Add Flex to views::BoxLayout.

ui/views/layout/box_layout_unittest.cc

Index: ui/views/layout/box_layout_unittest.cc
diff --git a/ui/views/layout/box_layout_unittest.cc b/ui/views/layout/box_layout_unittest.cc
index 5f58b15c8fd173afb7638ed94db7aab133a22ba0..6ab0c520b3330298073da1bf229b1768f7898a91 100644
--- a/ui/views/layout/box_layout_unittest.cc
+++ b/ui/views/layout/box_layout_unittest.cc
@@ -142,22 +142,6 @@ TEST_F(BoxLayoutTest, InvisibleChild) {
   EXPECT_EQ(gfx::Rect(10, 10, 10, 10), v2->bounds());
 }
 
-TEST_F(BoxLayoutTest, MainAxisAlignmentFill) {
-  layout_.reset(new BoxLayout(BoxLayout::kHorizontal, 10, 10, 10));
-  layout_->set_main_axis_alignment(BoxLayout::MAIN_AXIS_ALIGNMENT_FILL);
-
-  View* v1 = new StaticSizedView(gfx::Size(20, 20));
-  host_->AddChildView(v1);
-  View* v2 = new StaticSizedView(gfx::Size(10, 10));
-  host_->AddChildView(v2);
-  EXPECT_EQ(gfx::Size(60, 40), layout_->GetPreferredSize(host_.get()));
-
-  host_->SetBounds(0, 0, 100, 40);
-  layout_->Layout(host_.get());
-  EXPECT_EQ(gfx::Rect(10, 10, 40, 20).ToString(), v1->bounds().ToString());
-  EXPECT_EQ(gfx::Rect(60, 10, 30, 20).ToString(), v2->bounds().ToString());
-}
-
 TEST_F(BoxLayoutTest, UseHeightForWidth) {
   layout_.reset(new BoxLayout(BoxLayout::kVertical, 0, 0, 0));
   View* v1 = new StaticSizedView(gfx::Size(20, 10));
@@ -361,4 +345,200 @@ TEST_F(BoxLayoutTest, CrossAxisAlignmentVertical) {
   EXPECT_EQ(gfx::Rect(40, 40, 10, 10).ToString(), v2->bounds().ToString());
 }
 
