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SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectjavax.microedition.lcdui.Graphics
public class Graphics
Provides simple 2D geometric rendering capability.
All implementations MUST support double-buffered graphics.
Graphics may be rendered to the display's off-screen buffer or to an
off-screen image buffer. The destination of rendered graphics depends on
the provenance of the graphics object. A graphics object for rendering
to the display is passed to the Canvas
object's
paint()
method. This is the only means by which a graphics object may be obtained
whose destination is the display. Furthermore, applications may draw using
this graphics object only for the duration of the paint()
method.
A graphics object for rendering to an off-screen image buffer may be obtained
by calling the getGraphics()
method on the
desired image. A graphics object so obtained may be held indefinitely by the
application, and requests may be issued on this graphics object at any time.
In drawing methods that take an Image as a parameter: if the Image is an instance of ScalableImage, it MUST be rasterized before drawing. If the scalable image does not define an initial viewport size, the default viewport of 100 by 100 pixels MUST be used. If the scalable image contains animation, the rasterized starting frame of the animation MUST be used when drawing.
The default coordinate system's origin is at the upper left-hand corner of the destination. The X-axis direction is positive towards the right, and the Y-axis direction is positive downwards. Applications may assume that horizontal and vertical distances in the coordinate system represent equal distances on the actual device display, that is, pixels are square. A facility is provided for translating the origin of the coordinate system. All coordinates are specified as integers.
The coordinate system represents locations between pixels, not the pixels
themselves. Therefore, the first pixel in the upper left corner of the
display lies in the square bounded by coordinates
(0,0) , (1,0) , (0,1) , (1,1)
.
Under this definition, the semantics for fill operations are clear. Since coordinate grid lines lie between pixels, fill operations affect pixels that lie entirely within the region bounded by the coordinates of the operation. For example, the operation
g.fillRect(0, 0, 3, 2);
paints exactly six pixels. (In this example, and in all subsequent examples,
the variable g
is assumed to contain a reference to a
Graphics
object.)
An artifact of the coordinate system is that the area affected by a fill operation differs slightly from the area affected by a draw operation given the same coordinates. For example, consider the operations
g.fillRect(x, y, w, h); // 1 g.drawRect(x, y, w, h); // 2
Statement (1) fills a rectangle w
pixels wide and
h
pixels high. Statement (2) draws a rectangle whose left and
top edges are within the area filled by statement (1). However, the bottom
and right edges lie one pixel outside the filled area. This is
counterintuitive, but it preserves the invariant that
g.drawLine(x, y, x + w, y); g.drawLine(x + w, y, x + w, y + h); g.drawLine(x + w, y + h, x, y + h); g.drawLine(x, y + h, x, y);
has an effect identical to statement (2) above.
The exact pixels painted by drawLine()
and
drawArc()
are not specified. Pixels touched by a fill
operation must either exactly overlap or directly abut pixels touched by the
corresponding draw operation. A fill operation must never leave a gap between
the filled area and the pixels touched by the corresponding draw operation,
nor may the fill operation touch pixels outside the area bounded by the
corresponding draw operation.
The clip is the set of pixels in the destination of the Graphics
object that may be modified by graphics rendering operations.
There is a single clip per Graphics
object. The only pixels
modified by graphics operations are those that lie within the clip. Pixels
outside the clip are not modified by any graphics operations.
Operations are provided for intersecting the current clip with a given rectangle and for setting the current clip outright. The application may specify the clip by supplying a clip rectangle using coordinates relative to the current coordinate system.
It is legal to specify a clip rectangle whose width or height is zero or negative. In this case the clip is considered to be empty, that is, no pixels are contained within it. Therefore, if any graphics operations are issued under such a clip, no pixels will be modified.
It is legal to specify a clip rectangle that extends beyond or resides entirely beyond the bounds of the destination. No pixels exist outside the bounds of the destination, and the area of the clip rectangle that is outside the destination is ignored. Only the pixels that lie both within the destination and within the specified clip rectangle are considered to be part of the clip.
Operations on the coordinate system, such as
translate()
, do not modify the clip.
The methods getClipX()
,
getClipY()
,
getClipWidth()
and
getClipHeight()
must return a rectangle
that, if passed to setClip
without an intervening change to
the Graphics
object's coordinate system, must result in the
identical set of pixels in the clip. The rectangle returned from the
getClip
family of methods may differ from the clip rectangle
that was requested in setClip()
.
This can occur if the coordinate system has been changed or if the
implementation has chosen to intersect the clip rectangle with the bounds of
the destination of the Graphics
object.
If a graphics operation is affected by the clip, the pixels touched by that
operation must be the same ones that would be touched as if the clip did not
affect the operation. For example, consider a clip represented by the
rectangle (cx, cy, cw, ch)
and a point (x1, y1)
that lies outside this rectangle and a point (x2, y2)
that
lies within this rectangle. In the following code fragment,
g.setClip(0, 0, canvas.getWidth(), canvas.getHeight()); g.drawLine(x1, y1, x2, y2); // 3 g.setClip(cx, cy, cw, ch); g.drawLine(x1, y1, x2, y2); // 4
The pixels touched by statement (4) must be identical to the pixels within
(cx, cy, cw, ch)
touched by statement (3).
The API supports a 32-bit ARGB color model, with 8 bits for the alpha, red, green, and blue components of a color. Given its pervasive use for internet applications and adoption by the W3C, MIDP devices should conform to the sRGB color space as closely as possible when interpreting RGB color values.
Not all devices support a full 32 bits' worth of color and thus they will map colors requested by the application into colors available on the device. The color depth of off-screen images must not be lower than that of any display that is an integral part of the device. Auxiliary displays that the device connects to may have higher color depths, in which case colors are converted accordingly.
Facilities are provided in the Display
class for obtaining a
specific display's characteristics, such as whether color is available and
how many distinct gray levels are available. Applications may also use
getDisplayColor()
to obtain the actual
color that would be displayed for a requested color. This enables
applications to adapt their behavior to a device without compromising device
independence.
In addition to a drawing color, each Graphics object also has an alpha value that controls the overall opacity of the rendered pixels. As with color values, not all devices will support a full 8 bits of alpha channel information. However, all implementations must support at least 4-bit alpha values regardless of their display bit depths.
For the text, line, rectangle, and arc drawing and filling primitives, the source pixel is a pixel having the current color and alpha value of the graphics object.
