ej.microui.display

Class LLUIPainter

java.lang.Object

ej.microui.display.LLUIPainter

public class LLUIPainter
extends Object

This class provides implementations of native methods of MicroUI library which perform some drawings.

The equivalent of embedded structures and enumerations are LLUIPainter.MicroUIImage, LLUIPainter.MicroUIGraphicsContext and LLUIPainter.MicroUIImageFormat. They are used to identify the MicroUI graphical objects: GraphicsContext, Image, image format. etc.

Implementation must use the framework object LLUIDisplay.Instance as monitor to synchronize drawings.

All native methods has a byte array as first parameter. This identifies the destination target: the MicroUI GraphicsContext. This target is retrieved in MicroEJ application calling the method gc.getSNIContext(). The returned byte array must be mapped on a LLUIPainter.MicroUIGraphicsContext object in MicroUI native drawing method implementation (see LLUIDisplay.mapMicroUIGraphicsContext(byte[])).

For a MicroUI Image, MicroEJ application has to call image.getSNIContext() to get the image byte array. This byte array must be mapped it on a LLUIPainter.MicroUIImage object in MicroUI native drawing method implementation (see LLUIDisplay.mapMicroUIImage(byte[])).

A graphics context holds a clip and the drawer is not allowed to perform a drawing outside this clip (otherwise the behavior is unknown). Note the bottom-right coordinates might be smaller than top-left (in x and/or y) when the clip width and/or height is null. The clip may be disabled (when the current drawing fits the clip); this allows to reduce runtime. See LLUIPainter.MicroUIGraphicsContext.isClipEnabled(). Note: several clip methods are available in LLUIPainter.MicroUIGraphicsContext to check if a drawing fits the clip.

The drawing method must:

• Convert the MicroUI graphics context color calling LLUIPainter.MicroUIGraphicsContext.getRenderingColor() (in order to respect embedded display pixel representation constraints),
• Respect the graphics context clip; if not respected, the front panel behavior is unknown,
• Update the next Display.flush() area (dirty area); if not performed, the next call to Display.flush() will not call LLUIDisplayImpl#flush(MicroUIGraphicsContext, Image, int, int, int, int) method.

The native method implementation pattern is:

        void drawXxx(byte[] target, ...) {

                LLUIDisplay graphicalEngine = LLUIDisplay.Instance;

                // all calls to GraphicalEngine.Instance APIs must be synchronized on GraphicalEngine.Instance itself
                synchronized (graphicalEngine) {

                        // map a MicroUIGraphicsContext on given byte array which represents the destination target
                        MicroUIGraphicsContext gc = graphicalEngine.mapMicroUIGraphicsContext(target);

                        // ask to the graphical engine if a drawing can be performed on target
                        if (gc.requestDrawing()) {

                                // call current drawer's equivalent drawing method
                                getDrawer().drawXxx(gc, x, y);

                                // contrary to MicroUI native drawing methods implementation for embedded (LLUI_PAINTER_impl.h), there
                                // is no status to set in MicroUI graphical engine
                        }
                }
        }
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	LLUIPainter.MicroUIGraphicsContext Represents a MicroUI GraphicsContext.
static interface	LLUIPainter.MicroUIImage Represents a MicroUI Image.
static class	LLUIPainter.MicroUIImageFormat Enumerates all MicroUI Image RAW formats.

