Class EscherGraphics

java.lang.Object
java.awt.Graphics
org.apache.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().

  • Constructor Details

    • 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 Details

    • clearRect

      @NotImplemented public void clearRect(int x, int y, int width, int height)
      Specified by:
      clearRect in class Graphics
    • clipRect

      @NotImplemented public void clipRect(int x, int y, int width, int height)
      Specified by:
      clipRect in class Graphics
    • copyArea

      @NotImplemented 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

      @NotImplemented public void drawArc(int x, int y, int width, int height, int startAngle, int arcAngle)
      Specified by:
      drawArc in class Graphics
    • drawImage

      @NotImplemented 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

      @NotImplemented 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

      @NotImplemented public void drawPolyline(int[] xPoints, int[] yPoints, int nPoints)
      Specified by:
      drawPolyline in class Graphics
    • drawRect

      @NotImplemented public void drawRect(int x, int y, int width, int height)
      Overrides:
      drawRect in class Graphics
    • drawRoundRect

      @NotImplemented 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:
    • 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
    • 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

      @NotImplemented 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

      @NotImplemented public void setPaintMode()
      Specified by:
      setPaintMode in class Graphics
    • setXORMode

      @NotImplemented public void setXORMode(Color color)
      Specified by:
      setXORMode in class Graphics
    • translate

      @NotImplemented public void translate(int x, int y)
      Specified by:
      translate in class Graphics
    • getBackground

      public Color getBackground()
    • setBackground

      public void setBackground(Color background)