* A {@code 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 * {@code Graphics} object are considered relative to the * translation origin of this {@code 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 {@link Shape} * in user space and is controlled by the program using the * {@code 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 {@code setClip} or {@code clipRect} * methods. * All drawing or writing is done in the current color, * using the current paint mode, and in the current font. * * @author Sami Shaio * @author Arthur van Hoff * @see java.awt.Component * @see java.awt.Graphics#clipRect(int, int, int, int) * @see java.awt.Graphics#setColor(java.awt.Color) * @see java.awt.Graphics#setPaintMode() * @see java.awt.Graphics#setXORMode(java.awt.Color) * @see java.awt.Graphics#setFont(java.awt.Font) * @since 1.0 */ public abstract class Graphics { /** * Constructs a new {@code Graphics} object. * This constructor is the default constructor for a graphics * context. *
* Since {@code Graphics} is an abstract class, applications * cannot call this constructor directly. Graphics contexts are * obtained from other graphics contexts or are created by calling * {@code getGraphics} on a component. * @see java.awt.Graphics#create() * @see java.awt.Component#getGraphics */ protected Graphics() { } /** * Creates a new {@code Graphics} object that is * a copy of this {@code Graphics} object. * @return a new graphics context that is a copy of * this graphics context. */ public abstract Graphics create(); /** * Creates a new {@code Graphics} object based on this * {@code Graphics} object, but with a new translation and clip area. * The new {@code Graphics} object has its origin * translated to the specified point (x, y). * Its clip area is determined by the intersection of the original * clip area with the specified rectangle. The arguments are all * interpreted in the coordinate system of the original * {@code Graphics} object. The new graphics context is * identical to the original, except in two respects: * *
* 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.
* @param c1 the XOR alternation color
*/
public abstract void setXORMode(Color c1);
/**
* Gets the current font.
* @return this graphics context's current font.
* @see java.awt.Font
* @see java.awt.Graphics#setFont(Font)
*/
public abstract Font getFont();
/**
* 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.
* @param font the font.
* @see java.awt.Graphics#getFont
* @see java.awt.Graphics#drawString(java.lang.String, int, int)
* @see java.awt.Graphics#drawBytes(byte[], int, int, int, int)
* @see java.awt.Graphics#drawChars(char[], int, int, int, int)
*/
public abstract void setFont(Font font);
/**
* Gets the font metrics of the current font.
* @return the font metrics of this graphics
* context's current font.
* @see java.awt.Graphics#getFont
* @see java.awt.FontMetrics
* @see java.awt.Graphics#getFontMetrics(Font)
*/
public FontMetrics getFontMetrics() {
return getFontMetrics(getFont());
}
/**
* Gets the font metrics for the specified font.
* @return the font metrics for the specified font.
* @param f the specified font
* @see java.awt.Graphics#getFont
* @see java.awt.FontMetrics
* @see java.awt.Graphics#getFontMetrics()
*/
public abstract FontMetrics getFontMetrics(Font f);
/**
* 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 {@code setClip(null)}, this method returns
* {@code null}.
* The coordinates in the rectangle are relative to the coordinate
* system origin of this graphics context.
* @return the bounding rectangle of the current clipping area,
* or {@code null} if no clip is set.
* @see java.awt.Graphics#getClip
* @see java.awt.Graphics#clipRect
* @see java.awt.Graphics#setClip(int, int, int, int)
* @see java.awt.Graphics#setClip(Shape)
* @since 1.1
*/
public abstract Rectangle getClipBounds();
/**
* 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 {@code 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.
* @param x the x coordinate of the rectangle to intersect the clip with
* @param y the y coordinate of the rectangle to intersect the clip with
* @param width the width of the rectangle to intersect the clip with
* @param height the height of the rectangle to intersect the clip with
* @see #setClip(int, int, int, int)
* @see #setClip(Shape)
*/
public abstract void clipRect(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.
* @param x the x coordinate of the new clip rectangle.
* @param y the y coordinate of the new clip rectangle.
* @param width the width of the new clip rectangle.
* @param height the height of the new clip rectangle.
