GraphUI Layout: Fix BoxLayout scale, margin and padding; Add same padding behavior to BoxLayout and GridLayout.

For all:
- Padding is applied to each {@Shape} via {@link Shape#setPaddding(Padding)} if passed in constructor

BoxLayout:
- Optionally centered {@link Alignment.Bit#CenterHoriz horizontally}, {@link Alignment.Bit#CenterVert vertically} or {@link Alignment#Center both}.
- Optionally scaled to cell-size if given and {@link Alignment#Fill}
- Margin is ignored on dimension with center {@link Alignment}
- Not implemented {@link Alignment}: Top, Right, Bottom, Left

GridLayout:
- Optionally centered {@link Alignment.Bit#CenterHoriz horizontally}, {@link Alignment.Bit#CenterVert vertically} or {@link Alignment#Center both}.
- Optionally scaled to cell-size if given and {@link Alignment#Fill}
- Without cell-size behaves like a grid bag using individual shape sizes including padding
- Can be filled in {@link Order#COLUMN} or {@link Order#ROW} major-order.
- Not implemented {@link Alignment}: Top, Right, Bottom, Left

Changes to Group.Layout interface:
- Added preValidate(Shape) allowing to prepare the shape before validation, used to inject Padding

Changes to Margin:
- Removed the complex CENTER property and using Alignment in BoxLayout as well

Changes to BoxLayout:
- Using Alignment

+++

Tested via UILayoutBox01 and UILayoutGrid01,
try the tooltip by clicking on the group's description label.

3 files changed, 640 insertions, 391 deletions

diff --git a/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutBox01.java b/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutBox01.java
index 8d8a995d9..70db5d696 100644
--- a/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutBox01.java
+++ b/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutBox01.java
@@ -28,28 +28,33 @@
 package com.jogamp.opengl.demos.graph.ui;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import com.jogamp.graph.curve.Region;
 import com.jogamp.graph.font.Font;
 import com.jogamp.graph.font.FontFactory;
 import com.jogamp.graph.font.FontSet;
+import com.jogamp.graph.geom.plane.AffineTransform;
 import com.jogamp.graph.ui.Group;
 import com.jogamp.graph.ui.Scene;
 import com.jogamp.graph.ui.Shape;
+import com.jogamp.graph.ui.layout.Alignment;
 import com.jogamp.graph.ui.layout.BoxLayout;
 import com.jogamp.graph.ui.layout.Margin;
 import com.jogamp.graph.ui.layout.Padding;
 import com.jogamp.graph.ui.shapes.Button;
 import com.jogamp.graph.ui.shapes.Label;
-import com.jogamp.graph.ui.shapes.Rectangle;
 import com.jogamp.graph.ui.shapes.BaseButton;
 import com.jogamp.newt.event.MouseEvent;
 import com.jogamp.newt.event.WindowAdapter;
 import com.jogamp.newt.event.WindowEvent;
 import com.jogamp.newt.opengl.GLWindow;
 import com.jogamp.opengl.GL;
+import com.jogamp.opengl.GLAutoDrawable;
 import com.jogamp.opengl.GLCapabilities;
 import com.jogamp.opengl.GLProfile;
+import com.jogamp.opengl.demos.graph.ui.util.Tooltips;
 import com.jogamp.opengl.demos.util.CommandlineOptions;
 import com.jogamp.opengl.math.FloatUtil;
 import com.jogamp.opengl.math.Vec3f;
@@ -64,9 +69,10 @@ import com.jogamp.opengl.util.Animator;
  * </p>
  */
 public class UILayoutBox01 {
-    static CommandlineOptions options = new CommandlineOptions(1280, 720, Region.VBAA_RENDERING_BIT);
+    static CommandlineOptions options = new CommandlineOptions(1920, 1080, Region.VBAA_RENDERING_BIT);
 
-    static final boolean reLayout = false;
+    static boolean reLayout = true;
+    static final int reLayoutSleep = 500;
 
     public static void main(final String[] args) throws IOException {
         if( 0 != args.length ) {
@@ -109,8 +115,12 @@ public class UILayoutBox01 {
         });
 
 
+        final int zBits = 16;
         final Scene scene = new Scene(options.graphAASamples);
         scene.setPMVMatrixSetup(new Scene.DefaultPMVMatrixSetup(-1f));
+        System.err.println("Z16-Precision: default               "+Scene.DEFAULT_Z16_EPSILON);
+        System.err.println("Z16-Precision: zDist -1f, zNear 0.1f "+FloatUtil.getZBufferEpsilon(zBits, -1f, 0.1f));
+        System.err.println("Z16-Precision: current               "+scene.getZEpsilon(zBits));
         scene.setClearParams(new float[] { 1f, 1f, 1f, 1f}, GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
         scene.setFrustumCullingEnabled(true);
         scene.attachInputListenerTo(window);
@@ -145,124 +155,308 @@ public class UILayoutBox01 {
         System.err.println("Font: "+font.getFullFamilyName());
 
         final AABBox sceneBox = scene.getBounds();
-        System.err.println("SceneBox "+sceneBox);
+        final float zEps = scene.getZEpsilon(zBits); // Z Epsilon, i.e. minimum recognized delta (resolution)
+        System.err.println("SceneBox "+sceneBox+", zEps "+zEps);
 
-        final float sxy = 1/8f * sceneBox.getWidth();
+        final float cellGap = 1.5f;
+        final float sxy = 1/8.5f * sceneBox.getWidth();
         System.err.println("Scale xy "+sxy);
-        float nextPos = 0;
+        final Vec3f nextPos = new Vec3f();
+        final List<Group> groups = new ArrayList<Group>();
 
