Class Graphics

public abstract class Graphics
extends Object

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:

• The Component object on which to draw.
• A translation origin for rendering and clipping coordinates.
• The current clip.
• The current color.
• The current font.
• The current logical pixel operation function (XOR or Paint).
• The current XOR alternation color (see setXORMode(java.awt.Color)).

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:

• If you draw a figure that covers a given rectangle, that figure occupies one extra row of pixels on the right and bottom edges as compared to filling a figure that is bounded by that same rectangle.
• If you draw a horizontal line along the same y coordinate as the baseline of a line of text, that line is drawn entirely below the text, except for any descenders.

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.

Constructors

Graphics

protected Graphics()

See Also:

create(), Component.getGraphics()

Methods

create

public abstract Graphics create()

Creates a new Graphics object that is a copy of this Graphics object.

Returns:

a new graphics context that is a copy of this graphics context.

create

public Graphics create(int x,
                       int y,
                       int width,
                       int height)

Parameters:

x - the x coordinate.

y - the y coordinate.

width - the width of the clipping rectangle.

height - the height of the clipping rectangle.

Returns:

a new graphics context.

See Also:

translate(int, int), clipRect(int, int, int, int)

translate

public abstract void translate(int x,
                               int y)

Translates the origin of the graphics context to the point (x, y) in the current coordinate system. Modifies this graphics context so that its new origin corresponds to the point (x, y) in this graphics context's original coordinate system. All coordinates used in subsequent rendering operations on this graphics context will be relative to this new origin.

Parameters:

x - the x coordinate.

y - the y coordinate.

getColor

public abstract Color getColor()

Gets this graphics context's current color.

Returns:

this graphics context's current color.

See Also:

Color, setColor(Color)

setColor

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.

Parameters:

c - the new rendering color.

See Also:

Color, getColor()

setPaintMode

public abstract void setPaintMode()

Sets the paint mode of this graphics context to overwrite the destination with this graphics context's current color. This sets the logical pixel operation function to the paint or overwrite mode. All subsequent rendering operations will overwrite the destination with the current color.

setXORMode

public abstract void setXORMode(Color c1)

Parameters:

c1 - the XOR alternation color

getFont

public abstract Font getFont()

Gets the current font.

Returns:

this graphics context's current font.

See Also:

Font, setFont(Font)

setFont

public abstract void setFont(Font font)

Sets this graphics context's font to the specified font. All subsequent text operations using this graphics context use this font. A null argument is silently ignored.

Parameters:

font - the font.

See Also:

getFont(), drawString(java.lang.String, int, int), drawBytes(byte[], int, int, int, int), drawChars(char[], int, int, int, int)

getFontMetrics

public FontMetrics getFontMetrics()

Gets the font metrics of the current font.

Returns:

the font metrics of this graphics context's current font.

See Also:

getFont(), FontMetrics, getFontMetrics(Font)

getFontMetrics

public abstract FontMetrics getFontMetrics(Font f)

Gets the font metrics for the specified font.

Parameters:

f - the specified font

Returns:

the font metrics for the specified font.

See Also:

getFont(), FontMetrics, getFontMetrics()

getClipBounds

public abstract Rectangle getClipBounds()

Returns the bounding rectangle of the current clipping area. This method refers to the user clip, which is independent of the clipping associated with device bounds and window visibility. If no clip has previously been set, or if the clip has been cleared using setClip(null), this method returns null. The coordinates in the rectangle are relative to the coordinate system origin of this graphics context.

Returns:

the bounding rectangle of the current clipping area, or null if no clip is set.

Since:

JDK1.1

See Also:

getClip(), clipRect(int, int, int, int), setClip(int, int, int, int), setClip(Shape)

clipRect

public abstract void clipRect(int x,
                              int y,
                              int width,
                              int height)

Intersects the current clip with the specified rectangle. The resulting clipping area is the intersection of the current clipping area and the specified rectangle. If there is no current clipping area, either because the clip has never been set, or the clip has been cleared using setClip(null), the specified rectangle becomes the new clip. This method sets the user clip, which is independent of the clipping associated with device bounds and window visibility. This method can only be used to make the current clip smaller. To set the current clip larger, use any of the setClip methods. Rendering operations have no effect outside of the clipping area.

