Package org.apache.pdfbox.rendering

Class GroupGraphics

  • class GroupGraphics
extends java.awt.Graphics2D
    Graphics implementation for non-isolated transparency groups.

    Non-isolated groups require that the group backdrop (copied from parent group or page) is used as the initial contents of the image to which the group is rendered. This allows blend modes to blend the group contents with the graphics behind the group. Finally when the group rendering is done, backdrop removal must be computed (see removeBackdrop). It ensures the backdrop is not rendered twice on the parent but it leaves the effects of blend modes.

    This class renders the group contents to two images. groupImage is initialized with the backdrop and group contents are drawn over it. groupAlphaImage is initially fully transparent and it accumulates the total alpha of the group contents excluding backdrop.

    If a non-isolated group uses only the blend mode Normal, it can be optimized and rendered like an isolated group; backdrop usage and removal are not needed.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.awt.Graphics2D alphaG2D  
      private java.awt.image.BufferedImage groupAlphaImage  
      private java.awt.Graphics2D groupG2D  
      private java.awt.image.BufferedImage groupImage  

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      (package private) GroupGraphics​(java.awt.image.BufferedImage groupImage, java.awt.Graphics2D groupGraphics)  
      private GroupGraphics​(java.awt.image.BufferedImage groupImage, java.awt.Graphics2D groupGraphics, java.awt.image.BufferedImage groupAlphaImage, java.awt.Graphics2D alphaGraphics)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addRenderingHints​(java.util.Map<?,​?> hints)  
      private int backdropRemoval​(int groupRGB, int backdropRGB, int shift, float alphaFactor)
      Computes the backdrop removal equation.
      void clearRect​(int x, int y, int width, int height)  
      void clip​(java.awt.Shape s)  
      void clipRect​(int x, int y, int width, int height)  
      void copyArea​(int x, int y, int width, int height, int dx, int dy)  
      java.awt.Graphics create()  
      void dispose()  
      void draw​(java.awt.Shape s)  
      void drawArc​(int x, int y, int width, int height, int startAngle, int arcAngle)  
      void drawGlyphVector​(java.awt.font.GlyphVector g, float x, float y)  
      void drawImage​(java.awt.image.BufferedImage img, java.awt.image.BufferedImageOp op, int x, int y)  
      boolean drawImage​(java.awt.Image img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2, java.awt.Color bgcolor, java.awt.image.ImageObserver observer)  
      boolean drawImage​(java.awt.Image img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2, java.awt.image.ImageObserver observer)  
      boolean drawImage​(java.awt.Image img, int x, int y, int width, int height, java.awt.Color bgcolor, java.awt.image.ImageObserver observer)  
      boolean drawImage​(java.awt.Image img, int x, int y, int width, int height, java.awt.image.ImageObserver observer)  
      boolean drawImage​(java.awt.Image img, int x, int y, java.awt.Color bgcolor, java.awt.image.ImageObserver observer)  
      boolean drawImage​(java.awt.Image img, int x, int y, java.awt.image.ImageObserver observer)  
      boolean drawImage​(java.awt.Image img, java.awt.geom.AffineTransform xform, java.awt.image.ImageObserver obs)  
      void drawLine​(int x1, int y1, int x2, int y2)  
      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 drawRenderableImage​(java.awt.image.renderable.RenderableImage img, java.awt.geom.AffineTransform xform)  
      void drawRenderedImage​(java.awt.image.RenderedImage img, java.awt.geom.AffineTransform xform)  
      void drawRoundRect​(int x, int y, int width, int height, int arcWidth, int arcHeight)  
      void drawString​(java.lang.String str, float x, float y)  
      void drawString​(java.lang.String str, int x, int y)  
      void drawString​(java.text.AttributedCharacterIterator iterator, float x, float y)  
      void drawString​(java.text.AttributedCharacterIterator iterator, int x, int y)  
      void fill​(java.awt.Shape s)  
      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)  
      void fillRect​(int x, int y, int width, int height)  
      void fillRoundRect​(int x, int y, int width, int height, int arcWidth, int arcHeight)  
      java.awt.Color getBackground()  
      java.awt.Shape getClip()  
      java.awt.Rectangle getClipBounds()  
      java.awt.Color getColor()  
      java.awt.Composite getComposite()  
      java.awt.GraphicsConfiguration getDeviceConfiguration()  
      java.awt.Font getFont()  
      java.awt.FontMetrics getFontMetrics​(java.awt.Font f)  
      java.awt.font.FontRenderContext getFontRenderContext()  
      java.awt.Paint getPaint()  
      java.lang.Object getRenderingHint​(java.awt.RenderingHints.Key hintKey)  
      java.awt.RenderingHints getRenderingHints()  
      java.awt.Stroke getStroke()  
      java.awt.geom.AffineTransform getTransform()  
      boolean hit​(java.awt.Rectangle rect, java.awt.Shape s, boolean onStroke)  
      (package private) void removeBackdrop​(java.awt.image.BufferedImage backdrop, int offsetX, int offsetY)
      Computes backdrop removal.
      void rotate​(double theta)  
      void rotate​(double theta, double x, double y)  
      void scale​(double sx, double sy)  
      void setBackground​(java.awt.Color color)  
      void setClip​(int x, int y, int width, int height)  
      void setClip​(java.awt.Shape clip)  
      void setColor​(java.awt.Color c)  
      void setComposite​(java.awt.Composite comp)  
      void setFont​(java.awt.Font font)  
      void setPaint​(java.awt.Paint paint)  
      void setPaintMode()  
      void setRenderingHint​(java.awt.RenderingHints.Key hintKey, java.lang.Object hintValue)  
      void setRenderingHints​(java.util.Map<?,​?> hints)  
      void setStroke​(java.awt.Stroke s)  
      void setTransform​(java.awt.geom.AffineTransform tx)  
      void setXORMode​(java.awt.Color c1)  
      void shear​(double shx, double shy)  
      void transform​(java.awt.geom.AffineTransform tx)  
      void translate​(double tx, double ty)  
      void translate​(int x, int y)  

