Update RadialProgressView to draw progress track.

Progress track used to be a part of download state icon. Now that state
icon is programatically drawn the track should be a part of
RadialProgressView.

Bug: 820178
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I4b20faa6fbbc622de2763b962cc40539b22d24fc
Reviewed-on: https://chromium-review.googlesource.com/966936
Commit-Queue: Eugene But <eugenebut@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543910}

ios/chrome/browser/ui/download/download_manager_view_controller.mm

@@ -478,7 +478,8 @@ NSString* GetSizeString(long long size_in_bytes) {
     _progressView = [[RadialProgressView alloc] initWithFrame:CGRectZero];
     _progressView.translatesAutoresizingMaskIntoConstraints = NO;
     _progressView.lineWidth = 2;
-    _progressView.tintColor = [MDCPalette bluePalette].tint600;
+    _progressView.progressTintColor = [MDCPalette bluePalette].tint600;
+    _progressView.trackTintColor = [MDCPalette greyPalette].tint300;
     [self updateProgressView];
   }
   return _progressView;

ios/chrome/browser/ui/download/radial_progress_view.h

@@ -17,6 +17,11 @@
 // The line width used when stroking the progress arc.
 @property(nonatomic) CGFloat lineWidth;
 
+@property(nonatomic, nullable) UIColor* progressTintColor;
+
+// Track is drawn underneath the progress.
+@property(nonatomic, nullable) UIColor* trackTintColor;
+
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_DOWNLOAD_RADIAL_PROGRESS_VIEW_H_

ios/chrome/browser/ui/download/radial_progress_view.mm

@@ -13,14 +13,22 @@
 #endif
 
 @interface RadialProgressView ()
-// CALayer that backs this view up.
-@property(nonatomic, readonly) CAShapeLayer* shapeLayer;
+
+// CALayer that backs this view up. Serves as progress track.
+@property(nonatomic, readonly) CAShapeLayer* trackLayer;
+
+// CALayer added as a sublayer for self.layer. Serves as progress.
+@property(nonatomic, readonly) CAShapeLayer* progressLayer;
+
 @end
 
 @implementation RadialProgressView
 
 @synthesize progress = _progress;
 @synthesize lineWidth = _lineWidth;
+@synthesize progressTintColor = _progressTintColor;
+@synthesize trackTintColor = _trackTintColor;
+@synthesize progressLayer = _progressLayer;
 
 #pragma mark - UIView overrides
 
@@ -28,37 +36,62 @@
   return [CAShapeLayer class];
 }
 
+- (void)setBounds:(CGRect)bounds {
+  [super setBounds:bounds];
+
+  // progressPathWithEndAngle: relies on self.bounds and must be updated here.
+  // Track starts at 12 o'clock and ends at 12 o'clock.
+  self.trackLayer.path =
+      [self progressPathWithEndAngle:M_PI * 2 - M_PI_2].CGPath;
+}
+
 - (void)willMoveToSuperview:(UIView*)newSuperview {
-  if (newSuperview) {
-    self.shapeLayer.fillColor = [UIColor clearColor].CGColor;
-    self.shapeLayer.strokeColor = self.tintColor.CGColor;
-    self.shapeLayer.lineWidth = self.lineWidth;
+  if (newSuperview && !self.progressLayer.superlayer) {
+    self.trackLayer.fillColor = [UIColor clearColor].CGColor;
+    self.trackLayer.strokeColor = self.trackTintColor.CGColor;
+    self.trackLayer.lineWidth = self.lineWidth;
+
+    [self.trackLayer addSublayer:self.progressLayer];
   }
 }
 
 #pragma mark - Public
 
 - (void)setProgress:(float)progress {
-  if (_progress == progress)
-    return;
+  if (_progress != progress) {
+    _progress = progress;
+    self.progressLayer.path =
+        [self progressPathWithEndAngle:M_PI * 2 * progress - M_PI_2].CGPath;
+  }
+}
+
+#pragma mark - Private
 
-  _progress = progress;
+// Returns Bezier path for drawing radial progress or track. Start angle is
+// always 12 o'clock.
+- (UIBezierPath*)progressPathWithEndAngle:(CGFloat)endAngleInRadians {
   CGPoint center =
       CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
-  CGFloat radius = CGRectGetWidth(self.bounds) / 2 - 1;
-  UIBezierPath* path =
-      [UIBezierPath bezierPathWithArcCenter:center
-                                     radius:radius
-                                 startAngle:0 - M_PI_2  // 12 o'clock
-                                   endAngle:M_PI * 2 * progress - M_PI_2
-                                  clockwise:YES];
-  self.shapeLayer.path = path.CGPath;
+  CGFloat radius = CGRectGetWidth(self.bounds) / 2 - self.lineWidth;
+  return [UIBezierPath bezierPathWithArcCenter:center
+                                        radius:radius
+                                    startAngle:-M_PI_2
+                                      endAngle:endAngleInRadians
+                                     clockwise:YES];
 }
 
-#pragma mark - Private
-
-- (CAShapeLayer*)shapeLayer {
+- (CAShapeLayer*)trackLayer {
   return base::mac::ObjCCastStrict<CAShapeLayer>(self.layer);
 }
 
+- (CAShapeLayer*)progressLayer {
+  if (!_progressLayer) {
+    _progressLayer = [CAShapeLayer layer];
+    _progressLayer.fillColor = [UIColor clearColor].CGColor;
+    _progressLayer.strokeColor = self.progressTintColor.CGColor;
+    _progressLayer.lineWidth = self.lineWidth;
+  }
+  return _progressLayer;
+}
+
 @end