Parameters:

x - the x coordinate of the rectangle to intersect the clip with

y - the y coordinate of the rectangle to intersect the clip with

width - the width of the rectangle to intersect the clip with

height - the height of the rectangle to intersect the clip with

See Also:

setClip(int, int, int, int), setClip(Shape)

setClip

public abstract void setClip(int x,
                             int y,
                             int width,
                             int height)

Sets the current clip to the rectangle specified by the given coordinates. This method sets the user clip, which is independent of the clipping associated with device bounds and window visibility. Rendering operations have no effect outside of the clipping area.

Parameters:

x - the x coordinate of the new clip rectangle.

y - the y coordinate of the new clip rectangle.

width - the width of the new clip rectangle.

height - the height of the new clip rectangle.

Since:

JDK1.1

See Also:

clipRect(int, int, int, int), setClip(Shape), getClip()

getClip

public abstract Shape getClip()

Gets the current clipping area. This method returns the user clip, which is independent of the clipping associated with device bounds and window visibility. If no clip has previously been set, or if the clip has been cleared using setClip(null), this method returns null.

Returns:

a Shape object representing the current clipping area, or null if no clip is set.

Since:

JDK1.1

See Also:

getClipBounds(), clipRect(int, int, int, int), setClip(int, int, int, int), setClip(Shape)

setClip

public abstract void setClip(Shape clip)

Sets the current clipping area to an arbitrary clip shape. Not all objects that implement the Shape interface can be used to set the clip. The only Shape objects that are guaranteed to be supported are Shape objects that are obtained via the getClip method and via Rectangle objects. This method sets the user clip, which is independent of the clipping associated with device bounds and window visibility.

Parameters:

clip - the Shape to use to set the clip

Since:

JDK1.1

See Also:

getClip(), clipRect(int, int, int, int), setClip(int, int, int, int)

copyArea

public 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. From the point specified by x and y, this method copies downwards and to the right. To copy an area of the component to the left or upwards, specify a negative value for dx or dy. If a portion of the source rectangle lies outside the bounds of the component, or is obscured by another window or component, copyArea will be unable to copy the associated pixels. The area that is omitted can be refreshed by calling the component's paint method.

Parameters:

x - the x coordinate of the source rectangle.

y - the y coordinate of the source rectangle.

width - the width of the source rectangle.

height - the height of the source rectangle.

dx - the horizontal distance to copy the pixels.

dy - the vertical distance to copy the pixels.

drawLine

public 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.

Parameters:

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.

fillRect

public abstract void fillRect(int x,
                              int y,
                              int width,
                              int height)

Fills the specified rectangle. The left and right edges of the rectangle are at x and x + width - 1. The top and bottom edges are at y and y + height - 1. The resulting rectangle covers an area width pixels wide by height pixels tall. The rectangle is filled using the graphics context's current color.

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.

See Also:

clearRect(int, int, int, int), drawRect(int, int, int, int)

drawRect

public void drawRect(int x,
                     int y,
                     int width,
                     int height)

Draws the outline of the specified rectangle. The left and right edges of the rectangle are at x and x + width. The top and bottom edges are at y and y + height. The rectangle is drawn using the graphics context's current color.

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.

See Also:

fillRect(int, int, int, int), clearRect(int, int, int, int)

clearRect

public abstract void clearRect(int x,
                               int y,
                               int width,
                               int height)

Parameters:

x - the x coordinate of the rectangle to clear.

y - the y coordinate of the rectangle to clear.

width - the width of the rectangle to clear.

height - the height of the rectangle to clear.

See Also:

fillRect(int, int, int, int), drawRect(int, int, int, int), setColor(java.awt.Color), setPaintMode(), setXORMode(java.awt.Color)

drawRoundRect

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.

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.

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(int, int, int, int, int, int)

fillRoundRect

public 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. The left and right edges of the rectangle are at x and x + width - 1, respectively. The top and bottom edges of the rectangle are at y and y + height - 1.

