[ProgressView] Reverse the start point and end point of indeterminate…

… progress stroke to make it aligning with the animation direction.

PiperOrigin-RevId: 318494534

components/ProgressView/src/MDCProgressView.m

@@ -425,18 +425,18 @@ - (void)startAnimatingBar {
   [self.indeterminateProgressView.shapeLayer removeAllAnimations];
 
   // The numeric values used here conform to https://material.io/components/progress-indicators.
-  CABasicAnimation *progressViewHead = [CABasicAnimation animationWithKeyPath:@"strokeStart"];
-  progressViewHead.fromValue = @1;
-  progressViewHead.toValue = @0;
+  CABasicAnimation *progressViewHead = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
+  progressViewHead.fromValue = @0;
+  progressViewHead.toValue = @1;
   progressViewHead.duration = 0.75;
   progressViewHead.timingFunction =
       [[CAMediaTimingFunction alloc] initWithControlPoints:0.20f:0.00f:0.80f:1.00f];
-  progressViewHead.fillMode = kCAFillModeForwards;
+  progressViewHead.fillMode = kCAFillModeBackwards;
 
-  CABasicAnimation *progressViewTail = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
+  CABasicAnimation *progressViewTail = [CABasicAnimation animationWithKeyPath:@"strokeStart"];
   progressViewTail.beginTime = 0.333;
-  progressViewTail.fromValue = @1;
-  progressViewTail.toValue = @0;
+  progressViewTail.fromValue = @0;
+  progressViewTail.toValue = @1;
   progressViewTail.duration = 0.85;
   progressViewTail.timingFunction =
       [[CAMediaTimingFunction alloc] initWithControlPoints:0.40f:0.00f:1.00f:1.00f];
@@ -451,20 +451,20 @@ - (void)startAnimatingBar {
                                       forKey:@"kProgressViewAnimation"];
 
   CABasicAnimation *indeterminateProgressViewHead =
-      [CABasicAnimation animationWithKeyPath:@"strokeStart"];
-  indeterminateProgressViewHead.fromValue = @1;
-  indeterminateProgressViewHead.toValue = @0;
+      [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
+  indeterminateProgressViewHead.fromValue = @0;
+  indeterminateProgressViewHead.toValue = @1;
   indeterminateProgressViewHead.duration = 0.567;
   indeterminateProgressViewHead.beginTime = 1;
   indeterminateProgressViewHead.timingFunction =
       [[CAMediaTimingFunction alloc] initWithControlPoints:0.00f:0.00f:0.65f:1.00f];
   indeterminateProgressViewHead.fillMode = kCAFillModeBackwards;
 
   CABasicAnimation *indeterminateProgressViewTail =
-      [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
+      [CABasicAnimation animationWithKeyPath:@"strokeStart"];
   indeterminateProgressViewTail.beginTime = 1.267;
-  indeterminateProgressViewTail.fromValue = @1;
-  indeterminateProgressViewTail.toValue = @0;
+  indeterminateProgressViewTail.fromValue = @0;
+  indeterminateProgressViewTail.toValue = @1;
   indeterminateProgressViewTail.duration = 0.533;
   indeterminateProgressViewTail.timingFunction =
       [[CAMediaTimingFunction alloc] initWithControlPoints:0.10f:0.00f:0.45f:1.00f];
@@ -475,6 +475,7 @@ - (void)startAnimatingBar {
       @[ indeterminateProgressViewHead, indeterminateProgressViewTail ];
   indeterminateProgressViewAnimationGroup.duration = 1.8;
   indeterminateProgressViewAnimationGroup.repeatCount = HUGE_VALF;
+
   [self.indeterminateProgressView.shapeLayer addAnimation:indeterminateProgressViewAnimationGroup
                                                    forKey:@"kIndeterminateProgressViewAnimation"];
 }

components/ProgressView/src/private/MDCProgressGradientView.m

@@ -57,11 +57,11 @@ - (void)layoutSubviews {
   CGPoint rightPoint = CGPointMake(CGRectGetWidth(self.gradientLayer.bounds),
                                    CGRectGetMidY(self.gradientLayer.bounds));
   if (self.mdf_effectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirectionRightToLeft) {
-    [path moveToPoint:leftPoint];
-    [path addLineToPoint:rightPoint];
-  } else {
     [path moveToPoint:rightPoint];
     [path addLineToPoint:leftPoint];
+  } else {
+    [path moveToPoint:leftPoint];
+    [path addLineToPoint:rightPoint];
   }
   self.shapeLayer.frame = self.gradientLayer.bounds;
   self.shapeLayer.strokeColor = UIColor.blackColor.CGColor;