* @see java.awt.Graphics#clipRect
* @see java.awt.Graphics#setClip(Shape)
* @see java.awt.Graphics#getClip
* @since 1.1
*/
public abstract void setClip(int x, int y, int width, int height);
/**
* 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 {@code setClip(null)}, this method returns
* {@code null}.
* @return a {@code Shape} object representing the
* current clipping area, or {@code null} if
* no clip is set.
* @see java.awt.Graphics#getClipBounds
* @see java.awt.Graphics#clipRect
* @see java.awt.Graphics#setClip(int, int, int, int)
* @see java.awt.Graphics#setClip(Shape)
* @since 1.1
*/
public abstract Shape getClip();
/**
* Sets the current clipping area to an arbitrary clip shape.
* Not all objects that implement the {@code Shape}
* interface can be used to set the clip. The only
* {@code Shape} objects that are guaranteed to be
* supported are {@code Shape} objects that are
* obtained via the {@code getClip} method and via
* {@code Rectangle} objects. This method sets the
* user clip, which is independent of the clipping associated
* with device bounds and window visibility.
* @param clip the {@code Shape} to use to set the clip
* @see java.awt.Graphics#getClip()
* @see java.awt.Graphics#clipRect
* @see java.awt.Graphics#setClip(int, int, int, int)
* @since 1.1
*/
public abstract void setClip(Shape clip);
/**
* Copies an area of the component by a distance specified by
* {@code dx} and {@code dy}. From the point specified
* by {@code x} and {@code 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
* {@code dx} or {@code dy}.
* If a portion of the source rectangle lies outside the bounds
* of the component, or is obscured by another window or component,
* {@code copyArea} will be unable to copy the associated
* pixels. The area that is omitted can be refreshed by calling
* the component's {@code paint} method.
* @param x the x coordinate of the source rectangle.
* @param y the y coordinate of the source rectangle.
* @param width the width of the source rectangle.
* @param height the height of the source rectangle.
* @param dx the horizontal distance to copy the pixels.
* @param dy the vertical distance to copy the pixels.
*/
public abstract void copyArea(int x, int y, int width, int height,
int dx, int dy);
/**
* Draws a line, using the current color, between the points
* (x1, y1) and (x2, y2)
* in this graphics context's coordinate system.
* @param x1 the first point's x coordinate.
* @param y1 the first point's y coordinate.
* @param x2 the second point's x coordinate.
* @param y2 the second point's y coordinate.
*/
public abstract void drawLine(int x1, int y1, int x2, int y2);
/**
* Fills the specified rectangle.
* The left and right edges of the rectangle are at
* {@code x} and x + width - 1.
* The top and bottom edges are at
* {@code y} and y + height - 1.
* The resulting rectangle covers an area
* {@code width} pixels wide by
* {@code height} pixels tall.
* The rectangle is filled using the graphics context's current color.
* @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.
* @see java.awt.Graphics#clearRect
* @see java.awt.Graphics#drawRect
*/
public abstract void fillRect(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
* {@code x} and x + width.
* The top and bottom edges are at
* {@code y} and y + height.
* The rectangle is drawn using the graphics context's current color.
* @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.
* @see java.awt.Graphics#fillRect
* @see java.awt.Graphics#clearRect
*/
public void drawRect(int x, int y, int width, int height) {
if ((width < 0) || (height < 0)) {
return;
}
if (height == 0 || width == 0) {
drawLine(x, y, x + width, y + height);
} else {
drawLine(x, y, x + width - 1, y);
drawLine(x + width, y, x + width, y + height - 1);
drawLine(x + width, y + height, x + 1, y + height);
drawLine(x, y + height, x, y + 1);
}
}
/**
* Clears the specified rectangle by filling it with the background
* color of the current drawing surface. This operation does not
* use the current paint mode.
*
* Beginning with Java 1.1, the background color
* of offscreen images may be system dependent. Applications should
* use {@code setColor} followed by {@code fillRect} to
* ensure that an offscreen image is cleared to a specific color.
* @param x the x coordinate of the rectangle to clear.
* @param y the y coordinate of the rectangle to clear.
* @param width the width of the rectangle to clear.
* @param height the height of the rectangle to clear.
