fixed drag&drop when spacing changes

diy-layout-creator --username bancika@gmail.com/DIYLC/src/org/diylc/components/AbstractLeadedComponent.java

@@ -94,6 +94,7 @@ public abstract class AbstractLeadedComponent<T> extends AbstractTransparentComp
 		}
 		g2d.setColor(bodyColor);
 		g2d.fill(shape);
+		decorateComponentBody(g2d);
 		g2d.setComposite(oldComposite);
 		g2d.setStroke(ObjectCache.getInstance().fetchBasicStroke(1));
 		g2d.setColor(componentState == ComponentState.SELECTED
@@ -126,7 +127,7 @@ public abstract class AbstractLeadedComponent<T> extends AbstractTransparentComp
 		g2d.setFont(Constants.LABEL_FONT);
 		g2d
 				.setColor(componentState == ComponentState.SELECTED ? LABEL_COLOR_SELECTED
-						: LABEL_COLOR);
+						: getLabelColor());
 		FontMetrics fontMetrics = g2d.getFontMetrics();
 		String label = display == Display.NAME ? getName() : getValue().toString();
 		// Adjust label angle if needed to make sure that it's readable.
@@ -139,6 +140,14 @@ public abstract class AbstractLeadedComponent<T> extends AbstractTransparentComp
 				(int) (shapeRect.height - textRect.getHeight()) / 2 + fontMetrics.getAscent());
 	}
 
+	protected void decorateComponentBody(Graphics2D g2d) {
+		// Do nothing.
+	}
+
+	protected Color getLabelColor() {
+		return LABEL_COLOR;
+	}
+
 	protected boolean shouldShadeLeads() {
 		return true;
 	}

diy-layout-creator --username bancika@gmail.com/DIYLC/src/org/diylc/presenter/Presenter.java

@@ -652,14 +652,11 @@ public class Presenter implements IPlugInPort {
 			// We're dragging control point(s).
 			int dx = (scaledPoint.x - previousDragPoint.x);
 			int dy = (scaledPoint.y - previousDragPoint.y);
-			if (snapToGrid) {
+			// After we make the transfer and snap to grid, calculate actual dx
-				dx = CalcUtils.roundToGrid(dx, currentProject.getGridSpacing());
+			// and dy. We'll use them to translate the previous drag point.
-				dy = CalcUtils.roundToGrid(dy, currentProject.getGridSpacing());
+			int actualDx = 0;
-			}
+			int actualDy = 0;
-			// Only repaint if there's an actual change.
-			repaint = dx != 0 || dy != 0;
 
-			if (repaint) {
 			// Do a simulation of the move to see if any of them will
 			// collide.
 			for (Map.Entry<IDIYComponent<?>, Set<Integer>> entry : controlPointMap.entrySet()) {
@@ -669,21 +666,22 @@ public class Presenter implements IPlugInPort {
 					controlPoints[i] = new Point(c.getControlPoint(i));
 					if (entry.getValue().contains(i)) {
 						controlPoints[i].translate(dx, dy);
+						if (snapToGrid) {
+							CalcUtils.snapPointToGrid(controlPoints[i], currentProject
+									.getGridSpacing());
+						}
 					}
 				}
 				for (int i = 0; i < controlPoints.length - 1; i++) {
 					for (int j = i + 1; j < controlPoints.length; j++) {
 						if (controlPoints[i].equals(controlPoints[j])) {
-								LOG
+							LOG.error("Control points collision detected, cannot make this move.");
-										.error("Control points collision detected, cannot make this move.");
 							return true;
 						}
 					}
 				}
 			}
 
-				previousDragPoint.translate(dx, dy);
-
 			// Update all points.
 			for (Map.Entry<IDIYComponent<?>, Set<Integer>> entry : controlPointMap.entrySet()) {
 				IDIYComponent<?> c = entry.getKey();
@@ -691,9 +689,21 @@ public class Presenter implements IPlugInPort {
 				for (Integer index : entry.getValue()) {
 					Point p = new Point(c.getControlPoint(index));
 					p.translate(dx, dy);
+					if (snapToGrid) {
+						CalcUtils.snapPointToGrid(p, currentProject.getGridSpacing());
+					}
+					// When the first point is moved, calculate how much it
+					// actually moved after snapping.
+					if (actualDx == 0 && actualDy == 0) {
+						actualDx = p.x - c.getControlPoint(index).x;
+						actualDy = p.y - c.getControlPoint(index).y;
+					}
 					c.setControlPoint(p, index);
 				}
 			}
+			if (actualDx != 0 || actualDy != 0) {
+				previousDragPoint.translate(actualDx, actualDy);
+				repaint = true;
 			}
 		} else if (selectedComponents.isEmpty()
 				&& instantiationManager.getComponentTypeSlot() == null) {