loci.poi.hssf.usermodel

Class EscherGraphics

java.lang.Object

java.awt.Graphics

loci.poi.hssf.usermodel.EscherGraphics

public class EscherGraphics
extends Graphics

Translates Graphics calls into escher calls. The translation is lossy so many features are not supported and some just aren't implemented yet. If in doubt test the specific calls you wish to make. Graphics calls are always performed into an EscherGroup so one will need to be created.

Important:

One important concept worth considering is that of font size. One of the difficulties in converting Graphics calls into escher drawing calls is that Excel does not have the concept of absolute pixel positions. It measures it's cell widths in 'characters' and the cell heights in points. Unfortunately it's not defined exactly what a type of character it's measuring. Presumably this is due to the fact that the Excel will be using different fonts on different platforms or even within the same platform.

Because of this constraint we've had to calculate the verticalPointsPerPixel. This the amount the font should be scaled by when you issue commands such as drawString(). A good way to calculate this is to use the follow formula:

      multipler = groupHeightInPoints / heightOfGroup
 

The height of the group is calculated fairly simply by calculating the difference between the y coordinates of the bounding box of the shape. The height of the group can be calculated by using a convenience called HSSFClientAnchor.getAnchorHeightInPoints().

Author:

Glen Stampoultzis (glens at apache.org)

Constructor Summary

Constructors

Constructor and Description
EscherGraphics(HSSFShapeGroup escherGroup, HSSFWorkbook workbook, Color forecolor, float verticalPointsPerPixel) Construct an escher graphics object.

Method Summary

Methods

Modifier and Type	Method and Description
void	clearRect(int x, int y, int width, int height)
void	clipRect(int x, int y, int width, int height)
void	copyArea(int x, int y, int width, int height, int dx, int dy)
Graphics	create()
void	dispose()
void	drawArc(int x, int y, int width, int height, int startAngle, int arcAngle)
boolean	drawImage(Image image, int i, int j, Color color, ImageObserver imageobserver)
boolean	drawImage(Image image, int i, int j, ImageObserver imageobserver)
boolean	drawImage(Image image, int i, int j, int k, int l, Color color, ImageObserver imageobserver)
boolean	drawImage(Image image, int i, int j, int k, int l, ImageObserver imageobserver)
boolean	drawImage(Image img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2, Color bgcolor, ImageObserver observer)
boolean	drawImage(Image img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2, ImageObserver observer)
void	drawLine(int x1, int y1, int x2, int y2)
void	drawLine(int x1, int y1, int x2, int y2, int width)
void	drawOval(int x, int y, int width, int height)
void	drawPolygon(int[] xPoints, int[] yPoints, int nPoints)
void	drawPolyline(int[] xPoints, int[] yPoints, int nPoints)
void	drawRect(int x, int y, int width, int height)
void	drawRoundRect(int x, int y, int width, int height, int arcWidth, int arcHeight)
void	drawString(AttributedCharacterIterator iterator, int x, int y)
void	drawString(String str, int x, int y)
void	fillArc(int x, int y, int width, int height, int startAngle, int arcAngle)
void	fillOval(int x, int y, int width, int height)
void	fillPolygon(int[] xPoints, int[] yPoints, int nPoints) Fills a (closed) polygon, as defined by a pair of arrays, which hold the x and y coordinates.
void	fillRect(int x, int y, int width, int height)
void	fillRoundRect(int x, int y, int width, int height, int arcWidth, int arcHeight)
Color	getBackground()
Shape	getClip()
Rectangle	getClipBounds()
Rectangle	getClipRect()
Color	getColor()
Font	getFont()
FontMetrics	getFontMetrics(Font f)
void	setBackground(Color background)
void	setClip(int x, int y, int width, int height)
void	setClip(Shape shape)
void	setColor(Color color)
void	setFont(Font f)
void	setPaintMode()
void	setXORMode(Color color)
void	translate(int x, int y)

Methods inherited from class java.awt.Graphics

create, draw3DRect, drawBytes, drawChars, drawPolygon, fill3DRect, fillPolygon, finalize, getClipBounds, getFontMetrics, hitClip, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

EscherGraphics

public EscherGraphics(HSSFShapeGroup escherGroup,
              HSSFWorkbook workbook,
              Color forecolor,
              float verticalPointsPerPixel)

Construct an escher graphics object.

Parameters:

escherGroup - The escher group to write the graphics calls into.

workbook - The workbook we are using.

forecolor - The foreground color to use as default.

verticalPointsPerPixel - The font multiplier. (See class description for information on how this works.).

