Optimize impl of snappedTopInset() methods in Region

The 4 new methods added in RT-29805 only had simple implementations. They could benefit from caching the computed snapped insets in Region. The patch is pasted below:

Running controls.bm.CheckboxBenchmark with 1400x1000px on Mac desktop I get

32fps old impl
34fps new impl

so about 5% gain

diff -r b4cfc5409461 javafx-ui-common/src/javafx/scene/layout/Region.java
--- a/javafx-ui-common/src/javafx/scene/layout/Region.java Thu Apr 18 15:57:32 2013 -0700
+++ b/javafx-ui-common/src/javafx/scene/layout/Region.java Thu Apr 18 17:14:23 2013 -0700
@@ -353,6 +353,7 @@
         if (snapToPixel == null) {
             if (_snapToPixel != value) {
                 _snapToPixel = value;
+ updateSnappedInsets();
                 requestParentLayout();
             }
         } else {
@@ -374,6 +375,7 @@
                     boolean value = get();
                     if (_snapToPixel != value) {
                         _snapToPixel = value;
+ updateSnappedInsets();
                         requestParentLayout();
                     }
                 }
@@ -557,6 +559,7 @@
 
         void fireValueChanged() {
             cache = null;
+ updateSnappedInsets();
             requestLayout();
             ExpressionHelper.fireValueChangedEvent(helper);
         }
@@ -595,6 +598,31 @@
     };
 
     /**
+ * cached results of snapped insets, this are used a lot during layout so makes sense
+ * to keep fast access cached copies here.
+ */
+ private double snappedTopInset = 0;
+ private double snappedRightInset = 0;
+ private double snappedBottomInset = 0;
+ private double snappedLeftInset = 0;
+
+ /** Called to update the cached snapped insets */
+ private void updateSnappedInsets() {
+ final Insets insets = getInsets();
+ if (_snapToPixel) {
+ snappedTopInset = Math.ceil(insets.getTop());
+ snappedRightInset = Math.ceil(insets.getRight());
+ snappedBottomInset = Math.ceil(insets.getBottom());
+ snappedLeftInset = Math.ceil(insets.getLeft());
+ } else {
+ snappedTopInset = insets.getTop();
+ snappedRightInset = insets.getRight();
+ snappedBottomInset = insets.getBottom();
+ snappedLeftInset = insets.getLeft();
+ }
+ }
+
+ /**
     * The width of this resizable node. This property is set by the region's parent
     * during layout and may not be set by the application. If an application
     * needs to explicitly control the size of a region, it should override its
@@ -1362,8 +1390,8 @@
      * @since 8.0
      * @return Rounded up insets top
      */
- public final int snappedTopInset() {
- return (int)snapSize(getInsets().getTop());
+ public final double snappedTopInset() {
+ return snappedTopInset;
     }
 
     /**
@@ -1373,8 +1401,8 @@
      * @since 8.0
      * @return Rounded up insets bottom
      */
- public final int snappedBottomInset() {
- return (int)snapSize(getInsets().getBottom());
+ public final double snappedBottomInset() {
+ return snappedBottomInset;
     }
 
     /**
@@ -1384,8 +1412,8 @@
      * @since 8.0
      * @return Rounded up insets left
      */
- public final int snappedLeftInset() {
- return (int)snapSize(getInsets().getLeft());
+ public final double snappedLeftInset() {
+ return snappedLeftInset;
     }
 
     /**
@@ -1395,8 +1423,8 @@
      * @since 8.0
      * @return Rounded up insets right
      */
- public final int snappedRightInset() {
- return (int)snapSize(getInsets().getRight());
+ public final double snappedRightInset() {
+ return snappedRightInset;
     }