GraphUI GridLayout: Functional Grid Layout w/ Padding, demo'ed in UISceneDemo20 with button Groups

All layout magic is simply performed in Group.Layout.layout(..) @ validate, incl. updating the
bounding box to have the padding included.

This demonstrates GraphUI's capability to be used with correct layout,
i.e. its pure matrix based position, scale and rotation.

3 files changed, 198 insertions, 42 deletions

diff --git a/src/graphui/classes/com/jogamp/graph/ui/Group.java b/src/graphui/classes/com/jogamp/graph/ui/Group.java
index b3ae5b41d..e349b1302 100644
--- a/src/graphui/classes/com/jogamp/graph/ui/Group.java
+++ b/src/graphui/classes/com/jogamp/graph/ui/Group.java
@@ -48,10 +48,22 @@ import jogamp.graph.ui.TreeTool;
  * @see Group.Layout
  */
 public class Group extends Shape implements Container {
-    /** Layout for the group, called @ {@link Group#validate(GL2ES2)} or {@link Group#validate(GLProfile)}.  */
+    /** Layout for the GraphUI {@link Group}, called @ {@link Shape#validate(GL2ES2)} or {@link Shape#validate(GLProfile)}.  */
     public static interface Layout {
-        /** Performing the layout, called @ {@link Group#validate(GL2ES2)} or {@link Group#validate(GLProfile)}. */
-        void layout(Group g);
+        /**
+         * Performing the layout of {@link Group#getShapes()}, called @ {@link Shape#validate(GL2ES2)} or {@link Shape#validate(GLProfile)}.
+         * <p>
+         * According to the implemented layout, method
+         * - may scale the {@Link Shape}s
+         * - may move the {@Link Shape}s
+         * - may reuse the given {@link PMVMatrix} `pmv`
+         * - must update the given {@link AABBox} `box`
+         * </p>
+         * @param g the {@link Group} to layout
+         * @param box the bounding box of {@link Group} to be updated by this method.
+         * @param pmv a {@link PMVMatrix} which can be reused.
+         */
+        void layout(final Group g, final AABBox box, final PMVMatrix pmv);
     }
 
     private final List<Shape> shapes = new ArrayList<Shape>();
@@ -161,12 +173,6 @@ public class Group extends Shape implements Container {
         }
     }
 
-    private void layout() {
-        if( null != layouter ) {
-            layouter.layout(this);
-        }
-    }
-
     private boolean doFrustumCulling = false;
 
     @Override
@@ -200,21 +206,25 @@ public class Group extends Shape implements Container {
     @Override
     protected void validateImpl(final GLProfile glp, final GL2ES2 gl) {
         if( isShapeDirty() ) {
-            layout();
             final PMVMatrix pmv = new PMVMatrix();
             final AABBox tmpBox = new AABBox();
             for(final Shape s : shapes) {
-                // s.validateImpl(glp, gl);
                 if( null != gl ) {
                     s.validate(gl);
                 } else {
                     s.validate(glp);
                 }
-                pmv.glPushMatrix();
-                s.setTransform(pmv);
-                s.getBounds().transformMv(pmv, tmpBox);
-                pmv.glPopMatrix();
-                box.resize(tmpBox);
+            }
+            if( null != layouter ) {
+                layouter.layout(this, box, pmv);
+            } else {
+                for(final Shape s : shapes) {
+                    pmv.glPushMatrix();
+                    s.setTransform(pmv);
+                    s.getBounds().transformMv(pmv, tmpBox);
+                    pmv.glPopMatrix();
+                    box.resize(tmpBox);
+                }
             }
         }
     }
@@ -249,6 +259,11 @@ public class Group extends Shape implements Container {
     }
 