-        final Group groupA0 = new Group(new BoxLayout( new Padding(0.15f, 0.15f) ) );
-        {
-            groupA0.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1) );
-            groupA0.addShape( new Button(options.renderModes, font, "stack-0", 0.50f, 0.50f/2f).setCorner(0f).setDragAndResizeable(false) );
-            groupA0.addShape( new Label(options.renderModes, font, 0.70f/4f, "A0 pajq").setDragAndResizeable(false).setColor(0, 0, 1, 1) );
+        //
+        //
+        //
+        fillDemoScene(groups, reqGLP, scene, zEps, sxy, nextPos, cellGap,
+                      new Margin(0.04f, 0.04f, 0.10f, 0.10f),
+                      new Padding(0.03f, 0.03f, 0.07f, 0.07f), font, dragZoomRotateListener);
+
+        if( reLayout ) {
+            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
+            int idx = 0;
+            for(final Group g : groups) {
+                System.err.println("Group["+idx+"].2.0 "+g);
+                System.err.println("Group["+idx+"].2.0 "+g.getLayout());
+                g.markShapeDirty();
+                g.validate(reqGLP);
+                System.err.println("Group["+idx+"].2.1 "+g);
+                System.err.println("Group["+idx+"].2.1 "+g.getLayout());
+                ++idx;
+            }
         }
-        groupA0.setInteractive(true);
-        groupA0.addMouseListener(dragZoomRotateListener);
-        groupA0.scale(sxy, sxy, 1);
-        groupA0.moveTo(sceneBox.getLow()).move(nextPos, 0, 0);
-        groupA0.validate(reqGLP);
-        System.err.println("Group-A0 "+groupA0);
-        System.err.println("Group-A0 Layout "+groupA0.getLayout());
-        groupA0.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA0);
-        scene.addShape( new Rectangle(options.renderModes, 1f, 1f, 0.01f).scale(sxy, sxy, 1).moveTo(sceneBox.getLow()).move(nextPos, 0, 0).setInteractive(false).setColor(0, 0, 0, 1) );
-        nextPos = groupA0.getScaledWidth() * 1.5f;
-
-        final Group groupA1 = new Group(new BoxLayout( 1f, 1f, new Margin(0.05f, 0.05f), new Padding(0.10f, 0.10f) ) );
+
+        try { Thread.sleep(1000); } catch (final InterruptedException e1) { }
+        scene.screenshot(true, scene.nextScreenshotFile(null, UILayoutBox01.class.getSimpleName(), options.renderModes, caps, null));
         {
-            // groupA1.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1) );
-            groupA1.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1)
-                    .setBorder(0.01f).setPaddding(new Padding(0.0f)) );
-            groupA1.addShape( new Button(options.renderModes, font, "stack-1", 0.50f, 0.50f/2f).setCorner(0f).addMouseListener(dragZoomRotateListener) );
-            groupA1.addShape( new Label(options.renderModes, font, 0.70f/4f, "A1 pajq").setDragAndResizeable(false).setColor(0, 0, 1, 1) );
+            int idx = 0;
+            for(final Group g : groups) {
+                System.err.println("Group["+idx+"].2.0 "+g);
+                System.err.println("Group["+idx+"].2.0 "+g.getLayout());
+                ++idx;
+            }
         }
-        // groupA1.setInteractive(true);
-        groupA1.scale(sxy, sxy, 1);
-        groupA1.moveTo(sceneBox.getLow()).move(nextPos, 0, 0);
-        groupA1.validate(reqGLP);
-        System.err.println("Group-A1 "+groupA1);
-        System.err.println("Group-A1 Layout "+groupA1.getLayout());
-        groupA1.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA1);
-        // scene.addShape( new Rectangle(options.renderModes, 1f, 1f, 0.01f).scale(sxy, sxy, 1).moveTo(sceneBox.getLow()).move(nextPos, 0, 0).setInteractive(false).setColor(0, 0, 0, 1) );
-        scene.addShape( new Button(options.renderModes, font, "stack-1b", 0.50f, 0.50f/2f).setCorner(0f)
-                .scale(sxy, sxy, 1f).moveTo(sceneBox.getLow()).move(nextPos, groupA1.getScaledHeight(), 0)
-                .addMouseListener(dragZoomRotateListener) );
-
-        nextPos += groupA1.getScaledWidth() * 1.5f;
-
-        final Group groupA2 = new Group(new BoxLayout( 1f, 1f, new Margin(0.10f, Margin.CENTER), new Padding(0.05f, 0) ) );
-        {
-            // groupA2.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1) );
-            groupA2.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1)
-                    .setBorder(0.01f).setPaddding(new Padding(0.0f)).setBorderColor(1, 0, 0, 1) );
-            groupA2.addShape( new Button(options.renderModes, font, "stack-2", 0.50f, 0.50f/2f).setCorner(0f).setDragAndResizeable(false) );
-            groupA2.addShape( new Label(options.renderModes, font, 0.70f/4f, "A2 pajq").setDragAndResizeable(false).setColor(0, 0, 1, 1) );
+        window.invoke(true, (final GLAutoDrawable drawable) -> {
+            scene.removeAllShapes(drawable.getGL().getGL2ES2());
+            return true;
+        });
+        groups.clear();
+
+        //
+        //
+        //
+        nextPos.set(0, 0, 0);
+
+        fillDemoScene(groups, reqGLP, scene, zEps, sxy, nextPos, cellGap,
+                      new Margin(0.07f, 0.07f),
+                      new Padding(0.10f, 0.10f), font, dragZoomRotateListener);
+
+        if( reLayout ) {
+            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
+            int idx = 0;
+            for(final Group g : groups) {
+                System.err.println("Group["+idx+"].2.0 "+g);
+                System.err.println("Group["+idx+"].2.0 "+g.getLayout());
+                g.markShapeDirty();
+                g.validate(reqGLP);
+                System.err.println("Group["+idx+"].2.1 "+g);
+                System.err.println("Group["+idx+"].2.1 "+g.getLayout());
+                ++idx;
+            }
         }
-        groupA2.setInteractive(true);
-        groupA2.scale(sxy, sxy, 1);
-        groupA2.moveTo(sceneBox.getLow()).move(nextPos, 0, 0);
-        groupA2.validate(reqGLP);
-        System.err.println("Group-A2 "+groupA2);
-        System.err.println("Group-A2 Layout "+groupA2.getLayout());
-        groupA2.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA2);
-        // scene.addShape( new Rectangle(options.renderModes, 1f, 1f, 0.01f).scale(sxy, sxy, 1).moveTo(sceneBox.getLow()).move(nextPos, 0, 0).setInteractive(false).setColor(0, 0, 0, 1) );
-        nextPos += groupA2.getScaledWidth() * 1.5f;
-
-        final Group groupA3 = new Group(new BoxLayout( 1f, 1f, new Margin(0.10f, Margin.CENTER), new Padding(0.05f, 0f) ) );
+
+        try { Thread.sleep(1000); } catch (final InterruptedException e1) { }
+        scene.screenshot(true, scene.nextScreenshotFile(null, UILayoutBox01.class.getSimpleName(), options.renderModes, caps, null));
         {
-            // groupA3.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1) );
-            groupA3.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1)
-                    .setBorder(0.01f).setPaddding(new Padding(0.0f)).setBorderColor(0, 0, 1, 1) );
-            groupA3.addShape( new Button(options.renderModes, font, "stack-3", 0.50f, 0.50f/2f).setCorner(0f).setDragAndResizeable(false) );
-            groupA3.addShape( new Label(options.renderModes, font, 0.70f/4f, "A3 pajq").setDragAndResizeable(false).setColor(0, 0, 1, 1) );
+            int idx = 0;
+            for(final Group g : groups) {
+                System.err.println("Group["+idx+"].3.0 "+g);
+                System.err.println("Group["+idx+"].3.0 "+g.getLayout());
+                ++idx;
+            }
         }
-        groupA3.scale(sxy, sxy, 1);
-        groupA3.moveTo(sceneBox.getLow()).move(nextPos, 0, 0);
-        groupA3.validate(reqGLP);
-        System.err.println("Group-A3 "+groupA3);
-        System.err.println("Group-A3 Layout "+groupA3.getLayout());
-        groupA3.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA3);
-        // scene.addShape( new Rectangle(options.renderModes, 1f, 1f, 0.01f).scale(sxy, sxy, 1).moveTo(sceneBox.getLow()).move(nextPos, 0, 0).setInteractive(false).setColor(0, 0, 0, 1) );
-        nextPos += groupA3.getScaledWidth() * 1.5f;
-
-        final Group groupA4 = new Group(new BoxLayout( 1f, 1f, new Margin(Margin.CENTER), new Padding(0.0f, 0f) ) );
-        {
-            // groupA4.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1) );
-            groupA4.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setCorner(0f).setInteractive(false).setColor(0, 1, 0, 1)
-                    .setBorder(0.01f).setPaddding(new Padding(0.0f)).setBorderColor(0f, 0f, 0f, 1) );
-            groupA4.addShape( new Button(options.renderModes, font, "stack-4", 0.50f, 0.50f/2f).setCorner(0f).setDragAndResizeable(false) );
-            groupA4.addShape( new Label(options.renderModes, font, 0.70f/4f, "A4 pajq").setDragAndResizeable(false).setColor(0, 0, 1, 1) );
+
+        if( !options.stayOpen ) {
+            window.destroy();
         }
-        groupA4.scale(sxy, sxy, 1);
-        groupA4.moveTo(sceneBox.getLow()).move(nextPos, 0, 0);
-        groupA4.validate(reqGLP);
-        System.err.println("Group-A4 "+groupA4);
-        System.err.println("Group-A4 Layout "+groupA4.getLayout());
-        groupA4.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA4);
-        // scene.addShape( new Rectangle(options.renderModes, 1f, 1f, 0.01f).scale(sxy, sxy, 1).moveTo(sceneBox.getLow()).move(nextPos, 0, 0).setInteractive(false).setColor(0, 0, 0, 1) );
-        nextPos += groupA4.getScaledWidth() * 1.5f;
+    }
 
