8370652: Control and ScrollPaneSkin should snap computed width/height values to prevent scrollbars appearing due to rounding errors

Reviewed-by: angorya, kcr

Author: hjohn

modules/javafx.controls/src/main/java/javafx/scene/control/Control.java

@@ -607,8 +607,8 @@ protected Control() {
         if (skinBase != null) {
             final double x = snappedLeftInset();
             final double y = snappedTopInset();
-            final double w = snapSizeX(getWidth()) - x - snappedRightInset();
-            final double h = snapSizeY(getHeight()) - y - snappedBottomInset();
+            final double w = snapSpaceX(snapSizeX(getWidth()) - x - snappedRightInset());
+            final double h = snapSpaceY(snapSizeY(getHeight()) - y - snappedBottomInset());
             skinBase.layoutChildren(x, y, w, h);
         } else {
             Node n = getSkinNode();

modules/javafx.controls/src/main/java/javafx/scene/control/skin/ScrollPaneSkin.java

@@ -423,10 +423,10 @@ public final ScrollBar getVerticalScrollBar() {
         double minWidth = vsbWidth + snappedLeftInset() + snappedRightInset();
 
         if (sp.getPrefViewportWidth() > 0) {
-            return (sp.getPrefViewportWidth() + minWidth);
+            return snapSpaceX(sp.getPrefViewportWidth() + minWidth);
         }
         else if (sp.getContent() != null) {
-            return (sp.getContent().prefWidth(height) + minWidth);
+            return snapSpaceX(sp.getContent().prefWidth(height) + minWidth);
         }
         else {
             return Math.max(minWidth, DEFAULT_PREF_SIZE);
@@ -441,10 +441,10 @@ else if (sp.getContent() != null) {
         double minHeight = hsbHeight + snappedTopInset() + snappedBottomInset();
 
         if (sp.getPrefViewportHeight() > 0) {
-            return (sp.getPrefViewportHeight() + minHeight);
+            return snapSpaceY(sp.getPrefViewportHeight() + minHeight);
         }
         else if (sp.getContent() != null) {
-            return (sp.getContent().prefHeight(width) + minHeight);
+            return snapSpaceY(sp.getContent().prefHeight(width) + minHeight);
         }
         else {
             return Math.max(minHeight, DEFAULT_PREF_SIZE);
@@ -459,7 +459,7 @@ else if (sp.getContent() != null) {
         double minWidth = vsbWidth + snappedLeftInset() + snappedRightInset();
 
         if (sp.getMinViewportWidth() > 0) {
-            return (sp.getMinViewportWidth() + minWidth);
+            return snapSpaceX(sp.getMinViewportWidth() + minWidth);
         } else {
             double w = corner.minWidth(-1);
             return (w > 0) ? (3 * w) : (DEFAULT_MIN_SIZE);
@@ -475,7 +475,7 @@ else if (sp.getContent() != null) {
         double minHeight = hsbHeight + snappedTopInset() + snappedBottomInset();
 
         if (sp.getMinViewportHeight() > 0) {
-            return (sp.getMinViewportHeight() + minHeight);
+            return snapSpaceY(sp.getMinViewportHeight() + minHeight);
         } else {
             double h = corner.minHeight(-1);
             return (h > 0) ? (3 * h) : (DEFAULT_MIN_SIZE);