     @Override
+    public String getSubString() {
+        return super.getSubString()+", shapes "+shapes.size();
+    }
+
+    @Override
     public boolean forOne(final PMVMatrix pmv, final Shape shape, final Runnable action) {
         return TreeTool.forOne(shapes, pmv, shape, action);
     }
diff --git a/src/graphui/classes/com/jogamp/graph/ui/layout/GridLayout.java b/src/graphui/classes/com/jogamp/graph/ui/layout/GridLayout.java
index bd2fd2d76..7d1739dd6 100644
--- a/src/graphui/classes/com/jogamp/graph/ui/layout/GridLayout.java
+++ b/src/graphui/classes/com/jogamp/graph/ui/layout/GridLayout.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2010-2023 JogAmp Community. All rights reserved.
+ * 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:
@@ -27,43 +27,135 @@
  */
 package com.jogamp.graph.ui.layout;
 
+import java.util.List;
+
+import com.jogamp.graph.ui.GraphShape;
 import com.jogamp.graph.ui.Group;
 import com.jogamp.graph.ui.Shape;
-import com.jogamp.graph.ui.Group.Layout;
+import com.jogamp.opengl.math.geom.AABBox;
+import com.jogamp.opengl.util.PMVMatrix;
 
+/**
+ * GraphUI Grid {@link Group.Layout}.
+ */
 public class GridLayout implements Group.Layout {
-    private final int columns;
-    private final float padX, padY;
+    /** Layout order for {@link Group#getShapes()}} after population. */
+    public static enum Order {
+        /** COLUMN layout order of {@link Group#getShapes()}} is left to right and top to bottom. */
+        COLUMN,
+        /** ROW layout order of {@link Group#getShapes()}} is top to bottom and left to right. */
+        ROW
+    }
+    private final Order order;
+    private final int col_limit;
+    private final int row_limit;
+    private final float cellWidth, cellHeight;
+    private final Padding padding;
+    private int row_count, col_count;
+
+
+    /**
+     * Default layout order of {@link Group#getShapes()}} is {@link Order#COLUMN}.
+     * @param column_limit [1..inf)
+     * @param cellWidth
+     * @param cellHeight
+     */
+    public GridLayout(final int column_limit, final float cellWidth, final float cellHeight) {
+        this(Math.max(1, column_limit), -1, cellWidth, cellHeight, new Padding());
+    }
+
+    /**
+     * Default layout order of {@link Group#getShapes()}} is {@link Order#COLUMN}.
+     * @param column_limit [1..inf)
+     * @param cellWidth
+     * @param cellHeight
+     * @param padding
+     */
+    public GridLayout(final int column_limit, final float cellWidth, final float cellHeight, final Padding padding) {
+        this(Math.max(1, column_limit), -1, cellWidth, cellHeight, padding);
+    }
 
     /**
-     *
-     * @param columns [1..inf)
-     * @param padX
-     * @param padY
+     * Default layout order of {@link Group#getShapes()}} is {@link Order#ROW}.
+     * @param cellWidth
+     * @param cellHeight
+     * @param padding
+     * @param row_limit [1..inf)
      */
-    public GridLayout(final int columns, final float padX, final float padY) {
-        this.columns = Math.max(1, columns);
-        this.padX = padX;
-        this.padY = padY;
+    public GridLayout(final float cellWidth, final float cellHeight, final Padding padding, final int row_limit) {
+        this(-1, Math.max(1, row_limit), cellWidth, cellHeight, padding);
+    }
+
+    private GridLayout(final int column_limit, final int row_limit, final float cellWidth, final float cellHeight, final Padding padding) {
+        this.order = 0 < column_limit ? Order.COLUMN : Order.ROW;
+        this.col_limit = column_limit;
+        this.row_limit = row_limit;
+        this.cellWidth = cellWidth;
+        this.cellHeight = cellHeight;
+        this.padding = padding;;
+        row_count = 0;
+        col_count = 0;
     }
 