      • Methods inherited from class java.awt.Graphics2D

        draw3DRect, fill3DRect

      • Methods inherited from class java.awt.Graphics

        create, drawBytes, drawChars, drawPolygon, drawRect, fillPolygon, finalize, getClipBounds, getClipRect, getFontMetrics, hitClip, toString

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • groupImage

        private final java.awt.image.BufferedImage groupImage

      • groupAlphaImage

        private final java.awt.image.BufferedImage groupAlphaImage

      • groupG2D

        private final java.awt.Graphics2D groupG2D

      • alphaG2D

        private final java.awt.Graphics2D alphaG2D

    • Constructor Detail

      • GroupGraphics

        GroupGraphics​(java.awt.image.BufferedImage groupImage,
              java.awt.Graphics2D groupGraphics)

      • GroupGraphics

        private GroupGraphics​(java.awt.image.BufferedImage groupImage,
                      java.awt.Graphics2D groupGraphics,
                      java.awt.image.BufferedImage groupAlphaImage,
                      java.awt.Graphics2D alphaGraphics)

    • Method Detail

      • clearRect

        public void clearRect​(int x,
                      int y,
                      int width,
                      int height)
        Specified by:
        clearRect in class java.awt.Graphics

      • clipRect

        public void clipRect​(int x,
                     int y,
                     int width,
                     int height)
        Specified by:
        clipRect in class java.awt.Graphics

      • copyArea

        public void copyArea​(int x,
                     int y,
                     int width,
                     int height,
                     int dx,
                     int dy)
        Specified by:
        copyArea in class java.awt.Graphics

      • create

        public java.awt.Graphics create()
        Specified by:
        create in class java.awt.Graphics

      • dispose

        public void dispose()
        Specified by:
        dispose in class java.awt.Graphics

      • drawArc

        public void drawArc​(int x,
                    int y,
                    int width,
                    int height,
                    int startAngle,
                    int arcAngle)
        Specified by:
        drawArc in class java.awt.Graphics