However, the drawImage()
,
drawRegion()
, and drawRGB()
methods use
an image or array of pixel values as the source for rendering operations
instead of the current color of the graphics object. For these operations,
the alpha value of a given source pixel is multiplied by the alpha value of
the Graphics object to determine its overall opacity when rendered to the
destination. Hence, a fully opaque pixel in the source will adopt the alpha
level of the Graphics object. Similarly, the alpha values of the source
pixels will be rendered as-is if the alpha value of the graphics object is
fully opaque.
Rendered pixels are combined with the destination pixels according to the
Graphics object's current blending mode. Two of the Porter-Duff blending
modes are supported: SRC_OVER
, and SRC
.
SRC_OVER
is the default blending mode and blends the source
pixel on top of the destination pixel. If the source pixel is fully opaque,
the destination pixel is effectively replaced with the source pixel. If the
source pixel is fully transparent, the destination pixel is unchanged. If the
source pixel is partially transparent, its color is blended with the color of
the destination pixel. The opacity of the destination pixel cannot be reduced
using this blending mode, and thus it may be used on images and surfaces that
do not support alpha channels as their pixels are already fully opaque.
The SRC_OVER
mode computes the destination pixel's red, green,
blue, and alpha values according to the follow equations:
R(dest) = (R(src) * A(src)) + (R(dest) * (1 - A(src))) G(dest) = (G(src) * A(src)) + (G(dest) * (1 - A(src))) B(dest) = (B(src) * A(src)) + (B(dest) * (1 - A(src))) A(dest) = A(src) + A(dest) - (A(src) * A(dest))
where the alpha value A has a value between 0 and 1.0
The SRC
blending mode replaces the destination pixel with the
source pixel, regardless of the source pixel's opacity. Both the color and
the alpha value of the destination pixel are replaced, thus allowing the
opacity of the destination pixel to be decreased as well as increased. For
this reason, the Source blending mode can only be used for Graphics objects
that render to an Image with an alpha channel.
The SRC
mode computes the destination pixel's red, green,
blue, and alpha values according to the follow equations:
R(dest) = R(src) G(dest) = G(src) B(dest) = B(src) A(dest) = A(src)
Lines, arcs, rectangles, and rounded rectangles are drawn with either a
SOLID
or a DOTTED
stroke style, as set by the
setStrokeStyle()
method. The stroke style does not
affect fill, text, and image operations.
For the SOLID
stroke style, drawing operations are performed
with a one-pixel wide pen that fills the pixel immediately below and to the
right of the specified coordinate. Drawn lines touch pixels at both
endpoints. Thus, the operation
g.drawLine(0, 0, 0, 0);
paints exactly one pixel, the first pixel in the upper left corner of the display.
Drawing operations under the DOTTED
stroke style will touch a
subset of pixels that would have been touched under the SOLID
stroke style. The frequency and length of dots is implementation-dependent.
The endpoints of lines and arcs are not guaranteed to be drawn, nor are the
corner points of rectangles guaranteed to be drawn. Dots are drawn by
painting with the current color and alpha level; spaces between dots are left
untouched.
For a given font, each character is represented by a glyph. The glyph acts as an alpha channel mask containing pixels that form the shape of the character.
Basic font engines provide monochrome glyphs in which a pixel is either fully opaque (that is, part of the character to be drawn) or fully transparent. More sophisticated font engines provide graymap glyphs in which pixels may also be partially opaque to varying degrees, thereby allowing character edges to appear smoother.
When a character is painted, the opacity of a rendered pixel is determined by multiplying the alpha value of the glyph's pixel with that of the Graphics object. The color of the rendered pixel will be the color the Graphics object. Hence, pixels that are fully opaque in the glyph will be rendered with the Graphics object's opacity and color, and pixels that are fully transparent in the glyph will be rendered as fully transparent pixels.
The text drawing calls drawChar()
,
drawChars()
, drawString()
,
drawSubstring()
drawText()
all draw
text in this manner.
The text drawing calls drawChars()
, drawString()
,
and drawSubstring()
all render characters in their exact order.
In other words, no bi-directional processing is applied and the order of the characters is
preserved. If bi-directional text is required, the String or character data should be
pre-processed using a suitable library or the Text
class should be used instead.
stringWidth()
or charWidth()
to get the width
and then perform a combination of subtraction and division to compute the
proper location. The method to draw text is defined as follows:
public void drawString(String text, int x, int y, int anchor);This method draws text in the current color, using the current font with its anchor point at
(x,y)
. The definition of the anchor point
must be one of the horizontal constants (LEFT, HCENTER, RIGHT)
combined with one of the vertical constants
(TOP, BASELINE, BOTTOM)
using the bit-wise OR
operator. Zero may also be used as the value of an anchor point. Using zero
for the anchor point value gives results identical to using
TOP | LEFT
.
Vertical centering of the text is not specified since it is not considered
useful, it is hard to specify, and it is burdensome to implement. Thus, the
VCENTER
value is not allowed in the anchor point parameter of
text drawing calls.
The actual position of the bounding box of the text relative to the
(x, y)
location is determined by the anchor point. These
anchor points occur at named locations along the outer edge of the bounding
box. Thus, if f
is g
's current font (as
returned by g.getFont()
, the following calls will all have
identical results:
g.drawString(str, x, y, TOP | LEFT); g.drawString(str, x + f.stringWidth(str) / 2, y, TOP | HCENTER); g.drawString(str, x + f.stringWidth(str), y, TOP | RIGHT); g.drawString(str, x, y + f.getBaselinePosition(), BASELINE | LEFT); g.drawString(str, x + f.stringWidth(str) / 2, y + f.getBaselinePosition(), BASELINE | HCENTER); g.drawString(str, x + f.stringWidth(str), y + f.getBaselinePosition(), BASELINE | RIGHT); drawString(str, x, y + f.getHeight(), BOTTOM | LEFT); drawString(str, x + f.stringWidth(str) / 2, y + f.getHeight(), BOTTOM | HCENTER); drawString(str, x + f.stringWidth(str), y + f.getHeight(), BOTTOM | RIGHT);
For text drawing, the inter-character and inter-line spacing (leading)
specified by the font designer are included as part of the values returned in
the stringWidth()
and
getHeight()
calls of class Font
. For
example, given the following code:
// (5) g.drawString(string1 + string2, x, y, TOP | LEFT); // (6) g.drawString(string1, x, y, TOP | LEFT); g.drawString(string2, x + f.stringWidth(string1), y, TOP | LEFT);
Code fragments (5) and (6) behave similarly if not identically. This occurs
because f.stringWidth()
includes the inter-character spacing.
