Graphics


1   /*
2    * @(#)Graphics.java    1.69 04/05/18
3    *
4    * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   package java.awt;
8   
9   import java.io.*;
10  import java.lang.*;
11  import java.util.*;
12  import java.awt.image.ImageObserver  ;
13  import java.text.AttributedCharacterIterator  ;
14  
15  /**
16   * The <code>Graphics</code> class is the abstract base class for 
17   * all graphics contexts that allow an application to draw onto 
18   * components that are realized on various devices, as well as 
19   * onto off-screen images.
20   * <p>
21   * A <code>Graphics</code> object encapsulates state information needed
22   * for the basic rendering operations that Java supports.  This
23   * state information includes the following properties:
24   * <p>
25   * <ul>
26   * <li>The <code>Component</code> object on which to draw.
27   * <li>A translation origin for rendering and clipping coordinates.
28   * <li>The current clip.  
29   * <li>The current color.
30   * <li>The current font.
31   * <li>The current logical pixel operation function (XOR or Paint).
32   * <li>The current XOR alternation color 
33   *     (see {@link Graphics#setXORMode}).
34   * </ul>
35   * <p>
36   * Coordinates are infinitely thin and lie between the pixels of the
37   * output device.
38   * Operations that draw the outline of a figure operate by traversing
39   * an infinitely thin path between pixels with a pixel-sized pen that hangs
40   * down and to the right of the anchor point on the path.
41   * Operations that fill a figure operate by filling the interior
42   * of that infinitely thin path.
43   * Operations that render horizontal text render the ascending
44   * portion of character glyphs entirely above the baseline coordinate.
45   * <p>
46   * The graphics pen hangs down and to the right from the path it traverses. 
47   * This has the following implications:
48   * <p><ul>
49   * <li>If you draw a figure that covers a given rectangle, that 
50   * figure occupies one extra row of pixels on the right and bottom edges 
51   * as compared to filling a figure that is bounded by that same rectangle.
52   * <li>If you draw a horizontal line along the same <i>y</i> coordinate as
53   * the baseline of a line of text, that line is drawn entirely below
54   * the text, except for any descenders.
55   * </ul><p>
56   * All coordinates that appear as arguments to the methods of this
57   * <code>Graphics</code> object are considered relative to the 
58   * translation origin of this <code>Graphics</code> object prior to 
59   * the invocation of the method.
60   * <p>
61   * All rendering operations modify only pixels which lie within the
62   * area bounded by the current clip, which is specified by a {@link Shape} 
63   * in user space and is controlled by the program using the 
64   * <code>Graphics</code> object.  This <i>user clip</i> 
65   * is transformed into device space and combined with the 
66   * <i>device clip</i>, which is defined by the visibility of windows and
67   * device extents.  The combination of the user clip and device clip 
68   * defines the <i>composite clip</i>, which determines the final clipping
69   * region.  The user clip cannot be modified by the rendering 
70   * system to reflect the resulting composite clip. The user clip can only
71   * be changed through the <code>setClip</code> or <code>clipRect</code> 
72   * methods.
73   * All drawing or writing is done in the current color, 
74   * using the current paint mode, and in the current font. 
75   * 
76   * @version     1.69, 05/18/04
77   * @author  Sami Shaio
78   * @author  Arthur van Hoff
79   * @see     java.awt.Component
80   * @see     java.awt.Graphics#clipRect(int, int, int, int)
81   * @see     java.awt.Graphics#setColor(java.awt.Color)
82   * @see     java.awt.Graphics#setPaintMode()
83   * @see     java.awt.Graphics#setXORMode(java.awt.Color)
84   * @see     java.awt.Graphics#setFont(java.awt.Font)
85   * @since       JDK1.0
86   */
87  public abstract class Graphics {
88  
89      /**
90       * Constructs a new <code>Graphics</code> object.  
91       * This constructor is the default contructor for a graphics 
92       * context. 
93       * <p>
94       * Since <code>Graphics</code> is an abstract class, applications 
95       * cannot call this constructor directly. Graphics contexts are 
96       * obtained from other graphics contexts or are created by calling 
97       * <code>getGraphics</code> on a component. 
98       * @see        java.awt.Graphics#create()
99       * @see        java.awt.Component#getGraphics
100      */
101     protected Graphics() {
102     }
103 
104     /**
105      * Creates a new <code>Graphics</code> object that is 
106      * a copy of this <code>Graphics</code> object.
107      * @return     a new graphics context that is a copy of 
108      *                       this graphics context.
109      */
110     public abstract Graphics   create();
111 
112     /**
113      * Creates a new <code>Graphics</code> object based on this 
114      * <code>Graphics</code> object, but with a new translation and clip area.
115      * The new <code>Graphics</code> object has its origin 
116      * translated to the specified point (<i>x</i>,&nbsp;<i>y</i>). 
117      * Its clip area is determined by the intersection of the original
118      * clip area with the specified rectangle.  The arguments are all
119      * interpreted in the coordinate system of the original 
120      * <code>Graphics</code> object. The new graphics context is 
121      * identical to the original, except in two respects: 
122      * <p>
123      * <ul>
124      * <li>
125      * The new graphics context is translated by (<i>x</i>,&nbsp;<i>y</i>).  
126      * That is to say, the point (<code>0</code>,&nbsp;<code>0</code>) in the 
127      * new graphics context is the same as (<i>x</i>,&nbsp;<i>y</i>) in 
128      * the original graphics context. 