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.

arcWidth - the horizontal diameter of the arc at the four corners.

arcHeight - the vertical diameter of the arc at the four corners.

See Also:

drawRoundRect(int, int, int, int, int, int)

draw3DRect

public void draw3DRect(int x,
                       int y,
                       int width,
                       int height,
                       boolean raised)

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:

fill3DRect(int, int, int, int, boolean)

fill3DRect

public void fill3DRect(int x,
                       int y,
                       int width,
                       int height,
                       boolean raised)

Paints a 3-D highlighted rectangle filled with the current color. The edges of the rectangle will be 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 will be determined from the current color.

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:

draw3DRect(int, int, int, int, boolean)

drawOval

public abstract void drawOval(int x,
                              int y,
                              int width,
                              int height)

Parameters:

x - the x coordinate of the upper left corner of the oval to be drawn.

y - the y coordinate of the upper left corner of the oval to be drawn.

width - the width of the oval to be drawn.

height - the height of the oval to be drawn.

See Also:

fillOval(int, int, int, int)

fillOval

public abstract void fillOval(int x,
                              int y,
                              int width,
                              int height)

Fills an oval bounded by the specified rectangle with the current color.

Parameters:

x - the x coordinate of the upper left corner of the oval to be filled.

y - the y coordinate of the upper left corner of the oval to be filled.

width - the width of the oval to be filled.

height - the height of the oval to be filled.

See Also:

drawOval(int, int, int, int)

drawArc

public abstract void drawArc(int x,
                             int y,
                             int width,
                             int height,
                             int startAngle,
                             int arcAngle)

Parameters:

x - the x coordinate of the upper-left corner of the arc to be drawn.

y - the y coordinate of the upper-left corner of the arc to be drawn.

width - the width of the arc to be drawn.

height - the height of the arc to be drawn.

startAngle - the beginning angle.

arcAngle - the angular extent of the arc, relative to the start angle.

See Also:

fillArc(int, int, int, int, int, int)

fillArc

public abstract void fillArc(int x,
                             int y,
                             int width,
                             int height,
                             int startAngle,
                             int arcAngle)

Parameters:

x - the x coordinate of the upper-left corner of the arc to be filled.

y - the y coordinate of the upper-left corner of the arc to be filled.

width - the width of the arc to be filled.

height - the height of the arc to be filled.

startAngle - the beginning angle.

arcAngle - the angular extent of the arc, relative to the start angle.

See Also:

drawArc(int, int, int, int, int, int)

drawPolyline

public abstract void drawPolyline(int[] xPoints,
                                  int[] yPoints,
                                  int nPoints)

Draws a sequence of connected lines defined by arrays of x and y coordinates. Each pair of (x, y) coordinates defines a point. The figure is not closed if the first point differs from the last point.

Parameters:

xPoints - an array of x points

yPoints - an array of y points

nPoints - the total number of points

Since:

JDK1.1

See Also:

drawPolygon(int[], int[], int)

drawPolygon

public abstract void drawPolygon(int[] xPoints,
                                 int[] yPoints,
                                 int nPoints)

Parameters:

xPoints - a an array of x coordinates.

yPoints - a an array of y coordinates.

nPoints - a the total number of points.

See Also:

fillPolygon(int[], int[], int), drawPolyline(int[], int[], int)

drawPolygon

public void drawPolygon(Polygon p)

Draws the outline of a polygon defined by the specified Polygon object.

Parameters:

p - the polygon to draw.

See Also:

fillPolygon(int[], int[], int), drawPolyline(int[], int[], int)

fillPolygon

public abstract void fillPolygon(int[] xPoints,
                                 int[] yPoints,
                                 int nPoints)

Parameters:

xPoints - a an array of x coordinates.

yPoints - a an array of y coordinates.

nPoints - a the total number of points.

See Also:

drawPolygon(int[], int[], int)

fillPolygon

public void fillPolygon(Polygon p)

Parameters:

p - the polygon to fill.

See Also:

drawPolygon(int[], int[], int)

drawString

public 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. The baseline of the leftmost character is at position (x, y) in this graphics context's coordinate system.

