Start of display management for mus

ui/gfx/display_finder.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 "ui/gfx/display_finder.h"
+
+#include <limits>
+
+#include "base/logging.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/geometry/point.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace gfx {
+
+const Display* FindDisplayNearestPoint(const std::vector<Display>& displays,
+                                       const Point& point) {
+  DCHECK(!displays.empty());
+  int min_distance = std::numeric_limits<int>::max();
+  const Display* nearest_display = nullptr;
+  for (const auto& display : displays) {
+    const int distance = display.bounds().ManhattanDistanceToPoint(point);
+    if (distance < min_distance) {
+      min_distance = distance;
+      nearest_display = &display;
+    }
+  }
+  // There should always be at least one display that is less than INT_MAX away.
+  DCHECK(nearest_display);
+  return nearest_display;
+}
+
+const Display* FindDisplayWithBiggestIntersection(
+    const std::vector<Display>& displays,
+    const Rect& rect) {
+  DCHECK(!displays.empty());
+  int max_area = 0;
+  const Display* matching = nullptr;
+  for (const auto& display : displays) {
+    const Rect intersect = IntersectRects(display.bounds(), rect);
+    const int area = intersect.width() * intersect.height();
+    if (area > max_area) {
+      max_area = area;
+      matching = &display;
+    }
+  }
+  return matching;
+}
+
+}  // namespace gfx