129      * <li>
130      * The new graphics context has an additional clipping rectangle, in 
131      * addition to whatever (translated) clipping rectangle it inherited 
132      * from the original graphics context. The origin of the new clipping 
133      * rectangle is at (<code>0</code>,&nbsp;<code>0</code>), and its size  
134      * is specified by the <code>width</code> and <code>height</code>
135      * arguments.
136      * </ul>
137      * <p>
138      * @param      x   the <i>x</i> coordinate.
139      * @param      y   the <i>y</i> coordinate.
140      * @param      width   the width of the clipping rectangle.
141      * @param      height   the height of the clipping rectangle.
142      * @return     a new graphics context.
143      * @see        java.awt.Graphics#translate
144      * @see        java.awt.Graphics#clipRect
145      */
146     public Graphics   create(int x, int y, int width, int height) {
147     Graphics   g = create();
148     if (g == null) return null;
149     g.translate(x, y);
150     g.clipRect(0, 0, width, height);
151     return g;
152     }
153 
154     /**
155      * Translates the origin of the graphics context to the point
156      * (<i>x</i>,&nbsp;<i>y</i>) in the current coordinate system. 
157      * Modifies this graphics context so that its new origin corresponds 
158      * to the point (<i>x</i>,&nbsp;<i>y</i>) in this graphics context's 
159      * original coordinate system.  All coordinates used in subsequent 
160      * rendering operations on this graphics context will be relative 
161      * to this new origin.
162      * @param  x   the <i>x</i> coordinate.
163      * @param  y   the <i>y</i> coordinate.
164      */
165     public abstract void translate(int x, int y);
166 
167     /**
168      * Gets this graphics context's current color.
169      * @return    this graphics context's current color.
170      * @see       java.awt.Color
171      * @see       java.awt.Graphics#setColor(Color)
172      */
173     public abstract Color   getColor();
174 
175     /**
176      * Sets this graphics context's current color to the specified 
177      * color. All subsequent graphics operations using this graphics 
178      * context use this specified color. 
179      * @param     c   the new rendering color.
180      * @see       java.awt.Color
181      * @see       java.awt.Graphics#getColor
182      */
183     public abstract void setColor(Color   c);
184 
185     /**
186      * Sets the paint mode of this graphics context to overwrite the 
187      * destination with this graphics context's current color. 
188      * This sets the logical pixel operation function to the paint or
189      * overwrite mode.  All subsequent rendering operations will
190      * overwrite the destination with the current color. 
191      */
192     public abstract void setPaintMode();
193 
194     /**
195      * Sets the paint mode of this graphics context to alternate between 
196      * this graphics context's current color and the new specified color. 
197      * This specifies that logical pixel operations are performed in the 
198      * XOR mode, which alternates pixels between the current color and 
199      * a specified XOR color. 
200      * <p>
201      * When drawing operations are performed, pixels which are the 
202      * current color are changed to the specified color, and vice versa. 
203      * <p>
204      * Pixels that are of colors other than those two colors are changed 
205      * in an unpredictable but reversible manner; if the same figure is 
206      * drawn twice, then all pixels are restored to their original values. 
207      * @param     c1 the XOR alternation color
208      */
209     public abstract void setXORMode(Color   c1);
210 
211     /**
212      * Gets the current font.
213      * @return    this graphics context's current font.
214      * @see       java.awt.Font
215      * @see       java.awt.Graphics#setFont(Font)
216      */
217     public abstract Font   getFont();
218 
219     /**
220      * Sets this graphics context's font to the specified font. 
221      * All subsequent text operations using this graphics context 
222      * use this font. 
223      * @param  font   the font.
224      * @see     java.awt.Graphics#getFont
225      * @see     java.awt.Graphics#drawString(java.lang.String, int, int)
226      * @see     java.awt.Graphics#drawBytes(byte[], int, int, int, int)
227      * @see     java.awt.Graphics#drawChars(char[], int, int, int, int)
228     */
229     public abstract void setFont(Font   font);
230 
231     /**
232      * Gets the font metrics of the current font.
233      * @return    the font metrics of this graphics 
234      *                    context's current font.
235      * @see       java.awt.Graphics#getFont
236      * @see       java.awt.FontMetrics
237      * @see       java.awt.Graphics#getFontMetrics(Font)
238      */
239     public FontMetrics   getFontMetrics() {
240     return getFontMetrics(getFont());
241     }
242 
243     /**
244      * Gets the font metrics for the specified font.
245      * @return    the font metrics for the specified font.
246      * @param     f the specified font
247      * @see       java.awt.Graphics#getFont
248      * @see       java.awt.FontMetrics
249      * @see       java.awt.Graphics#getFontMetrics()
250      */
251     public abstract FontMetrics   getFontMetrics(Font   f);
252 
253 
254     /**
255      * Returns the bounding rectangle of the current clipping area.
256      * This method refers to the user clip, which is independent of the
257      * clipping associated with device bounds and window visibility.  
258      * If no clip has previously been set, or if the clip has been 
259      * cleared using <code>setClip(null)</code>, this method returns
260      * <code>null</code>.
261      * The coordinates in the rectangle are relative to the coordinate
262      * system origin of this graphics context.
263      * @return      the bounding rectangle of the current clipping area,
264      *              or <code>null</code> if no clip is set.