* @see java.awt.Graphics#fillRect(int, int, int, int)
* @see java.awt.Graphics#drawRect
* @see java.awt.Graphics#setColor(java.awt.Color)
* @see java.awt.Graphics#setPaintMode
* @see java.awt.Graphics#setXORMode(java.awt.Color)
*/
public abstract void clearRect(int x, int y, int width, int height);
/**
* Draws an outlined round-cornered rectangle using this graphics
* context's current color. The left and right edges of the rectangle
* are at {@code x} and x + width,
* respectively. The top and bottom edges of the rectangle are at
* {@code y} and y + height.
* @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 arcWidth the horizontal diameter of the arc
* at the four corners.
* @param arcHeight the vertical diameter of the arc
* at the four corners.
* @see java.awt.Graphics#fillRoundRect
*/
public abstract void drawRoundRect(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 {@code x} and x + width - 1,
* respectively. The top and bottom edges of the rectangle are at
* {@code y} and y + height - 1.
* @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 arcWidth the horizontal diameter
* of the arc at the four corners.
* @param arcHeight the vertical diameter
* of the arc at the four corners.
* @see java.awt.Graphics#drawRoundRect
*/
public abstract void fillRoundRect(int x, int y, int width, int height,
int arcWidth, int arcHeight);
/**
* Draws a 3-D highlighted outline of the specified rectangle.
* The edges of the rectangle are highlighted so that they
* appear to be beveled and lit from the upper left corner.
*
* The colors used for the highlighting effect are determined
* based on the current color.
* The resulting rectangle covers an area that is
* width + 1 pixels wide
* by height + 1 pixels tall.
* @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) {
Color c = getColor();
Color brighter = c.brighter();
Color darker = c.darker();
setColor(raised ? brighter : darker);
drawLine(x, y, x, y + height);
drawLine(x + 1, y, x + width - 1, y);
setColor(raised ? darker : brighter);
drawLine(x + 1, y + height, x + width, y + height);
drawLine(x + width, y, x + width, y + height - 1);
setColor(c);
}
/**
* 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.
* @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) {
Color c = getColor();
Color brighter = c.brighter();
Color darker = c.darker();
if (!raised) {
setColor(darker);
}
fillRect(x+1, y+1, width-2, height-2);
setColor(raised ? brighter : darker);
drawLine(x, y, x, y + height - 1);
drawLine(x + 1, y, x + width - 2, y);
setColor(raised ? darker : brighter);
drawLine(x + 1, y + height - 1, x + width - 1, y + height - 1);
drawLine(x + width - 1, y, x + width - 1, y + height - 2);
setColor(c);
}
/**
* Draws the outline of an oval.
* The result is a circle or ellipse that fits within the
* rectangle specified by the {@code x}, {@code y},
* {@code width}, and {@code height} arguments.
*
* The oval covers an area that is
* width + 1 pixels wide
* and height + 1 pixels tall.
* @param x the x coordinate of the upper left
* corner of the oval to be drawn.
* @param y the y coordinate of the upper left
* corner of the oval to be drawn.
* @param width the width of the oval to be drawn.
* @param height the height of the oval to be drawn.
* @see java.awt.Graphics#fillOval
*/
public abstract void drawOval(int x, int y, int width, int height);
/**
* Fills an oval bounded by the specified rectangle with the
* current color.
* @param x the x coordinate of the upper left corner
* of the oval to be filled.
* @param y the y coordinate of the upper left corner
* of the oval to be filled.
* @param width the width of the oval to be filled.
* @param height the height of the oval to be filled.
* @see java.awt.Graphics#drawOval
*/
public abstract void fillOval(int x, int y, int width, int height);
/**
* Draws the outline of a circular or elliptical arc
* covering the specified rectangle.