-        if( reLayout ) {
-            try { Thread.sleep(1000); } catch (final InterruptedException e1) { }
-            groupA4.markShapeDirty();
-            groupA4.validate(reqGLP);
-            System.err.println("Group-A4.2 "+groupA4);
-            System.err.println("Group-A4 Layout.2 "+groupA4.getLayout());
+    @SuppressWarnings("unused")
+    static void fillDemoScene(final List<Group> groups, final GLProfile reqGLP, final Scene scene,
+                              final float zEps, final float sxy, final Vec3f nextPos, final float cellGap,
+                              final Margin margin, final Padding padding,
+                              final Font font, final Shape.MouseGestureListener dragZoomRotateListener)
+    {
+        //
+        // 1. Row
+        //
+        int id = 11;
+        if( true ) {
+            // 11
+            final Group g = fillDemoGroup(new Group( new BoxLayout() ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            // 12
+            final Group g = fillDemoGroup(new Group( new BoxLayout( padding ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            // 13
+            final Group g = fillDemoGroup(new Group( new BoxLayout(1f, 1f) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            // 14
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, margin ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            // 15
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, padding ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            // 16
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, margin, padding ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
         }
+        ++id;
+        nextPos.set(0, nextPos.y() + sxy * cellGap, 0);
 
         //
+        // 2. Row
         //
+        id = 21;
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, new Alignment(Alignment.Bit.CenterHoriz) ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, new Alignment(Alignment.Bit.CenterVert) ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Center ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Fill ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.FillCenter ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        ++id;
+        nextPos.set(0, nextPos.y() + sxy * cellGap, 0);
+
         //
-        nextPos = 0;
+        // 3. Row
+        //
+        id = 31;
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Center, margin, null ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
 