Method Summary

Modifier and Type	Method and Description
static void	drawCircle(byte[] target, int x, int y, int diameter) MicroUI native "drawCircle".
static void	drawCircleArc(byte[] target, int x, int y, int diameter, float startAngle, float arcAngle) MicroUI native "drawCircleArc".
static void	drawEllipse(byte[] target, int x, int y, int width, int height) MicroUI native "drawEllipse".
static void	drawEllipseArc(byte[] target, int x, int y, int width, int height, float startAngle, float arcAngle) MicroUI native "drawEllipseArc".
static void	drawHorizontalLine(byte[] target, int x, int y, int width) MicroUI native "drawHorizontalLine".
static void	drawImage(byte[] target, byte[] source, int regionX, int regionY, int width, int height, int x, int y, int alpha) MicroUI native "drawImage".
static void	drawLine(byte[] target, int x1, int y1, int x2, int y2) MicroUI native "drawLine".
static void	drawRectangle(byte[] target, int x, int y, int width, int height) MicroUI native "drawRectangle".
static void	drawRoundedRectangle(byte[] target, int x, int y, int width, int height, int arcWidth, int arcHeight) MicroUI native "drawRoundedRectangle".
static void	drawVerticalLine(byte[] target, int x, int y, int height) MicroUI native "drawVerticalLine".
static void	fillCircle(byte[] target, int x, int y, int diameter) MicroUI native "fillCircle".
static void	fillCircleArc(byte[] target, int x, int y, int diameter, float startAngle, float arcAngle) MicroUI native "fillCircleArc".
static void	fillEllipse(byte[] target, int x, int y, int width, int height) MicroUI native "fillEllipse".
static void	fillEllipseArc(byte[] target, int x, int y, int width, int height, float startAngle, float arcAngle) MicroUI native "fillEllipseArc".
static void	fillRectangle(byte[] target, int x, int y, int width, int height) MicroUI native "fillRectangle".
static void	fillRoundedRectangle(byte[] target, int x, int y, int width, int height, int arcWidth, int arcHeight) MicroUI native "fillRoundedRectangle".
static UIDrawing	getDrawer() Returns the current drawer used by all implementation of MicroUI drawings native methods.
static void	setDrawer(UIDrawing drawer) Sets the given drawer as current drawer.
static void	writePixel(byte[] target, int x, int y) MicroUI native "writePixel".

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

drawCircle

public static void drawCircle(byte[] target,
                              int x,
                              int y,
                              int diameter)

MicroUI native "drawCircle". Draws a circle covering the square defined by top-left point x,y (included) and bottom-right point x+diameter-1,y+diameter-1 (included).

If the given diameter is negative or zero, nothing is drawn.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

diameter - the circle square size.

drawCircleArc

public static void drawCircleArc(byte[] target,
                                 int x,
                                 int y,
                                 int diameter,
                                 float startAngle,
                                 float arcAngle)

MicroUI native "drawCircleArc". Draws a circular arc covering the square defined by top-left point x,y (included) and bottom-right point x+diameter-1,y+diameter-1 (included).

The arc is drawn from startAngle up to arcAngle degrees. The center of the arc is defined as the center of the square whose origin is at (x,y) (upper-left corner) and whose dimension is given by diameter.

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.

If either the given diameter is negative or zero, or if arcAngle is zero, nothing is drawn.

The angles are given relative to the square. For instance an angle of 45 degrees is always defined by the line from the center of the square to the upper right corner of the square.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

diameter - the diameter of the arc to draw.

startAngle - the beginning angle of the arc to draw

arcAngle - the angular extent of the arc from startAngle

drawEllipse

public static void drawEllipse(byte[] target,
                               int x,
                               int y,
                               int width,
                               int height)

MicroUI native "drawEllipse". Draws an ellipse covering the rectangle defined by top-left point x,y (included) and bottom-right point x+width-1,y+height-1 (included).

If either the given width or height is negative or zero, nothing is drawn.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the ellipse width.

height - the ellipse height.

drawEllipseArc

public static void drawEllipseArc(byte[] target,
                                  int x,
                                  int y,
                                  int width,
                                  int height,
                                  float startAngle,
                                  float arcAngle)

MicroUI native "drawEllipseArc". Draws an elliptical arc covering the rectangle defined by top-left point x,y (included) and bottom-right point x+width-1,y+height-1 (included).

The arc is drawn from startAngle up to arcAngle degrees. The center of the arc is defined as the center of the rectangle whose origin is at (x,y) (upper-left corner) and whose dimension is given by width and height.

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.

If either the given width or height is negative or zero, or if arcAngle is zero, nothing is drawn.

The angles are given relative to the rectangle. For instance an angle of 45 degrees is always defined by the line from the center of the rectangle to the upper right corner of the rectangle. Thus for a non squared rectangle angles are skewed along either height or width.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the rectangle width.

height - the rectangle height.

startAngle - the beginning angle of the arc to draw

arcAngle - the angular extent of the arc from startAngle

drawHorizontalLine

public static void drawHorizontalLine(byte[] target,
                                      int x,
                                      int y,
                                      int width)

MicroUI native "drawHorizontalLine". Draws a horizontal line at between points x,y (included) and x+width-1,y (included).