+TEST_F(BoxLayoutTest, FlexAll) {
+  layout_.reset(new BoxLayout(BoxLayout::kHorizontal, 10, 10, 10));
+  layout_->set_default_flex(1);
+
+  View* v1 = new StaticSizedView(gfx::Size(20, 20));
+  host_->AddChildView(v1);
+  View* v2 = new StaticSizedView(gfx::Size(10, 10));
+  host_->AddChildView(v2);
+  EXPECT_EQ(gfx::Size(60, 40), layout_->GetPreferredSize(host_.get()));
+
+  host_->SetBounds(0, 0, 100, 40);
+  layout_->Layout(host_.get());
+  EXPECT_EQ(gfx::Rect(10, 10, 40, 20).ToString(), v1->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(60, 10, 30, 20).ToString(), v2->bounds().ToString());
+}
+
+TEST_F(BoxLayoutTest, FlexGrowVertical) {
+  layout_.reset(new BoxLayout(BoxLayout::kVertical, 10, 10, 10));
+
+  View* v1 = new StaticSizedView(gfx::Size(20, 20));
+  host_->AddChildView(v1);
+  View* v2 = new StaticSizedView(gfx::Size(10, 10));
+  host_->AddChildView(v2);
+  View* v3 = new StaticSizedView(gfx::Size(30, 30));
+  host_->AddChildView(v3);
+
+  host_->SetBounds(0, 0, 50, 130);
+
+  // Views don't fill the available space by default.
+  layout_->Layout(host_.get());
+  EXPECT_EQ(gfx::Rect(10, 10, 30, 20).ToString(), v1->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(10, 40, 30, 10).ToString(), v2->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(10, 60, 30, 30).ToString(), v3->bounds().ToString());
+
+  std::vector<BoxLayout::MainAxisAlignment> main_alignments;
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_START);
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_CENTER);
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_END);
+
+  for (size_t i = 0; i < main_alignments.size(); ++i) {
+    // Set the first view to consume all free space.
+    layout_->SetFlexForViewAt(0, 1);
+    layout_->ClearFlexForViewAt(1);
+    layout_->ClearFlexForViewAt(2);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(10, 10, 30, 50).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(10, 70, 30, 10).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(10, 90, 30, 30).ToString(), v3->bounds().ToString());
+
+    // Set the third view to take 2/3s of the free space and leave the first
+    // view
+    // with 1/3.
+    layout_->SetFlexForViewAt(2, 2);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(10, 10, 30, 30).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(10, 50, 30, 10).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(10, 70, 30, 50).ToString(), v3->bounds().ToString());
+
+    // Clear the previously set flex values and set the second view to take all
+    // the free space.
+    layout_->ClearFlexForViewAt(0);
+    layout_->ClearFlexForViewAt(2);
+    layout_->SetFlexForViewAt(1, 1);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(10, 10, 30, 20).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(10, 40, 30, 40).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(10, 90, 30, 30).ToString(), v3->bounds().ToString());
+  }
+}
+
+TEST_F(BoxLayoutTest, FlexGrowHorizontalWithRemainder) {
+  layout_.reset(new BoxLayout(BoxLayout::kHorizontal, 0, 0, 0));
+  layout_->set_default_flex(1);
+  std::vector<View*> views;
+  for (int i = 0; i < 5; ++i) {
+    View* view = new StaticSizedView(gfx::Size(10, 10));
+    views.push_back(view);
+    host_->AddChildView(view);
+  }
+
+  EXPECT_EQ(gfx::Size(50, 10), layout_->GetPreferredSize(host_.get()));
+
+  host_->SetBounds(0, 0, 52, 10);
+  layout_->Layout(host_.get());
+  // The 2nd and 4th views should have an extra pixel as they correspond to 20.8
+  // and 41.6 which round up.
+  EXPECT_EQ(gfx::Rect(0, 0, 10, 10).ToString(), views[0]->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(10, 0, 11, 10).ToString(), views[1]->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(21, 0, 10, 10).ToString(), views[2]->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(31, 0, 11, 10).ToString(), views[3]->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(42, 0, 10, 10).ToString(), views[4]->bounds().ToString());
+}
+
+TEST_F(BoxLayoutTest, FlexShrinkHorizontal) {
+  layout_.reset(new BoxLayout(BoxLayout::kHorizontal, 10, 10, 10));
+
+  View* v1 = new StaticSizedView(gfx::Size(20, 20));
+  host_->AddChildView(v1);
+  View* v2 = new StaticSizedView(gfx::Size(10, 10));
+  host_->AddChildView(v2);
+  View* v3 = new StaticSizedView(gfx::Size(30, 30));
+  host_->AddChildView(v3);
+
+  host_->SetBounds(0, 0, 85, 50);
+
+  // Truncate width by default.
+  layout_->Layout(host_.get());
+  EXPECT_EQ(gfx::Rect(10, 10, 20, 30).ToString(), v1->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(40, 10, 10, 30).ToString(), v2->bounds().ToString());
+  EXPECT_EQ(gfx::Rect(60, 10, 15, 30).ToString(), v3->bounds().ToString());
+
+  std::vector<BoxLayout::MainAxisAlignment> main_alignments;
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_START);
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_CENTER);
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_END);
+
+  for (size_t i = 0; i < main_alignments.size(); ++i) {
+    // Set the first view to shrink as much as necessary.
+    layout_->SetFlexForViewAt(0, 1);
+    layout_->ClearFlexForViewAt(1);
+    layout_->ClearFlexForViewAt(2);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(10, 10, 5, 30).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(25, 10, 10, 30).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(45, 10, 30, 30).ToString(), v3->bounds().ToString());
+
+    // Set the third view to shrink 2/3s of the free space and leave the first
+    // view with 1/3.
+    layout_->SetFlexForViewAt(2, 2);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(10, 10, 15, 30).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(35, 10, 10, 30).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(55, 10, 20, 30).ToString(), v3->bounds().ToString());
+
+    // Clear the previously set flex values and set the second view to take all
+    // the free space with MAIN_AXIS_ALIGNMENT_END set. This causes the second
+    // view to shrink to zero and the third view still doesn't fit so it
+    // overflows.
+    layout_->ClearFlexForViewAt(0);
+    layout_->ClearFlexForViewAt(2);
+    layout_->SetFlexForViewAt(1, 2);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(10, 10, 20, 30).ToString(), v1->bounds().ToString());
+    // Conceptually this view is at 10, 40, 0, 0.
+    EXPECT_EQ(gfx::Rect(0, 0, 0, 0).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(50, 10, 25, 30).ToString(), v3->bounds().ToString());
+  }
+}
+
+TEST_F(BoxLayoutTest, FlexShrinkVerticalWithRemainder) {
+  layout_.reset(new BoxLayout(BoxLayout::kVertical, 0, 0, 0));
+  View* v1 = new StaticSizedView(gfx::Size(20, 10));
+  host_->AddChildView(v1);
+  View* v2 = new StaticSizedView(gfx::Size(20, 20));
+  host_->AddChildView(v2);
+  View* v3 = new StaticSizedView(gfx::Size(20, 10));
+  host_->AddChildView(v3);
+  host_->SetBounds(0, 0, 20, 20);
+
+  std::vector<BoxLayout::MainAxisAlignment> main_alignments;
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_START);
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_CENTER);
+  main_alignments.push_back(BoxLayout::MAIN_AXIS_ALIGNMENT_END);
+
+  for (size_t i = 0; i < main_alignments.size(); ++i) {
+    // The first view shrinks by 1/3 of the excess, the second view shrinks by
+    // 2/3 of the excess and the third view should maintain its preferred size.
+    layout_->SetFlexForViewAt(0, 1);
+    layout_->SetFlexForViewAt(1, 2);
+    layout_->ClearFlexForViewAt(2);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(0, 0, 20, 3).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(0, 3, 20, 7).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(0, 10, 20, 10).ToString(), v3->bounds().ToString());
+
+    // The second view shrinks to 2/3 of the excess, the third view shrinks to
+    // 1/3 of the excess and the first view should maintain its preferred size.
+    layout_->ClearFlexForViewAt(0);
+    layout_->SetFlexForViewAt(1, 2);
+    layout_->SetFlexForViewAt(2, 1);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(0, 0, 20, 10).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(0, 10, 20, 7).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(0, 17, 20, 3).ToString(), v3->bounds().ToString());
+
+    // Each view shrinks equally to fit within the available space.
+    layout_->SetFlexForViewAt(0, 1);
+    layout_->SetFlexForViewAt(1, 1);
+    layout_->SetFlexForViewAt(2, 1);
+    layout_->Layout(host_.get());
+    EXPECT_EQ(gfx::Rect(0, 0, 20, 3).ToString(), v1->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(0, 3, 20, 14).ToString(), v2->bounds().ToString());
+    EXPECT_EQ(gfx::Rect(0, 17, 20, 3).ToString(), v3->bounds().ToString());
+  }
+}
+
 }  // namespace views