[layoutng] Add a function to compute the min- and max-content contribution

third_party/WebKit/Source/core/layout/ng/ng_length_utils_test.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/ng/ng_length_utils.h"
 
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/layout/ng/ng_fragment_builder.h"
@@ skipping 104 matching lines @@
   EXPECT_EQ(LayoutUnit(0), ResolveBlockLength(Length(Auto)));
   EXPECT_EQ(LayoutUnit(300), ResolveBlockLength(Length(FillAvailable)));
 
   EXPECT_EQ(LayoutUnit(0),
             ResolveBlockLength(Length(Auto), LengthResolveType::kContentSize));
   EXPECT_EQ(LayoutUnit(300),
             ResolveBlockLength(Length(FillAvailable),
                                LengthResolveType::kContentSize));
 }
 
+TEST_F(NGLengthUtilsTest, testComputeContentContribution) {
+  MinAndMaxContentSizes sizes;
+  sizes.min_content = LayoutUnit(30);
+  sizes.max_content = LayoutUnit(40);
+
+  MinAndMaxContentSizes expected{LayoutUnit(), LayoutUnit()};
+  style_->setLogicalWidth(Length(30, Percent));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  style_->setLogicalWidth(Length(FillAvailable));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = MinAndMaxContentSizes{LayoutUnit(150), LayoutUnit(150)};
+  style_->setLogicalWidth(Length(150, Fixed));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = sizes;
+  style_->setLogicalWidth(Length(Auto));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = MinAndMaxContentSizes{LayoutUnit(430), LayoutUnit(440)};
+  style_->setPaddingLeft(Length(400, Fixed));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = MinAndMaxContentSizes{LayoutUnit(100), LayoutUnit(100)};
+  style_->setPaddingLeft(Length(0, Fixed));
+  style_->setLogicalWidth(Length(CalculationValue::create(
+      PixelsAndPercent(100, -10), ValueRangeNonNegative)));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = MinAndMaxContentSizes{LayoutUnit(30), LayoutUnit(35)};
+  style_->setLogicalWidth(Length(Auto));
+  style_->setMaxWidth(Length(35, Fixed));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = MinAndMaxContentSizes{LayoutUnit(80), LayoutUnit(80)};
+  style_->setLogicalWidth(Length(50, Fixed));
+  style_->setMinWidth(Length(80, Fixed));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = MinAndMaxContentSizes{LayoutUnit(150), LayoutUnit(150)};
+  style_ = ComputedStyle::create();
+  style_->setLogicalWidth(Length(100, Fixed));
+  style_->setPaddingLeft(Length(50, Fixed));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected = MinAndMaxContentSizes{LayoutUnit(100), LayoutUnit(100)};
+  style_->setBoxSizing(BoxSizingBorderBox);
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  // Content size should never be below zero, even with box-sizing: border-box
+  // and a large padding...
+  expected = MinAndMaxContentSizes{LayoutUnit(400), LayoutUnit(400)};
+  style_->setPaddingLeft(Length(400, Fixed));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+
+  expected.min_content = expected.max_content =
+      sizes.min_content + LayoutUnit(400);
+  style_->setLogicalWidth(Length(MinContent));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+  style_->setLogicalWidth(Length(100, Fixed));
+  style_->setMaxWidth(Length(MaxContent));
+  // Due to padding and box-sizing, width computes to 400px and max-width to
+  // 440px, so the result is 400.
+  expected = MinAndMaxContentSizes{LayoutUnit(400), LayoutUnit(400)};
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+  expected = MinAndMaxContentSizes{LayoutUnit(40), LayoutUnit(40)};
+  style_->setPaddingLeft(Length(0, Fixed));
+  EXPECT_EQ(expected, ComputeMinAndMaxContentContribution(*style_, sizes));
+}
+
 TEST_F(NGLengthUtilsTest, testComputeInlineSizeForFragment) {
   MinAndMaxContentSizes sizes;
   sizes.min_content = LayoutUnit(30);
   sizes.max_content = LayoutUnit(40);
 
   style_->setLogicalWidth(Length(30, Percent));
   EXPECT_EQ(LayoutUnit(60), ComputeInlineSizeForFragment());
 
   style_->setLogicalWidth(Length(150, Fixed));
   EXPECT_EQ(LayoutUnit(150), ComputeInlineSizeForFragment());
@@ skipping 287 matching lines @@
   EXPECT_EQ(125, GetUsedColumnWidth(4, 100, 10, 530));
   EXPECT_EQ(4, GetUsedColumnCount(4, 100, 10, 530));
   EXPECT_EQ(100, GetUsedColumnWidth(6, 100, 10, 540));
   EXPECT_EQ(5, GetUsedColumnCount(6, 100, 10, 540));
   EXPECT_EQ(100, GetUsedColumnWidth(0, 100, 10, 540));
   EXPECT_EQ(5, GetUsedColumnCount(0, 100, 10, 540));
 }
 
 }  // namespace
 }  // namespace blink