      • drawImage

        public boolean drawImage​(java.awt.Image img,
                         int x,
                         int y,
                         java.awt.Color bgcolor,
                         java.awt.image.ImageObserver observer)
        Specified by:
        drawImage in class java.awt.Graphics

      • drawImage

        public boolean drawImage​(java.awt.Image img,
                         int x,
                         int y,
                         java.awt.image.ImageObserver observer)
        Specified by:
        drawImage in class java.awt.Graphics

      • drawImage

        public boolean drawImage​(java.awt.Image img,
                         int x,
                         int y,
                         int width,
                         int height,
                         java.awt.Color bgcolor,
                         java.awt.image.ImageObserver observer)
        Specified by:
        drawImage in class java.awt.Graphics

      • drawImage

        public boolean drawImage​(java.awt.Image img,
                         int x,
                         int y,
                         int width,
                         int height,
                         java.awt.image.ImageObserver observer)
        Specified by:
        drawImage in class java.awt.Graphics

      • drawImage

        public boolean drawImage​(java.awt.Image img,
                         int dx1,
                         int dy1,
                         int dx2,
                         int dy2,
                         int sx1,
                         int sy1,
                         int sx2,
                         int sy2,
                         java.awt.Color bgcolor,
                         java.awt.image.ImageObserver observer)
        Specified by:
        drawImage in class java.awt.Graphics

      • drawImage

        public boolean drawImage​(java.awt.Image img,
                         int dx1,
                         int dy1,
                         int dx2,
                         int dy2,
                         int sx1,
                         int sy1,
                         int sx2,
                         int sy2,
                         java.awt.image.ImageObserver observer)
        Specified by:
        drawImage in class java.awt.Graphics

      • drawLine

        public void drawLine​(int x1,
                     int y1,
                     int x2,
                     int y2)
        Specified by:
        drawLine in class java.awt.Graphics

      • drawOval

        public void drawOval​(int x,
                     int y,
                     int width,
                     int height)
        Specified by:
        drawOval in class java.awt.Graphics

      • drawPolygon

        public void drawPolygon​(int[] xPoints,
                        int[] yPoints,
                        int nPoints)
        Specified by:
        drawPolygon in class java.awt.Graphics

      • drawPolyline

        public void drawPolyline​(int[] xPoints,
                         int[] yPoints,
                         int nPoints)
        Specified by:
        drawPolyline in class java.awt.Graphics

      • drawRoundRect

        public void drawRoundRect​(int x,
                          int y,
                          int width,
                          int height,
                          int arcWidth,
                          int arcHeight)
        Specified by:
        drawRoundRect in class java.awt.Graphics

      • drawString

        public void drawString​(java.text.AttributedCharacterIterator iterator,
                       int x,
                       int y)
        Specified by:
        drawString in class java.awt.Graphics2D

      • drawString

        public void drawString​(java.lang.String str,
                       int x,
                       int y)
        Specified by:
        drawString in class java.awt.Graphics2D

      • fillArc

        public void fillArc​(int x,
                    int y,
                    int width,
                    int height,
                    int startAngle,
                    int arcAngle)
        Specified by:
        fillArc in class java.awt.Graphics

      • fillOval

        public void fillOval​(int x,
                     int y,
                     int width,
                     int height)
        Specified by:
        fillOval in class java.awt.Graphics

      • fillPolygon

        public void fillPolygon​(int[] xPoints,
                        int[] yPoints,
                        int nPoints)
        Specified by:
        fillPolygon in class java.awt.Graphics

      • fillRect

        public void fillRect​(int x,
                     int y,
                     int width,
                     int height)
        Specified by:
        fillRect in class java.awt.Graphics

      • fillRoundRect

        public void fillRoundRect​(int x,
                          int y,
                          int width,
                          int height,
                          int arcWidth,
                          int arcHeight)
        Specified by:
        fillRoundRect in class java.awt.Graphics

      • getClip

        public java.awt.Shape getClip()
        Specified by:
        getClip in class java.awt.Graphics

