Refactors std::vector<Display> out of ScreenMus

ui/views/mus/display_list_unittest.cc

Index: ui/views/mus/display_list_unittest.cc
diff --git a/ui/views/mus/display_list_unittest.cc b/ui/views/mus/display_list_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..93cdc81e608b0e8d46f78eea2be6cd9a74f01f96
--- /dev/null
+++ b/ui/views/mus/display_list_unittest.cc
@@ -0,0 +1,113 @@
+// 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 "ui/views/mus/display_list.h"
+
+#include <string>
+#include <vector>
+
+#include "base/strings/string_number_conversions.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/display/display.h"
+#include "ui/display/display_observer.h"
+
+using display::Display;
+
+namespace views {
+namespace {
+
+class DisplayObserverImpl : public display::DisplayObserver {
+ public:
+  DisplayObserverImpl() {}
+  ~DisplayObserverImpl() override {}
+
+  std::string GetAndClearChanges() {
+    std::string changes;
+    std::swap(changes, changes_);
+    return changes;
+  }
+
+ private:
+  static void AddPartChange(uint32_t changed,
+                            uint32_t part,
+                            const std::string& description,
+                            std::string* changed_string) {
+    if ((changed & part) != part)
+      return;
+
+    *changed_string += " ";
+    *changed_string += description;
+  }
+
+  void AddChange(const std::string& change) {
+    if (!changes_.empty())
+      changes_ += "\n";
+    changes_ += change;
+  }
+
+  void OnDisplayAdded(const Display& new_display) override {
+    AddChange("Added id=" + base::Int64ToString(new_display.id()));
+  }
+  void OnDisplayRemoved(const Display& old_display) override {
+    AddChange("Removed id=" + base::Int64ToString(old_display.id()));
+  }
+  void OnDisplayMetricsChanged(const Display& display,
+                               uint32_t changed_metrics) override {
+    std::string parts;
+    AddPartChange(changed_metrics, DISPLAY_METRIC_BOUNDS, "bounds", &parts);
+    AddPartChange(changed_metrics, DISPLAY_METRIC_WORK_AREA, "work_area",
+                  &parts);
+    AddPartChange(changed_metrics, DISPLAY_METRIC_DEVICE_SCALE_FACTOR,
+                  "scale_factor", &parts);
+    AddPartChange(changed_metrics, DISPLAY_METRIC_ROTATION, "rotation", &parts);
+    AddPartChange(changed_metrics, DISPLAY_METRIC_PRIMARY, "primary", &parts);
+
+    AddChange("Changed id=" + base::Int64ToString(display.id()) + parts);
+  }
+
+  std::string changes_;
+
+  DISALLOW_COPY_AND_ASSIGN(DisplayObserverImpl);
+};
+
+TEST(DisplayListTest, AddUpdateRemove) {
+  DisplayList display_list;
+  DisplayObserverImpl observer;
+  display_list.AddObserver(&observer);
+  display_list.AddDisplay(display::Display(2, gfx::Rect(0, 0, 801, 802)),
+                          DisplayList::Type::PRIMARY);
+  EXPECT_EQ("Added id=2", observer.GetAndClearChanges());
+
+  // Update the bounds.
+  {
+    display::Display updated_display = *(display_list.displays().begin());
+    updated_display.set_bounds(gfx::Rect(0, 0, 803, 802));
+    display_list.UpdateDisplay(updated_display, DisplayList::Type::PRIMARY);
+    EXPECT_EQ("Changed id=2 bounds", observer.GetAndClearChanges());
+  }
+
+  // Add another.
+  display_list.AddDisplay(display::Display(3, gfx::Rect(0, 0, 809, 802)),
+                          DisplayList::Type::NOT_PRIMARY);
+  EXPECT_EQ("Added id=3", observer.GetAndClearChanges());
+  ASSERT_EQ(2u, display_list.displays().size());
+  EXPECT_EQ(2, display_list.displays()[0].id());
+  EXPECT_EQ(3, display_list.displays()[1].id());
+  EXPECT_EQ(2, display_list.GetPrimaryDisplayIterator()->id());
+
+  // Make the second the primary.
+  display_list.UpdateDisplay(display_list.displays()[1],
+                             DisplayList::Type::PRIMARY);
+  EXPECT_EQ("Changed id=3 primary", observer.GetAndClearChanges());
+  EXPECT_EQ(3, display_list.GetPrimaryDisplayIterator()->id());
+
+  // Delete the first.
+  display_list.RemoveDisplay(2);
+  ASSERT_EQ(1u, display_list.displays().size());
+  EXPECT_EQ("Removed id=2", observer.GetAndClearChanges());
+  EXPECT_EQ(3, display_list.GetPrimaryDisplayIterator()->id());
+}
+
+}  // namespace
+}  // namespace views