Parameters:

str - the string to be drawn.

x - the x coordinate.

y - the y coordinate.

Throws:

NullPointerException - if str is null.

See Also:

drawBytes(byte[], int, int, int, int), drawChars(char[], int, int, int, int)

drawString

public abstract void drawString(AttributedCharacterIterator iterator,
                                int x,
                                int y)

Parameters:

iterator - the iterator whose text is to be drawn

x - the x coordinate.

y - the y coordinate.

Throws:

NullPointerException - if iterator is null.

See Also:

drawBytes(byte[], int, int, int, int), drawChars(char[], int, int, int, int)

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 this graphics context's coordinate system.

Parameters:

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 of the baseline of the text

y - the y coordinate of the baseline of the text

Throws:

NullPointerException - if data is null.

IndexOutOfBoundsException - if offset or lengthis less than zero, or offset+length is greater than the length of the data array.

See Also:

drawBytes(byte[], int, int, int, int), drawString(java.lang.String, int, int)

drawBytes

public void drawBytes(byte[] data,
                      int offset,
                      int length,
                      int x,
                      int y)

Parameters:

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 of the baseline of the text

y - the y coordinate of the baseline of the text

Throws:

NullPointerException - if data is null.

IndexOutOfBoundsException - if offset or lengthis less than zero, or offset+length is greater than the length of the data array.

See Also:

drawChars(char[], int, int, int, int), drawString(java.lang.String, int, int)

drawImage

public abstract boolean drawImage(Image img,
                                  int x,
                                  int y,
                                  ImageObserver observer)

Parameters:

img - the specified image to be drawn. This method does nothing if img is null.

x - the x coordinate.

y - the y coordinate.

observer - object to be notified as more of the image is converted.

Returns:

false if the image pixels are still changing; true otherwise.

See Also:

Image, ImageObserver, ImageObserver.imageUpdate(java.awt.Image, int, int, int, int, int)

drawImage

public abstract boolean drawImage(Image img,
                                  int x,
                                  int y,
                                  int width,
                                  int height,
                                  ImageObserver observer)

Parameters:

img - the specified image to be drawn. This method does nothing if img is null.

x - the x coordinate.

y - the y coordinate.

width - the width of the rectangle.

height - the height of the rectangle.

observer - object to be notified as more of the image is converted.

Returns:

false if the image pixels are still changing; true otherwise.

See Also:

Image, ImageObserver, ImageObserver.imageUpdate(java.awt.Image, int, int, int, int, int)

drawImage

public abstract boolean drawImage(Image img,
                                  int x,
                                  int y,
                                  Color bgcolor,
                                  ImageObserver observer)

Parameters:

img - the specified image to be drawn. This method does nothing if img is null.

x - the x coordinate.

y - the y coordinate.

bgcolor - the background color to paint under the non-opaque portions of the image.

observer - object to be notified as more of the image is converted.

Returns:

false if the image pixels are still changing; true otherwise.

See Also:

Image, ImageObserver, ImageObserver.imageUpdate(java.awt.Image, int, int, int, int, int)

drawImage

public abstract boolean drawImage(Image img,
                                  int x,
                                  int y,
                                  int width,
                                  int height,
                                  Color bgcolor,
                                  ImageObserver observer)

Parameters:

img - the specified image to be drawn. This method does nothing if img is null.

x - the x coordinate.

y - the y coordinate.

width - the width of the rectangle.

height - the height of the rectangle.

bgcolor - the background color to paint under the non-opaque portions of the image.

observer - object to be notified as more of the image is converted.

Returns:

false if the image pixels are still changing; true otherwise.