The exact spacing may differ between these calls if the system supports
font kerning and support for bi-directional text rendering.
Similarly, reasonable vertical spacing may be achieved simply by adding the font height to the Y-position of subsequent lines. For example:
g.drawString(string1, x, y, TOP | LEFT); g.drawString(string2, x, y + f.fontHeight(), TOP | LEFT);
draws string1
and string2
on separate lines
with an appropriate amount of inter-line spacing.
The stringWidth()
of the string and the
fontHeight()
of the font in which it is drawn define the size
of the bounding box of a piece of text. As described above, this box includes
inter-line and inter-character spacing. The implementation is required to put
this space below and to right of the pixels actually belonging to the
characters drawn. Applications that wish to position graphics closely with
respect to text (for example, to paint a rectangle around a string of text)
may assume that there is space below and to the right of a string and that
there is no space above and to the left of the string.
Anchor points are also used for positioning of images. Similar to text
drawing, the anchor point for an image specifies the point on the bounding
rectangle of the destination that is to positioned at the (x,y)
location given in the graphics request. Unlike text, vertical centering of
images is well-defined, and thus the VCENTER
value may be used
within the anchor point parameter of image drawing requests. Because images
have no notion of a baseline, the BASELINE
value may not be
used within the anchor point parameter of image drawing requests.
The use of 16-bit formats reduces memory consumption since only two bytes are needed per pixel, but due to the lower number of distinct levels, a smaller set of unique pixel values can be represented. This shortcoming will be most noticeable on displays that support higher color depths. Conversely, 32-bit formats require twice as much memory since four bytes are needed per pixel, but the resulting color depth exceeds that of most mobile device displays.
Unless the device happens to use the same pixel format natively, some conversion will occur when rendering or retrieving pixel values; the computing overhead associated with this conversion will depend on specific formats involved.
This format uses the int
type to encode both color and
opacity information for a single pixel. Eight bits are used to encode the
alpha value, red component, green component, and blue component. For each
color component, a value of 0xFF represents maximum intensity and a value of
0x00 represents minimum intensity. For the alpha value, a value of 0xFF
represents full opacity and a value of 0x00 represents full transparency.
This format is encoded exactly the same at the 32-bit ARGB, with the exception of the alpha value. Full opacity is assumed since this format does not include an alpha value, and the contents of the upper byte are ignored.
This format uses the char
type to encode both color and
opacity information for a single pixel. Four bits are used to encode the
alpha value, red component, green component, and blue component. For each
color component, a value of 0xF represents maximum intensity and a value of
0x00 represents minimum intensity. For the alpha value, a value of 0xF
represents full opacity and a value of 0x00 represents full transparency.
This format uses the char
type to encode color information
for a single pixel. 5 bits are used to encode the red component and blue
component, for which a value of 0x1F represents maximum intensity and a value
of 0x00 represents minimum intensity. 6 bits are used to encode the green
component, for which a value of 0x3F represents maximum intensity and a value
of 0x00 represents minimum intensity. Full opacity is assumed since this
format does not include an alpha value.
Field Summary | |
---|---|
static int |
BASELINE
Constant for positioning the anchor point at the baseline of text. |
static int |
BOTTOM
Constant for positioning the anchor point of text and images below the text or image. |
static int |
DOTTED
Constant for the DOTTED stroke style. |
static int |
HCENTER
Constant for centering text and images horizontally around the anchor point |
static int |
LEFT
Constant for positioning the anchor point of text and images to the left of the text or image. |
static int |
RIGHT
Constant for positioning the anchor point of text and images to the right of the text or image. |
static int |
SOLID
Constant for the SOLID stroke style. |
static int |
SRC
Constant for the SRC blending mode. |
static int |
SRC_OVER
Constant for the SRC_OVER blending mode. |
static int |
TOP
Constant for positioning the anchor point of text and images above the text or image. |
static int |
VCENTER
Constant for centering images vertically around the anchor point. |
Method Summary | |
---|---|
void |
clipRect(int x,
int y,
int width,
int height)
Intersects the current clip with the specified rectangle. |
void |
copyArea(int x_src,
int y_src,
int width,
int height,
int x_dest,
int y_dest,
int anchor)
Copies the contents of a rectangular area (x_src, y_src, width, height) to a destination area, whose
anchor point identified by anchor is located at
(x_dest, y_dest) . |
void |
drawArc(int x,
int y,
int width,
int height,
int startAngle,
int arcAngle)
Draws the outline of a circular or elliptical arc covering the specified rectangle, using the current color, alpha, and stroke style. |
void |
drawARGB16(short[] argbData,
int offset,
int scanlength,
int x,
int y,
int width,
int height)
Renders a series of device-independent ARGB values in a specified region. |
void |
drawChar(char character,
int x,
int y,
int anchor)
Draws the specified character using the current font, color, and alpha. |
void |
drawChars(char[] data,
int offset,
int length,
int x,
int y,
int anchor)
Draws the specified characters using the current font, color, and alpha. |
void |
drawImage(Image img,
int x,
int y,
int anchor)
Draws the specified image by using the anchor point. |
void |
drawLine(int x1,
int y1,
int x2,
int y2)
Draws a line between the coordinates (x1,y1) and
(x2,y2) using the current color, alpha, and stroke style. |
void |
drawRect(int x,
int y,
int width,
int height)
Draws the outline of the specified rectangle using the current color, alpha, and stroke style. |
void |
drawRegion(Image src,
int x_src,
int y_src,
int width,
int height,
int transform,
int x_dest,
int y_dest,
int anchor)
Copies a region of the specified source image to a location within the destination, possibly transforming (rotating and reflecting) the image data using the chosen transform function. |
void |
drawRegion(Image src,
int x_src,
int y_src,
int width,
int height,
int transform,
int x_dest,
int y_dest,
int anchor,
int width_dest,
int height_dest)