Method Detail

clearRect

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

Specified by:

clearRect in class Graphics

clipRect

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

Specified by:

clipRect in class Graphics

copyArea

public void copyArea(int x,
            int y,
            int width,
            int height,
            int dx,
            int dy)

Specified by:

copyArea in class Graphics

create

public Graphics create()

Specified by:

create in class Graphics

dispose

public void dispose()

Specified by:

dispose in class Graphics

drawArc

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

Specified by:

drawArc in class Graphics

drawImage

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

Specified by:

drawImage in class Graphics

drawImage

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

Specified by:

drawImage in class Graphics

drawImage

public boolean drawImage(Image image,
                int i,
                int j,
                int k,
                int l,
                Color color,
                ImageObserver imageobserver)

Specified by:

drawImage in class Graphics

drawImage

public boolean drawImage(Image image,
                int i,
                int j,
                int k,
                int l,
                ImageObserver imageobserver)

Specified by:

drawImage in class Graphics

drawImage

public boolean drawImage(Image image,
                int i,
                int j,
                Color color,
                ImageObserver imageobserver)

Specified by:

drawImage in class Graphics

drawImage

public boolean drawImage(Image image,
                int i,
                int j,
                ImageObserver imageobserver)

Specified by:

drawImage in class Graphics

drawLine

public void drawLine(int x1,
            int y1,
            int x2,
            int y2)

Specified by:

drawLine in class Graphics

drawLine

public void drawLine(int x1,
            int y1,
            int x2,
            int y2,
            int width)

drawOval

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

Specified by:

drawOval in class Graphics

drawPolygon

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

Specified by:

drawPolygon in class Graphics

drawPolyline

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

Specified by:

drawPolyline in class Graphics

drawRect

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

Overrides:

drawRect in class Graphics

drawRoundRect

public void drawRoundRect(int x,
                 int y,
                 int width,
                 int height,
                 int arcWidth,
                 int arcHeight)

Specified by:

drawRoundRect in class Graphics

drawString

public void drawString(String str,
              int x,
              int y)

Specified by:

drawString in class Graphics

drawString

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

Specified by:

drawString in class Graphics

fillArc

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

Specified by:

fillArc in class Graphics

fillOval

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

Specified by:

fillOval in class Graphics

fillPolygon

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

Fills a (closed) polygon, as defined by a pair of arrays, which hold the x and y coordinates.

This draws the polygon, with nPoint line segments. The first nPoint - 1 line segments are drawn between sequential points (xPoints[i],yPoints[i],xPoints[i+1],yPoints[i+1]). The final line segment is a closing one, from the last point to the first (assuming they are different).

The area inside of the polygon is defined by using an even-odd fill rule (also known as the alternating rule), and the area inside of it is filled.

Specified by:

fillPolygon in class Graphics

Parameters:

xPoints - array of the x coordinates.

yPoints - array of the y coordinates.

nPoints - the total number of points in the polygon.

See Also:

Graphics.drawPolygon(int[], int[], int)

fillRect

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

Specified by:

fillRect in class Graphics

fillRoundRect

public void fillRoundRect(int x,
                 int y,
                 int width,
                 int height,
                 int arcWidth,
                 int arcHeight)

Specified by:

fillRoundRect in class Graphics

getClip

public Shape getClip()

Specified by:

getClip in class Graphics

getClipBounds

public Rectangle getClipBounds()

Specified by:

getClipBounds in class Graphics

getClipRect

public Rectangle getClipRect()

Overrides:

getClipRect in class Graphics

getColor

public Color getColor()

Specified by:

getColor in class Graphics

getFont

public Font getFont()

Specified by:

getFont in class Graphics

getFontMetrics

public FontMetrics getFontMetrics(Font f)

Specified by:

getFontMetrics in class Graphics

setClip

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

Specified by:

setClip in class Graphics

setClip

public void setClip(Shape shape)

Specified by:

setClip in class Graphics

setColor

public void setColor(Color color)

Specified by:

setColor in class Graphics

setFont

public void setFont(Font f)

Specified by:

setFont in class Graphics

setPaintMode

public void setPaintMode()

Specified by:

setPaintMode in class Graphics

setXORMode

public void setXORMode(Color color)

Specified by:

setXORMode in class Graphics

translate

public void translate(int x,
             int y)

Specified by:

translate in class Graphics

getBackground

public Color getBackground()

setBackground

public void setBackground(Color background)