abstract class java.awt.Graphics
extends java.lang.Object
{
// Constructors
protected Graphics();
// Methods
public abstract void clearRect(int x, int y,
int width, int height);
public abstract void clipRect(int x, int y,
int width, int height);
public abstract void
copyArea(int x, int y, int width,
int height, int dx, int dy);
public abstract Graphics create();
public Graphics create(int x, int y,
int width, int height);
public abstract void dispose();
public void draw3DRect(int x, int y, int width,
int height, boolean raised);
public abstract voiddrawArc(int x, int y, int width,
int height, int startAngle,
int arcAngle);
public void drawBytes(byte data[], int offset,
int length, int x, int y);
public void drawChars(char data[], int offset,
int length, int x, int y);
public abstract boolean
drawImage(Image img, int x, int y, Color bgcolor,
ImageObserver observer);
public abstract boolean
drawImage(Image img, int x, int y,
ImageObserver observer);
public abstract boolean
drawImage(Image img, int x, int y,
int width, int height, Color bgcolor,
ImageObserver observer);
public abstract boolean
drawImage(Image img, int x, int y,
int width, int height,
ImageObserver observer);
public abstract void drawLine(int x1, int y1,
int x2, int y2);
public abstract void drawOval(int x, int y,
int width, int height);
public abstract void
drawPolygon(int xPoints[], int yPoints[],
int nPoints);
public void drawPolygon(Polygon p);
public void drawRect(int x, int y,
int width, int height);
public abstract void
drawRoundRect(int x, int y, int width,
int height, int arcWidth,
int arcHeight);
public abstract void
drawString(String str, int x, int y);
public void
fill3DRect(int x, int y, int width,
int height, boolean raised);
public abstract void
fillArc(int x, int y, int width,
int height, int startAngle,
int arcAngle);
public abstract void
fillOval(int x, int y, int width, int height);
public abstract void
fillPolygon(int xPoints[], int yPoints[], int nPoints);
public void fillPolygon(Polygon p);
public abstract void
fillRect(int x, int y, int width, int height);
public abstract void
fillRoundRect(int x, int y, int width, int height,
int arcWidth, int arcHeight);
public void finalize();
public abstract Rectangle getClipRect();
public abstract Color getColor();
public abstract Font getFont();
public FontMetrics getFontMetrics();
public abstract FontMetrics getFontMetrics(Font f);
public abstract void setColor(Color c);
public abstract void setFont(Font font);
public abstract void setPaintMode();
public abstract void setXORMode(Color c1);
public String toString();
public abstract void translate(int x, int y);
}
The Graphics class is the abstract base class for all graphics contexts which allow an application to draw onto components or onto off-screen images.
Unless otherwise stated, all graphics operations performed with a graphics context object only modify bits within the graphic context's clipping region . All drawing or writing is done in the current color using the current paint mode (setPaintMode, setXORMode) and in the current font .
protected Graphics()This constructor is the default contructor for a graphics context.
Since Graphics is an abstract class, applications cannot call this constructor directly. Graphics contexts are obtained from other graphics contexts or are created by a component .
public abstract void clearRect(int x, int y, int width, int height)Clears the specified rectangle by filling it with the background color of the screen(1). This operation does not use the current paint mode (setPaintMode, setXORMode).
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle
public abstract void clipRect(int x, int y, int width, int height)Sets a clipping rectangle for this graphics context. The resulting clipping area is the intersection of the current clipping area and the specified rectangle.
Graphics operations performed with this graphics context have no effect outside the clipping area.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle See Also: getClipRect .
public abstract void copyArea(int x, int y, int width, int height, int dx, int dy)Copies an area. The source is the rectangle with origin (x,y), and size specified by the width and height arguments. The destination is the rectangle with origin (x+dx, y+dy) and the same width and height.
The clipping rectangle of this graphics context affects only the destination, not the source.
Parameter Description x the x-coordinate of the source y the y-coordinate of the source width the width height the height dx the horizontal distance dy the vertical distance
public abstract Graphics create()Return Value:
Returns a new graphics context that is a copy of this graphics context.
public Graphics create(int x, int y, int width, int height)Creates a new graphics context The new graphics context is identical to this graphics context, except in two respects:
- The new context is translated by (x,y). That is to say, the point (0,0) in the new graphics context is the same as (x,y) in this graphics context.
- The graphics context has an additional clipping rectangle with origin (0,0), and size specified by the width and height arguments, in addition to whatever (translated) clipping rectangle it inherited from this graphics context.
Return Value:
Returns a new graphics context.
Parameter Description x the x coordinate y the y coordinate width the width of the clipping rectangle height the height of the clipping rectangle See Also: translate .
public abstract void dispose()Disposes of this graphics context.
The graphics context cannot be used after being disposed.
See Also: finalize .
public void draw3DRect(int x, int y, int width, int height, boolean raised)Draws a highlighted 3-D rectangle.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle raised if true, the rectangle appears raised; if false, it appears lowered
public abstract void drawArc(int x, int y, int width, int height, int startAngle, int arcAngle)Draws a single circular or elliptical arc.
