align rulers with extra space

diylc/diylc-core/src/org/diylc/common/IPlugInPort.java

@@ -353,4 +353,9 @@ public interface IPlugInPort extends ISelectionProcessor, IMouseProcessor, IKeyP
    * @param xAxisFirst
    */
   void renumberSelectedComponents(boolean xAxisFirst);
+  
+  /**   
+   * @return size of extra space around the canvas
+   */
+  double getExtraSpace();
 }

diylc/diylc-core/src/org/diylc/presenter/Presenter.java

@@ -2503,4 +2503,20 @@ public class Presenter implements IPlugInPort {
       ConfigurationManager.getInstance().writeValue(BLOCKS_KEY, blocks);
     }
   }
+  
+  @Override
+  public double getExtraSpace() {
+    if (!ConfigurationManager.getInstance().readBoolean(EXTRA_SPACE_KEY, true))
+      return 0;
+    
+    double extraSpace = drawingManager.getExtraSpace(currentProject);
+    boolean metric = ConfigurationManager.getInstance().readBoolean(Presenter.METRIC_KEY, true);    
+
+    extraSpace /= Constants.PIXELS_PER_INCH;
+    
+    if (metric)
+       extraSpace *= SizeUnit.in.getFactor() / SizeUnit.cm.getFactor();
+    
+    return extraSpace;
+  }
 }

diylc/diylc-swing/src/org/diylc/swing/plugins/canvas/CanvasPlugin.java

@@ -34,6 +34,7 @@ import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.awt.event.MouseWheelEvent;
 import java.awt.event.MouseWheelListener;
+import java.awt.geom.Point2D;
 import java.awt.geom.Rectangle2D;
 import java.util.ArrayList;
 import java.util.EnumSet;
@@ -175,6 +176,9 @@ public class CanvasPlugin implements IPlugIn, ClipboardOwner {
             (canvasPanel.getHeight() - visibleRect.height) / 2);
         canvasPanel.scrollRectToVisible(visibleRect);
         canvasPanel.revalidate();
+        
+        double extraSpace = CanvasPlugin.this.plugInPort.getExtraSpace();
+        getScrollPane().setZeroLocation(new Point2D.Double(extraSpace, extraSpace));
       }
     });
   }
@@ -293,7 +297,10 @@ public class CanvasPlugin implements IPlugIn, ClipboardOwner {
         }
       });
       
-      // disable scrolling
+      double extraSpace = plugInPort.getExtraSpace();
+      scrollPane.setZeroLocation(new Point2D.Double(extraSpace, extraSpace));
+
+      // disable built-in scrolling mechanism, we'll do it manually
       scrollPane.setWheelScrollingEnabled(false);
 
       scrollPane.addMouseWheelListener(new MouseWheelListener() {
@@ -680,6 +687,9 @@ public class CanvasPlugin implements IPlugIn, ClipboardOwner {
         canvasPanel.scrollRectToVisible(visibleRect);
         canvasPanel.revalidate();
         
+        double extraSpace = CanvasPlugin.this.plugInPort.getExtraSpace();
+        getScrollPane().setZeroLocation(new Point2D.Double(extraSpace, extraSpace));
+
         zoomLevel = (Double) params[0];
         break;
       case REPAINT: