Add display task to trigger display configuration

ui/display/chromeos/display_util.cc

Index: ui/display/chromeos/display_util.cc
diff --git a/ui/display/chromeos/display_util.cc b/ui/display/chromeos/display_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7e2fcf4e7a3729e5c6d67e1984edbbff91c35f5a
--- /dev/null
+++ b/ui/display/chromeos/display_util.cc
@@ -0,0 +1,76 @@
+// Copyright 2014 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/display/chromeos/display_util.h"
+
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/stringprintf.h"
+#include "ui/display/types/display_snapshot.h"
+
+namespace ui {
+
+// Returns a string describing |state|.

[Daniel Erat, 2014/12/11 23:34:07]

nit: these functions are already commented in the header; delete the comments in
this file

+std::string DisplayPowerStateToString(chromeos::DisplayPowerState state) {
+  switch (state) {
+    case chromeos::DISPLAY_POWER_ALL_ON:
+      return "ALL_ON";
+    case chromeos::DISPLAY_POWER_ALL_OFF:
+      return "ALL_OFF";
+    case chromeos::DISPLAY_POWER_INTERNAL_OFF_EXTERNAL_ON:
+      return "INTERNAL_OFF_EXTERNAL_ON";
+    case chromeos::DISPLAY_POWER_INTERNAL_ON_EXTERNAL_OFF:
+      return "INTERNAL_ON_EXTERNAL_OFF";
+    default:
+      return "unknown (" + base::IntToString(state) + ")";
+  }
+}
+
+// Returns a string describing |state|.
+std::string DisplayStateToString(MultipleDisplayState state) {
+  switch (state) {
+    case MULTIPLE_DISPLAY_STATE_INVALID:
+      return "INVALID";
+    case MULTIPLE_DISPLAY_STATE_HEADLESS:
+      return "HEADLESS";
+    case MULTIPLE_DISPLAY_STATE_SINGLE:
+      return "SINGLE";
+    case MULTIPLE_DISPLAY_STATE_DUAL_MIRROR:
+      return "DUAL_MIRROR";
+    case MULTIPLE_DISPLAY_STATE_DUAL_EXTENDED:
+      return "DUAL_EXTENDED";
+    case MULTIPLE_DISPLAY_STATE_MULTI_EXTENDED:
+      return "MULTI_EXTENDED";
+  }
+  NOTREACHED() << "Unknown state " << state;
+  return "INVALID";
+}
+
+// Returns the number of displays in |displays| that should be turned on, per
+// |state|.  If |display_power| is non-NULL, it is updated to contain the
+// on/off state of each corresponding entry in |displays|.
+int GetDisplayPower(
+    const std::vector<DisplayConfigurator::DisplayState>& display_states,
+    chromeos::DisplayPowerState state,
+    std::vector<bool>* display_power) {
+  int num_on_displays = 0;
+  if (display_power)
+    display_power->resize(display_states.size());
+
+  for (size_t i = 0; i < display_states.size(); ++i) {
+    bool internal =
+        display_states[i].display->type() == DISPLAY_CONNECTION_TYPE_INTERNAL;
+    bool on =
+        state == chromeos::DISPLAY_POWER_ALL_ON ||
+        (state == chromeos::DISPLAY_POWER_INTERNAL_OFF_EXTERNAL_ON &&
+         !internal) ||
+        (state == chromeos::DISPLAY_POWER_INTERNAL_ON_EXTERNAL_OFF && internal);
+    if (display_power)
+      (*display_power)[i] = on;
+    if (on)
+      num_on_displays++;
+  }
+  return num_on_displays;
+}
+
+}  // namespace ui