From b21efa45e6c0ef2d7b6d85b25e9b4262f8167b18 Mon Sep 17 00:00:00 2001
From: Emil Sjolander <emilsj@fb.com>
Date: Mon, 17 Oct 2016 04:07:54 -0700
Subject: [PATCH] Fix justify content + min dimension usage in root

Summary: Min dimension was not respected when calculating justify content. This diff ensures that the min dimension is taken into account when at most measure spec is used.

Reviewed By: gkassabli, lucasr

Differential Revision: D4021443

fbshipit-source-id: 00f58c6078ac3076221e1148aacc34712786deb5
---
 CSSLayout/CSSLayout.c                  | 10 ++-
 tests/CSSLayoutMinMaxDimensionTest.cpp | 84 ++++++++++++++++++++++++++
 2 files changed, 91 insertions(+), 3 deletions(-)

diff --git a/CSSLayout/CSSLayout.c b/CSSLayout/CSSLayout.c
index e44429b7..c50095bf 100644
--- a/CSSLayout/CSSLayout.c
+++ b/CSSLayout/CSSLayout.c
@@ -1514,10 +1514,14 @@ static void layoutNodeImpl(const CSSNodeRef node,
     // that are aligned "stretch". We need to compute these stretch values and
     // set the final positions.
 
-    // If we are using "at most" rules in the main axis, we won't distribute
-    // any remaining space at this point.
+    // If we are using "at most" rules in the main axis. Calculate the remaining space when
+    // constraint by the min size defined for the main axis.
     if (measureModeMainDim == CSSMeasureModeAtMost) {
-      remainingFreeSpace = 0;
+      if (!CSSValueIsUndefined(node->style.minDimensions[dim[mainAxis]]) && node->style.minDimensions[dim[mainAxis]] >= 0) {
+        remainingFreeSpace = fmaxf(0, node->style.minDimensions[dim[mainAxis]] - (availableInnerMainDim - remainingFreeSpace));
+      } else {
+        remainingFreeSpace = 0;
+      }
     }
 
     switch (justifyContent) {
diff --git a/tests/CSSLayoutMinMaxDimensionTest.cpp b/tests/CSSLayoutMinMaxDimensionTest.cpp
index 4bcb4911..72501e43 100644
--- a/tests/CSSLayoutMinMaxDimensionTest.cpp
+++ b/tests/CSSLayoutMinMaxDimensionTest.cpp
@@ -27,6 +27,14 @@
   <div style="flex-grow: 1; min-width: 60px;"></div>
   <div style="flex-grow: 1;"></div>
 </div>
+
+<div id="justify_content_min_max" style="max-height: 200px; min-height: 100px; width: 100px; justify-content: center;">
+  <div style="width: 60px; height: 60px;"></div>
+</div>
+
+<div id="align_items_min_max" style="max-width: 200px; min-width: 100px; height: 100px; align-items: center;">
+  <div style="width: 60px; height: 60px;"></div>
+</div>
  *
  */
 
@@ -206,3 +214,79 @@ TEST(CSSLayoutTest, min_width) {
 
   CSSNodeFreeRecursive(root);
 }
+
+TEST(CSSLayoutTest, justify_content_min_max) {
+  const CSSNodeRef root = CSSNodeNew();
+  CSSNodeStyleSetJustifyContent(root, CSSJustifyCenter);
+  CSSNodeStyleSetWidth(root, 100);
+  CSSNodeStyleSetMinHeight(root, 100);
+  CSSNodeStyleSetMaxHeight(root, 200);
+
+  const CSSNodeRef root_child0 = CSSNodeNew();
+  CSSNodeStyleSetWidth(root_child0, 60);
+  CSSNodeStyleSetHeight(root_child0, 60);
+  CSSNodeInsertChild(root, root_child0, 0);
+  CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionLTR);
+
+  ASSERT_EQ(0, CSSNodeLayoutGetLeft(root));
+  ASSERT_EQ(0, CSSNodeLayoutGetTop(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetWidth(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetHeight(root));
+
+  ASSERT_EQ(0, CSSNodeLayoutGetLeft(root_child0));
+  ASSERT_EQ(20, CSSNodeLayoutGetTop(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetWidth(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetHeight(root_child0));
+
+  CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionRTL);
+
+  ASSERT_EQ(0, CSSNodeLayoutGetLeft(root));
+  ASSERT_EQ(0, CSSNodeLayoutGetTop(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetWidth(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetHeight(root));
+
+  ASSERT_EQ(40, CSSNodeLayoutGetLeft(root_child0));
+  ASSERT_EQ(20, CSSNodeLayoutGetTop(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetWidth(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetHeight(root_child0));
+
+  CSSNodeFreeRecursive(root);
+}
+
+TEST(CSSLayoutTest, align_items_min_max) {
+  const CSSNodeRef root = CSSNodeNew();
+  CSSNodeStyleSetAlignItems(root, CSSAlignCenter);
+  CSSNodeStyleSetMinWidth(root, 100);
+  CSSNodeStyleSetMaxWidth(root, 200);
+  CSSNodeStyleSetHeight(root, 100);
+
+  const CSSNodeRef root_child0 = CSSNodeNew();
+  CSSNodeStyleSetWidth(root_child0, 60);
+  CSSNodeStyleSetHeight(root_child0, 60);
+  CSSNodeInsertChild(root, root_child0, 0);
+  CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionLTR);
+
+  ASSERT_EQ(0, CSSNodeLayoutGetLeft(root));
+  ASSERT_EQ(0, CSSNodeLayoutGetTop(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetWidth(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetHeight(root));
+
+  ASSERT_EQ(20, CSSNodeLayoutGetLeft(root_child0));
+  ASSERT_EQ(0, CSSNodeLayoutGetTop(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetWidth(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetHeight(root_child0));
+
+  CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionRTL);
+
+  ASSERT_EQ(0, CSSNodeLayoutGetLeft(root));
+  ASSERT_EQ(0, CSSNodeLayoutGetTop(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetWidth(root));
+  ASSERT_EQ(100, CSSNodeLayoutGetHeight(root));
+
+  ASSERT_EQ(20, CSSNodeLayoutGetLeft(root_child0));
+  ASSERT_EQ(0, CSSNodeLayoutGetTop(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetWidth(root_child0));
+  ASSERT_EQ(60, CSSNodeLayoutGetHeight(root_child0));
+
+  CSSNodeFreeRecursive(root);
+}