See Also:

Image, ImageObserver, ImageObserver.imageUpdate(java.awt.Image, int, int, int, int, int)

drawImage

public abstract boolean drawImage(Image img,
                                  int dx1,
                                  int dy1,
                                  int dx2,
                                  int dy2,
                                  int sx1,
                                  int sy1,
                                  int sx2,
                                  int sy2,
                                  ImageObserver observer)

Parameters:

img - the specified image to be drawn. This method does nothing if img is null.

dx1 - the x coordinate of the first corner of the destination rectangle.

dy1 - the y coordinate of the first corner of the destination rectangle.

dx2 - the x coordinate of the second corner of the destination rectangle.

dy2 - the y coordinate of the second corner of the destination rectangle.

sx1 - the x coordinate of the first corner of the source rectangle.

sy1 - the y coordinate of the first corner of the source rectangle.

sx2 - the x coordinate of the second corner of the source rectangle.

sy2 - the y coordinate of the second corner of the source rectangle.

observer - object to be notified as more of the image is scaled and converted.

Returns:

false if the image pixels are still changing; true otherwise.

Since:

JDK1.1

See Also:

Image, ImageObserver, ImageObserver.imageUpdate(java.awt.Image, int, int, int, int, int)

drawImage

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)

Parameters:

img - the specified image to be drawn. This method does nothing if img is null.

dx1 - the x coordinate of the first corner of the destination rectangle.

dy1 - the y coordinate of the first corner of the destination rectangle.

dx2 - the x coordinate of the second corner of the destination rectangle.

dy2 - the y coordinate of the second corner of the destination rectangle.

sx1 - the x coordinate of the first corner of the source rectangle.

sy1 - the y coordinate of the first corner of the source rectangle.

sx2 - the x coordinate of the second corner of the source rectangle.

sy2 - the y coordinate of the second corner of the source rectangle.

bgcolor - the background color to paint under the non-opaque portions of the image.

observer - object to be notified as more of the image is scaled and converted.

Returns:

false if the image pixels are still changing; true otherwise.

Since:

JDK1.1

See Also:

Image, ImageObserver, ImageObserver.imageUpdate(java.awt.Image, int, int, int, int, int)

dispose

public abstract void dispose()

See Also:

finalize(), Component.paint(java.awt.Graphics), Component.update(java.awt.Graphics), Component.getGraphics(), create()

finalize

public void finalize()

Disposes of this graphics context once it is no longer referenced.

Overrides:

finalize in class Object

See Also:

dispose()

toString

public String toString()

Returns a String object representing this Graphics object's value.

Overrides:

toString in class Object

Returns:

a string representation of this graphics context.

getClipRect

@Deprecated
public Rectangle getClipRect()

Deprecated. As of JDK version 1.1, replaced by getClipBounds().

Returns the bounding rectangle of the current clipping area.

Returns:

the bounding rectangle of the current clipping area or null if no clip is set.

hitClip

public boolean hitClip(int x,
                       int y,
                       int width,
                       int height)

Returns true if the specified rectangular area might intersect the current clipping area. The coordinates of the specified rectangular area are in the user coordinate space and are relative to the coordinate system origin of this graphics context. This method may use an algorithm that calculates a result quickly but which sometimes might return true even if the specified rectangular area does not intersect the clipping area. The specific algorithm employed may thus trade off accuracy for speed, but it will never return false unless it can guarantee that the specified rectangular area does not intersect the current clipping area. The clipping area used by this method can represent the intersection of the user clip as specified through the clip methods of this graphics context as well as the clipping associated with the device or image bounds and window visibility.

Parameters:

x - the x coordinate of the rectangle to test against the clip

y - the y coordinate of the rectangle to test against the clip

width - the width of the rectangle to test against the clip

height - the height of the rectangle to test against the clip

Returns:

true if the specified rectangle intersects the bounds of the current clip; false otherwise.

getClipBounds

public Rectangle getClipBounds(Rectangle r)

Returns the bounding rectangle of the current clipping area. The coordinates in the rectangle are relative to the coordinate system origin of this graphics context. This method differs from getClipBounds in that an existing rectangle is used instead of allocating a new one. This method refers to the user clip, which is independent of the clipping associated with device bounds and window visibility. If no clip has previously been set, or if the clip has been cleared using setClip(null), this method returns the specified Rectangle.

Parameters:

r - the rectangle where the current clipping area is copied to. Any current values in this rectangle are overwritten.

Returns:

the bounding rectangle of the current clipping area.