-        try { Thread.sleep(1000); } catch (final InterruptedException e1) { }
-        if( !options.stayOpen ) {
-            window.destroy();
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Center, new Margin(), padding ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Center, margin, padding ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Fill, margin, null ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Fill, new Margin(), padding ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        nextPos.setX( nextPos.x() + sxy * cellGap );
+        ++id;
+
+        if( true ) {
+            final Group g = fillDemoGroup(new Group( new BoxLayout( 1f, 1f, Alignment.Fill, margin, padding ) ),
+                                          reqGLP, scene, zEps, sxy, nextPos, font, id, dragZoomRotateListener);
+            groups.add(g);
+        }
+        ++id;
+        nextPos.set(0, nextPos.y() + sxy * cellGap, 0);
+
+        {
+            final AABBox sceneDim = scene.getBounds();
+            final String text = " Press group description to magnify! ";
+            final AABBox textDim = font.getGlyphBounds(text, new AffineTransform(), new AffineTransform());
+            final float l_sxy = 1/4f * sceneDim.getWidth() / textDim.getWidth();
+
+            final Shape label = new Label(options.renderModes, font, text).setColor(0, 0, 0, 1).setInteractive(false)
+                                    .scale(l_sxy, l_sxy, 1).moveTo(sceneDim.getLow())
+                                    .move(0, sceneDim.getHeight() - textDim.getHeight()*l_sxy, 0);
+            scene.addShape(label);
+        }
+
+    }
+    static Group fillDemoGroup(final Group g, final GLProfile reqGLP, final Scene scene, final float zEps, final float sxy, final Vec3f nextPos,
+                               final Font font, final int id,
+                               final Shape.MouseGestureListener dragZoomRotateListener)
+    {
+        final String suffix = String.format("%2d", id);
+        g.setName(id);
+        final AABBox sceneBox = scene.getBounds();
+        {
+            g.addShape( new BaseButton(options.renderModes, 0.70f, 0.70f).setPerp().setColor(0, 1, 0, 1).setBorder(0.01f).setBorderColor(0, 0, 1, 1.0f).addMouseListener(dragZoomRotateListener) );
+            g.addShape( new Button(options.renderModes, font, "stack-"+suffix, 0.50f, 0.50f/2f, zEps).setPerp().move(0, 0, zEps).setInteractive(false) );
+            g.addShape( new Label(options.renderModes, font, 0.70f/4f, "A"+suffix+" pajq").setColor(0, 0, 1, 1).move(0, 0, 2*zEps).setInteractive(false) );
+        }
+        g.scale(sxy, sxy, 1);
+        g.moveTo(sceneBox.getLow()).move(nextPos);
+        g.setBorder(0.01f).setBorderColor(0, 0, 0, 0.6f);
+        g.validate(reqGLP);
+        System.err.println("Group-A"+suffix+" "+g);
+        System.err.println("Group-A"+suffix+" Layout "+g.getLayout());
+        g.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        scene.addShape(g);
+        {
+            final float X_width = font.getGlyph(font.getGlyphID(' ')).getAdvance();
+            /**
+             * G 23, size[total 2.1 x 1.7, cell 1.0 x 0.5]
+             * Padding[t 0.05, r 0.05, b 0.05, l 0.05]
+             * Margin[t 0.05, r 0.05, b 0.05, l 0.05]
+             * Align [CenterHoriz, CenterVert, Fill]
+             */
+            final String fixed_text = "G 23, size[total 2.1 x 1.7, cell 1.0";
+            // final float l_sxy = g.getScaledWidth() / font.getGlyphBounds(fixed_text, new AffineTransform(), new AffineTransform()).getWidth();
+            final float l_sxy = sxy / font.getGlyphBounds(fixed_text, new AffineTransform(), new AffineTransform()).getWidth();
+
+            final BoxLayout l = (BoxLayout)g.getLayout();
+            final String text = String.format("G %2d, size[total %.1f x %.1f, cell %.1f x %.1f]%n%s%n%s%nAlign %s",
+                                    id, g.getBounds().getWidth(), g.getBounds().getHeight(), l.getCellSize().x(), l.getCellSize().y(),
+                                    ( null == l.getPadding() || l.getPadding().zeroSumSize() ) ? "Padding none" : l.getPadding().toString(),
+                                    l.getMargin().zeroSumSize() ? "Margin none" : l.getMargin().toString(),
+                                    l.getAlignment() );
+            final Shape label = new Label(options.renderModes, font, text).setColor(0, 0, 0, 1).validate(reqGLP);
+            label.scale(l_sxy, l_sxy, 1).moveTo(sceneBox.getLow()).move(nextPos).move(l_sxy*X_width, g.getScaledHeight(), 0)
+                .addMouseListener(new Tooltips.ZoomLabelOnClickListener(scene, options.renderModes, 1/4f)).setDragAndResizeable(false);
+            scene.addShape(label);
+            System.err.println("ID "+id+": "+label);
         }
+        return g;
     }
 }
diff --git a/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutGrid01.java b/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutGrid01.java
index 8fe989344..1a5881d00 100644
--- a/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutGrid01.java
+++ b/src/demos/com/jogamp/opengl/demos/graph/ui/UILayoutGrid01.java
@@ -33,6 +33,7 @@ import com.jogamp.graph.curve.Region;
 import com.jogamp.graph.font.Font;
 import com.jogamp.graph.font.FontFactory;
 import com.jogamp.graph.font.FontSet;
+import com.jogamp.graph.geom.plane.AffineTransform;
 import com.jogamp.graph.ui.Group;
 import com.jogamp.graph.ui.Scene;
 import com.jogamp.graph.ui.Shape;
@@ -41,13 +42,16 @@ import com.jogamp.graph.ui.layout.Gap;
 import com.jogamp.graph.ui.layout.GridLayout;
 import com.jogamp.graph.ui.layout.Padding;
 import com.jogamp.graph.ui.shapes.Button;
+import com.jogamp.graph.ui.shapes.Label;
 import com.jogamp.newt.event.MouseEvent;
 import com.jogamp.newt.event.WindowAdapter;
 import com.jogamp.newt.event.WindowEvent;
 import com.jogamp.newt.opengl.GLWindow;
 import com.jogamp.opengl.GL;
+import com.jogamp.opengl.GLAutoDrawable;
 import com.jogamp.opengl.GLCapabilities;
 import com.jogamp.opengl.GLProfile;
+import com.jogamp.opengl.demos.graph.ui.util.Tooltips;
 import com.jogamp.opengl.demos.util.CommandlineOptions;
 import com.jogamp.opengl.math.FloatUtil;
 import com.jogamp.opengl.math.Vec3f;
@@ -63,7 +67,7 @@ import com.jogamp.opengl.util.Animator;
  * </p>
  */
 public class UILayoutGrid01 {
-    static CommandlineOptions options = new CommandlineOptions(1280, 720, Region.VBAA_RENDERING_BIT);
+    static CommandlineOptions options = new CommandlineOptions(1920, 1080, Region.VBAA_RENDERING_BIT);
 
     static boolean reLayout = true;
     static final int reLayoutSleep = 500;
@@ -109,8 +113,12 @@ public class UILayoutGrid01 {
         });
 
 
+        final int zBits = 16;
         final Scene scene = new Scene(options.graphAASamples);
         scene.setPMVMatrixSetup(new Scene.DefaultPMVMatrixSetup(-1f));
+        System.err.println("Z16-Precision: default               "+Scene.DEFAULT_Z16_EPSILON);
+        System.err.println("Z16-Precision: zDist -1f, zNear 0.1f "+FloatUtil.getZBufferEpsilon(zBits, -1f, 0.1f));
+        System.err.println("Z16-Precision: current               "+scene.getZEpsilon(zBits));
         scene.setClearParams(new float[] { 1f, 1f, 1f, 1f}, GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
         scene.setFrustumCullingEnabled(true);
         scene.attachInputListenerTo(window);
@@ -145,318 +153,203 @@ public class UILayoutGrid01 {
         System.err.println("Font: "+font.getFullFamilyName());
 
         final AABBox sceneBox = scene.getBounds();
-        System.err.println("SceneBox "+sceneBox);
+        final float zEps = scene.getZEpsilon(zBits); // Z Epsilon, i.e. minimum recognized delta (resolution)
+        System.err.println("SceneBox "+sceneBox+", zEps "+zEps);
 