*
* The resulting arc begins at {@code startAngle} and extends * for {@code 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 * {@code width} and {@code 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. * @param x the x coordinate of the * upper-left corner of the arc to be drawn. * @param y the y coordinate of the * upper-left corner of the arc to be drawn. * @param width the width of the arc to be drawn. * @param height the height of the arc to be drawn. * @param startAngle the beginning angle. * @param arcAngle the angular extent of the arc, * relative to the start angle. * @see java.awt.Graphics#fillArc */ public abstract void drawArc(int x, int y, int width, int height, int startAngle, int arcAngle); /** * Fills a circular or elliptical arc covering the specified rectangle. *
* The resulting arc begins at {@code startAngle} and extends * for {@code 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 * {@code width} and {@code 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. * @param x the x coordinate of the * upper-left corner of the arc to be filled. * @param y the y coordinate of the * upper-left corner of the arc to be filled. * @param width the width of the arc to be filled. * @param height the height of the arc to be filled. * @param startAngle the beginning angle. * @param arcAngle the angular extent of the arc, * relative to the start angle. * @see java.awt.Graphics#drawArc */ public abstract void fillArc(int x, int y, int width, int height, int startAngle, int arcAngle); /** * 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. * @param xPoints an array of x points * @param yPoints an array of y points * @param nPoints the total number of points * @see java.awt.Graphics#drawPolygon(int[], int[], int) * @since 1.1 */ public abstract void drawPolyline(int[] xPoints, int[] yPoints, int nPoints); /** * Draws a closed polygon defined by * arrays of x and y coordinates. * Each pair of (x, y) coordinates defines a point. *
* This method draws the polygon defined by {@code 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 ≤ {@code nPoints}.
* The figure is automatically closed by drawing a line connecting
* the final point to the first point, if those points are different.
* @param xPoints a an array of {@code x} coordinates.
* @param yPoints a an array of {@code y} coordinates.
* @param nPoints a the total number of points.
* @see java.awt.Graphics#fillPolygon
* @see java.awt.Graphics#drawPolyline
*/
public abstract void drawPolygon(int[] xPoints, int[] yPoints,
int nPoints);
/**
* Draws the outline of a polygon defined by the specified
* {@code Polygon} object.
* @param p the polygon to draw.
* @see java.awt.Graphics#fillPolygon
* @see java.awt.Graphics#drawPolyline
*/
public void drawPolygon(Polygon p) {
drawPolygon(p.xpoints, p.ypoints, p.npoints);
}
/**
* Fills a closed polygon defined by
* arrays of x and y coordinates.
*
* This method draws the polygon defined by {@code 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 ≤ {@code 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. * @param xPoints a an array of {@code x} coordinates. * @param yPoints a an array of {@code y} coordinates. * @param nPoints a the total number of points. * @see java.awt.Graphics#drawPolygon(int[], int[], int) */ public abstract void fillPolygon(int[] xPoints, int[] yPoints, int nPoints); /** * Fills the polygon defined by the specified Polygon object with * the graphics context's current color. *
* The area inside the polygon is defined using an * even-odd fill rule, also known as the alternating rule. * @param p the polygon to fill. * @see java.awt.Graphics#drawPolygon(int[], int[], int) */ public void fillPolygon(Polygon p) { fillPolygon(p.xpoints, p.ypoints, p.npoints); } /** * 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. * @param str the string to be drawn. * @param x the x coordinate. * @param y the y coordinate. * @throws NullPointerException if {@code str} is {@code null}. * @see java.awt.Graphics#drawBytes * @see java.awt.Graphics#drawChars */ public abstract void drawString(String str, int x, int y); /** * Renders the text of the specified iterator applying its attributes * in accordance with the specification of the * {@link java.awt.font.TextAttribute TextAttribute} class. *
* The baseline of the leftmost character is at position * (x, y) in this graphics context's coordinate system. * @param iterator the iterator whose text is to be drawn * @param x the x coordinate. * @param y the y coordinate. * @throws NullPointerException if {@code iterator} is * {@code null}. * @see java.awt.Graphics#drawBytes * @see java.awt.Graphics#drawChars */ public abstract void drawString(AttributedCharacterIterator iterator, 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. * @param data the array of characters to be drawn * @param offset the start offset in the data * @param length the number of characters to be drawn * @param x the x coordinate of the baseline of the text * @param y the y coordinate of the baseline of the text * @throws NullPointerException if {@code data} is {@code null}. * @throws IndexOutOfBoundsException if {@code offset} or * {@code length} is less than zero, or * {@code offset+length} is greater than the length of the * {@code data} array. * @see java.awt.Graphics#drawBytes * @see java.awt.Graphics#drawString */ public void drawChars(char[] data, int offset, int length, int x, int y) { drawString(new String(data, offset, length), x, 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. *