+    public Order getOrder() { return order; }
+    public int getColumnCount() { return col_count; }
+    public int getRowCount() { return row_count; }
+
     @Override
-    public void layout(final Group g) {
-        int col = 0;
-        float x=0;
-        float y=0;
-        for(final Shape s : g.getShapes()) {
-            s.moveTo(x, y, 0);
-            if( col + 1 == columns ) {
-                col = 0;
-                // row++;
-                x  = 0;
-                y -= padY;
-            } else {
-                col++;
-                x += padX;
+    public void layout(final Group g, final AABBox box, final PMVMatrix pmv) {
+        final List<Shape> shapes = g.getShapes();
+        if( Order.COLUMN == order ) {
+            row_count = (int) Math.ceil( (double)shapes.size() / (double)col_limit );
+            col_count = col_limit;
+        } else { // Order.ROW_MAJOR == order
+            row_count = row_limit;
+            col_count = (int) Math.ceil( (double)shapes.size() / (double)row_limit );
+        }
+        int col_i = 0, row_i = 0;
+        final AABBox sbox = new AABBox();
+        for(final Shape s : shapes) {
+            // measure size
+            pmv.glPushMatrix();
+            s.setTransform(pmv);
+            s.getBounds().transformMv(pmv, sbox);
+            pmv.glPopMatrix();
+
+            // adjust size and position (centered)
+            final float x =  ( (             col_i     ) * ( cellWidth  + padding.width()  ) ) + padding.left;
+            final float y =  ( ( row_count - row_i - 1 ) * ( cellHeight + padding.height() ) ) + padding.bottom;
+            final float sx = cellWidth / sbox.getWidth();
+            final float sy = cellHeight/ sbox.getHeight();
+            final float sxy = sx < sy ? sx : sy;
+            final float dxh = sbox.getWidth()  * ( sx - sxy ) * 0.5f;
+            final float dyh = sbox.getHeight() * ( sy - sxy ) * 0.5f;
+            s.moveTo( x + dxh, y + dyh, 0f );
+            s.scale( sxy, sxy, 1f);
+            box.resize( x + cellWidth + padding.right, y + cellHeight + padding.top,    0);
+            box.resize( x             - padding.left,  y -              padding.bottom, 0);
+            // System.err.println("["+row_i+"]["+col_i+"]: "+x+" / "+y);
+
+            // position for next cell
+            if( Order.COLUMN == order ) {
+                if( col_i + 1 == col_limit ) {
+                    col_i = 0;
+                    row_i++;
+                } else {
+                    col_i++;
+                }
+            } else { // Order.ROW_MAJOR == order
+                if( row_i + 1 == row_limit ) {
+                    row_i = 0;
+                    col_i++;
+                } else {
+                    row_i++;
+                }
             }
         }
     }
+
+    @Override
+    public String toString() {
+        return "Grid["+row_count+"x"+col_count+", "+order+", cell["+cellWidth+" x "+cellHeight+"], "+padding+"]";
+    }
 }
 
diff --git a/src/graphui/classes/com/jogamp/graph/ui/layout/Padding.java b/src/graphui/classes/com/jogamp/graph/ui/layout/Padding.java
new file mode 100644
index 000000000..f4b35e723
--- /dev/null
+++ b/src/graphui/classes/com/jogamp/graph/ui/layout/Padding.java
@@ -0,0 +1,49 @@
+/**
+ * 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.graph.ui.layout;
+
+/**
+ * GraphUI Padding of cells, e.g. {@link GridLayout}.
+ */
+public class Padding {
+    public final float left, right, bottom, top;
+
+    public Padding() {
+        left = 0f; right = 0f; bottom = 0f; top = 0f;
+    }
+    public Padding(final float width, final float height) {
+        left = width/2f; right = width/2f; bottom = height/2f; top = height/2f;
+    }
+    public Padding(final float left, final float right, final float bottom, final float top) {
+        this.left = left; this.right = right; this.bottom = bottom; this.top = top;
+    }
+    public float width() { return left + right; }
+    public float height() { return bottom + top; }
+    @Override
+    public String toString() { return "Padding[l "+left+", r "+right+", b "+bottom+", t "+top+"]"; }
+}