Add countdown when session time is limited

ash/system/session_length_limit/tray_session_length_limit.cc

+// Copyright (c) 2012 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 "ash/system/session_length_limit/tray_session_length_limit.h"
+
+#include <cmath>
+
+#include "ash/shelf_types.h"
+#include "ash/shell.h"
+#include "ash/system/tray/system_tray.h"
+#include "ash/system/tray/system_tray_delegate.h"
+#include "ash/system/tray/system_tray_notifier.h"
+#include "ash/system/tray/tray_constants.h"
+#include "ash/system/tray/tray_views.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/string16.h"
+#include "base/string_number_conversions.h"
+#include "base/time.h"
+#include "base/utf_string_conversions.h"
+#include "grit/ash_strings.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/font.h"
+#include "ui/gfx/text_constants.h"
+#include "ui/views/border.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/layout/box_layout.h"
+#include "ui/views/layout/grid_layout.h"
+#include "ui/views/view.h"
+
+namespace ash {
+namespace internal {
+
+namespace tray {
+
+namespace {
+
+// Warning threshold for the remaining sessiont time.
+const int kRemainingTimeWarningThresholdInSeconds = 5 * 60;  // 5 minutes.
+// Color in which the remaining session time is normally shown.
+const SkColor kRemainingTimeColor = SK_ColorWHITE;
+// Color in which the remaining session time is shown when it falls below the
+// warning threshold.
+const SkColor kRemainingTimeWarningColor = SK_ColorRED;
+
+views::Label* CreateAndSetupLabel() {
+  views::Label* label = new views::Label;
+  label->SetHorizontalAlignment(gfx::ALIGN_LEFT);
+  label->set_owned_by_client();

[stevenjb, 2012/12/14 18:02:21]

We really shouldn't be using set_owned_by_client under normal circumstances, see
comment below.

[bartfab (slow), 2012/12/14 20:11:09]

Done.

+  SetupLabelForTray(label);
+  gfx::Font font = label->font();
+  label->SetFont(font.DeriveFont(0, font.GetStyle() & ~gfx::Font::BOLD));
+  return label;
+}
+
+string16 IntToTwoDigitString(int value) {
+  DCHECK_GE(value, 0);
+  DCHECK_LE(value, 99);
+  if (value < 10)
+    return ASCIIToUTF16("0") + base::IntToString16(value);
+  return base::IntToString16(value);
+}
+
+}  // namespace
+
+class RemainingSessionTimeTrayView : public views::View {
+ public:
+  RemainingSessionTimeTrayView(bool is_session_length_limited,
+                               const base::TimeDelta& remaining,
+                               bool horizontal_layout);
+  virtual ~RemainingSessionTimeTrayView();
+
+  void OnSessionLengthUnlimited();
+  void OnRemainingSessionTimeChanged(const base::TimeDelta& remaining);

[stevenjb, 2012/12/14 18:02:21]

The names of these imply that they are callbacks, when really these are setters
called by the observer. We should rename them to Set* instead of On*

[bartfab (slow), 2012/12/14 20:11:09]

Done.

+
+  void UpdateClockLayout(bool horizontal_layout);
+
+ private:
+  void SetBorder(bool horizontal_layout);
+  void SetupLabels();
+
+  scoped_ptr<views::Label> label_;
+  scoped_ptr<views::Label> label_hours_left_;
+  scoped_ptr<views::Label> label_hours_right_;
+  scoped_ptr<views::Label> label_minutes_left_;
+  scoped_ptr<views::Label> label_minutes_right_;
+  scoped_ptr<views::Label> label_seconds_left_;
+  scoped_ptr<views::Label> label_seconds_right_;

[stevenjb, 2012/12/14 18:02:21]

I see that this pattern is copied from TimeView, but I'm not a fan. I think this
would be much simpler if the views were just owned by the view hierarchy and the
entire class rebuilt when the structure changes. Unowned pointers can be used
instead for the views that need to be modified. That said, I won't push back on
this since we already use the pattern. It might be worthwhile in the future to
create a time view as a helper class that both of this and TimeView could use.