+        final float cellGap = 1.1f;
         final Vec4f borderColor = new Vec4f(0, 0, 1f, 0.6f);
         final float borderThickness = 0.01f;
-        final float sxy = 1/10f * sceneBox.getWidth();
-        float nextXPos = 0, nextYTop = sceneBox.getHeight();
-
-        final Group groupA0 = new Group(new GridLayout(1, 1f, 1/2f, Alignment.Fill, new Gap(0.10f)));
-        groupA0.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-        groupA0.setBorder(borderThickness).setBorderColor(borderColor);
-        groupA0.scale(sxy, sxy, 1);
-        groupA0.setInteractive(true);
-        groupA0.validate(reqGLP);
-        groupA0.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupA0.getScaledHeight(), 0);
-        System.err.println("Group-A0 "+groupA0);
-        System.err.println("Group-A0 Layout "+groupA0.getLayout());
-        groupA0.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA0);
-        nextXPos += groupA0.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupA0.markShapeDirty();
-            groupA0.validate(reqGLP);
-            System.err.println("Group-A0.2 "+groupA0);
-            System.err.println("Group-A0 Layout.2 "+groupA0.getLayout());
-            groupA0.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        // final float sxy = 1/10f * sceneBox.getWidth();
+        final float sxy = 1/11f * sceneBox.getWidth();
+        // final float sxy = 1/4f * sceneBox.getHeight();
+        final Vec3f nextPos = new Vec3f();
+
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(1, 1f, 1/2f, Alignment.Fill, new Gap(0.10f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 11,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupA1 = new Group(new GridLayout(1, 1, 1/2f, Alignment.Fill, new Gap(0.10f)));
-        groupA1.addShape( new Button(options.renderModes, font, "ro co", 1f, 1/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-        groupA1.addShape( new Button(options.renderModes, font, "r1 r1", 1f, 1/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-        groupA1.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        groupA1.scale(sxy, sxy, 1);
-        groupA1.setInteractive(true);
-        groupA1.validate(reqGLP);
-        groupA1.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupA1.getScaledHeight(), 0);
-        System.err.println("Group-A1 "+groupA1);
-        System.err.println("Group-A1 Layout "+groupA1.getLayout());
-        groupA1.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA1);
-        nextXPos += groupA1.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupA1.markShapeDirty();
-            groupA1.validate(reqGLP);
-            System.err.println("Group-A1.2 "+groupA1);
-            System.err.println("Group-A1 Layout.2 "+groupA1.getLayout());
-            groupA1.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(1, 1f, 1/2f, Alignment.Fill, new Gap(0.10f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 12,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 r1", 1f, 1/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupA2 = new Group(new GridLayout(1, 1/2f, Alignment.Fill, new Gap(0.10f), 1));
-        groupA2.addShape( new Button(options.renderModes, font, "ro co", 1f, 1/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-        groupA2.addShape( new Button(options.renderModes, font, "r1 c1", 1f, 1/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-        groupA2.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        groupA2.scale(sxy, sxy, 1);
-        groupA2.setInteractive(true);
-        groupA2.validate(reqGLP);
-        groupA2.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupA2.getScaledHeight(), 0);
-        System.err.println("Group-A2 "+groupA2);
-        System.err.println("Group-A2 Layout "+groupA2.getLayout());
-        groupA2.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA2);
-        nextXPos += groupA2.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupA2.markShapeDirty();
-            groupA2.validate(reqGLP);
-            System.err.println("Group-A2.2 "+groupA2);
-            System.err.println("Group-A2 Layout.2 "+groupA2.getLayout());
-            groupA2.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(1f, 1/2f, Alignment.Fill, new Gap(0.10f), 1)),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 13,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c1", 1f, 1/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupA3 = new Group(new GridLayout(2, 1f, 1/2f, Alignment.Fill, new Gap(0.10f)));
-        {
-            groupA3.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupA3.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupA3.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupA3.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-        }
-        groupA3.setBorder(borderThickness).setBorderColor(borderColor);
-        groupA3.scale(sxy, sxy, 1);
-        groupA3.setInteractive(true);
-        groupA3.validate(reqGLP);
-        groupA3.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupA3.getScaledHeight(), 0);
-        System.err.println("Group-A3 "+groupA3);
-        System.err.println("Group-A3 Layout "+groupA3.getLayout());
-        groupA3.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA3);
-        nextXPos += groupA3.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupA3.markShapeDirty();
-            groupA3.validate(reqGLP);
-            System.err.println("Group-A3.2 "+groupA3);
-            System.err.println("Group-A3 Layout.2 "+groupA3.getLayout());
-            groupA3.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 1f, 1/2f, Alignment.Fill, new Gap(0.10f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 14,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupA4 = new Group(new GridLayout(2, 1f, 1/2f, Alignment.Fill, new Gap(0.10f)));
-        {
-            groupA4.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupA4.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupA4.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupA4.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupA4.addShape( new Button(options.renderModes, font, "r3 c1", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-        }
-        groupA4.setBorder(borderThickness).setBorderColor(borderColor);
-        groupA4.scale(sxy, sxy, 1);
-        groupA4.setInteractive(true);
-        groupA4.validate(reqGLP);
-        groupA4.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupA4.getScaledHeight(), 0);
-        System.err.println("Group-A4 "+groupA4);
-        System.err.println("Group-A4 Layout "+groupA4.getLayout());
-        groupA4.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupA4);
-        nextXPos += groupA4.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupA4.markShapeDirty();
-            groupA4.validate(reqGLP);
-            System.err.println("Group-A4.2 "+groupA4);
-            System.err.println("Group-A4 Layout.2 "+groupA4.getLayout());
-            groupA4.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 1f, 1/2f, Alignment.Fill, new Gap(0.10f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 15,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r3 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
+        //
+        //
         // next line
-        nextXPos = 0;
-        nextYTop = 2f*sceneBox.getHeight()/3f;
-
-        final Group groupB0 = new Group(new GridLayout(2, sxy, sxy/2f, Alignment.Fill, new Gap(sxy*0.10f)));
-        {
-            groupB0.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB0.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupB0.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupB0.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB0.addShape( new Button(options.renderModes, font, "r3 c1", 1f, 1f/2f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-        }
-        groupB0.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        // groupB0.scale(2*sxy, 2*sxy, 1);
-        groupB0.setInteractive(true);
-        groupB0.validate(reqGLP);
-        groupB0.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupB0.getScaledHeight(), 0);
-        System.err.println("Group-B0 "+groupB0);
-        System.err.println("Group-B0 Layout "+groupB0.getLayout());
-        groupB0.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupB0);
-        nextXPos += groupB0.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupB0.markShapeDirty();
-            groupB0.validate(reqGLP);
-            System.err.println("Group-B0.2 "+groupB0);
-            System.err.println("Group-B0 Layout.2 "+groupB0.getLayout());
-            groupB0.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        nextPos.set(0, nextPos.y() + sceneBox.getHeight()/3f, 0 );
+
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 1f, 1/2f, Alignment.Fill, new Gap(0.10f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 21,
+                sxy*borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r3 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupB1 = new Group(new GridLayout(2, sxy, sxy/2f, Alignment.FillCenter, new Gap(sxy*0.10f)));
-        {
-            final Padding p = new Padding(0.05f);
-            groupB1.addShape( new Button(options.renderModes, font, "ro co", 1, 1/2f).setCorner(0f).setPaddding(p).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB1.addShape( new Button(options.renderModes, font, "r1 c2", 1, 1/2f).setCorner(0f).setPaddding(p).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupB1.addShape( new Button(options.renderModes, font, "r2 c1", 1, 1/2f).setCorner(0f).setPaddding(p).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupB1.addShape( new Button(options.renderModes, font, "r2 c2", 1, 1/2f).setCorner(0f).setPaddding(p).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB1.addShape( new Button(options.renderModes, font, "r3 c1", 1, 1/2f).setCorner(0f).setPaddding(p).setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
-        }
-        groupB1.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        // groupB1.scale(2*sxy, 2*sxy, 1);
-        groupB1.setInteractive(true);
-        groupB1.validate(reqGLP);
