Package org.apache.poi.hssf.usermodel

Class 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 its 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: 

    
      multiplier = 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 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

      • 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

      • 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

      • drawRoundRect

        @NotImplemented
public void drawRoundRect​(int x,
                          int y,
                          int width,
                          int height,
                          int arcWidth,
                          int arcHeight)
        Specified by:
        drawRoundRect 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

      • setClip

        public void setClip​(int x,
                    int y,
                    int width,
                    int height)
        Specified by:
        setClip in class Graphics

      • getBackground

        public Color getBackground()

      • setBackground

        public void setBackground​(Color background)