Also, label_ should have a better name (maybe label_full_ or label_all_) and a
comment above it and above the others explaining that one is for horizontal
layout and the others for vertical.

[bartfab (slow), 2012/12/14 20:11:09]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(RemainingSessionTimeTrayView);
+};
+
+RemainingSessionTimeTrayView::RemainingSessionTimeTrayView(
+    bool is_session_length_limited,
+    const base::TimeDelta& remaining,
+    bool horizontal_layout) {

[stevenjb, 2012/12/14 18:02:21]

Use ShelfAlignment instead of a bool for layout and in UpdateClockLayout() and
SetBorder(); enums are generally better than bools, especially as function
parameters.

[bartfab (slow), 2012/12/14 20:11:09]

Done.

+  SetupLabels();
+  if (is_session_length_limited)
+    OnRemainingSessionTimeChanged(remaining);
+  else
+    OnSessionLengthUnlimited();
+  UpdateClockLayout(horizontal_layout);
+}
+
+RemainingSessionTimeTrayView::~RemainingSessionTimeTrayView() {
+}
+
+void RemainingSessionTimeTrayView::OnSessionLengthUnlimited() {
+  SetVisible(false);
+}
+
+void RemainingSessionTimeTrayView::OnRemainingSessionTimeChanged(
+    const base::TimeDelta& remaining) {
+  int seconds = round(remaining.InSecondsF());
+  DCHECK_LE(seconds, 24 * 60 * 60);  // 24 hours.
+  int minutes = seconds / 60;
+  seconds %= 60;
+  int hours = minutes / 60;
+  minutes %= 60;
+
+  string16 hours_str = IntToTwoDigitString(hours);
+  string16 minutes_str = IntToTwoDigitString(minutes);
+  string16 seconds_str = IntToTwoDigitString(seconds);
+
+  label_->SetText(l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_REMAINING_SESSION_TIME,
+      hours_str, minutes_str, seconds_str));
+  label_hours_left_->SetText(hours_str.substr(0, 1));
+  label_hours_right_->SetText(hours_str.substr(1, 1));
+  label_minutes_left_->SetText(minutes_str.substr(0, 1));
+  label_minutes_right_->SetText(minutes_str.substr(1, 1));
+  label_seconds_left_->SetText(seconds_str.substr(0, 1));
+  label_seconds_right_->SetText(seconds_str.substr(1, 1));
+
+  const SkColor color = seconds < kRemainingTimeWarningThresholdInSeconds ?
+      kRemainingTimeWarningColor : kRemainingTimeColor;
+  label_->SetEnabledColor(color);
+  label_hours_left_->SetEnabledColor(color);
+  label_hours_right_->SetEnabledColor(color);
+  label_minutes_left_->SetEnabledColor(color);
+  label_minutes_right_->SetEnabledColor(color);
+  label_seconds_left_->SetEnabledColor(color);
+  label_seconds_right_->SetEnabledColor(color);
+
+  Layout();
+  SetVisible(true);
+}
+
+void RemainingSessionTimeTrayView::UpdateClockLayout(bool horizontal_layout) {
+  SetBorder(horizontal_layout);
+  if (horizontal_layout) {
+    RemoveChildView(label_hours_left_.get());
+    RemoveChildView(label_hours_right_.get());
+    RemoveChildView(label_minutes_left_.get());
+    RemoveChildView(label_minutes_right_.get());
+    RemoveChildView(label_seconds_left_.get());
+    RemoveChildView(label_seconds_right_.get());
+    SetLayoutManager(
+        new views::BoxLayout(views::BoxLayout::kHorizontal, 0, 0, 0));
+    AddChildView(label_.get());
+  } else {
+    RemoveChildView(label_.get());