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 two axes of the arc are given by the width and height arguments.
The arc is drawn from startAngle to startAngle + arcAngle. The start angle and arc angle are in degrees, not radians.
A start angle of 0 indicates the 3-o'clock position. A positive arc angle indicates a counter-clockwise rotation; a negative arc angle indicates a clockwise rotation.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle startAngle the beginning angle arcAngle the angle of the arc (relative to startAngle). See Also: fillArc .
public 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. The baseline of the first character is at position (x,y) in this graphics context's coordinate system.
Parameter Description data the data to be drawn offset the start offset in the data length the number of bytes that are drawn x the x coordinate y the y coordinate See Also: drawString drawChars .
public 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. The baseline of the first character is at position (x,y) in the graphics context's coordinate system.
Parameter Description data the array of characters to be drawn offset the start offset in the data length the number of characters to be drawn x the x coordinate y the y coordinate See Also: drawString drawBytes .
public abstract boolean drawImage(Image img, int x, int y, Color bgcolor, ImageObserver observer)Draws the specified image with its top left corner at (x,y) in this graphics context's coordinate space. Transparent pixels in the image are drawn in the specified background color.
If the image has not yet been completely loaded, the image observer's imageUpdate method is notified as more of the image becomes available.
Return Value:
Returns true if all bits of the image are available; false otherwise.
Parameter Description img the specified image to be drawn x the x coordinate y the y coordinate bgcolor the background color observer object to notify when the image is loaded. See Also: Image ImageObserver .
public abstract boolean drawImage(Image img, int x, int y, ImageObserver observer)Draws the specified image with its top left corner at (x,y) in this graphics context's coordinate space. Transparent pixels in the image do not affect whatever pixels are already there.
If the image has not yet been completely loaded, the image observer's imageUpdate method is notified as more of the image becomes available.
Return Value:
Returns true if all bits of the image are available; false otherwise.
Parameter Description img the specified image to be drawn x the x coordinate y the y coordinate observer object to notify when the image is loaded See Also: Image ImageObserver .
public abstract boolean drawImage(Image img, int x, int y, int width, int height, Color bgcolor, ImageObserver observer)Draws the specified image inside the specified rectangle of this graphics context's coordinate space. The image is scaled if necessary. Transparent pixels in the image are drawn in the specified background color.
If the image has not yet been completely loaded, the image observer's imageUpdate method is notified as more of the image becomes available.
Return Value:
Returns true if all bits of the image are available; false otherwise.
Parameter Description img the specified image to be drawn x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle bgcolor background color for the image observer object to notify when the image is loaded See Also: Image ImageObserver .
public abstract boolean drawImage(Image img, int x, int y, int width, int height, ImageObserver observer)Draws the specified image inside the specified rectangle of this graphics context's coordinate space. The image is scaled if necessary. Transparent pixels in the image do not affect whatever pixels are already there.
If the image has not yet been completely loaded, the image observer's imageUpdate method is notified as more of the image becomes available.
Return Value:
Returns true if all bits of the image are available; false otherwise.
Parameter Description img the specified image to be drawn x the x coordinate y the y coordinate width the width of the rectangle bgcolor background color for the image observer object to notify when the image is loaded See Also: Image ImageObserver .
public abstract void drawLine(int x1, int y1, int x2, int y2)Draws a line from (x1,y1) to (x2,y2) in this graphics context's coordinate system.
The line is drawn below and to the right of the logical coordinates.
Parameter Description x1 the first point's x coordinate y1 the first point's y coordinate x2 the second point's x coordinate y2 the second point's y coordinate
public abstract void drawOval(int x, int y, int width, int height)Draws a circle or an ellipse such that it fits within the rectangle specified by the x, y, width and height arguments.
The center of the oval is the center of the rectangle whose origin is (x,y) is this graphics context's coordinate system and whose size is specified by the width and height arguments.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle See Also: fillOval .
public abstract void drawPolygon(int xPoints[], int yPoints[], int nPoints)Draws a closed polygon defined by an array of x points and y points.
This method draws the polygon defined by npoint line segments, where the first npoint-1 line segments are lines segments from (xPoints[i-1], yPoints[i-1]) to (xPoints[i], yPoints[i]), for 1 £ i < npoint. The last line segment starts at the final point and ends at the first point.
Parameter Description xPoints an array of x points yPoints an array of y points nPoints the total number of points See Also: fillPolygon .
public void drawPolygon(Polygon p)Draws a polygon defined by the specified polygon argument.