      • getClipBounds

        public java.awt.Rectangle getClipBounds()
        Specified by:
        getClipBounds in class java.awt.Graphics

      • getColor

        public java.awt.Color getColor()
        Specified by:
        getColor in class java.awt.Graphics

      • getFont

        public java.awt.Font getFont()
        Specified by:
        getFont in class java.awt.Graphics

      • getFontMetrics

        public java.awt.FontMetrics getFontMetrics​(java.awt.Font f)
        Specified by:
        getFontMetrics in class java.awt.Graphics

      • setClip

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

      • setClip

        public void setClip​(java.awt.Shape clip)
        Specified by:
        setClip in class java.awt.Graphics

      • setColor

        public void setColor​(java.awt.Color c)
        Specified by:
        setColor in class java.awt.Graphics

      • setFont

        public void setFont​(java.awt.Font font)
        Specified by:
        setFont in class java.awt.Graphics

      • setPaintMode

        public void setPaintMode()
        Specified by:
        setPaintMode in class java.awt.Graphics

      • setXORMode

        public void setXORMode​(java.awt.Color c1)
        Specified by:
        setXORMode in class java.awt.Graphics

      • translate

        public void translate​(int x,
                      int y)
        Specified by:
        translate in class java.awt.Graphics2D

      • addRenderingHints

        public void addRenderingHints​(java.util.Map<?,​?> hints)
        Specified by:
        addRenderingHints in class java.awt.Graphics2D

      • clip

        public void clip​(java.awt.Shape s)
        Specified by:
        clip in class java.awt.Graphics2D

      • draw

        public void draw​(java.awt.Shape s)
        Specified by:
        draw in class java.awt.Graphics2D

      • drawGlyphVector

        public void drawGlyphVector​(java.awt.font.GlyphVector g,
                            float x,
                            float y)
        Specified by:
        drawGlyphVector in class java.awt.Graphics2D

      • drawImage

        public void drawImage​(java.awt.image.BufferedImage img,
                      java.awt.image.BufferedImageOp op,
                      int x,
                      int y)
        Specified by:
        drawImage in class java.awt.Graphics2D

      • drawImage

        public boolean drawImage​(java.awt.Image img,
                         java.awt.geom.AffineTransform xform,
                         java.awt.image.ImageObserver obs)
        Specified by:
        drawImage in class java.awt.Graphics2D

      • drawRenderableImage

        public void drawRenderableImage​(java.awt.image.renderable.RenderableImage img,
                                java.awt.geom.AffineTransform xform)
        Specified by:
        drawRenderableImage in class java.awt.Graphics2D

      • drawRenderedImage

        public void drawRenderedImage​(java.awt.image.RenderedImage img,
                              java.awt.geom.AffineTransform xform)
        Specified by:
        drawRenderedImage in class java.awt.Graphics2D

      • drawString

        public void drawString​(java.text.AttributedCharacterIterator iterator,
                       float x,
                       float y)
        Specified by:
        drawString in class java.awt.Graphics2D

      • drawString

        public void drawString​(java.lang.String str,
                       float x,
                       float y)
        Specified by:
        drawString in class java.awt.Graphics2D

      • fill

        public void fill​(java.awt.Shape s)
        Specified by:
        fill in class java.awt.Graphics2D

      • getBackground

        public java.awt.Color getBackground()
        Specified by:
        getBackground in class java.awt.Graphics2D

      • getComposite

        public java.awt.Composite getComposite()
        Specified by:
        getComposite in class java.awt.Graphics2D

      • getDeviceConfiguration

        public java.awt.GraphicsConfiguration getDeviceConfiguration()
        Specified by:
        getDeviceConfiguration in class java.awt.Graphics2D

      • getFontRenderContext

        public java.awt.font.FontRenderContext getFontRenderContext()
        Specified by:
        getFontRenderContext in class java.awt.Graphics2D

      • getPaint

        public java.awt.Paint getPaint()
        Specified by:
        getPaint in class java.awt.Graphics2D