Scales and transforms a region of the specified source image to a region within the destination, possibly transforming (rotating and reflecting) the image data using the chosen transform function and scaling the pixels to fit the destination region. |
void |
drawRGB(int[] rgbData,
int offset,
int scanlength,
int x,
int y,
int width,
int height,
boolean processAlpha)
Renders a series of device-independent ARGB values in a specified region. |
void |
drawRGB16(short[] rgbData,
int offset,
int scanlength,
int x,
int y,
int width,
int height)
Renders a series of device-independent RGB values in a specified region. |
void |
drawRoundRect(int x,
int y,
int width,
int height,
int arcWidth,
int arcHeight)
Draws the outline of the specified rounded corner rectangle using the current color, alpha, and stroke style. |
void |
drawString(java.lang.String str,
int x,
int y,
int anchor)
Draws the specified String using the current font, color,
and alpha. |
void |
drawSubstring(java.lang.String str,
int offset,
int len,
int x,
int y,
int anchor)
Draws the specified String using the current font, color,
and alpha. |
void |
drawText(Text text,
int x,
int y)
Draw a Text object to the Graphics context at the requested location. |
void |
fillArc(int x,
int y,
int width,
int height,
int startAngle,
int arcAngle)
Fills a circular or elliptical arc covering the specified rectangle using the current color and alpha. |
void |
fillRect(int x,
int y,
int width,
int height)
Fills the specified rectangle with the current color and alpha. |
void |
fillRoundRect(int x,
int y,
int width,
int height,
int arcWidth,
int arcHeight)
Fills the specified rounded corner rectangle with the current color and alpha. |
void |
fillTriangle(int x1,
int y1,
int x2,
int y2,
int x3,
int y3)
Fills the specified triangle will the current color and alpha level. |
int |
getAlpha()
Gets the current alpha value. |
int |
getAlphaColor()
Gets the current drawing color and alpha value. |
int |
getBlendingMode()
Gets the current blending mode for this Graphics object. |
int |
getBlueComponent()
Gets the blue component of the current color. |
int |
getClipHeight()
Gets the height of the current clipping area. |
int |
getClipWidth()
Gets the width of the current clipping area. |
int |
getClipX()
Gets the X offset of the current clipping area, relative to the coordinate system origin of this graphics context. |
int |
getClipY()
Gets the Y offset of the current clipping area, relative to the coordinate system origin of this graphics context. |
int |
getColor()
Gets the current drawing color. |
int |
getDisplayColor(int color)
Gets the color that will be displayed if the specified color is requested. |
Font |
getFont()
Gets the current font. |
int |
getGrayScale()
Gets the current grayscale value of the color being used for rendering operations. |
int |
getGreenComponent()
Gets the green component of the current color. |
int |
getRedComponent()
Gets the red component of the current color. |
int |
getStrokeStyle()
Gets the stroke style used for drawing operations. |
int |
getTranslateX()
Gets the X coordinate of the translated origin of this graphics context. |
int |
getTranslateY()
Gets the Y coordinate of the translated origin of this graphics context. |
void |
setAlpha(int alpha)
Sets the alpha value for this Graphics object. |
void |
setAlphaColor(int ARGB)
Sets the current color and alpha to the specified 32-bit ARGB value. |
void |
setAlphaColor(int alpha,
int red,
int green,
int blue)
Sets the current color and alpha to the specified values. |
void |
setBlendingMode(int mode)
Sets the current blending mode for this Graphics object. |
void |
setClip(int x,
int y,
int width,
int height)
Sets the current clip to the rectangle specified by the given coordinates. |
void |
setColor(int RGB)
Sets the current color to the specified 24-bit RGB value. |
void |
setColor(int red,
int green,
int blue)
Sets the current color to the specified RGB values. |
void |
setFont(Font font)
Sets the font for all subsequent text rendering operations. |
void |
setGrayScale(int value)
Sets the current grayscale to be used for all subsequent rendering operations. |
void |
setStrokeStyle(int style)
Sets the stroke style used for drawing lines, arcs, rectangles, and rounded rectangles. |
void |
translate(int x,
int y)
Translates the origin of the graphics context to the point (x, y) in the current coordinate system. |
Methods inherited from class java.lang.Object |
---|
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
---|
public static final int HCENTER
Value 1
is assigned to HCENTER
.
public static final int VCENTER
Value 2
is assigned to VCENTER
.
public static final int LEFT
Value 4
is assigned to LEFT
.
public static final int RIGHT
Value 8
is assigned to RIGHT
.
public static final int TOP
Value 16
is assigned to TOP
.
public static final int BOTTOM
Value 32
is assigned to BOTTOM
.
public static final int BASELINE
Value 64
is assigned to BASELINE
.
public static final int SOLID
SOLID
stroke style.
Value 0
is assigned to SOLID
.
public static final int DOTTED
DOTTED
stroke style.
Value 1
is assigned to DOTTED
.
public static final int SRC_OVER
SRC_OVER
blending mode. The source is
composited over the destination.
Value 0
is assigned to SRC_OVER
.
public static final int SRC
SRC
blending mode. The destination's
color and alpha value are replaced with those of the source.
Value 1
is assigned to SRC
.
Method Detail |
---|
public void translate(int x, int y)
(x, y)
in the current coordinate system. All coordinates
used in subsequent rendering operations on this graphics context will be
relative to this new origin.
The coordinates passed to this method are interpreted relative to the
current translated origin, and thus the effect of calls to
translate()
are cumulative. For
example, calling translate(1, 2)
and then
translate(3, 4)
has the same effect as calling
translate(4, 6)
.
The application can set the origin in terms of absolute coordinates
(ax, ay)
using the following technique:
g.translate(ax - g.getTranslateX(), ay - g.getTranslateY())
x
- the x coordinate of the new translation originy
- the y coordinate of the new translation origingetTranslateX()
,
getTranslateY()
public int getTranslateX()
public int getTranslateY()
public int getColor()
setColor(int, int, int)
public int getAlphaColor()
setColor(int, int, int)
public int getRedComponent()
0-255
setColor(int, int, int)
public int getGreenComponent()
0-255
setColor(int, int, int)
public int getBlueComponent()
0-255
setColor(int, int, int)
public int getGrayScale()
setGrayScale()
, that
value is simply returned. If the color was set by one of the methods that
allows setting of the red, green, and blue components, the value returned
is computed from the RGB color components (possibly in a device-specific
fashion) that best approximates the brightness of that color.
