Implement material throbber and use it in one place (Autofill card

ui/views/controls/throbber.cc

Index: ui/views/controls/throbber.cc
diff --git a/ui/views/controls/throbber.cc b/ui/views/controls/throbber.cc
index d1d5c1d892369a72213428a065f38d43ab2451a3..30cfb3b33a422df9fa9092a61cb2e304aa3e3e6b 100644
--- a/ui/views/controls/throbber.cc
+++ b/ui/views/controls/throbber.cc
@@ -111,7 +111,7 @@ SmoothedThrobber::~SmoothedThrobber() {}
 void SmoothedThrobber::Start() {
   stop_timer_.Stop();
 
-  if (!running_ && !start_timer_.IsRunning()) {
+  if (!running() && !start_timer_.IsRunning()) {
     start_timer_.Start(FROM_HERE, TimeDelta::FromMilliseconds(start_delay_ms_),
                        this, &SmoothedThrobber::StartDelayOver);
   }
@@ -122,7 +122,7 @@ void SmoothedThrobber::StartDelayOver() {
 }
 
 void SmoothedThrobber::Stop() {
-  if (!running_)
+  if (!running())
     start_timer_.Stop();
 
   stop_timer_.Stop();
@@ -134,35 +134,87 @@ void SmoothedThrobber::StopDelayOver() {
   Throbber::Stop();
 }
 
-// Checkmark throbber ---------------------------------------------------------
+// Material throbber -----------------------------------------------------------
+
+// The length of a frame in milliseconds.
+// TODO(estade): remove the +10 when the -10 is removed from Throbber::Start().
+static const int kMaterialThrobberFrameTimeMs = 30 + 10;
 
-CheckmarkThrobber::CheckmarkThrobber()
-    : Throbber(kFrameTimeMs, false),
-      checked_(false),
-      checkmark_(ui::ResourceBundle::GetSharedInstance().GetImageNamed(
-          IDR_CHECKMARK).ToImageSkia()) {
+MaterialThrobber::MaterialThrobber() :
+    Throbber(kMaterialThrobberFrameTimeMs, false),
+    preferred_diameter_(0),
+    checked_(false),
+    checkmark_(nullptr) {
 }
 
-void CheckmarkThrobber::SetChecked(bool checked) {
-  bool changed = checked != checked_;
-  if (changed) {
-    checked_ = checked;
-    SchedulePaint();
-  }
+MaterialThrobber::~MaterialThrobber() {
 }
 
-void CheckmarkThrobber::OnPaint(gfx::Canvas* canvas) {
-  if (running_) {
-    // Let the throbber throb...
-    Throbber::OnPaint(canvas);
+void MaterialThrobber::SetChecked(bool checked) {
+  if (checked == checked_)
+    return;
+
+  checked_ = checked;
+  SchedulePaint();
+}
+
+gfx::Size MaterialThrobber::GetPreferredSize() const {
+  if (preferred_diameter_ == 0)
+    return Throbber::GetPreferredSize();
+
+  return gfx::Size(preferred_diameter_, preferred_diameter_);
+}
+
+int MaterialThrobber::GetHeightForWidth(int w) const {
+  return w;
+}
+
+void MaterialThrobber::OnPaint(gfx::Canvas* canvas) {
+  if (!running()) {
+    if (checked_) {
+      if (!checkmark_) {
+        checkmark_ = ui::ResourceBundle::GetSharedInstance().GetImageNamed(
+            IDR_CHECKMARK).ToImageSkia();
+      }
+
+      int checkmark_x = (width() - checkmark_->width()) / 2;
+      int checkmark_y = (height() - checkmark_->height()) / 2;
+      canvas->DrawImageInt(*checkmark_, checkmark_x, checkmark_y);
+    }
     return;
   }
-  // Otherwise we paint our tick mark or nothing depending on our state.
-  if (checked_) {
-    int checkmark_x = (width() - checkmark_->width()) / 2;
-    int checkmark_y = (height() - checkmark_->height()) / 2;
-    canvas->DrawImageInt(*checkmark_, checkmark_x, checkmark_y);
-  }
+
+  gfx::Rect bounds = GetContentsBounds();
+  // Inset by half the stroke width to make sure the whole arc is inside
+  // the visible rect.
+  SkScalar stroke_width = SkIntToScalar(bounds.width()) / 10.0;
+  gfx::Rect oval = bounds;
+  int inset = SkScalarCeilToInt(stroke_width / 2.0);
+  oval.Inset(inset, inset);
+
+  // Calculate start and end points. The angles are counter-clockwise because
+  // the throbber spins counter-clockwise. The finish angle starts at 12 o'clock
+  // (90 degrees) and rotates steadily. The start angle trails 180 degrees
+  // behind, except for the first half revolution, when it stays at 12 o'clock.
+  base::TimeDelta revolution_time = base::TimeDelta::FromMilliseconds(1320);
+  base::TimeDelta elapsed_time = base::Time::Now() - start_time();
+  int64_t twelve_oclock = 90;
+  int64_t finish_angle = twelve_oclock + 360 * elapsed_time / revolution_time;
+  int64_t start_angle = std::max(finish_angle - 180, twelve_oclock);
+
+  SkPath path;
+  // Negate the angles to convert to the clockwise numbers Skia expects.
+  path.arcTo(gfx::RectToSkRect(oval), -start_angle,
+             -(finish_angle - start_angle), true);
+
+  SkPaint paint;
+  // TODO(estade): find a place for this color.
+  paint.setColor(SkColorSetRGB(0x42, 0x85, 0xF4));
+  paint.setStrokeCap(SkPaint::kRound_Cap);
+  paint.setStrokeWidth(stroke_width);
+  paint.setStyle(SkPaint::kStroke_Style);
+  paint.setAntiAlias(true);
+  canvas->DrawPath(path, paint);
 }
 
 }  // namespace views