From f56e8a5163739004de47488597c15a9618d7e6ee Mon Sep 17 00:00:00 2001
From: Emil Sjolander <emilsj@fb.com>
Date: Mon, 21 Nov 2016 11:03:56 -0800
Subject: [PATCH] Move measure code for empty containers out of main layout
 function

Summary: Try to move more code out of the main measure function

Reviewed By: gkassabli

Differential Revision: D4213313

fbshipit-source-id: 2061a809202f7f948bff1b3ee8dc4c230692a223
---
 CSSLayout/CSSLayout.c | 57 ++++++++++++++++++++++++++-----------------
 1 file changed, 35 insertions(+), 22 deletions(-)

diff --git a/CSSLayout/CSSLayout.c b/CSSLayout/CSSLayout.c
index 00b03ef6..2b8e2d61 100644
--- a/CSSLayout/CSSLayout.c
+++ b/CSSLayout/CSSLayout.c
@@ -1247,6 +1247,34 @@ static void setMeasuredDimensionsForNodeWithMeasureFunc(const CSSNodeRef node,
   }
 }
 
+// For nodes with no children, use the available values if they were provided,
+// or the minimum size as indicated by the padding and border sizes.
+static void setMeasuredDimensionsForEmptyContainer(const CSSNodeRef node,
+                                                   const float availableWidth,
+                                                   const float availableHeight,
+                                                   const CSSMeasureMode widthMeasureMode,
+                                                   const CSSMeasureMode heightMeasureMode) {
+  const float paddingAndBorderAxisRow = getPaddingAndBorderAxis(node, CSSFlexDirectionRow);
+  const float paddingAndBorderAxisColumn = getPaddingAndBorderAxis(node, CSSFlexDirectionColumn);
+  const float marginAxisRow = getMarginAxis(node, CSSFlexDirectionRow);
+  const float marginAxisColumn = getMarginAxis(node, CSSFlexDirectionColumn);
+
+  node->layout.measuredDimensions[CSSDimensionWidth] =
+      boundAxis(node,
+                CSSFlexDirectionRow,
+                (widthMeasureMode == CSSMeasureModeUndefined ||
+                 widthMeasureMode == CSSMeasureModeAtMost)
+                    ? paddingAndBorderAxisRow
+                    : availableWidth - marginAxisRow);
+  node->layout.measuredDimensions[CSSDimensionHeight] =
+      boundAxis(node,
+                CSSFlexDirectionColumn,
+                (heightMeasureMode == CSSMeasureModeUndefined ||
+                 heightMeasureMode == CSSMeasureModeAtMost)
+                    ? paddingAndBorderAxisColumn
+                    : availableHeight - marginAxisColumn);
+}
+
 //
 // This is the main routine that implements a subset of the flexbox layout
 // algorithm
@@ -1375,11 +1403,6 @@ static void layoutNodeImpl(const CSSNodeRef node,
              "availableHeight is indefinite so heightMeasureMode must be "
              "CSSMeasureModeUndefined");
 
-  const float paddingAndBorderAxisRow = getPaddingAndBorderAxis(node, CSSFlexDirectionRow);
-  const float paddingAndBorderAxisColumn = getPaddingAndBorderAxis(node, CSSFlexDirectionColumn);
-  const float marginAxisRow = getMarginAxis(node, CSSFlexDirectionRow);
-  const float marginAxisColumn = getMarginAxis(node, CSSFlexDirectionColumn);
-
   // Set the resolved resolution in the node's layout.
   const CSSDirection direction = resolveDirection(node, parentDirection);
   node->layout.direction = direction;
@@ -1390,28 +1413,18 @@ static void layoutNodeImpl(const CSSNodeRef node,
     return;
   }
 
-  // For nodes with no children, use the available values if they were provided,
-  // or
-  // the minimum size as indicated by the padding and border sizes.
   const uint32_t childCount = CSSNodeListCount(node->children);
   if (childCount == 0) {
-    node->layout.measuredDimensions[CSSDimensionWidth] =
-        boundAxis(node,
-                  CSSFlexDirectionRow,
-                  (widthMeasureMode == CSSMeasureModeUndefined ||
-                   widthMeasureMode == CSSMeasureModeAtMost)
-                      ? paddingAndBorderAxisRow
-                      : availableWidth - marginAxisRow);
-    node->layout.measuredDimensions[CSSDimensionHeight] =
-        boundAxis(node,
-                  CSSFlexDirectionColumn,
-                  (heightMeasureMode == CSSMeasureModeUndefined ||
-                   heightMeasureMode == CSSMeasureModeAtMost)
-                      ? paddingAndBorderAxisColumn
-                      : availableHeight - marginAxisColumn);
+    setMeasuredDimensionsForEmptyContainer(
+        node, availableWidth, availableHeight, widthMeasureMode, heightMeasureMode);
     return;
   }
 
+  const float paddingAndBorderAxisRow = getPaddingAndBorderAxis(node, CSSFlexDirectionRow);
+  const float paddingAndBorderAxisColumn = getPaddingAndBorderAxis(node, CSSFlexDirectionColumn);
+  const float marginAxisRow = getMarginAxis(node, CSSFlexDirectionRow);
+  const float marginAxisColumn = getMarginAxis(node, CSSFlexDirectionColumn);
+
   // If we're not being asked to perform a full layout, we can handle a number
   // of common
   // cases here without incurring the cost of the remaining function.