0-255
setGrayScale(int)
public void setColor(int red, int green, int blue)
red
- the red component of the color being set in range
0-255
green
- the green component of the color being set in range
0-255
blue
- the blue component of the color being set in range
0-255
java.lang.IllegalArgumentException
- if any of the color components are outside of range
0-255
getColor()
public void setColor(int RGB)
Note that this method only changes the drawing color. The upper byte of the RGB value is ignored and the alpha value of the Graphics object is unaffected by this method.
RGB
- the new drawing color encoded using the
24-bit RGB formatgetColor()
public void setGrayScale(int value)
0-255
.
value
- the desired grayscale value
java.lang.IllegalArgumentException
- if the gray value is out of rangegetGrayScale()
public void setAlpha(int alpha)
An alpha value of 255 is fully opaque, and a value of 0 is fully transparent. The alpha value is 255 (fully opaque) by default.
alpha
- the new alpha value for this Graphics object
java.lang.IllegalArgumentException
- if the alpha value is outside of range 0-255
public void setAlphaColor(int ARGB)
ARGB
- the new drawing color and alpha value encoded using the
32-bit ARGB formatgetColor()
public void setAlphaColor(int alpha, int red, int green, int blue)
alpha
- the alpha component of the color being set in range
0-255
red
- the red component of the color being set in range
0-255
green
- the green component of the color being set in range
0-255
blue
- the blue component of the color being set in range
0-255
java.lang.IllegalArgumentException
- if any parameter is outside of the range 0-255
getColor()
public int getAlpha()
An alpha value of 255 is fully opaque, and a value of 0 is fully transparent. The alpha value is 255 (fully opaque) by default.
public void setBlendingMode(int mode)
If SRC_OVER
is used, the source pixel is blended on top of
the destination pixel.
If SRC
is used, the destination pixel is fully replaced
with the source pixel, including the source pixel's alpha value. This
mode can only be used on a Graphics object that renders to an Image with
an alpha channel, as determined by calling
Image.hasAlpha
The SRC_OVER
blending mode is used by default.
mode
- the desired blending mode (SRC
or
SRC_OVER
)
java.lang.IllegalArgumentException
- if mode is not a valid value
java.lang.IllegalArgumentException
- if the SRC mode is requested on a Graphics object that
renders to a surface without an alpha channelgetBlendingMode()
public int getBlendingMode()
SRC
or
SRC_OVER
)setBlendingMode(int)
public Font getFont()
Font
,
setFont(javax.microedition.lcdui.Font)
public void setStrokeStyle(int style)
style
- can be SOLID
or DOTTED
java.lang.IllegalArgumentException
- if the style
is illegalgetStrokeStyle()
public int getStrokeStyle()
SOLID
or DOTTED
setStrokeStyle(int)
public void setFont(Font font)
null
, it is equivalent to
setFont(Font.getDefaultFont())
.
font
- the specified fontFont
,
getFont()
,
drawString(java.lang.String, int, int, int)
,
drawChars(char[], int, int, int, int, int)
public int getClipX()
getClip
operation into two methods returning integers is
more performance and memory efficient than one getClip()
call returning an object.
clipRect(int, int, int, int)
,
setClip(int, int, int, int)
public int getClipY()
getClip
operation into two methods returning integers is
more performance and memory efficient than one getClip()
call returning an object.
clipRect(int, int, int, int)
,
setClip(int, int, int, int)
public int getClipWidth()
clipRect(int, int, int, int)
,
setClip(int, int, int, int)
public int getClipHeight()
clipRect(int, int, int, int)
,
setClip(int, int, int, int)
public void clipRect(int x, int y, int width, int height)
setClip
method. Rendering operations have no effect
outside of the clipping area.
x
- the x coordinate of the rectangle to intersect the clip withy
- the y coordinate of the rectangle to intersect the clip withwidth
- the width of the rectangle to intersect the clip withheight
- the height of the rectangle to intersect the clip withsetClip(int, int, int, int)
public void setClip(int x, int y, int width, int height)
x
- the x coordinate of the new clip rectangley
- the y coordinate of the new clip rectanglewidth
- the width of the new clip rectangleheight
- the height of the new clip rectangleclipRect(int, int, int, int)
public void drawLine(int x1, int y1, int x2, int y2)
(x1,y1)
and
(x2,y2)
using the current color, alpha, and stroke style.
x1
- the x coordinate of the start of the liney1
- the y coordinate of the start of the linex2
- the x coordinate of the end of the liney2
- the y coordinate of the end of the linepublic void fillRect(int x, int y, int width, int height)
x
- the x coordinate of the rectangle to be filledy
- the y coordinate of the rectangle to be filledwidth
- the width of the rectangle to be filledheight
- the height of the rectangle to be filleddrawRect(int, int, int, int)
public void drawRect(int x, int y, int width, int height)
(width + 1)
pixels wide by (height + 1)
pixels tall. If either width or height is less than zero, nothing is
drawn.
x
- the x coordinate of the rectangle to be drawny
- the y coordinate of the rectangle to be drawnwidth
- the width of the rectangle to be drawnheight
- the height of the rectangle to be drawnfillRect(int, int, int, int)
public void drawRoundRect(int x, int y, int width, int height, int arcWidth, int arcHeight)
(width +
1)
pixels wide by
(height + 1)
pixels tall. If either width
or height
is less than zero, nothing is drawn.
x
- the x coordinate of the rectangle to be drawny
- the y coordinate of the rectangle to be drawnwidth
- the width of the rectangle to be drawnheight
- the height of the rectangle to be drawnarcWidth
- the horizontal diameter of the arc at the four cornersarcHeight
- the vertical diameter of the arc at the four cornersfillRoundRect(int, int, int, int, int, int)
public void fillRoundRect(int x, int y, int width, int height, int arcWidth, int arcHeight)
width
or height
is zero or
less, nothing is drawn.
x
- the x coordinate of the rectangle to be filledy
- the y coordinate of the rectangle to be filledwidth
- the width of the rectangle to be filledheight
- the height of the rectangle to be filledarcWidth
- the horizontal diameter of the arc at the four cornersarcHeight
- the vertical diameter of the arc at the four cornersdrawRoundRect(int, int, int, int, int, int)
public void fillArc(int x, int y, int width, int height, int startAngle, int arcAngle)
The resulting arc begins at startAngle
and extends for
arcAngle
degrees. Angles are interpreted such that
0
degrees is at the 3
o'clock position. A
positive value indicates a counter-clockwise rotation while a negative
value indicates a clockwise rotation.
The center of the arc is the center of the rectangle whose origin is (x, y)
and whose size is specified by the width
and
height
arguments.