265      * @see         java.awt.Graphics#getClip
266      * @see         java.awt.Graphics#clipRect
267      * @see         java.awt.Graphics#setClip(int, int, int, int)
268      * @see         java.awt.Graphics#setClip(Shape)
269      * @since       JDK1.1
270      */
271     public abstract Rectangle   getClipBounds();
272 
273     /** 
274      * Intersects the current clip with the specified rectangle.
275      * The resulting clipping area is the intersection of the current
276      * clipping area and the specified rectangle.  If there is no 
277      * current clipping area, either because the clip has never been 
278      * set, or the clip has been cleared using <code>setClip(null)</code>, 
279      * the specified rectangle becomes the new clip.
280      * This method sets the user clip, which is independent of the
281      * clipping associated with device bounds and window visibility.  
282      * This method can only be used to make the current clip smaller.
283      * To set the current clip larger, use any of the setClip methods.
284      * Rendering operations have no effect outside of the clipping area.
285      * @param x the x coordinate of the rectangle to intersect the clip with
286      * @param y the y coordinate of the rectangle to intersect the clip with
287      * @param width the width of the rectangle to intersect the clip with
288      * @param height the height of the rectangle to intersect the clip with
289      * @see #setClip(int, int, int, int)
290      * @see #setClip(Shape)
291      */
292     public abstract void clipRect(int x, int y, int width, int height);
293 
294     /**
295      * Sets the current clip to the rectangle specified by the given
296      * coordinates.  This method sets the user clip, which is 
297      * independent of the clipping associated with device bounds
298      * and window visibility.  
299      * Rendering operations have no effect outside of the clipping area.
300      * @param       x the <i>x</i> coordinate of the new clip rectangle.
301      * @param       y the <i>y</i> coordinate of the new clip rectangle.
302      * @param       width the width of the new clip rectangle.
303      * @param       height the height of the new clip rectangle.
304      * @see         java.awt.Graphics#clipRect
305      * @see         java.awt.Graphics#setClip(Shape)
306      * @see     java.awt.Graphics#getClip
307      * @since       JDK1.1
308      */
309     public abstract void setClip(int x, int y, int width, int height);
310 
311     /**
312      * Gets the current clipping area.
313      * This method returns the user clip, which is independent of the
314      * clipping associated with device bounds and window visibility.
315      * If no clip has previously been set, or if the clip has been 
316      * cleared using <code>setClip(null)</code>, this method returns 
317      * <code>null</code>.
318      * @return      a <code>Shape</code> object representing the 
319      *              current clipping area, or <code>null</code> if
320      *              no clip is set.
321      * @see         java.awt.Graphics#getClipBounds
322      * @see         java.awt.Graphics#clipRect
323      * @see         java.awt.Graphics#setClip(int, int, int, int)
324      * @see         java.awt.Graphics#setClip(Shape)
325      * @since       JDK1.1
326      */
327     public abstract Shape   getClip();
328 
329     /**
330      * Sets the current clipping area to an arbitrary clip shape.
331      * Not all objects that implement the <code>Shape</code> 
332      * interface can be used to set the clip.  The only 
333      * <code>Shape</code> objects that are guaranteed to be 
334      * supported are <code>Shape</code> objects that are
335      * obtained via the <code>getClip</code> method and via 
336      * <code>Rectangle</code> objects.  This method sets the
337      * user clip, which is independent of the clipping associated
338      * with device bounds and window visibility.
339      * @param clip the <code>Shape</code> to use to set the clip
340      * @see         java.awt.Graphics#getClip()
341      * @see         java.awt.Graphics#clipRect
342      * @see         java.awt.Graphics#setClip(int, int, int, int)
343      * @since       JDK1.1
344      */
345     public abstract void setClip(Shape   clip);
346 
347     /**
348      * Copies an area of the component by a distance specified by 
349      * <code>dx</code> and <code>dy</code>. From the point specified
350      * by <code>x</code> and <code>y</code>, this method
351      * copies downwards and to the right.  To copy an area of the 
352      * component to the left or upwards, specify a negative value for 
353      * <code>dx</code> or <code>dy</code>.
354      * If a portion of the source rectangle lies outside the bounds 
355      * of the component, or is obscured by another window or component, 
356      * <code>copyArea</code> will be unable to copy the associated
357      * pixels. The area that is omitted can be refreshed by calling 
358      * the component's <code>paint</code> method.
359      * @param       x the <i>x</i> coordinate of the source rectangle.
360      * @param       y the <i>y</i> coordinate of the source rectangle.
361      * @param       width the width of the source rectangle.
362      * @param       height the height of the source rectangle.
363      * @param       dx the horizontal distance to copy the pixels.
364      * @param       dy the vertical distance to copy the pixels.
365      */
366     public abstract void copyArea(int x, int y, int width, int height,
367                   int dx, int dy);
368 
369     /** 
370      * Draws a line, using the current color, between the points 
371      * <code>(x1,&nbsp;y1)</code> and <code>(x2,&nbsp;y2)</code> 
372      * in this graphics context's coordinate system. 
373      * @param   x1  the first point's <i>x</i> coordinate.
374      * @param   y1  the first point's <i>y</i> coordinate.
375      * @param   x2  the second point's <i>x</i> coordinate.
376      * @param   y2  the second point's <i>y</i> coordinate.
377      */
378     public abstract void drawLine(int x1, int y1, int x2, int y2);
379 
380     /** 
381      * Fills the specified rectangle. 