+    views::GridLayout* layout = new views::GridLayout(this);
+    SetLayoutManager(layout);
+    views::ColumnSet* columns = layout->AddColumnSet(0);
+    columns->AddPaddingColumn(0, 6);
+    columns->AddColumn(views::GridLayout::CENTER, views::GridLayout::CENTER,
+                       0, views::GridLayout::USE_PREF, 0, 0);
+    columns->AddColumn(views::GridLayout::CENTER, views::GridLayout::CENTER,
+                       0, views::GridLayout::USE_PREF, 0, 0);
+    layout->AddPaddingRow(0, kTrayLabelItemVerticalPaddingVeriticalAlignment);
+    layout->StartRow(0, 0);
+    layout->AddView(label_hours_left_.get());
+    layout->AddView(label_hours_right_.get());
+    layout->StartRow(0, 0);
+    layout->AddView(label_minutes_left_.get());
+    layout->AddView(label_minutes_right_.get());
+    layout->StartRow(0, 0);
+    layout->AddView(label_seconds_left_.get());
+    layout->AddView(label_seconds_right_.get());
+    layout->AddPaddingRow(0, kTrayLabelItemVerticalPaddingVeriticalAlignment);
+  }
+  Layout();
+}
+
+void RemainingSessionTimeTrayView::SetBorder(bool horizontal_layout) {
+  if (horizontal_layout) {
+    set_border(views::Border::CreateEmptyBorder(
+        0, kTrayLabelItemHorizontalPaddingBottomAlignment,
+        0, kTrayLabelItemHorizontalPaddingBottomAlignment));
+  } else {
+    set_border(NULL);
+  }
+}
+
+void RemainingSessionTimeTrayView::SetupLabels() {
+  label_.reset(CreateAndSetupLabel());
+  label_hours_left_.reset(CreateAndSetupLabel());
+  label_hours_right_.reset(CreateAndSetupLabel());
+  label_minutes_left_.reset(CreateAndSetupLabel());
+  label_minutes_right_.reset(CreateAndSetupLabel());
+  label_seconds_left_.reset(CreateAndSetupLabel());
+  label_seconds_right_.reset(CreateAndSetupLabel());
+}
+
+}  // namespace tray
+
+TraySessionLengthLimit::TraySessionLengthLimit(SystemTray* system_tray)
+    : SystemTrayItem(system_tray),
+      tray_view_(NULL) {
+  Shell::GetInstance()->system_tray_notifier()->
+      AddSessionLengthLimitObserver(this);
+}
+
+TraySessionLengthLimit::~TraySessionLengthLimit() {
+  Shell::GetInstance()->system_tray_notifier()->
+      RemoveSessionLengthLimitObserver(this);
+}
+
+views::View* TraySessionLengthLimit::CreateTrayView(user::LoginStatus status) {
+  CHECK(tray_view_ == NULL);
+  ash::SystemTrayDelegate* delegate =
+      ash::Shell::GetInstance()->system_tray_delegate();
+  tray_view_ = new tray::RemainingSessionTimeTrayView(
+      delegate->GetSessionLengthLimited(),
+      delegate->GetRemainingSessionTime(),
+      system_tray()->shelf_alignment() == SHELF_ALIGNMENT_BOTTOM);
+  return tray_view_;
+}
+
+void TraySessionLengthLimit::DestroyTrayView() {
+  tray_view_ = NULL;
+}
+
+void TraySessionLengthLimit::UpdateAfterShelfAlignmentChange(
+    ShelfAlignment alignment) {
+  if (tray_view_)
+    tray_view_->UpdateClockLayout(alignment == SHELF_ALIGNMENT_BOTTOM);
+}
+
+void TraySessionLengthLimit::OnSessionLengthUnlimited() {
+  tray_view_->OnSessionLengthUnlimited();
+}
+
+void TraySessionLengthLimit::OnRemainingSessionTimeChanged(
+    const base::TimeDelta& remaining) {
+  tray_view_->OnRemainingSessionTimeChanged(remaining);
+}
+
+}  // namespace internal
+}  // namespace ash