If either width
or height
is zero or less,
nothing is drawn.
The filled region consists of the "pie wedge" region bounded by
the arc segment as if drawn by drawArc()
, the radius
extending from the center to this arc at startAngle
degrees, and radius extending from the center to this arc at
startAngle + arcAngle
degrees.
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.
x
- the x coordinate of the upper-left corner of the
arc to be filled.y
- the y coordinate of the upper-left corner of the
arc to be filled.width
- the width of the arc to be filledheight
- the height of the arc to be filledstartAngle
- the beginning angle.arcAngle
- the angular extent of the arc, relative to the start angle.drawArc(int, int, int, int, int, int)
public void drawArc(int x, int y, int width, int height, int startAngle, int arcAngle)
The resulting arc begins at startAngle
and extends for
arcAngle
degrees, using the current color and alpha.
Angles are interpreted such that 0
degrees is at the
3
o'clock position. A positive value indicates a
counter-clockwise rotation while a negative value indicates a clockwise
rotation.
The center of the arc is the center of the rectangle whose origin is (x, y)
and whose size is specified by the width
and
height
arguments.
The resulting arc covers an area width + 1
pixels wide by height + 1
pixels tall. If either
width
or height
is less than zero, nothing
is drawn.
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.
x
- the x coordinate of the upper-left corner of the
arc to be drawny
- the y coordinate of the upper-left corner of the
arc to be drawnwidth
- the width of the arc to be drawnheight
- the height of the arc to be drawnstartAngle
- the beginning anglearcAngle
- the angular extent of the arc, relative to the start anglefillArc(int, int, int, int, int, int)
public void drawString(java.lang.String str, int x, int y, int anchor)
String
using the current font, color,
and alpha. The x,y
position is the position of the anchor
point. See anchor points.
str
- the String
to be drawnx
- the x coordinate of the anchor pointy
- the y coordinate of the anchor pointanchor
- the anchor point for positioning the text
java.lang.NullPointerException
- if str
is null
java.lang.IllegalArgumentException
- if anchor is not a legal valuedrawChars(char[], int, int, int, int, int)
public void drawSubstring(java.lang.String str, int offset, int len, int x, int y, int anchor)
String
using the current font, color,
and alpha. The x,y
position is the position of the anchor
point. See anchor points.
The offset
and len
parameters must specify
a valid range of characters within the string str
. The
offset
parameter must be within the range
[0..(str.length())]
, inclusive. The len
parameter must be a non-negative integer such that
(offset + len) <= str.length()
.
str
- the String
to be drawnoffset
- zero-based index of first character in the substringlen
- length of the substringx
- the x coordinate of the anchor pointy
- the y coordinate of the anchor pointanchor
- the anchor point for positioning the text
java.lang.StringIndexOutOfBoundsException
- if offset
and length
do not
specify a valid range within the
String
str
java.lang.IllegalArgumentException
- if anchor
is not a legal value
java.lang.NullPointerException
- if str
is null
drawString(String, int, int, int).
public void drawChar(char character, int x, int y, int anchor)
character
- the character to be drawnx
- the x coordinate of the anchor pointy
- the y coordinate of the anchor pointanchor
- the anchor point for positioning the text; see anchor points
java.lang.IllegalArgumentException
- if anchor
is not a legal valuedrawString(java.lang.String, int, int, int)
,
drawChars(char[], int, int, int, int, int)
public void drawChars(char[] data, int offset, int length, int x, int y, int anchor)
The offset
and length
parameters must
specify a valid range of characters within the character array
data
. The offset
parameter must be within
the range [0..(data.length)]
, inclusive. The
length
parameter must be a non-negative integer such that
(offset + length) <= data.length
.
data
- the array of characters to be drawnoffset
- the start offset in the datalength
- the number of characters to be drawnx
- the x coordinate of the anchor pointy
- the y coordinate of the anchor pointanchor
- the anchor point for positioning the text; see anchor points
java.lang.ArrayIndexOutOfBoundsException
- if offset
and length
do not
specify a valid range within the data array
java.lang.IllegalArgumentException
- if anchor is not a legal value
java.lang.NullPointerException
- if data
is null
drawString(java.lang.String, int, int, int)
public void drawImage(Image img, int x, int y, int anchor)
If img
is the same as the destination of this Graphics
object, the result is undefined. For copying areas within an
Image
, copyArea
should be used instead.
The alpha value of each pixel in the image is multiplied by the alpha value of the Graphics object to determine its effective opacity when rendered.
img
- the specified image to be drawnx
- the x coordinate of the anchor pointy
- the y coordinate of the anchor pointanchor
- the anchor point for positioning the image
java.lang.IllegalArgumentException
- if anchor
is not a legal value
java.lang.NullPointerException
- if img
is null
Image
public void drawRegion(Image src, int x_src, int y_src, int width, int height, int transform, int x_dest, int y_dest, int anchor)
The destination, if it is an image, must not be the same image as the source image. If it is, an exception is thrown. This restriction is present in order to avoid ill-defined behaviors that might occur if overlapped, transformed copies were permitted.
The transform function used must be one of the following, as defined in
the Sprite
class:
Sprite.TRANS_NONE
- causes the specified image region to
be copied unchanged
Sprite.TRANS_ROT90
- causes the specified image region to
be rotated clockwise by 90 degrees.
Sprite.TRANS_ROT180
- causes the specified image region to
be rotated clockwise by 180 degrees.
Sprite.TRANS_ROT270
- causes the specified image region to
be rotated clockwise by 270 degrees.
Sprite.TRANS_MIRROR
- causes the specified image region to
be reflected about its vertical center.
Sprite.TRANS_MIRROR_ROT90
- causes the specified image
region to be reflected about its vertical center and then rotated
clockwise by 90 degrees.
Sprite.TRANS_MIRROR_ROT180
- causes the specified image
region to be reflected about its vertical center and then rotated
clockwise by 180 degrees.
Sprite.TRANS_MIRROR_ROT270
- causes the specified image
region to be reflected about its vertical center and then rotated
clockwise by 270 degrees.
The (x_src, y_src)
coordinates are relative to the upper
left corner of the source image. The x_src
,
y_src
, width
, and height
parameters specify a rectangular region of the source image. It is
illegal for this region to extend beyond the bounds of the source image.