382      * The left and right edges of the rectangle are at 
383      * <code>x</code> and <code>x&nbsp;+&nbsp;width&nbsp;-&nbsp;1</code>. 
384      * The top and bottom edges are at 
385      * <code>y</code> and <code>y&nbsp;+&nbsp;height&nbsp;-&nbsp;1</code>. 
386      * The resulting rectangle covers an area 
387      * <code>width</code> pixels wide by 
388      * <code>height</code> pixels tall.
389      * The rectangle is filled using the graphics context's current color. 
390      * @param         x   the <i>x</i> coordinate 
391      *                         of the rectangle to be filled.
392      * @param         y   the <i>y</i> coordinate 
393      *                         of the rectangle to be filled.
394      * @param         width   the width of the rectangle to be filled.
395      * @param         height   the height of the rectangle to be filled.
396      * @see           java.awt.Graphics#clearRect
397      * @see           java.awt.Graphics#drawRect
398      */
399     public abstract void fillRect(int x, int y, int width, int height);
400 
401     /** 
402      * Draws the outline of the specified rectangle. 
403      * The left and right edges of the rectangle are at 
404      * <code>x</code> and <code>x&nbsp;+&nbsp;width</code>. 
405      * The top and bottom edges are at 
406      * <code>y</code> and <code>y&nbsp;+&nbsp;height</code>. 
407      * The rectangle is drawn using the graphics context's current color.
408      * @param         x   the <i>x</i> coordinate 
409      *                         of the rectangle to be drawn.
410      * @param         y   the <i>y</i> coordinate 
411      *                         of the rectangle to be drawn.
412      * @param         width   the width of the rectangle to be drawn.
413      * @param         height   the height of the rectangle to be drawn.
414      * @see          java.awt.Graphics#fillRect
415      * @see          java.awt.Graphics#clearRect
416      */
417     public void drawRect(int x, int y, int width, int height) {
418     if ((width < 0) || (height < 0)) {
419         return;
420     }
421 
422     if (height == 0 || width == 0) {
423         drawLine(x, y, x + width, y + height);
424     } else {
425         drawLine(x, y, x + width - 1, y);
426         drawLine(x + width, y, x + width, y + height - 1);
427         drawLine(x + width, y + height, x + 1, y + height);
428         drawLine(x, y + height, x, y + 1);
429     }
430     }
431     
432     /** 
433      * Clears the specified rectangle by filling it with the background
434      * color of the current drawing surface. This operation does not 
435      * use the current paint mode. 
436      * <p>
437      * Beginning with Java&nbsp;1.1, the background color 
438      * of offscreen images may be system dependent. Applications should 
439      * use <code>setColor</code> followed by <code>fillRect</code> to 
440      * ensure that an offscreen image is cleared to a specific color. 
441      * @param       x the <i>x</i> coordinate of the rectangle to clear.
442      * @param       y the <i>y</i> coordinate of the rectangle to clear.
443      * @param       width the width of the rectangle to clear.
444      * @param       height the height of the rectangle to clear.
445      * @see         java.awt.Graphics#fillRect(int, int, int, int)
446      * @see         java.awt.Graphics#drawRect
447      * @see         java.awt.Graphics#setColor(java.awt.Color)
448      * @see         java.awt.Graphics#setPaintMode
449      * @see         java.awt.Graphics#setXORMode(java.awt.Color)
450      */
451     public abstract void clearRect(int x, int y, int width, int height);
452 
453     /** 
454      * Draws an outlined round-cornered rectangle using this graphics 
455      * context's current color. The left and right edges of the rectangle 
456      * are at <code>x</code> and <code>x&nbsp;+&nbsp;width</code>, 
457      * respectively. The top and bottom edges of the rectangle are at 
458      * <code>y</code> and <code>y&nbsp;+&nbsp;height</code>. 
459      * @param      x the <i>x</i> coordinate of the rectangle to be drawn.
460      * @param      y the <i>y</i> coordinate of the rectangle to be drawn.
461      * @param      width the width of the rectangle to be drawn.
462      * @param      height the height of the rectangle to be drawn.
463      * @param      arcWidth the horizontal diameter of the arc 
464      *                    at the four corners.
465      * @param      arcHeight the vertical diameter of the arc 
466      *                    at the four corners.
467      * @see        java.awt.Graphics#fillRoundRect
468      */
469     public abstract void drawRoundRect(int x, int y, int width, int height,
470                        int arcWidth, int arcHeight);
471 
472     /** 
473      * Fills the specified rounded corner rectangle with the current color.
474      * The left and right edges of the rectangle 
475      * are at <code>x</code> and <code>x&nbsp;+&nbsp;width&nbsp;-&nbsp;1</code>, 
476      * respectively. The top and bottom edges of the rectangle are at 
477      * <code>y</code> and <code>y&nbsp;+&nbsp;height&nbsp;-&nbsp;1</code>. 
478      * @param       x the <i>x</i> coordinate of the rectangle to be filled.
479      * @param       y the <i>y</i> coordinate of the rectangle to be filled.
480      * @param       width the width of the rectangle to be filled.
481      * @param       height the height of the rectangle to be filled.
482      * @param       arcWidth the horizontal diameter 
483      *                     of the arc at the four corners.
484      * @param       arcHeight the vertical diameter 
485      *                     of the arc at the four corners.
