rectpacking: Fix micro layout for rectpacking including content align…

…ment and label placement. (#997)

* rectpacking: Do node micro layout before and after layout.

Previously it was only done after because whitespace elimination might
change node sizes. However, if the node size cannot fit the label, we
need to do this before the layout too.

* rectpacking: Corrected comments for minsize processors.

* Fixes #989. Content alignment for rectpacking.

Translate inner content based on the real width and the width of the
parent.

plugins/org.eclipse.elk.alg.rectpacking/src/org/eclipse/elk/alg/rectpacking/RectPackingLayoutProvider.java

@@ -20,6 +20,7 @@
 import org.eclipse.elk.core.alg.ILayoutProcessor;
 import org.eclipse.elk.core.alg.LayoutProcessorConfiguration;
 import org.eclipse.elk.core.math.ElkPadding;
+import org.eclipse.elk.core.math.KVector;
 import org.eclipse.elk.core.options.CoreOptions;
 import org.eclipse.elk.core.util.BasicProgressMonitor;
 import org.eclipse.elk.core.util.BoxLayoutProvider;
@@ -58,6 +59,11 @@ public void layout(final ElkNode layoutGraph, final IElkProgressMonitor progress
         boolean tryBox = layoutGraph.getProperty(RectPackingOptions.TRYBOX);
         List<ElkNode> rectangles = layoutGraph.getChildren();
 
+        // if requested, compute nodes's dimensions, place node labels, ports, port labels, etc.
+        if (!layoutGraph.getProperty(RectPackingOptions.OMIT_NODE_MICRO_LAYOUT)) {
+            NodeMicroLayout.forGraph(layoutGraph).execute();
+        }
+
         // Check whether regions are stackable and do box layout instead.
         boolean stackable = false;
         if (tryBox && rectangles.size() >= 3) {
@@ -119,6 +125,20 @@ public void layout(final ElkNode layoutGraph, final IElkProgressMonitor progress
             progressMonitor.logGraph(layoutGraph, slotIndex + "-Finished");
         }
         // elkjs-exclude-end
+
+        // Content alignment
+        double realWidth = 0;
+        double realHeight = 0;
+        for (ElkNode rect : rectangles) {
+            realWidth = Math.max(realWidth, rect.getX() + rect.getWidth());
+            realHeight = Math.max(realHeight, rect.getY() + rect.getHeight());
+        }
+
+        ElkUtil.translate(layoutGraph,
+                new KVector(
+                        layoutGraph.getProperty(InternalProperties.DRAWING_WIDTH),
+                        layoutGraph.getProperty(InternalProperties.DRAWING_HEIGHT)),
+                new KVector(realWidth, realHeight));
 
         // Final touch.
         applyPadding(rectangles, padding);
@@ -129,7 +149,7 @@ public void layout(final ElkNode layoutGraph, final IElkProgressMonitor progress
                     layoutGraph.getProperty(InternalProperties.DRAWING_HEIGHT) + padding.getVertical(), false, true);
         }
 
-        // if requested, compute nodes's dimensions, place node labels, ports, port labels, etc.
+        // Do micro layout again since the whitspace elimination and other things might have changed node sizes.
         if (!layoutGraph.getProperty(RectPackingOptions.OMIT_NODE_MICRO_LAYOUT)) {
             NodeMicroLayout.forGraph(layoutGraph).execute();
         }

plugins/org.eclipse.elk.alg.rectpacking/src/org/eclipse/elk/alg/rectpacking/intermediate/MinSizePostProcessor.java

@@ -15,7 +15,7 @@
 import org.eclipse.elk.graph.ElkNode;
 
 /**
- * Sorts all child nodes by their desired position.
+ * Sets a target width at least as high as the minimum width of the parent
  * 
  * <dl>
  *   <dt>Precondition:</dt>

plugins/org.eclipse.elk.alg.rectpacking/src/org/eclipse/elk/alg/rectpacking/intermediate/MinSizePreProcessor.java

@@ -17,7 +17,7 @@
 import org.eclipse.elk.graph.ElkNode;
 
 /**
- * Sorts all child nodes by their desired position.
+ * Sets the minimum width and height of the parent since this influences decisions based on the aspect ratio.
  * 
  * <dl>
  *   <dt>Precondition:</dt>