-        groupB1.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupB1.getScaledHeight(), 0);
-        System.err.println("Group-B1 "+groupB1);
-        System.err.println("Group-B1 Layout "+groupB1.getLayout());
-        groupB1.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupB1);
-        nextXPos += groupB1.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupB1.markShapeDirty();
-            groupB1.validate(reqGLP);
-            System.err.println("Group-B1.2 "+groupB1);
-            System.err.println("Group-B1 Layout.2 "+groupB1.getLayout());
-            groupB1.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 1f, 1/2f, Alignment.FillCenter, new Gap(0.10f), new Padding(0.05f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 22,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r3 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupB2 = new Group(new GridLayout(2, sxy, sxy/2f, Alignment.FillCenter, new Gap(sxy*0.10f)));
-        {
-            final Padding p = new Padding(sxy/2f*0.05f);
-            groupB2.addShape( new Button(options.renderModes, font, "ro co", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB2.addShape( new Button(options.renderModes, font, "r1 c2", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).setDragAndResizeable(false) );
-            groupB2.addShape( new Button(options.renderModes, font, "r2 c1", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).setDragAndResizeable(false) );
-            groupB2.addShape( new Button(options.renderModes, font, "r2 c2", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB2.addShape( new Button(options.renderModes, font, "r3 c1", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).addMouseListener(dragZoomRotateListener) );
-        }
-        groupB2.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        // groupB2.scale(2*sxy, 2*sxy, 1);
-        groupB2.setInteractive(true);
-        groupB2.validate(reqGLP);
-        groupB2.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupB2.getScaledHeight(), 0);
-        System.err.println("Group-B2 "+groupB2);
-        System.err.println("Group-B2 Layout "+groupB2.getLayout());
-        groupB2.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupB2);
-        nextXPos += groupB2.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupB2.markShapeDirty();
-            groupB2.validate(reqGLP);
-            System.err.println("Group-B2.2 "+groupB2);
-            System.err.println("Group-B2 Layout.2 "+groupB2.getLayout());
-            groupB2.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 1f, 1/2f, Alignment.FillCenter, new Gap(0.10f), new Padding(0.05f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 23,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r3 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupB3 = new Group(new GridLayout(2, sxy, sxy/2f, Alignment.Fill, new Gap(sxy*0.10f)));
-        {
-            final Padding p = new Padding(sxy/2f*0.05f);
-            groupB3.addShape( new Button(options.renderModes, font, "ro co", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB3.addShape( new Button(options.renderModes, font, "r1 c2", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).setDragAndResizeable(false) );
-            groupB3.addShape( new Button(options.renderModes, font, "r2 c1", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).setDragAndResizeable(false) );
-            groupB3.addShape( new Button(options.renderModes, font, "r2 c2", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupB3.addShape( new Button(options.renderModes, font, "r3 c1", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy/2f*borderThickness).addMouseListener(dragZoomRotateListener) );
-        }
-        groupB3.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        // groupB3.scale(2*sxy, 2*sxy, 1);
-        groupB3.setInteractive(true);
-        groupB3.validate(reqGLP);
-        groupB3.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupB3.getScaledHeight(), 0);
-        System.err.println("Group-B3 "+groupB3);
-        System.err.println("Group-B3 Layout "+groupB3.getLayout());
-        groupB3.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupB3);
-        nextXPos += groupB3.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupB3.markShapeDirty();
-            groupB3.validate(reqGLP);
-            System.err.println("Group-B3.2 "+groupB3);
-            System.err.println("Group-B3 Layout.2 "+groupB3.getLayout());
-            groupB3.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 1f, 1/2f, Alignment.Fill, new Gap(0.10f), new Padding(0.05f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 24,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c2", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r3 c1", 1f, 1f/2f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
         // next line
-        nextXPos = 0;
-        nextYTop = sceneBox.getHeight()/3f;
-
-        final Group groupC0 = new Group(new GridLayout(2, 0, 0, Alignment.Fill, new Gap(0.03f)));
-        {
-            final Group glyphGrid = new Group(new GridLayout(2, 0.3f, 0.3f, Alignment.Fill, new Gap(0.3f * 0.10f)));
-            glyphGrid.addShape( new Button(options.renderModes, font, "0.0", 1f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            glyphGrid.addShape( new Button(options.renderModes, font, "0.1", 1f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            glyphGrid.addShape( new Button(options.renderModes, font, "1.0", 1f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            glyphGrid.addShape( new Button(options.renderModes, font, "1.1", 1f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupC0.addShape(glyphGrid.setBorder(borderThickness));
-
-            final Group infoGrid = new Group(new GridLayout(1, 1/4f, 1/2f, Alignment.Fill, new Gap(0.02f)));
-            // final Group glyphView = new Group();
-            // glyphView.addShape(new Rectangle(options.renderModes, 1f, 1f, 0.005f).setInteractive(false));
-            // glyphView.addShape(new Button(options.renderModes, font, "S", 1f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            // infoGrid.addShape(glyphView.setBorder(borderThickness));
-            infoGrid.addShape(new Button(options.renderModes, font, " S ", 1/2f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-
-            // final Group infoView = new Group();
-            // infoView.addShape(new Button(options.renderModes, font, "Info", 1f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            // infoGrid.addShape(infoView.setBorder(borderThickness));
-            infoGrid.addShape(new Button(options.renderModes, font, " Info ", 1/2f, 1f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-            groupC0.addShape(infoGrid.setBorder(borderThickness));
-            // groupC0.addShape(new Button(options.renderModes, font, "S", 1/4f, 0.5f).setCorner(0f).setBorder(borderThickness).setDragAndResizeable(false) );
-        }
-        groupC0.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        groupC0.scale(2*sxy, 2*sxy, 1);
-        groupC0.setInteractive(true);
-        groupC0.validate(reqGLP);
-        groupC0.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupC0.getScaledHeight(), 0);
-        System.err.println("Group-C0 "+groupC0);
-        System.err.println("Group-C0 Layout "+groupC0.getLayout());
-        groupC0.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupC0);
-        nextXPos += groupC0.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupC0.markShapeDirty();
-            groupC0.validate(reqGLP);
-            System.err.println("Group-C0.2 "+groupC0);
-            System.err.println("Group-C0 Layout.2 "+groupC0.getLayout());
-            groupC0.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        nextPos.set(0, nextPos.y() + sceneBox.getHeight()/3f, 0 );
+
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 0, 0, Alignment.Fill, new Gap(0.03f))),
+                reqGLP, scene, zEps,
+                2*sxy, nextPos, cellGap,
+                font, 31,
+                borderThickness, borderColor, (final Group gp) -> {
+                    final Group glyphGrid = new Group(new GridLayout(2, 0.3f, 0.3f, Alignment.Fill, new Gap(0.3f * 0.10f)));
+                    glyphGrid.addShape( new Button(options.renderModes, font, "0.0", 1f, 1f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    glyphGrid.addShape( new Button(options.renderModes, font, "0.1", 1f, 1f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    glyphGrid.addShape( new Button(options.renderModes, font, "1.0", 1f, 1f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    glyphGrid.addShape( new Button(options.renderModes, font, "1.1", 1f, 1f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape(glyphGrid.setBorder(borderThickness));
+
+                    final Group infoGrid = new Group(new GridLayout(1, 1/4f, 1/2.2f, Alignment.Fill, new Gap(0.02f)));
+                    // final Group glyphView = new Group();
+                    // glyphView.addShape(new Rectangle(options.renderModes, 1f, 1f, 0.005f).setInteractive(false));
+                    // glyphView.addShape(new Button(options.renderModes, font, "S", 1f, 1f).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    // infoGrid.addShape(glyphView.setBorder(borderThickness));
+                    infoGrid.addShape(new Button(options.renderModes, font, " S ", 1/2f, 1f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+
+                    // final Group infoView = new Group();
+                    // infoView.addShape(new Button(options.renderModes, font, "Info", 1f, 1f).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    // infoGrid.addShape(infoView.setBorder(borderThickness));
+                    infoGrid.addShape(new Button(options.renderModes, font, " Info ", 1/2f, 1f, zEps).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                    gp.addShape(infoGrid.setBorder(borderThickness));
+                    // groupC0.addShape(new Button(options.renderModes, font, "S", 1/4f, 0.5f).setPerp().setBorder(borderThickness).setDragAndResizeable(false) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
 