This requires that:
x_src >= 0 y_src >= 0 x_src + width <= source width y_src + height <= source height
The (x_dest, y_dest)
coordinates are relative to the
coordinate system of this Graphics object. It is legal for the
destination area to extend beyond the bounds of the Graphics
object. Pixels outside of the bounds of the Graphics
object will not be drawn.
The transform is applied to the image data from the region of the source
image, and the result is rendered with its anchor point positioned at
location (x_dest, y_dest)
in the destination.
The alpha value of each pixel in the image is multiplied by the alpha value of the Graphics object to determine its effective opacity when rendered.
src
- the source image to copy fromx_src
- the x coordinate of the upper left corner of the region within
the source image to copyy_src
- the y coordinate of the upper left corner of the region within
the source image to copywidth
- the width of the region to copyheight
- the height of the region to copytransform
- the desired transformation for the selected region being
copiedx_dest
- the x coordinate of the anchor point in the destination
drawing areay_dest
- the y coordinate of the anchor point in the destination
drawing areaanchor
- the anchor point for positioning the region within the
destination image
java.lang.IllegalArgumentException
- if src
is the same image as the destination of
this Graphics
object
java.lang.NullPointerException
- if src
is null
java.lang.IllegalArgumentException
- if transform
is invalid
java.lang.IllegalArgumentException
- if anchor
is invalid
java.lang.IllegalArgumentException
- if the region to be copied exceeds the bounds of the source
imagepublic void drawRegion(Image src, int x_src, int y_src, int width, int height, int transform, int x_dest, int y_dest, int anchor, int width_dest, int height_dest)
The destination, if it is an image, must not be the same image as the
source image. If it is, an exception is thrown. This restriction is
present in order to avoid ill-defined behaviors that might occur if
overlapped, transformed copies were permitted.
If either width_dest
or height_dest
is zero or
less, nothing is drawn.
The transform function used must be one of the following, as defined in
the Sprite
class:
Sprite.TRANS_NONE
- causes the specified image region to
be copied unchanged
Sprite.TRANS_ROT90
- causes the specified image region to
be rotated clockwise by 90 degrees.
Sprite.TRANS_ROT180
- causes the specified image region to
be rotated clockwise by 180 degrees.
Sprite.TRANS_ROT270
- causes the specified image region to
be rotated clockwise by 270 degrees.
Sprite.TRANS_MIRROR
- causes the specified image region to
be reflected about its vertical center.
Sprite.TRANS_MIRROR_ROT90
- causes the specified image
region to be reflected about its vertical center and then rotated
clockwise by 90 degrees.
Sprite.TRANS_MIRROR_ROT180
- causes the specified image
region to be reflected about its vertical center and then rotated
clockwise by 180 degrees.
Sprite.TRANS_MIRROR_ROT270
- causes the specified image
region to be reflected about its vertical center and then rotated
clockwise by 270 degrees.
The (x_src, y_src)
coordinates are relative to the upper
left corner of the source image. The x_src
,
y_src
,width
, and height
parameters specify a rectangular region of the source image. It is
illegal for this region to extend beyond the bounds of the source image.
This requires that:
|
The (x_dest, y_dest)
coordinates are relative to the
coordinate system of this Graphics object. It is legal for the
destination area to extend beyond the bounds of the Graphics
object. Pixels outside of the bounds of the Graphics
object will not be drawn.
The scaling and transform is applied to the image data from the region of the source
image, and the result is rendered with its anchor point positioned at
location (x_dest, y_dest)
in the destination.
The alpha value of each pixel in the image is multiplied by the alpha value of the Graphics object to determine its effective opacity when rendered.
src
- the source image to copy fromx_src
- the x coordinate of the upper left corner of the region within
the source image to copyy_src
- the y coordinate of the upper left corner of the region within
the source image to copywidth
- the width of the source regionheight
- the height of the source regiontransform
- the desired transformation for the selected region being
copiedx_dest
- the x coordinate of the anchor point in the destination
drawing areay_dest
- the y coordinate of the anchor point in the destination
drawing areaanchor
- the anchor point for positioning the region within the
destination imagewidth_dest
- the width of the region in the destination drawing areaheight_dest
- the height of the region in the destination drawing area
java.lang.IllegalArgumentException
- if src
is the same image as the destination of
this Graphics
object
java.lang.NullPointerException
- if src
is null
java.lang.IllegalArgumentException
- if transform
is invalid
java.lang.IllegalArgumentException
- if anchor
is invalid
java.lang.IllegalArgumentException
- if the region to be copied exceeds the bounds of the source
imagepublic void copyArea(int x_src, int y_src, int width, int height, int x_dest, int y_dest, int anchor)
(x_src, y_src, width, height)
to a destination area, whose
anchor point identified by anchor is located at
(x_dest, y_dest)
. The effect must be that the destination
area contains an exact copy of the contents of the source area
immediately prior to the invocation of this method. This result must
occur even if the source and destination areas overlap.
The points (x_src, y_src)
and (x_dest,
y_dest)
are both specified relative to the coordinate system of the
Graphics
object. It is illegal for the source region to
extend beyond the bounds of the graphic object. This requires that:
x_src + tx >= 0 y_src + ty >= 0 x_src + tx + width <= width of Graphics object's destination y_src + ty + height <= height of Graphics object's destination
where tx
and ty
represent the X and Y
coordinates of the translated origin of this graphics object, as returned
by getTranslateX()
and getTranslateY()
,
respectively.
However, it is legal for the destination area to extend beyond the bounds
of the Graphics
object. Pixels outside of the bounds of
the Graphics
object will not be drawn.
The copyArea
method is allowed on all
Graphics
objects except those whose destination is an
actual display device. This restriction is necessary because allowing a
copyArea
method on the display would adversely impact
certain techniques for implementing double-buffering.