486      * @see         java.awt.Graphics#drawRoundRect
487      */
488     public abstract void fillRoundRect(int x, int y, int width, int height,
489                        int arcWidth, int arcHeight);
490 
491     /**
492      * Draws a 3-D highlighted outline of the specified rectangle.
493      * The edges of the rectangle are highlighted so that they
494      * appear to be beveled and lit from the upper left corner.
495      * <p>
496      * The colors used for the highlighting effect are determined 
497      * based on the current color.
498      * The resulting rectangle covers an area that is 
499      * <code>width&nbsp;+&nbsp;1</code> pixels wide
500      * by <code>height&nbsp;+&nbsp;1</code> pixels tall.
501      * @param       x the <i>x</i> coordinate of the rectangle to be drawn.
502      * @param       y the <i>y</i> coordinate of the rectangle to be drawn.
503      * @param       width the width of the rectangle to be drawn.
504      * @param       height the height of the rectangle to be drawn.
505      * @param       raised a boolean that determines whether the rectangle
506      *                      appears to be raised above the surface 
507      *                      or sunk into the surface.
508      * @see         java.awt.Graphics#fill3DRect
509      */
510     public void draw3DRect(int x, int y, int width, int height,
511                boolean raised) {
512     Color   c = getColor();
513     Color   brighter = c.brighter();
514     Color   darker = c.darker();
515 
516     setColor(raised ? brighter : darker);
517     drawLine(x, y, x, y + height);
518     drawLine(x + 1, y, x + width - 1, y);
519     setColor(raised ? darker : brighter);
520     drawLine(x + 1, y + height, x + width, y + height);
521     drawLine(x + width, y, x + width, y + height - 1);
522     setColor(c);
523     }    
524 
525     /**
526      * Paints a 3-D highlighted rectangle filled with the current color.
527      * The edges of the rectangle will be highlighted so that it appears
528      * as if the edges were beveled and lit from the upper left corner.
529      * The colors used for the highlighting effect will be determined from
530      * the current color.
531      * @param       x the <i>x</i> coordinate of the rectangle to be filled.
532      * @param       y the <i>y</i> coordinate of the rectangle to be filled.
533      * @param       width the width of the rectangle to be filled.
534      * @param       height the height of the rectangle to be filled.
535      * @param       raised a boolean value that determines whether the 
536      *                      rectangle appears to be raised above the surface 
537      *                      or etched into the surface.
538      * @see         java.awt.Graphics#draw3DRect
539      */
540     public void fill3DRect(int x, int y, int width, int height,
541                boolean raised) {
542     Color   c = getColor();
543     Color   brighter = c.brighter();
544     Color   darker = c.darker();
545 
546     if (!raised) {
547         setColor(darker);
548     }
549     fillRect(x+1, y+1, width-2, height-2);
550     setColor(raised ? brighter : darker);
551     drawLine(x, y, x, y + height - 1);
552     drawLine(x + 1, y, x + width - 2, y);
553     setColor(raised ? darker : brighter);
554     drawLine(x + 1, y + height - 1, x + width - 1, y + height - 1);
555     drawLine(x + width - 1, y, x + width - 1, y + height - 2);
556     setColor(c);
557     }    
558 
559     /** 
560      * Draws the outline of an oval.
561      * The result is a circle or ellipse that fits within the 
562      * rectangle specified by the <code>x</code>, <code>y</code>, 
563      * <code>width</code>, and <code>height</code> arguments. 
564      * <p> 
565      * The oval covers an area that is 
566      * <code>width&nbsp;+&nbsp;1</code> pixels wide 
567      * and <code>height&nbsp;+&nbsp;1</code> pixels tall. 
568      * @param       x the <i>x</i> coordinate of the upper left 
569      *                     corner of the oval to be drawn.
570      * @param       y the <i>y</i> coordinate of the upper left 
571      *                     corner of the oval to be drawn.
572      * @param       width the width of the oval to be drawn.
573      * @param       height the height of the oval to be drawn.
574      * @see         java.awt.Graphics#fillOval
575      */
576     public abstract void drawOval(int x, int y, int width, int height);
577 
578     /** 
579      * Fills an oval bounded by the specified rectangle with the
580      * current color.
581      * @param       x the <i>x</i> coordinate of the upper left corner 
582      *                     of the oval to be filled.
583      * @param       y the <i>y</i> coordinate of the upper left corner 
584      *                     of the oval to be filled.
585      * @param       width the width of the oval to be filled.
586      * @param       height the height of the oval to be filled.
587      * @see         java.awt.Graphics#drawOval
588      */
589     public abstract void fillOval(int x, int y, int width, int height);
590 
591     /**
592      * Draws the outline of a circular or elliptical arc 
593      * covering the specified rectangle.
594      * <p>
595      * The resulting arc begins at <code>startAngle</code> and extends  
596      * for <code>arcAngle</code> degrees, using the current color.
597      * Angles are interpreted such that 0&nbsp;degrees 
598      * is at the 3&nbsp;o'clock position. 
599      * A positive value indicates a counter-clockwise rotation
600      * while a negative value indicates a clockwise rotation.
601      * <p>
602      * The center of the arc is the center of the rectangle whose origin 
603      * is (<i>x</i>,&nbsp;<i>y</i>) and whose size is specified by the 
604      * <code>width</code> and <code>height</code> arguments. 