-        final Group groupC3 = new Group(new GridLayout(2, sxy, sxy/2f, Alignment.Center, new Gap(sxy*0.10f)));
-        {
-            final Padding p = new Padding(sxy*0.05f);
-            groupC3.addShape( new Button(options.renderModes, font, "ro co", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy*borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupC3.addShape( new Button(options.renderModes, font, "r1 c2", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy*borderThickness).setDragAndResizeable(false) );
-            groupC3.addShape( new Button(options.renderModes, font, "r2 c1", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy*borderThickness).setDragAndResizeable(false) );
-            groupC3.addShape( new Button(options.renderModes, font, "r2 c2", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy*borderThickness).addMouseListener(dragZoomRotateListener) );
-            groupC3.addShape( new Button(options.renderModes, font, "r3 c1", sxy/2f, sxy/4f).setCorner(0f).setPaddding(p).setBorder(sxy*borderThickness).addMouseListener(dragZoomRotateListener) );
+        if( true ) {
+            final Group g = setupGroup(new Group(new GridLayout(2, 1, 1/2f, Alignment.Center, new Gap(0.10f), new Padding(0.05f))),
+                reqGLP, scene, zEps,
+                sxy, nextPos, cellGap,
+                font, 32,
+                borderThickness, borderColor, (final Group gp) -> {
+                    gp.addShape( new Button(options.renderModes, font, "ro co", 1/2f, 1/4.1f, zEps).setPerp().setBorder(sxy*borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r1 c2", 1/2f, 1/4.1f, zEps).setPerp().setBorder(sxy*borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c1", 1/2f, 1/4.1f, zEps).setPerp().setBorder(sxy*borderThickness).setDragAndResizeable(false) );
+                    gp.addShape( new Button(options.renderModes, font, "r2 c2", 1/2f, 1/4.1f, zEps).setPerp().setBorder(sxy*borderThickness).addMouseListener(dragZoomRotateListener) );
+                    gp.addShape( new Button(options.renderModes, font, "r3 c1", 1/2f, 1/4.1f, zEps).setPerp().setBorder(sxy*borderThickness).addMouseListener(dragZoomRotateListener) );
+                } );
+            nextPos.setX( nextPos.x() + g.getScaledWidth() * cellGap );
         }
-        groupC3.setBorder(sxy*borderThickness).setBorderColor(borderColor);
-        // groupC3.scale(2*sxy, 2*sxy, 1);
-        groupC3.setInteractive(true);
-        groupC3.validate(reqGLP);
-        groupC3.moveTo(sceneBox.getLow()).move(nextXPos, nextYTop-groupC3.getScaledHeight(), 0);
-        System.err.println("Group-C3 "+groupC3);
-        System.err.println("Group-C3 Layout "+groupC3.getLayout());
-        groupC3.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
-        scene.addShape(groupC3);
-        nextXPos += groupC3.getScaledWidth() * 1.1f;
-        if( reLayout ) {
-            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
-            groupC3.markShapeDirty();
-            groupC3.validate(reqGLP);
-            System.err.println("Group-C3.2 "+groupC3);
-            System.err.println("Group-C3 Layout.2 "+groupC3.getLayout());
-            groupC3.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        {
+            final AABBox sceneDim = scene.getBounds();
+            final String text = " Press group description to magnify! ";
+            final AABBox textDim = font.getGlyphBounds(text, new AffineTransform(), new AffineTransform());
+            final float l_sxy = 1/4f * sceneDim.getWidth() / textDim.getWidth();
+
+            final Shape label = new Label(options.renderModes, font, text).setColor(0, 0, 0, 1).setInteractive(false)
+                                    .scale(l_sxy, l_sxy, 1).moveTo(sceneDim.getLow())
+                                    .move(sceneDim.getWidth() - textDim.getWidth()*l_sxy, sceneDim.getHeight() - textDim.getHeight()*l_sxy, 0);
+            scene.addShape(label);
         }
 
