Package org.openpdf.renderer

Class PDFRenderer

java.lang.Object
org.openpdf.renderer.BaseWatchable
org.openpdf.renderer.PDFRenderer
All Implemented Interfaces:
Runnable, Watchable
public class PDFRenderer extends BaseWatchable implements Runnable
This class turns a set of PDF Commands from a PDF page into an image. It encapsulates the state of drawing in terms of stroke, fill, transform, etc., as well as pushing and popping these states. When the run method is called, this class goes through all remaining commands in the PDF Page and draws them to its buffered image. It then updates any ImageConsumers with the drawn data.

  • Field Details

    • page

      private PDFPage page
      the page we were generate from

    • currentCommand

      private int currentCommand
      where we are in the page's command list

    • imageRef

      private WeakReference<BufferedImage> imageRef
      a weak reference to the image we render into. For the image to remain available, some other code must retain a strong reference to it.

    • g

      private Graphics2D g
      the graphics object for use within an iteration. Note this must be set to null at the end of each iteration, or the image will not be collected

    • state

      private PDFRenderer.GraphicsState state
      the current graphics state

    • stack

      private Stack<PDFRenderer.GraphicsState> stack
      the stack of push()ed graphics states

    • globalDirtyRegion

      private Rectangle2D globalDirtyRegion
      the total region of this image that has been written to

    • observers

      private final List<ImageObserver> observers
      the image observers that will be updated when this image changes

    • lastShape

      private GeneralPath lastShape
      the last shape we drew (to check for overlaps)

    • lastTransform

      private AffineTransform lastTransform

    • imageinfo

      private final ImageInfo imageinfo
      the info about the image, if we need to recreate it

    • then

      private long then
      the next time the image should be notified about updates

    • unupdatedRegion

      private Rectangle2D unupdatedRegion
      the sum of all the individual dirty regions since the last update

    • UPDATE_DURATION

      public static final long UPDATE_DURATION
      how long (in milliseconds) to wait between image updates
      See Also:

    • NOPHASE

      public static final float NOPHASE
      See Also:

    • NOWIDTH

      public static final float NOWIDTH
      See Also:

    • NOLIMIT

      public static final float NOLIMIT
      See Also:

    • NOCAP

      public static final int NOCAP
      See Also:

    • NODASH

      public static final float[] NODASH

    • NOJOIN

      public static final int NOJOIN
      See Also:

  • Constructor Details

    • PDFRenderer

      public PDFRenderer(PDFPage page, ImageInfo imageinfo, BufferedImage bi)
      create a new PDFGraphics state
      Parameters:
      page - the current page
      imageinfo - the paramters of the image to render

    • PDFRenderer

      public PDFRenderer(PDFPage page, Graphics2D g, Rectangle imgbounds, Rectangle2D clip, Color bgColor)
      create a new PDFGraphics state, given a Graphics2D. This version will not create an image, and you will get a NullPointerException if you attempt to call getImage().
      Parameters:
      page - the current page
      g - the Graphics2D object to use for drawing
      imgbounds - the bounds of the image into which to fit the page
      clip - the portion of the page to draw, in page space, or null if the whole page should be drawn
      bgColor - the color to draw the background of the image, or null for no color (0 alpha value)

  • Method Details

    • setupRendering

      private void setupRendering(Graphics2D g)
      Set up the graphics transform to match the clip region to the image size.

    • push

      public void push()
      push the current graphics state onto the stack. Continue working with the current object; calling pop() restores the state of this object to its state when push() was called.

    • pop

      public void pop()
      restore the state of this object to what it was when the previous push() was called.

    • stroke

      public Rectangle2D stroke(GeneralPath s, boolean autoAdjustStroke)
      draw an outline using the current stroke and draw paint
      Parameters:
      s - the path to stroke
      Returns:
      a Rectangle2D to which the current region being drawn will be added. May also be null, in which case no dirty region will be recorded.

    • autoAdjustStrokeWidth

      private BasicStroke autoAdjustStrokeWidth(Graphics2D g, BasicStroke bs)
      auto adjust the stroke width, according to 6.5.4, which presumes that the device characteristics (an image) require a single pixel wide line, even if the width is set to less. We determine the scaling to see if we would produce a line that was too small, and if so, scale it up to produce a graphics line of 1 pixel, or so. This matches our output with Adobe Reader.
      Parameters:
      g -
      bs -
      Returns:

    • draw

      public void draw(GeneralPath p, BasicStroke bs)
      draw an outline.
      Parameters:
      p - the path to draw
      bs - the stroke with which to draw the path

    • fill

      public Rectangle2D fill(GeneralPath s)
      fill an outline using the current fill paint
      Parameters:
      s - the path to fill

    • drawImage

      public Rectangle2D drawImage(PDFImage image)
      draw an image.
      Parameters:
      image - the image to draw

    • smartDrawImage

      private Rectangle2D smartDrawImage(PDFImage image, BufferedImage bi, Rectangle r, AffineTransform at)

    • clip

      public void clip(GeneralPath s)
      add the path to the current clip. The new clip will be the intersection of the old clip and given path.

    • setClip

      private void setClip(Shape s)
      set the clip to be the given shape. The current clip is not taken into account.

    • getTransform

      public AffineTransform getTransform()
      get the current affinetransform

    • transform

      public void transform(AffineTransform at)
      concatenate the given transform with the current transform

    • setTransform

      public void setTransform(AffineTransform at)
      replace the current transform with the given one.

    • getInitialTransform

      public AffineTransform getInitialTransform()
      get the initial transform from page space to Java space

    • setStrokeParts

      public void setStrokeParts(float w, int cap, int join, float limit, float[] ary, float phase)
      Set some or all aspects of the current stroke.
      Parameters:
      w - the width of the stroke, or NOWIDTH to leave it unchanged
      cap - the end cap style, or NOCAP to leave it unchanged
      join - the join style, or NOJOIN to leave it unchanged
      limit - the miter limit, or NOLIMIT to leave it unchanged
      phase - the phase of the dash array, or NOPHASE to leave it unchanged
      ary - the dash array, or null to leave it unchanged. phase and ary must both be valid, or phase must be NOPHASE while ary is null.

    • getStroke

      public BasicStroke getStroke()
      get the current stroke as a BasicStroke

    • setStroke

      public void setStroke(BasicStroke bs)
      set the current stroke as a BasicStroke

    • setStrokePaint

      public void setStrokePaint(PDFPaint paint)
      set the stroke color

    • setFillPaint

      public void setFillPaint(PDFPaint paint)
      set the fill color

    • setStrokeAlpha

      public void setStrokeAlpha(float alpha)
      set the stroke alpha

    • setFillAlpha

      public void setFillAlpha(float alpha)
      set the stroke alpha

    • addObserver

      public void addObserver(ImageObserver observer)
      Add an image observer

    • removeObserver

      public void removeObserver(ImageObserver observer)
      Remove an image observer

    • setLastShape

      public void setLastShape(GeneralPath shape)
      Set the last shape drawn

    • getLastShape

      public GeneralPath getLastShape()
      Get the last shape drawn

    • getImage

      public BufferedImage getImage()
      If exists, returns the image which is used by the renderer.
      Returns:
      a BufferedImage or null

    • setup

      public void setup()
      Setup rendering. Called before iteration begins
      Overrides:
      setup in class BaseWatchable

    • iterate

      public int iterate() throws Exception
      Draws the next command in the PDFPage to the buffered image. The image will be notified about changes no less than every UPDATE_DURATION milliseconds.
      Specified by:
      iterate in class BaseWatchable
      Returns:
      • Watchable.RUNNING when there are commands to be processed
      • Watchable.NEEDS_DATA when there are no commands to be processed, but the page is not yet complete
      • Watchable.COMPLETED when the page is done and all the commands have been processed
      • Watchable.STOPPED if the image we are rendering into has gone away
      Throws:
      Exception

    • cleanup

      public void cleanup()
      Called when iteration has stopped
      Overrides:
      cleanup in class BaseWatchable

    • addDirtyRegion

      private Rectangle2D addDirtyRegion(Rectangle2D region, Rectangle2D glob)
      Append a rectangle to the total dirty region of this shape

    • rendererFinished

      private boolean rendererFinished()
      Determine if we are finished

    • notifyObservers

      private void notifyObservers(BufferedImage bi, Rectangle2D region)
      Notify the observer that a region of the image has changed

    • getMaskedImage

      private BufferedImage getMaskedImage(BufferedImage bi)
      Convert an image mask into an image by painting over any pixels that have a value in the image with the current paint

    • getLastTransform

      public AffineTransform getLastTransform()
      Returns:
      Returns the lastTransform.

    • rememberTransformation

      public void rememberTransformation()
      Remember the current transformation