* 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. * @param data the data to be drawn * @param offset the start offset in the data * @param length the number of bytes that are drawn * @param x the x coordinate of the baseline of the text * @param y the y coordinate of the baseline of the text * @throws NullPointerException if {@code data} is {@code null}. * @throws IndexOutOfBoundsException if {@code offset} or * {@code length} is less than zero, or {@code offset+length} * is greater than the length of the {@code data} array. * @see java.awt.Graphics#drawChars * @see java.awt.Graphics#drawString */ @SuppressWarnings("deprecation") public void drawBytes(byte[] data, int offset, int length, int x, int y) { drawString(new String(data, 0, offset, length), x, y); } /** * Draws as much of the specified image as is currently available. * The image is drawn 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. *
* 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 * {@code drawImage} returns {@code true}. * Otherwise, {@code drawImage} returns {@code 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. * @param img the specified image to be drawn. This method does * nothing if {@code img} is null. * @param x the x coordinate. * @param y the y coordinate. * @param observer object to be notified as more of * the image is converted. * @return {@code false} if the image pixels are still changing; * {@code true} otherwise. * @see java.awt.Image * @see java.awt.image.ImageObserver * @see java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int) */ public abstract boolean drawImage(Image img, int x, int y, ImageObserver observer); /** * Draws as much of the specified image as has already been scaled * to fit inside the specified rectangle. *
* 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 * {@code drawImage} returns {@code false}. As more of * the image becomes available, the process that loads the image notifies * the image observer by calling its {@code 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. * @param img the specified image to be drawn. This method does * nothing if {@code img} is null. * @param x the x coordinate. * @param y the y coordinate. * @param width the width of the rectangle. * @param height the height of the rectangle. * @param observer object to be notified as more of * the image is converted. * @return {@code false} if the image pixels are still changing; * {@code true} otherwise. * @see java.awt.Image * @see java.awt.image.ImageObserver * @see java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int) */ public abstract boolean drawImage(Image img, int x, int y, int width, int height, ImageObserver observer); /** * Draws as much of the specified image as is currently available. * The image is drawn with its top-left corner at * (x, y) in this graphics context's coordinate * space. 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 * 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 * {@code drawImage} returns {@code true}. * Otherwise, {@code drawImage} returns {@code 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. * @param img the specified image to be drawn. This method does * nothing if {@code img} is null. * @param x the x coordinate. * @param y the y coordinate. * @param bgcolor the background color to paint under the * non-opaque portions of the image. * @param observer object to be notified as more of * the image is converted. * @return {@code false} if the image pixels are still changing; * {@code true} otherwise. * @see java.awt.Image * @see java.awt.image.ImageObserver * @see java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int) */ public abstract boolean drawImage(Image img, int x, int y, Color bgcolor, ImageObserver observer); /** * Draws as much of the specified image as has already been scaled * to fit inside the specified rectangle. *
* 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 * {@code drawImage} returns {@code 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. * @param img the specified image to be drawn. This method does * nothing if {@code img} is null. * @param x the x coordinate. * @param y the y coordinate. * @param width the width of the rectangle. * @param height the height of the rectangle. * @param bgcolor the background color to paint under the * non-opaque portions of the image. * @param observer object to be notified as more of * the image is converted. * @return {@code false} if the image pixels are still changing; * {@code true} otherwise. * @see java.awt.Image * @see java.awt.image.ImageObserver * @see java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int) */ public abstract boolean drawImage(Image img, int x, int y, int width, int height, 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. Transparent pixels * do not affect whatever pixels are already there. *
* 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 * {@code drawImage} returns {@code 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. * @param img the specified image to be drawn. This method does * nothing if {@code img} is null. * @param dx1 the x coordinate of the first corner of the * destination rectangle. * @param dy1 the y coordinate of the first corner of the * destination rectangle. * @param dx2 the x coordinate of the second corner of the * destination rectangle. * @param dy2 the y coordinate of the second corner of the * destination rectangle. * @param sx1 the x coordinate of the first corner of the * source rectangle. * @param sy1 the y coordinate of the first corner of the * source rectangle. * @param sx2 the x coordinate of the second corner of the * source rectangle. * @param sy2 the y coordinate of the second corner of the * source rectangle. * @param observer object to be notified as more of the image is * scaled and converted. * @return {@code false} if the image pixels are still changing; * {@code true} otherwise. * @see java.awt.Image * @see java.awt.image.ImageObserver * @see java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int) * @since 1.1 */ public 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. *
