[ProgressIndicator] Updated SpringAnimation's minimum visible change and added APIs to customize spring force in DeterminateDrawable.

PiperOrigin-RevId: 798225060

Author: pekingme

lib/java/com/google/android/material/progressindicator/DeterminateDrawable.java

@@ -18,6 +18,8 @@
 
 import com.google.android.material.R;
 
+import static java.lang.Math.min;
+
 import android.animation.TimeInterpolator;
 import android.animation.ValueAnimator;
 import android.content.Context;
@@ -57,7 +59,6 @@ public final class DeterminateDrawable<S extends BaseProgressIndicatorSpec>
   private DrawingDelegate<S> drawingDelegate;
 
   // Animation.
-  private final SpringForce springForce;
   private final SpringAnimation springAnimation;
   // Active indicator for the progress.
   private final ActiveIndicator activeIndicator;
@@ -83,13 +84,11 @@ public final class DeterminateDrawable<S extends BaseProgressIndicatorSpec>
     activeIndicator.isDeterminate = true;
 
     // Initializes a spring animator for progress animation.
-    springForce = new SpringForce();
-
-    springForce.setDampingRatio(SpringForce.DAMPING_RATIO_NO_BOUNCY);
-    springForce.setStiffness(SPRING_FORCE_STIFFNESS);
-
     springAnimation = new SpringAnimation(this, INDICATOR_LENGTH_IN_LEVEL);
-    springAnimation.setSpring(springForce);
+    springAnimation.setSpring(
+        new SpringForce()
+            .setDampingRatio(SpringForce.DAMPING_RATIO_NO_BOUNCY)
+            .setStiffness(SPRING_FORCE_STIFFNESS));
 
     // Initializes a linear animator to enforce phase animation when progress is unchanged.
     phaseAnimator = new ValueAnimator();
@@ -231,7 +230,9 @@ boolean setVisibleInternal(boolean visible, boolean restart, boolean animate) {
       skipAnimationOnLevelChange = true;
     } else {
       skipAnimationOnLevelChange = false;
-      springForce.setStiffness(SPRING_FORCE_STIFFNESS / systemAnimatorDurationScale);
+      springAnimation
+          .getSpring()
+          .setStiffness(SPRING_FORCE_STIFFNESS / systemAnimatorDurationScale);
     }
 
     return changed;
@@ -260,12 +261,34 @@ protected boolean onLevelChange(int level) {
       setIndicatorFraction((float) level / MAX_DRAWABLE_LEVEL);
       setAmplitudeFraction(nextAmplitudeFraction);
     } else {
+      // Update min visible change to the recommended value.
+      updateSpringMinVisibleChange();
       springAnimation.setStartValue(getIndicatorFraction() * MAX_DRAWABLE_LEVEL);
       springAnimation.animateToFinalPosition(level);
     }
     return true;
   }
 
+  /**
+   * Updates the minimum visible change of the spring animation controlling the indicator length
+   * (progress) to the recommended value based on the track's length.
+   */
+  private void updateSpringMinVisibleChange() {
+    int width = getBounds().width();
+    int height = getBounds().height();
+    if (width <= 0 || height <= 0) {
+      return;
+    }
+    if (drawingDelegate instanceof LinearDrawingDelegate) {
+      // Track length is the width of the drawable.
+      springAnimation.setMinimumVisibleChange((float) MAX_DRAWABLE_LEVEL / width);
+    } else {
+      // Track length is the perimeter of the circle fit in the drawable.
+      springAnimation.setMinimumVisibleChange(
+          (float) (MAX_DRAWABLE_LEVEL / (min(height, width) * Math.PI)));
+    }
+  }
+
   @Override
   public int getIntrinsicWidth() {
     return drawingDelegate.getPreferredWidth();
@@ -276,6 +299,17 @@ public int getIntrinsicHeight() {
     return drawingDelegate.getPreferredHeight();
   }
 
+  /** Returns the spring force of the spring animation for the progress. */
+  @NonNull
+  public SpringForce getSpringForce() {
+    return springAnimation.getSpring();
+  }
+
+  /** Sets the spring force of the spring animation for the progress. */
+  public void setSpringForce(@NonNull SpringForce spring) {
+    springAnimation.setSpring(spring);
+  }
+
   /**
    * Sets the drawable level with a fraction [0,1] of the progress. Note: this function is not used
    * to force updating the level in opposite to the automatic level updates by framework {@link