Copying is performed using direct pixel replacement. That is, both the color and the alpha value of the destination pixel are replaced with those of the source pixel. The color and alpha value of the Graphics object have no impact on the copy operation.
x_src
- the x coordinate of upper left corner of source areay_src
- the y coordinate of upper left corner of source areawidth
- the width of the source areaheight
- the height of the source areax_dest
- the x coordinate of the destination anchor pointy_dest
- the y coordinate of the destination anchor pointanchor
- the anchor point for positioning the region within the
destination image
java.lang.IllegalStateException
- if the destination of this Graphics
object is
a display device
java.lang.IllegalArgumentException
- if the region to be copied exceeds the bounds of the source
imagepublic void fillTriangle(int x1, int y1, int x2, int y2, int x3, int y3)
x1
- the x coordinate of the first vertex of the triangley1
- the y coordinate of the first vertex of the trianglex2
- the x coordinate of the second vertex of the triangley2
- the y coordinate of the second vertex of the trianglex3
- the x coordinate of the third vertex of the triangley3
- the y coordinate of the third vertex of the trianglepublic void drawRGB(int[] rgbData, int offset, int scanlength, int x, int y, int width, int height, boolean processAlpha)
rgbData
int array using the
32-bit ARGB or 24-bit RGB
format. The scanlength
specifies the relative offset
within the array between the corresponding pixels of consecutive rows.
Any value for scanlength
is acceptable (even negative
values) provided that all resulting references are within the bounds of
the rgbData
array. The ARGB data is rasterized
horizontally from left to right within each row. The ARGB values are
rendered in the region specified by x
, y
,
width
and height
, and the operation is
subject to the current clip region and translation for this
Graphics
object.
Consider P(a,b)
to be the value of the pixel located at
column a
and row b
of the Image, where rows
and columns are numbered downward from the top starting at zero, and
columns are numbered rightward from the left starting at zero. This
operation can then be defined as:
P(a, b) = rgbData[offset + (a - x) + (b - y) * scanlength]
for
x <= a < x + width y <= b < y + height
If either width or height is zero or less, no exception is thrown, and nothing is drawn.
If processAlpha
is true
, the pixel values
are assumed to be in the 32-bit RGB format and
high-order byte specifies opacity. The alpha value of each pixel in the
array is multiplied by the alpha value of the Graphics object to
determine its effective opacity when rendered.
If processAlpha
is false
, the pixel values
are assumed to be in the 24-bit RGB format. The
value in the high-order byte is ignored and all pixels are rendered with
the alpha value of the Graphics object.
rgbData
- an array of 32-bit ARGB or 24-bit RGB valuesoffset
- the array index of the first ARGB valuescanlength
- the relative array offset between the corresponding pixels in
consecutive rows in the rgbData
arrayx
- the horizontal location of the region to be renderedy
- the vertical location of the region to be renderedwidth
- the width of the region to be renderedheight
- the height of the region to be renderedprocessAlpha
- true
if the pixel values should be processed
assuming a 32-bit ARGB format, false
if the
pixel values should be processed assuming a 24-bit RGB format
java.lang.ArrayIndexOutOfBoundsException
- if the requested operation will attempt to access an element
of rgbData
whose index is either negative or
beyond its length
java.lang.NullPointerException
- if rgbData
is null
public void drawARGB16(short[] argbData, int offset, int scanlength, int x, int y, int width, int height)
argbData
char array in a 16-bit ARGB format, with the first value stored at
the specified offset. The scanlength
specifies the
relative offset within the array between the corresponding pixels of
consecutive rows. Any value for scanlength
is acceptable
(even negative values) provided that all resulting references are within
the bounds of the argbData
array. The ARGB data is
rasterized horizontally from left to right within each row. The ARGB
values are rendered in the region specified by x
,
y
, width
and height
, and
the operation is subject to the current clip region and translation for
this Graphics
object.
Consider P(a,b)
to be the value of the pixel located at
column a
and row b
of the Image, where rows
and columns are numbered downward from the top starting at zero, and
columns are numbered rightward from the left starting at zero. This
operation can then be defined as:
P(a, b) = argbData[offset + (a - x) + (b - y) * scanlength]
for
x <= a < x + width y <= b < y + height
If either width or height is zero or less, no exception is thrown, and nothing is drawn.
The alpha value of each pixel in the array is multiplied by the alpha value of the Graphics object to determine its effective opacity when rendered.
argbData
- an array of 16-bit ARGB valuesoffset
- the array index of the first ARGB valuescanlength
- the relative array offset between the corresponding pixels in
consecutive rows in the argbData
arrayx
- the horizontal location of the region to be renderedy
- the vertical location of the region to be renderedwidth
- the width of the region to be renderedheight
- the height of the region to be rendered
java.lang.ArrayIndexOutOfBoundsException
- if the requested operation will attempt to access an element
of argbData
whose index is either negative or
beyond its length
java.lang.NullPointerException
- if argbData
is null
public void drawRGB16(short[] rgbData, int offset, int scanlength, int x, int y, int width, int height)
rgbData
char array in a 16-bit RGB format, with the first value stored at the
specified offset. The scanlength
specifies the relative
offset within the array between the corresponding pixels of consecutive
rows. Any value for scanlength
is acceptable (even
negative values) provided that all resulting references are within the
bounds of the rgbData
array. The RGB data is rasterized
horizontally from left to right within each row. The RGB values are
rendered in the region specified by x
, y
,
width
and height
, and the operation is
subject to the current clip region and translation for this
Graphics
object.
Consider P(a,b)
to be the value of the pixel located at
column a
and row b
of the Image, where rows
and columns are numbered downward from the top starting at zero, and
columns are numbered rightward from the left starting at zero. This
operation can then be defined as:
P(a, b) = rgbData[offset + (a - x) + (b - y) * scanlength]
for
x <= a < x + width y <= b < y + height
If either width or height is zero or less, no exception is thrown, and nothing is drawn.
The alpha value of the Graphics object determines the effective opacity of the pixel values when rendered.
rgbData
- an array of 16-bit RGB valuesoffset
- the array index of the first RGB valuescanlength
- the relative array offset between the corresponding pixels in
consecutive rows in the rgbData
arrayx
- the horizontal location of the region to be renderedy
- the vertical location of the region to be renderedwidth
- the width of the region to be renderedheight
- the height of the region to be rendered
java.lang.ArrayIndexOutOfBoundsException
- if the requested operation will attempt to access an element
of rgbData
whose index is either negative or
beyond its length
java.lang.NullPointerException
- if rgbData
is null
public int getDisplayColor(int color)
0xFFFFFF
(white) or 0x000000
(black) depending on the brightness of the specified color.
color
- the desired color encoded in the
24-bit RGB format
public void drawText(Text text, int x, int y)
Text
class. The alpha value of the Graphics object is uniformly
applied to the entire text and it is rendered according to the current
blending mode.
text
- the Text object to draw.x
- the x offset of the upper left corner of the text bounding boxy
- the y offset of the upper left corner of the text bounding box
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