See class comment to have more information about native method implementation.

Parameters:

target - drawing destination target: a byte array to map on a LLUIPainter.MicroUIGraphicsContext.

x - the first pixel line X coordinate.

y - the first pixel line Y coordinate.

width - the line size.

drawImage

public static void drawImage(byte[] target,
                             byte[] source,
                             int regionX,
                             int regionY,
                             int width,
                             int height,
                             int x,
                             int y,
                             int alpha)

MicroUI native "drawImage". Draws a region of an image. The region of the image to draw is given relative to the image (origin at the upper-left corner) as a rectangle.

If the specified source region exceeds the image bounds, the copied region is limited to the image boundary. If the copied region goes out of the bounds of the graphics context area, pixels out of the range will not be drawn.

A global opacity value is given. When this value is 0xff (255, opaque), that means the image is drawn on the graphics context without managing an extra opacity. Only the image transparent pixels must have been merged with destination. All image opaque pixels override destination.

When this value is a value between 0 and 0xff, that means each pixel of the image must be merged with destination in addition with the image transparent pixels. An image opaque pixel becomes transparent (its opacity is the given alpha) and the opacity of an image transparent pixel becomes (alpha * alpha(pixel)) / 255.

Parameters:

target - the MicroUI GraphicsContext target.

source - the MicroUI Image to draw.

regionX - the x coordinate of the upper-left corner of the region to copy.

regionY - the x coordinate of the upper-left corner of the region to copy.

width - the width of the region to copy.

height - the height of the region to copy.

x - the x coordinate of the top-left point in the destination.

y - the y coordinate of the top-left point in the destination.

alpha - the opacity level to apply to the region.

drawLine

public static void drawLine(byte[] target,
                            int x1,
                            int y1,
                            int x2,
                            int y2)

MicroUI native "drawLine". Draws a line at between points x1,y1 (included) and x2,y2 (included). Note: x1 may be higher than x2 (and/or y1 may be higher than y2).

See class comment to have more information about native method implementation.

Parameters:

target - drawing destination target: a byte array to map on a LLUIPainter.MicroUIGraphicsContext.

x1 - the first pixel line X coordinate.

y1 - the first pixel line Y coordinate.

x2 - the last pixel line X coordinate.

y2 - the last pixel line Y coordinate.

drawRectangle

public static void drawRectangle(byte[] target,
                                 int x,
                                 int y,
                                 int width,
                                 int height)

MicroUI native "drawRectangle". Draws a rectangle at from top-left point x,y (included) and bottom-right point x+width-1,y+height-1 (included).

See class comment to have more information about native method implementation.

Parameters:

target - drawing destination target: a byte array to map on a LLUIPainter.MicroUIGraphicsContext.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the rectangle width.

height - the rectangle height.

drawRoundedRectangle

public static void drawRoundedRectangle(byte[] target,
                                        int x,
                                        int y,
                                        int width,
                                        int height,
                                        int arcWidth,
                                        int arcHeight)

MicroUI native "drawRoundedRectangle". Draws a rounded rectangle at from top-left point x,y (included) and bottom-right point x+width-1,y+height-1 (included).

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the rectangle width.

height - the rectangle height.

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

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

drawVerticalLine

public static void drawVerticalLine(byte[] target,
                                    int x,
                                    int y,
                                    int height)

MicroUI native "drawVerticalLine". Draws a vertical line at between points x,y (included) and x,y+height-1 (included).

See class comment to have more information about native method implementation.

Parameters:

target - drawing destination target: a byte array to map on a LLUIPainter.MicroUIGraphicsContext.

x - the first pixel line X coordinate.

y - the first pixel line Y coordinate.

height - the line size.

fillCircle

public static void fillCircle(byte[] target,
                              int x,
                              int y,
                              int diameter)

MicroUI native "fillCircle". Fills a circle covering the square defined by top-left point x,y (included) and bottom-right point x+diameter-1,y+diameter-1 (included).

