show selection bounds on rulers

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

@@ -1,6 +1,7 @@
 package org.diylc.common;
 
 import java.awt.Point;
+import java.awt.geom.Rectangle2D;
 import java.util.Collection;
 import java.util.List;
 
@@ -25,7 +26,8 @@ public interface ISelectionProcessor {
   void updateSelection(Collection<IDIYComponent<?>> newSelection);
 
   /**
-   * Finds all components at the specified location, sorted by z-index from top to bottom.
+   * Finds all components at the specified location, sorted by z-index from top to bottom. Location
+   * depends on the current zoom level.
    * 
    * @param point
    * @return
@@ -54,7 +56,7 @@ public interface ISelectionProcessor {
    * @param direction 1 for clockwise, -1 for counter-clockwise
    */
   void rotateSelection(int direction);
-  
+
   /**
    * Groups all selected components.
    */
@@ -64,6 +66,19 @@ public interface ISelectionProcessor {
    * Ungroups all selected components.
    */
   void ungroupSelectedComponents();
-  
+
+  /**
+   * Mirrors selected components in the given axis.
+   * 
+   * @param direction
+   */
   void mirrorSelection(int direction);
+
+  /**
+   * Returns the minimum rectangle containing all selected components, or null if none exists.
+   * Rectangle is scaled by the current zoom level.
+   * 
+   * @return
+   */
+  Rectangle2D getSelectionBounds();
 }

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

@@ -6,8 +6,10 @@ import java.awt.Graphics2D;
 import java.awt.Point;
 import java.awt.Rectangle;
 import java.awt.dnd.DnDConstants;
+import java.awt.geom.AffineTransform;
 import java.awt.geom.Area;
 import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
 import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
@@ -813,6 +815,26 @@ public class Presenter implements IPlugInPort {
     messageDispatcher.dispatchMessage(EventType.REPAINT);
   }
 
+  @Override
+  public Rectangle2D getSelectionBounds() {
+    if (selectedComponents == null || selectedComponents.isEmpty())
+      return null;
+
+    Area totalArea = new Area();
+    for (IDIYComponent<?> c : selectedComponents) {
+      Area compArea = drawingManager.getComponentArea(c);
+      if (compArea != null)
+        totalArea.add(compArea);
+      else
+        LOG.info("Area is null");
+    }
+    if (drawingManager.getZoomLevel() != 1) {
+      totalArea
+          .transform(AffineTransform.getScaleInstance(drawingManager.getZoomLevel(), drawingManager.getZoomLevel()));
+    }
+    return totalArea.getBounds2D();
+  }
+
   @Override
   public VersionNumber getCurrentVersionNumber() {
     return CURRENT_VERSION;