bundles/org.simantics.diagram/src/org/simantics/diagram/export/ImageBuilder.java

   1 package org.simantics.diagram.export;
   2
   3 import java.awt.Graphics2D;
   4 import java.awt.Point;
   5 import java.awt.RenderingHints;
   6 import java.awt.geom.AffineTransform;
   7 import java.awt.geom.Rectangle2D;
   8 import java.awt.image.BufferedImage;
   9 import java.io.File;
  10
  11 import javax.imageio.ImageIO;
  12
  13 import org.simantics.g2d.canvas.ICanvasContext;
  14 import org.simantics.g2d.diagram.DiagramHints;
  15 import org.simantics.g2d.diagram.DiagramUtils;
  16 import org.simantics.g2d.diagram.IDiagram;
  17 import org.simantics.g2d.participant.TransformUtil;
  18 import org.simantics.scenegraph.g2d.G2DRenderingHints;
  19 import org.simantics.scenegraph.utils.QualityHints;
  20 import org.simantics.utils.page.MarginUtils;
  21
  22 public class ImageBuilder {
  23         File file;
  24         Double dpi;
  25         Point size;
  26         double margin;
  27
  28
  29         /**
  30          *
  31          * @param file File to write the image (optional)
  32          * @param dpi Dots Per Inch
  33          * @param size Image size in pixels
  34          * @param margin percentage of image width for margins. 0.05 is 5%.
  35          */
  36         public ImageBuilder(File file, Double dpi, Point size, double margin) {
  37                 this.file = file;
  38                 this.dpi = dpi;
  39                 this.size = size;
  40                 this.margin = Math.max(margin,0.0);
  41
  42         }
  43
  44         /**
  45          * @param canvasContext
  46          *            the canvas context to paint
  47          * @param writeResults
  48          *            <code>true</code> to actually write the resulting Image to the file.
  49          */
  50         public BufferedImage paint(ICanvasContext canvasContext) throws Exception {
  51
  52                 Graphics2D g2 = null;
  53                 BufferedImage image = null;
  54                 try {
  55                         IDiagram diagram = canvasContext.getDefaultHintContext().getHint(DiagramHints.KEY_DIAGRAM);
  56                         Rectangle2D diagramRect = DiagramUtils.getContentRect(diagram);
  57
  58                         if (diagramRect == null)
  59                                 diagramRect = new Rectangle2D.Double(0, 0, 100, 100);
  60
  61                         // add margins to content.
  62                         double off = Math.max(diagramRect.getWidth(), diagramRect.getHeight()) * margin*0.5;
  63                         diagramRect = new Rectangle2D.Double(diagramRect.getX() - off, diagramRect.getY() - off, diagramRect.getWidth() + off * 2.0, diagramRect.getHeight() + off * 2.0);
  64
  65                         // Make sure the transformation is reset.
  66                         AffineTransform tr = new AffineTransform();
  67
  68                         Rectangle2D controlArea;
  69                         if (dpi != null) {
  70                                 double mmToInch = 1.0 / 25.0;
  71                                 controlArea = new Rectangle2D.Double(0, 0, diagramRect.getWidth() * mmToInch * dpi, diagramRect.getHeight() * mmToInch * dpi);
  72
  73                         } else {
  74                                 controlArea = new Rectangle2D.Double(0, 0, size.getX(), size.getY());
  75                         }
  76
  77                         canvasContext.getSingleItem(TransformUtil.class).fitArea(controlArea, diagramRect, MarginUtils.NO_MARGINS);
  78
  79                         int width = (int) controlArea.getWidth();
  80                         int height = (int) controlArea.getHeight();
  81                         long sizeBytes = width*height*3;
  82                         long free = Runtime.getRuntime().freeMemory();
  83                         if (sizeBytes >= free) { // TODO: should we estimate memory required for rendering?
  84                                 System.gc();
  85                                 free = Runtime.getRuntime().freeMemory();
  86                         }
  87
  88                         if (sizeBytes >= free) {
  89                                 throw new Exception("There is not enough available memory to create the image; required " + sizeBytes + ", available " + free);
  90                         }
  91
  92                         image = new BufferedImage(width, height , BufferedImage.TYPE_3BYTE_BGR);
  93                         g2 = (Graphics2D) image.getGraphics();
  94
  95                         QualityHints.HIGH_QUALITY_HINTS.setQuality(g2);
  96                         g2.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
  97
  98
  99                         g2.setTransform(tr);
 100                         g2.setClip(new Rectangle2D.Double(0, 0, controlArea.getWidth(), controlArea.getHeight()));
 101
 102                         g2.setRenderingHint(G2DRenderingHints.KEY_CONTROL_BOUNDS, new Rectangle2D.Double(0, 0, controlArea.getWidth(), controlArea.getHeight()));
 103
 104                         if (canvasContext.isLocked())
 105                                 throw new IllegalStateException("cannot render image, canvas context is locked: " + canvasContext);
 106
 107                         canvasContext.getSceneGraph().render(g2);
 108
 109                         if (file != null) {
 110                                 String name = file.getName();
 111                                 name = name.substring(name.lastIndexOf(".") + 1);
 112                                 ImageIO.write(image, name, file);
 113                         }
 114
 115                 } finally {
 116                         if (g2 != null)
 117                                 g2.dispose();
 118
 119
 120
 121                 }
 122                 return image;
 123         }
 124 }