If the given diameter is negative or zero, nothing is drawn.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

diameter - the circle square size.

fillCircleArc

public static void fillCircleArc(byte[] target,
                                 int x,
                                 int y,
                                 int diameter,
                                 float startAngle,
                                 float arcAngle)

MicroUI native "fillCircleArc". Fills a circular arc covering the square defined by top-left point x,y (included) and bottom-right point x+diameter-1,y+diameter-1 (included). The arc is drawn from startAngle up to arcAngle degrees. The center of the arc is defined as the center of the square whose origin is at (x,y) (upper-left corner) and whose dimension is given by width and height. 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. If either the given diameter is negative or zero, or if arcAngle is zero, nothing is drawn. The angles are given relative to the square. For instance an angle of 45 degrees is always defined by the line from the center of the square to the upper right corner of the square.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

diameter - the diameter of the arc to draw.

startAngle - the beginning angle of the arc to draw

arcAngle - the angular extent of the arc from startAngle

fillEllipse

public static void fillEllipse(byte[] target,
                               int x,
                               int y,
                               int width,
                               int height)

MicroUI native "fillEllipse". Fills an ellipse covering the rectangle defined by top-left point x,y (included) and bottom-right point x+width-1,y+height-1 (included).

If either the given width or height is negative or zero, nothing is drawn.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the ellipse width.

height - the ellipse height.

fillEllipseArc

public static void fillEllipseArc(byte[] target,
                                  int x,
                                  int y,
                                  int width,
                                  int height,
                                  float startAngle,
                                  float arcAngle)

MicroUI native "fillEllipseArc". Fills an arc covering the rectangle defined by top-left point x,y (included) and bottom-right point x+width-1,y+height-1 (included).

The arc is drawn from startAngle up to arcAngle degrees. The center of the arc is defined as the center of the rectangle whose origin is at (x,y) (upper-left corner) and whose dimension is given by width and height.

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.

If either the given width or height is negative or zero, or if arcAngle is zero, nothing is drawn.

The angles are given relative to the rectangle. For instance an angle of 45 degrees is always defined by the line from the center of the rectangle to the upper right corner of the rectangle. Thus for a non squared rectangle angles are skewed along either height or width.

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the rectangle width.

height - the rectangle height.

startAngle - the beginning angle of the arc to draw

arcAngle - the angular extent of the arc from startAngle

fillRectangle

public static void fillRectangle(byte[] target,
                                 int x,
                                 int y,
                                 int width,
                                 int height)

MicroUI native "fillRectangle". Fills a rectangle at from top-left point x1,y1 (included) and bottom-right point x2,y2 (included). Caller ensures that x1 <= x2 and y1 <= y2.

See class comment to have more information about native method implementation.

Parameters:

target - drawing destination target: a byte array to map on a LLUIPainter.MicroUIGraphicsContext.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the rectangle width.

height - the rectangle height.

fillRoundedRectangle

public static void fillRoundedRectangle(byte[] target,
                                        int x,
                                        int y,
                                        int width,
                                        int height,
                                        int arcWidth,
                                        int arcHeight)

MicroUI native "fillRoundedRectangle". Fills a rounded rectangle at from top-left point x,y (included) and bottom-right point x+width-1,y+height-1 (included).

Parameters:

target - the MicroUI GraphicsContext target.

x - the top-left pixel X coordinate.

y - the top-left pixel Y coordinate.

width - the rectangle width.

height - the rectangle height.

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

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

getDrawer

public static UIDrawing getDrawer()

Returns the current drawer used by all implementation of MicroUI drawings native methods.

Returns:

the current drawer (MicroUI graphical engine's internal software drawer if no other drawer has been set).

setDrawer

public static void setDrawer(UIDrawing drawer)

Sets the given drawer as current drawer. This drawer is used by all implementation of MicroUI drawings native methods.

The drawer has the responsibility to check the clip (draw outside current clip is forbidden) and has to update the new Display.flush() area (dirty area) as mentioned in LLUIPainter class comment.

Default drawer is the MicroUI graphical engine's internal software drawer.

Parameters:

drawer - the new drawer to use or null to use the MicroUI graphical engine's internal software drawer.

writePixel

public static void writePixel(byte[] target,
                              int x,
                              int y)

MicroUI native "writePixel". Draws a pixel at given position.

See class comment to have more information about native method implementation.

Parameters:

target - drawing destination target: a byte array to map on a LLUIPainter.MicroUIGraphicsContext.

x - the pixel X coordinate.

y - the pixel Y coordinate.