Parameter Description p a polygon See Also: fillPolygon .
public void drawRect(int x, int y, int width, int height)Draws the outline of the specified rectangle using the current color. The left and right edges of the rectangle are at x and x + width respectively. The top and bottom edges of the rectangle are at y and y + height. respectively.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle
public 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. The left and right edges of the rectangle are at x and x + width respectively. The top and bottom edges of the rectangle are at y and y + height.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle arcWidth the horizontal diameter of the arc at the four corners arcHeight the vertical diameter of the arc at the four corners See Also: fillRoundRect .
public abstract void drawString(String str, int x, int y)Draws the string using this graphics context's current font and color. The baseline of the first character is at position (x,y) in the graphics context's coordinate system.
Parameter Description str the string to be drawn x the x coordinate y the y coordinate
public void fill3DRect(int x, int y, int width, int height, boolean raised)Draws a highlighted 3-D rectangle that is filled with this graphics context's current color.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle raised if true, the rectangle is raised; if false, it is lowered
public abstract void fillArc(int x, int y, int width, int height, int startAngle, int arcAngle)Draws a single circular or elliptical arc that is filled with this graphics context's current color. The result is a pie shape.
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 two axes of the arc are given by the width and height arguments.
The arc is drawn from startAngle to startAngle + arcAngle. The start angle and arc angle are in degrees, not radians.
A start angle of 0 indicates the 3-o'clock position. A positive arc angle indicates a counter-clockwise rotation; a negative arc angle indicates a clockwise rotation.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle startAngle the beginning angle arcAngle the angle of the arc (relative to startAngle). See Also: drawArc .
public abstract void fillOval(int x, int y, int width, int height)Draws a filled circle or a filled ellipse using this graphics context's current color.
The center of the oval is the center of the rectangle whose origin is (x,y) is the graphics context's coordinate system and whose size is specified by the width and height arguments.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle See Also: drawOval .
public abstract void fillPolygon(int xPoints[], int yPoints[], int nPoints)Fills a polygon defined by an array of x points and y points with this graphics context's current color.
This method fills the polygon defined by npoint line segments, where the first npoint-1 line segments are lines segments from (xPoints[i-1], yPoints[i-1]) to (xPoints[i], yPoints[i]), for 1 £ i < npoints. The last line segment starts at the final point and ends at the first point.
The area inside the polygon is defined using an "even-odd" fill rule, also known as the "alternating rule."
Parameter Description xPoints an array of x points yPoints an array of y points nPoints the total number of points See Also: drawPolygon .
public void fillPolygon(Polygon p)Fills a polygon defined by the specified polygon argument with this graphics context's current color.
The area inside the polygon is defined using an "even-odd" fill rule, also known as the "alternating rule."
Parameter Description p the polygon See Also: drawPolygon .
public abstract void fillRect(int x, int y, int width, int height)Fills the specified rectangle with this graphics context's current color. The left and right edges are at x and x + width - 1 respectively. The top and bottom edges are at y and y + height - 1 respectively.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle
public abstract void fillRoundRect(int x, int y, int width, int height, int arcWidth, int arcHeight)Fills an outlined rounded corner rectangle with this graphics context's current color. The left and right edges are at x and x + width - 1 respectively. The top and bottom edges are at y and y + height - 1 respectively.
Parameter Description x the x coordinate y the y coordinate width the width of the rectangle height the height of the rectangle arcWidth the horizontal diameter of the arc at the four corners arcHeight the vertical diameter of the arc at the four corners Remarks:
Draws a rounded rectangle filled in with the current color.
See Also: drawRoundRect .
public void finalize()The finalize method ensures that this graphics context's dispose method is called when this graphics context is no longer referenced.
Overrides:
finalize in class Object .
public abstract Rectangle getClipRect()Return Value:
Returns the bounding rectangle of this graphics context's clipping area.
See Also: clipRect .
public abstract Color getColor()Return Value:
Returns this graphics context's current color.
See Also: setColor .
public abstract Font getFont()Return Value:
Returns this graphics context's current font.
See Also: setFont .
public FontMetrics getFontMetrics()Return Value:
Returns this font metrics of the graphics context's current font.
See Also: getFont .
public abstract FontMetrics getFontMetrics(Font f)Return Value:
Returns the font metrics for the specified font.
Parameter Description f the specified font See Also: getFont .
public abstract void setColor(Color c)Sets this graphics context's current color to the specified color. All subsequent graphics operations using this graphics context use this specified color.
Parameter Description c the color
public abstract void setFont(Font font)Sets this graphics context's font to the specified font.
All subsequent text operations (such as drawString , drawBytes , and drawChars ) using this graphics context use this font.
Parameter Description font the font
public abstract void setPaintMode()Sets the paint mode of this graphics context to overwrite the destination with this graphics context's current color.
public 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.
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.
Parameter Description c1 the second color
public String toString()Return Value:
Returns a string representation of this graphics context.
Overrides:
toString in class Object .
public abstract void translate(int x, int y)Modifies this graphics context so that its new origin corresponds to the point (x,y) in this graphics context's original coordinate system.
Parameter Description x the x coordinate y the y coordinate
(1)In Java 1.0, the background color of offscreen images is white. In 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.
© 1996 Sun Microsystems, Inc. All rights reserved.