605      * <p>
606      * The resulting arc covers an area 
607      * <code>width&nbsp;+&nbsp;1</code> pixels wide
608      * by <code>height&nbsp;+&nbsp;1</code> pixels tall.
609      * <p>
610      * The angles are specified relative to the non-square extents of
611      * the bounding rectangle such that 45 degrees always falls on the
612      * line from the center of the ellipse to the upper right corner of
613      * the bounding rectangle. As a result, if the bounding rectangle is
614      * noticeably longer in one axis than the other, the angles to the
615      * start and end of the arc segment will be skewed farther along the
616      * longer axis of the bounds.
617      * @param        x the <i>x</i> coordinate of the 
618      *                    upper-left corner of the arc to be drawn.
619      * @param        y the <i>y</i>  coordinate of the 
620      *                    upper-left corner of the arc to be drawn.
621      * @param        width the width of the arc to be drawn.
622      * @param        height the height of the arc to be drawn.
623      * @param        startAngle the beginning angle.
624      * @param        arcAngle the angular extent of the arc, 
625      *                    relative to the start angle.
626      * @see         java.awt.Graphics#fillArc
627      */
628     public abstract void drawArc(int x, int y, int width, int height,
629                  int startAngle, int arcAngle);
630 
631     /** 
632      * Fills a circular or elliptical arc covering the specified rectangle.
633      * <p>
634      * The resulting arc begins at <code>startAngle</code> and extends  
635      * for <code>arcAngle</code> degrees.
636      * Angles are interpreted such that 0&nbsp;degrees 
637      * is at the 3&nbsp;o'clock position. 
638      * A positive value indicates a counter-clockwise rotation
639      * while a negative value indicates a clockwise rotation.
640      * <p>
641      * The center of the arc is the center of the rectangle whose origin 
642      * is (<i>x</i>,&nbsp;<i>y</i>) and whose size is specified by the 
643      * <code>width</code> and <code>height</code> arguments. 
644      * <p>
645      * The resulting arc covers an area 
646      * <code>width&nbsp;+&nbsp;1</code> pixels wide
647      * by <code>height&nbsp;+&nbsp;1</code> pixels tall.
648      * <p>
649      * The angles are specified relative to the non-square extents of
650      * the bounding rectangle such that 45 degrees always falls on the
651      * line from the center of the ellipse to the upper right corner of
652      * the bounding rectangle. As a result, if the bounding rectangle is
653      * noticeably longer in one axis than the other, the angles to the
654      * start and end of the arc segment will be skewed farther along the
655      * longer axis of the bounds.
656      * @param        x the <i>x</i> coordinate of the 
657      *                    upper-left corner of the arc to be filled.
658      * @param        y the <i>y</i>  coordinate of the 
659      *                    upper-left corner of the arc to be filled.
660      * @param        width the width of the arc to be filled.
661      * @param        height the height of the arc to be filled.
662      * @param        startAngle the beginning angle.
663      * @param        arcAngle the angular extent of the arc, 
664      *                    relative to the start angle.
665      * @see         java.awt.Graphics#drawArc
666      */
667     public abstract void fillArc(int x, int y, int width, int height,
668                  int startAngle, int arcAngle);
669 
670     /** 
671      * Draws a sequence of connected lines defined by 
672      * arrays of <i>x</i> and <i>y</i> coordinates. 
673      * Each pair of (<i>x</i>,&nbsp;<i>y</i>) coordinates defines a point.
674      * The figure is not closed if the first point 
675      * differs from the last point.
676      * @param       xPoints an array of <i>x</i> points
677      * @param       yPoints an array of <i>y</i> points
678      * @param       nPoints the total number of points
679      * @see         java.awt.Graphics#drawPolygon(int[], int[], int)
680      * @since       JDK1.1
681      */
682     public abstract void drawPolyline(int xPoints[], int yPoints[],
683                       int nPoints);
684 
685     /** 
686      * Draws a closed polygon defined by 
687      * arrays of <i>x</i> and <i>y</i> coordinates. 
688      * Each pair of (<i>x</i>,&nbsp;<i>y</i>) coordinates defines a point.
689      * <p>
690      * This method draws the polygon defined by <code>nPoint</code> line 
691      * segments, where the first <code>nPoint&nbsp;-&nbsp;1</code> 
692      * line segments are line segments from 
693      * <code>(xPoints[i&nbsp;-&nbsp;1],&nbsp;yPoints[i&nbsp;-&nbsp;1])</code> 
694      * to <code>(xPoints[i],&nbsp;yPoints[i])</code>, for 
695      * 1&nbsp;&le;&nbsp;<i>i</i>&nbsp;&le;&nbsp;<code>nPoints</code>.  
696      * The figure is automatically closed by drawing a line connecting
697      * the final point to the first point, if those points are different.
698      * @param        xPoints   a an array of <code>x</code> coordinates.
699      * @param        yPoints   a an array of <code>y</code> coordinates.
700      * @param        nPoints   a the total number of points.
701      * @see          java.awt.Graphics#fillPolygon
702      * @see          java.awt.Graphics#drawPolyline
703      */
704     public abstract void drawPolygon(int xPoints[], int yPoints[],
705                      int nPoints);
706 
707     /** 
708      * Draws the outline of a polygon defined by the specified 
709      * <code>Polygon</code> object. 
710      * @param        p the polygon to draw.
