Implement an indeterminate progress-bar

ui/message_center/views/notification_progress_bar.cc

+// Copyright 2015 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/message_center/views/notification_progress_bar.h"
+
+#include "third_party/skia/include/core/SkPaint.h"
+#include "third_party/skia/include/core/SkPath.h"
+#include "ui/gfx/canvas.h"
+#include "ui/message_center/message_center_style.h"
+
+namespace {
+
+// Dimensions.
+const int kProgressBarWidth = message_center::kNotificationWidth -
+    message_center::kTextLeftPadding - message_center::kTextRightPadding;
+
+const int kAnimationFrameRateHz = 60;
+
+const int kAnimationDuration = 2000;  // In millisecond
+
+} // namespace
+
+namespace message_center {
+
+// NotificationProgressBarBase /////////////////////////////////////////////////
+
+gfx::Size NotificationProgressBarBase::GetPreferredSize() const {
+  gfx::Size pref_size(kProgressBarWidth, message_center::kProgressBarThickness);
+  gfx::Insets insets = GetInsets();
+  pref_size.Enlarge(insets.width(), insets.height());
+  return pref_size;
+}
+
+// NotificationProgressBar /////////////////////////////////////////////////////
+
+NotificationProgressBar::NotificationProgressBar() {
+}
+
+NotificationProgressBar::~NotificationProgressBar() {
+}
+
+bool NotificationProgressBar::is_indeterminate() {
+  return false;
+}
+
+void NotificationProgressBar::OnPaint(gfx::Canvas* canvas) {
+  gfx::Rect content_bounds = GetContentsBounds();
+
+  // Draw background.
+  SkPath background_path;
+  background_path.addRoundRect(gfx::RectToSkRect(content_bounds),
+                               message_center::kProgressBarCornerRadius,
+                               message_center::kProgressBarCornerRadius);
+  SkPaint background_paint;
+  background_paint.setStyle(SkPaint::kFill_Style);
+  background_paint.setFlags(SkPaint::kAntiAlias_Flag);
+  background_paint.setColor(message_center::kProgressBarBackgroundColor);
+  canvas->DrawPath(background_path, background_paint);
+
+  // Draw slice.
+  SkPath slice_path;
+  const int slice_width =
+      static_cast<int>(content_bounds.width() * GetNormalizedValue() + 0.5);
+  if (slice_width < 1)
+    return;
+
+  gfx::Rect slice_bounds = content_bounds;
+  slice_bounds.set_width(slice_width);
+  slice_path.addRoundRect(gfx::RectToSkRect(slice_bounds),
+                          message_center::kProgressBarCornerRadius,
+                          message_center::kProgressBarCornerRadius);
+
+  SkPaint slice_paint;
+  slice_paint.setStyle(SkPaint::kFill_Style);
+  slice_paint.setFlags(SkPaint::kAntiAlias_Flag);
+  slice_paint.setColor(message_center::kProgressBarSliceColor);
+  canvas->DrawPath(slice_path, slice_paint);
+}
+
+// NotificationIndeteminateProgressBar /////////////////////////////////////////
+
+NotificationIndeterminateProgressBar::NotificationIndeterminateProgressBar() {
+  indeterminate_bar_animation_.reset(
+      new gfx::LinearAnimation(kAnimationFrameRateHz, this));
+  indeterminate_bar_animation_->SetDuration(kAnimationDuration);
+  indeterminate_bar_animation_->Start();
+}
+
+NotificationIndeterminateProgressBar::~NotificationIndeterminateProgressBar() {
+  indeterminate_bar_animation_->Stop();  // Just in case
+}
+
+bool NotificationIndeterminateProgressBar::is_indeterminate() {
+  return true;
+}
+
+void NotificationIndeterminateProgressBar::OnPaint(gfx::Canvas* canvas) {
+  gfx::Rect content_bounds = GetContentsBounds();
+
+  // Draw background.
+  SkPath background_path;
+  background_path.addRoundRect(gfx::RectToSkRect(content_bounds),
+                               message_center::kProgressBarCornerRadius,
+                               message_center::kProgressBarCornerRadius);
+  SkPaint background_paint;
+  background_paint.setStyle(SkPaint::kFill_Style);
+  background_paint.setFlags(SkPaint::kAntiAlias_Flag);
+  background_paint.setColor(message_center::kProgressBarBackgroundColor);
+  canvas->DrawPath(background_path, background_paint);
+
+  // Draw slice.
+  SkPath slice_path;
+  double time = indeterminate_bar_animation_->GetCurrentValue();
+
+  // The animation spec corresponds to the material design lite's parameter.
+  // (cf. https://github.com/google/material-design-lite/)
+  double bar1_left;
+  double bar1_width;
+  double bar2_left;
+  double bar2_width;
+  if (time < 0.50) {
+    bar1_left = time / 2;
+    bar1_width = time * 1.5;
+    bar2_left = 0;
+    bar2_width = 0;
+  } else if (time < 0.75) {
+    bar1_left = time * 3 - 1.25;
+    bar1_width = 0.75 - (time - 0.5)  * 3;
+    bar2_left = 0;
+    bar2_width = time - 0.5;
+  } else {
+    bar1_left = 1;
+    bar1_width = 0;
+    bar2_left = (time - 0.75) * 4;
+    bar2_width = 0.25 - (time - 0.75);
+  }
+
+  int bar1_x = static_cast<int>(content_bounds.width() * bar1_left);
+  int bar1_w =
+      std::min(static_cast<int>(content_bounds.width() * bar1_width + 0.5),
+               content_bounds.width() - bar1_x);
+  int bar2_x = static_cast<int>(content_bounds.width() * bar2_left);
+  int bar2_w =
+      std::min(static_cast<int>(content_bounds.width() * bar2_width + 0.5),
+               content_bounds.width() - bar2_x);
+
+
+  gfx::Rect slice_bounds = content_bounds;
+  slice_bounds.set_x(content_bounds.x() + bar1_x);
+  slice_bounds.set_width(bar1_w);
+  slice_path.addRoundRect(gfx::RectToSkRect(slice_bounds),
+                          message_center::kProgressBarCornerRadius,
+                          message_center::kProgressBarCornerRadius);
+  slice_bounds.set_x(content_bounds.x() + bar2_x);
+  slice_bounds.set_width(bar2_w);
+  slice_path.addRoundRect(gfx::RectToSkRect(slice_bounds),
+                          message_center::kProgressBarCornerRadius,
+                          message_center::kProgressBarCornerRadius);
+
+  SkPaint slice_paint;
+  slice_paint.setStyle(SkPaint::kFill_Style);
+  slice_paint.setFlags(SkPaint::kAntiAlias_Flag);
+  slice_paint.setColor(message_center::kProgressBarSliceColor);
+  canvas->DrawPath(slice_path, slice_paint);
+}
+
+void NotificationIndeterminateProgressBar::AnimationProgressed(
+    const gfx::Animation* animation) {
+  if (animation == indeterminate_bar_animation_.get()) {
+    DCHECK(indeterminate_bar_animation_);
+    SchedulePaint();
+  }
+}
+
+void NotificationIndeterminateProgressBar::AnimationEnded(
+    const gfx::Animation* animation) {
+  // Restarts animation.
+  if (animation == indeterminate_bar_animation_.get()) {
+    DCHECK(indeterminate_bar_animation_);
+    indeterminate_bar_animation_->Start();
+  }
+}
+
+}  // namespace message_center