      • getRenderingHint

        public java.lang.Object getRenderingHint​(java.awt.RenderingHints.Key hintKey)
        Specified by:
        getRenderingHint in class java.awt.Graphics2D

      • getRenderingHints

        public java.awt.RenderingHints getRenderingHints()
        Specified by:
        getRenderingHints in class java.awt.Graphics2D

      • getStroke

        public java.awt.Stroke getStroke()
        Specified by:
        getStroke in class java.awt.Graphics2D

      • getTransform

        public java.awt.geom.AffineTransform getTransform()
        Specified by:
        getTransform in class java.awt.Graphics2D

      • hit

        public boolean hit​(java.awt.Rectangle rect,
                   java.awt.Shape s,
                   boolean onStroke)
        Specified by:
        hit in class java.awt.Graphics2D

      • rotate

        public void rotate​(double theta)
        Specified by:
        rotate in class java.awt.Graphics2D

      • rotate

        public void rotate​(double theta,
                   double x,
                   double y)
        Specified by:
        rotate in class java.awt.Graphics2D

      • scale

        public void scale​(double sx,
                  double sy)
        Specified by:
        scale in class java.awt.Graphics2D

      • setBackground

        public void setBackground​(java.awt.Color color)
        Specified by:
        setBackground in class java.awt.Graphics2D

      • setComposite

        public void setComposite​(java.awt.Composite comp)
        Specified by:
        setComposite in class java.awt.Graphics2D

      • setPaint

        public void setPaint​(java.awt.Paint paint)
        Specified by:
        setPaint in class java.awt.Graphics2D

      • setRenderingHint

        public void setRenderingHint​(java.awt.RenderingHints.Key hintKey,
                             java.lang.Object hintValue)
        Specified by:
        setRenderingHint in class java.awt.Graphics2D

      • setRenderingHints

        public void setRenderingHints​(java.util.Map<?,​?> hints)
        Specified by:
        setRenderingHints in class java.awt.Graphics2D

      • setStroke

        public void setStroke​(java.awt.Stroke s)
        Specified by:
        setStroke in class java.awt.Graphics2D

      • setTransform

        public void setTransform​(java.awt.geom.AffineTransform tx)
        Specified by:
        setTransform in class java.awt.Graphics2D

      • shear

        public void shear​(double shx,
                  double shy)
        Specified by:
        shear in class java.awt.Graphics2D

      • transform

        public void transform​(java.awt.geom.AffineTransform tx)
        Specified by:
        transform in class java.awt.Graphics2D

      • translate

        public void translate​(double tx,
                      double ty)
        Specified by:
        translate in class java.awt.Graphics2D

      • removeBackdrop

        void removeBackdrop​(java.awt.image.BufferedImage backdrop,
                    int offsetX,
                    int offsetY)
        Computes backdrop removal. The backdrop removal equation is given in section 11.4.4 in the PDF 32000-1:2008 standard. It returns the final color C for each pixel in the group:
        C = Cn + (Cn - C0) * (alpha0 / alphagn - alpha0)
        where
        Cn is the group color including backdrop (read from groupImage),
        C0 is the backdrop color,
        alpha0 is the backdrop alpha,
        alphagn is the group alpha excluding backdrop (read the alpha channel from groupAlphaImage)

        The alpha of the result is equal to alphagn, i.e., the alpha channel of groupAlphaImage.

        The backdrop image may be much larger than groupImage if, for example, the current page is used as the backdrop. Only a specific rectangular region of backdrop is used in the backdrop removal: upper-left corner is at (offsetX, offsetY); width and height are equal to those of groupImage.

        Parameters:
        backdrop - group backdrop
        offsetX - backdrop left X coordinate
        offsetY - backdrop upper Y coordinate

      • backdropRemoval

        private int backdropRemoval​(int groupRGB,
                            int backdropRGB,
                            int shift,
                            float alphaFactor)
        Computes the backdrop removal equation. C = Cn + (Cn - C0) * (alpha0 / alphagn - alpha0)