711      * @see          java.awt.Graphics#fillPolygon
712      * @see          java.awt.Graphics#drawPolyline
713      */
714     public void drawPolygon(Polygon   p) {
715     drawPolygon(p.xpoints, p.ypoints, p.npoints);
716     }
717 
718     /** 
719      * Fills a closed polygon defined by 
720      * arrays of <i>x</i> and <i>y</i> coordinates. 
721      * <p>
722      * This method draws the polygon defined by <code>nPoint</code> line 
723      * segments, where the first <code>nPoint&nbsp;-&nbsp;1</code> 
724      * line segments are line segments from 
725      * <code>(xPoints[i&nbsp;-&nbsp;1],&nbsp;yPoints[i&nbsp;-&nbsp;1])</code> 
726      * to <code>(xPoints[i],&nbsp;yPoints[i])</code>, for 
727      * 1&nbsp;&le;&nbsp;<i>i</i>&nbsp;&le;&nbsp;<code>nPoints</code>.  
728      * The figure is automatically closed by drawing a line connecting
729      * the final point to the first point, if those points are different.
730      * <p>
731      * The area inside the polygon is defined using an 
732      * even-odd fill rule, also known as the alternating rule.
733      * @param        xPoints   a an array of <code>x</code> coordinates.
734      * @param        yPoints   a an array of <code>y</code> coordinates.
735      * @param        nPoints   a the total number of points.
736      * @see          java.awt.Graphics#drawPolygon(int[], int[], int)
737      */
738     public abstract void fillPolygon(int xPoints[], int yPoints[],
739                      int nPoints);
740 
741     /** 
742      * Fills the polygon defined by the specified Polygon object with
743      * the graphics context's current color. 
744      * <p>
745      * The area inside the polygon is defined using an 
746      * even-odd fill rule, also known as the alternating rule.
747      * @param        p the polygon to fill.
748      * @see          java.awt.Graphics#drawPolygon(int[], int[], int)
749      */
750     public void fillPolygon(Polygon   p) {
751     fillPolygon(p.xpoints, p.ypoints, p.npoints);
752     }
753 
754     /** 
755      * Draws the text given by the specified string, using this 
756      * graphics context's current font and color. The baseline of the 
757      * leftmost character is at position (<i>x</i>,&nbsp;<i>y</i>) in this 
758      * graphics context's coordinate system. 
759      * @param       str      the string to be drawn.
760      * @param       x        the <i>x</i> coordinate.
761      * @param       y        the <i>y</i> coordinate.
762      * @see         java.awt.Graphics#drawBytes
763      * @see         java.awt.Graphics#drawChars
764      */
765     public abstract void drawString(String   str, int x, int y);
766 
767     /** 
768      * Draws the text given by the specified iterator, using this 
769      * graphics context's current color. The iterator has to specify a font
770      * for each character. The baseline of the 
771      * leftmost character is at position (<i>x</i>,&nbsp;<i>y</i>) in this 
772      * graphics context's coordinate system. 
773      * @param       iterator the iterator whose text is to be drawn
774      * @param       x        the <i>x</i> coordinate.
775      * @param       y        the <i>y</i> coordinate.
776      * @see         java.awt.Graphics#drawBytes
777      * @see         java.awt.Graphics#drawChars
778      */
779    public abstract void drawString(AttributedCharacterIterator   iterator,
780                                     int x, int y);
781 
782     /** 
783      * Draws the text given by the specified character array, using this 
784      * graphics context's current font and color. The baseline of the 
785      * first character is at position (<i>x</i>,&nbsp;<i>y</i>) in this 
786      * graphics context's coordinate system. 
787      * @param data the array of characters to be drawn
788      * @param offset the start offset in the data
789      * @param length the number of characters to be drawn
790      * @param x the <i>x</i> coordinate of the baseline of the text
791      * @param y the <i>y</i> coordinate of the baseline of the text
792      * @see         java.awt.Graphics#drawBytes
793      * @see         java.awt.Graphics#drawString
794      */
795     public void drawChars(char data[], int offset, int length, int x, int y) {
796     drawString(new String  (data, offset, length), x, y);
797     }
798 
799     /** 
800      * Draws the text given by the specified byte array, using this 
801      * graphics context's current font and color. The baseline of the 
802      * first character is at position (<i>x</i>,&nbsp;<i>y</i>) in this 
803      * graphics context's coordinate system.
804      * @param data the data to be drawn
805      * @param offset the start offset in the data
806      * @param length the number of bytes that are drawn
807      * @param x the <i>x</i> coordinate of the baseline of the text
808      * @param y the <i>y</i> coordinate of the baseline of the text
809      * @see         java.awt.Graphics#drawChars
810      * @see         java.awt.Graphics#drawString
811      */
812     public void drawBytes(byte data[], int offset, int length, int x, int y) {
813     drawString(new String  (data, 0, offset, length), x, y);
814     }
815 
816     /** 
817      * Draws as much of the specified image as is currently available.
818      * The image is drawn with its top-left corner at 
819      * (<i>x</i>,&nbsp;<i>y</i>) in this graphics context's coordinate 
820      * space. Transparent pixels in the image do not affect whatever 
821      * pixels are already there. 
822      * <p>
823      * This method returns immediately in all cases, even if the
824      * complete image has not yet been loaded, and it has not been dithered 
825      * and converted for the current output device.
826      * <p>
827      * If the image has completely loaded and its pixels are
828      * no longer being changed, then
829      * <code>drawImage</code> returns <code>true</code>. 