         try { Thread.sleep(1000); } catch (final InterruptedException e1) { }
@@ -465,4 +358,57 @@ public class UILayoutGrid01 {
             window.destroy();
         }
     }
+
+    static interface GroupMod {
+        void mod(Group group);
+    }
+    static Group setupGroup(final Group g, final GLProfile reqGLP, final Scene scene, final float zEps,
+                            final float sxy, final Vec3f nextPos, final float cellGap,
+                            final Font font, final int id,
+                            final float borderThickness, final Vec4f borderColor, final GroupMod modImpl) {
+        final String suffix = String.format("%2d", id);
+        g.setName(id);
+        final AABBox sceneBox = scene.getBounds();
+        modImpl.mod(g);
+        g.setBorder(borderThickness).setBorderColor(borderColor);
+        g.scale(sxy, sxy, 1);
+        g.setInteractive(true);
+        g.validate(reqGLP);
+        g.moveTo(sceneBox.getLow()).move(nextPos);
+        System.err.println("Group-"+suffix+" "+g);
+        System.err.println("Group-"+suffix+" Layout "+g.getLayout());
+        g.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        scene.addShape(g);
+        {
+            final float X_width = font.getGlyph(font.getGlyphID(' ')).getAdvance();
+            /**
+             * ID 23: G 23, size[total 2.1 x 1.7, cell 1.0 x 0.5]
+             * Padding[t 0.05, r 0.05, b 0.05, l 0.05]
+             * Gap[r 0.1, c 0.1], Align [CenterHoriz, CenterVert, Fill]
+             */
+            final String fixed_text = "Gap[r 0.1, c 0.1], Align [CenterHoriz, CenterVert, Fi";
+            final float l_sxy = g.getScaledWidth() / font.getGlyphBounds(fixed_text, new AffineTransform(), new AffineTransform()).getWidth();
+
+            final GridLayout l = (GridLayout)g.getLayout();
+            final String text = String.format("G %2d, size[total %.1f x %.1f, cell %.1f x %.1f]%n%s%n%s, Align %s",
+                                    id, g.getBounds().getWidth(), g.getBounds().getHeight(), l.getCellSize().x(), l.getCellSize().y(),
+                                    ( null == l.getPadding() || l.getPadding().zeroSumSize() ) ? "Padding none" : l.getPadding().toString(),
+                                    l.getGap().zeroSumSize() ? "Gap none" : l.getGap().toString(),
+                                    l.getAlignment() );
+            final Shape label = new Label(options.renderModes, font, text).setColor(0, 0, 0, 1).validate(reqGLP);
+            label.scale(l_sxy, l_sxy, 1).moveTo(sceneBox.getLow()).move(nextPos).move(l_sxy*X_width, g.getScaledHeight(), 0)
+                .addMouseListener(new Tooltips.ZoomLabelOnClickListener(scene, options.renderModes, 1/6f)).setDragAndResizeable(false);
+            scene.addShape(label);
+        }
+        if( reLayout ) {
+            try { Thread.sleep(reLayoutSleep); } catch (final InterruptedException e1) { }
+            g.markShapeDirty();
+            g.validate(reqGLP);
+            System.err.println("Group-"+suffix+".2 "+g);
+            System.err.println("Group-"+suffix+" Layout.2 "+g.getLayout());
+            g.forAll( (shape) -> { System.err.println("Shape... "+shape); return false; });
+        }
+        return g;
+    }
+
 }
diff --git a/src/demos/com/jogamp/opengl/demos/graph/ui/util/Tooltips.java b/src/demos/com/jogamp/opengl/demos/graph/ui/util/Tooltips.java
new file mode 100644
index 000000000..aaf1bba20
--- /dev/null
+++ b/src/demos/com/jogamp/opengl/demos/graph/ui/util/Tooltips.java
@@ -0,0 +1,109 @@
+/**
+ * Copyright 2023 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+package com.jogamp.opengl.demos.graph.ui.util;
+
+import com.jogamp.graph.curve.Region;
+import com.jogamp.graph.curve.opengl.GLRegion;
+import com.jogamp.graph.ui.Scene;
+import com.jogamp.graph.ui.Shape;
+import com.jogamp.graph.ui.shapes.Button;
+import com.jogamp.graph.ui.shapes.Label;
+import com.jogamp.newt.event.MouseEvent;
+import com.jogamp.opengl.GLAutoDrawable;
+import com.jogamp.opengl.GLProfile;
+import com.jogamp.opengl.math.geom.AABBox;
+import com.jogamp.opengl.util.texture.TextureSequence;
+
+public class Tooltips {
+    /**
+     * Shows the {@link Label#getText()} within a given proportion of {@link Scene#getBounds()} height within a rectangular {@link Button} tool-tip on click.
+     * <p>
+     * This {@link Shape.MouseGestureAdapter} must be {@link Shape#addMouseListener(com.jogamp.graph.ui.Shape.MouseGestureListener) added}
+     * to a {@link Label} to be functional.
+     * </p>
+     */
+    public static class ZoomLabelOnClickListener extends Shape.MouseGestureAdapter {
+        private final Scene scene;
+        private final int renderModes;
+        private final float sceneHeightScale;
+        private Button buttonLabel = null;
+
+        /**
+         * Ctor of {@link ZoomLabelOnClickListener}.
+         * @param scene the {@link Scene} to be attached to while pressed
+         * @param renderModes Graph's {@link Region} render modes, see {@link GLRegion#create(GLProfile, int, TextureSequence) create(..)}.
+         * @param sceneHeightScale proportion of {@link Scene#getBounds()} height to cover with this tool-tip
+         */
+        public ZoomLabelOnClickListener(final Scene scene, final int renderModes, final float sceneHeightScale) {
+            this.scene = scene;
+            this.renderModes = renderModes;
+            this.sceneHeightScale = sceneHeightScale;
+        }
+
+        @Override
+        public void mousePressed(final MouseEvent e) {
+            final AABBox sceneDim = scene.getBounds();
+            final float zEps = scene.getZEpsilon(16);
+
+            final Shape.EventInfo shapeEvent = (Shape.EventInfo) e.getAttachment();
+            if( !( shapeEvent.shape instanceof Label ) ) {
+                return;
+            }
+            final Label label = (Label)shapeEvent.shape;
+            final AABBox textDim = label.getBounds();
+            final float l_sxy = sceneHeightScale * sceneDim.getHeight() / textDim.getHeight(); // text width independent
+            buttonLabel = (Button) new Button(renderModes, label.getFont(), label.getText(), textDim.getWidth(), textDim.getHeight(), zEps)
+                    .setPerp().scale(l_sxy, l_sxy, 1).move(0, 0, 10*zEps)
+                    .setColor(0.97f, 0.97f, 0.97f, 0.92f).setBorder(0.05f).setBorderColor(0, 0, 0, 1)
+                    .setInteractive(false);
+            buttonLabel.setLabelColor(0, 0, 0);
+            buttonLabel.setSpacing(Button.DEFAULT_SPACING_X, Button.DEFAULT_SPACING_X);
+            final Shape s = buttonLabel;
+            scene.invoke(false, (final GLAutoDrawable drawable) -> {
+                s.validate(drawable.getGL().getGL2ES2());
+                s.move(-s.getScaledWidth()/2f, -s.getScaledHeight()/2f, 0);
+                // System.err.println("Add "+s);
+                scene.addShape(s);
+                return true;
+            });
+        }
+        @Override
+        public void mouseReleased(final MouseEvent e) {
+            if( null != buttonLabel ) {
+                final Shape s = buttonLabel;
+                buttonLabel = null;
+                scene.invoke(false, (final GLAutoDrawable drawable) -> {
+                    // System.err.println("Remove "+s);
+                    scene.removeShape(drawable.getGL().getGL2ES2(), s);
+                    return true;
+                });
+            }
+        }
+    };
+
+}