* 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 * {@code drawImage} returns {@code 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. * @param img the specified image to be drawn. This method does * nothing if {@code img} is null. * @param dx1 the x coordinate of the first corner of the * destination rectangle. * @param dy1 the y coordinate of the first corner of the * destination rectangle. * @param dx2 the x coordinate of the second corner of the * destination rectangle. * @param dy2 the y coordinate of the second corner of the * destination rectangle. * @param sx1 the x coordinate of the first corner of the * source rectangle. * @param sy1 the y coordinate of the first corner of the * source rectangle. * @param sx2 the x coordinate of the second corner of the * source rectangle. * @param sy2 the y coordinate of the second corner of the * source rectangle. * @param bgcolor the background color to paint under the * non-opaque portions of the image. * @param observer object to be notified as more of the image is * scaled and converted. * @return {@code false} if the image pixels are still changing; * {@code true} otherwise. * @see java.awt.Image * @see java.awt.image.ImageObserver * @see java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int) * @since 1.1 */ 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); /** * Disposes of this graphics context and releases * any system resources that it is using. * A {@code Graphics} object cannot be used after * {@code dispose} has been called. *
* When a Java program runs, a large number of {@code 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 * {@code paint} and {@code update} methods * of components are automatically released by the system when * those methods return. For efficiency, programmers should * call {@code dispose} when finished using * a {@code Graphics} object only if it was created * directly from a component or another {@code Graphics} object. * @see java.awt.Graphics#finalize * @see java.awt.Component#paint * @see java.awt.Component#update * @see java.awt.Component#getGraphics * @see java.awt.Graphics#create */ public abstract void dispose(); /** * Disposes of this graphics context once it is no longer referenced. * * @deprecated The {@code finalize} method has been deprecated. * Subclasses that override {@code finalize} in order to perform cleanup * should be modified to use alternative cleanup mechanisms and * to remove the overriding {@code finalize} method. * When overriding the {@code finalize} method, its implementation must explicitly * ensure that {@code super.finalize()} is invoked as described in {@link Object#finalize}. * See the specification for {@link Object#finalize()} for further * information about migration options. * @see #dispose */ @Deprecated(since="9") public void finalize() { dispose(); } /** * Returns a {@code String} object representing this * {@code Graphics} object's value. * @return a string representation of this graphics context. */ public String toString() { return getClass().getName() + "[font=" + getFont() + ",color=" + getColor() + "]"; } /** * Returns the bounding rectangle of the current clipping area. * @return the bounding rectangle of the current clipping area * or {@code null} if no clip is set. * @deprecated As of JDK version 1.1, * replaced by {@code getClipBounds()}. */ @Deprecated public Rectangle getClipRect() { return getClipBounds(); } /** * 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. * * @param x the x coordinate of the rectangle to test against the clip * @param y the y coordinate of the rectangle to test against the clip * @param width the width of the rectangle to test against the clip * @param height the height of the rectangle to test against the clip * @return {@code true} if the specified rectangle intersects * the bounds of the current clip; {@code false} * otherwise. */ public boolean hitClip(int x, int y, int width, int height) { // Note, this implementation is not very efficient. // Subclasses should override this method and calculate // the results more directly. Rectangle clipRect = getClipBounds(); if (clipRect == null) { return true; } return clipRect.intersects(x, y, width, height); } /** * 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 {@link #getClipBounds() 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 {@code setClip(null)}, this method returns the * specified {@code Rectangle}. * @param r the rectangle where the current clipping area is * copied to. Any current values in this rectangle are * overwritten. * @return the bounding rectangle of the current clipping area. */ public Rectangle getClipBounds(Rectangle r) { // Note, this implementation is not very efficient. // Subclasses should override this method and avoid // the allocation overhead of getClipBounds(). Rectangle clipRect = getClipBounds(); if (clipRect != null) { r.x = clipRect.x; r.y = clipRect.y; r.width = clipRect.width; r.height = clipRect.height; } else if (r == null) { throw new NullPointerException("null rectangle parameter"); } return r; } }