830      * Otherwise, <code>drawImage</code> returns <code>false</code>
831      * and as more of
832      * the image becomes available 
833      * or it is time to draw another frame of animation,
834      * the process that loads the image notifies 
835      * the specified image observer.
836      * @param    img the specified image to be drawn. This method does
837      *               nothing if <code>img</code> is null.
838      * @param    x   the <i>x</i> coordinate.
839      * @param    y   the <i>y</i> coordinate.
840      * @param    observer    object to be notified as more of 
841      *                          the image is converted.
842      * @return   <code>false</code> if the image pixels are still changing;
843      *           <code>true</code> otherwise.
844      * @see      java.awt.Image
845      * @see      java.awt.image.ImageObserver
846      * @see      java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int)
847      */
848     public abstract boolean drawImage(Image   img, int x, int y, 
849                       ImageObserver   observer);
850 
851     /**
852      * Draws as much of the specified image as has already been scaled
853      * to fit inside the specified rectangle.
854      * <p>
855      * The image is drawn inside the specified rectangle of this 
856      * graphics context's coordinate space, and is scaled if 
857      * necessary. Transparent pixels do not affect whatever pixels
858      * are already there. 
859      * <p>
860      * This method returns immediately in all cases, even if the
861      * entire image has not yet been scaled, dithered, and converted
862      * for the current output device.
863      * If the current output representation is not yet complete, then
864      * <code>drawImage</code> returns <code>false</code>. As more of
865      * the image becomes available, the process that loads the image notifies
866      * the image observer by calling its <code>imageUpdate</code> method.
867      * <p>
868      * A scaled version of an image will not necessarily be
869      * available immediately just because an unscaled version of the
870      * image has been constructed for this output device.  Each size of
871      * the image may be cached separately and generated from the original
872      * data in a separate image production sequence.
873      * @param    img    the specified image to be drawn. This method does
874      *                  nothing if <code>img</code> is null.
875      * @param    x      the <i>x</i> coordinate.
876      * @param    y      the <i>y</i> coordinate.
877      * @param    width  the width of the rectangle.
878      * @param    height the height of the rectangle.
879      * @param    observer    object to be notified as more of 
880      *                          the image is converted.
881      * @return   <code>false</code> if the image pixels are still changing;
882      *           <code>true</code> otherwise.
883      * @see      java.awt.Image
884      * @see      java.awt.image.ImageObserver
885      * @see      java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int)
886      */
887     public abstract boolean drawImage(Image   img, int x, int y,
888                       int width, int height, 
889                       ImageObserver   observer);
890     
891     /** 
892      * Draws as much of the specified image as is currently available.
893      * The image is drawn with its top-left corner at 
894      * (<i>x</i>,&nbsp;<i>y</i>) in this graphics context's coordinate 
895      * space.  Transparent pixels are drawn in the specified
896      * background color.
897      * <p> 
898      * This operation is equivalent to filling a rectangle of the
899      * width and height of the specified image with the given color and then
900      * drawing the image on top of it, but possibly more efficient.
901      * <p>
902      * This method returns immediately in all cases, even if the
903      * complete image has not yet been loaded, and it has not been dithered 
904      * and converted for the current output device.
905      * <p>
906      * If the image has completely loaded and its pixels are
907      * no longer being changed, then
908      * <code>drawImage</code> returns <code>true</code>. 
909      * Otherwise, <code>drawImage</code> returns <code>false</code>
910      * and as more of
911      * the image becomes available 
912      * or it is time to draw another frame of animation,
913      * the process that loads the image notifies 
914      * the specified image observer.
915      * @param    img the specified image to be drawn. This method does
916      *               nothing if <code>img</code> is null.
917      * @param    x      the <i>x</i> coordinate.
918      * @param    y      the <i>y</i> coordinate.
919      * @param    bgcolor the background color to paint under the
920      *                         non-opaque portions of the image.
921      * @param    observer    object to be notified as more of 
922      *                          the image is converted.
923      * @return   <code>false</code> if the image pixels are still changing;
924      *           <code>true</code> otherwise.
925      * @see      java.awt.Image
926      * @see      java.awt.image.ImageObserver
927      * @see      java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int)
928      */
929     public abstract boolean drawImage(Image   img, int x, int y, 
930                       Color   bgcolor,
931                       ImageObserver   observer);
932 
933     /**
934      * Draws as much of the specified image as has already been scaled
935      * to fit inside the specified rectangle.
936      * <p>
937      * The image is drawn inside the specified rectangle of this 
938      * graphics context's coordinate space, and is scaled if 
939      * necessary. Transparent pixels are drawn in the specified
940      * background color. 
941      * This operation is equivalent to filling a rectangle of the
942      * width and height of the specified image with the given color and then
943      * drawing the image on top of it, but possibly more efficient.
944      * <p>
945      * This method returns immediately in all cases, even if the
946      * entire image has not yet been scaled, dithered, and converted
947      * for the current output device.
948      * If the current output representation is not yet complete then
949      * <code>drawImage</code> returns <code>false</code>. As more of
950      * the image becomes available, the process that loads the image notifies 
951      * the specified image observer.
952      * <p>
953      * A scaled version of an image will not necessarily be
954      * available immediately just because an unscaled version of the
955      * image has been constructed for this output device.  Each size of
956      * the image may be cached separately and generated from the original
957      * data