Merge "Fixed inaccurate brightness slider UI" into tm-qpr-dev am: 4f33cbd64f am: 7954582e7c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19669170

Change-Id: I9c39a763dc6294b0526c66aca81a328a87b4ad71
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

packages/SystemUI/src/com/android/systemui/util/RoundedCornerProgressDrawable.kt

@@ -33,6 +33,11 @@ import android.graphics.drawable.InsetDrawable
  * Meant to be used with a rounded ends background, it will also prevent deformation when the slider
  * is meant to be smaller than the rounded corner. The background should have rounded corners that
  * are half of the height.
+ *
+ * This class also assumes that a "thumb" icon exists within the end's edge of the progress
+ * drawable, and the slider's width, when interacted on, if offset by half the size of the thumb
+ * icon which puts the icon directly underneath the user's finger.
+ *
  */
 class RoundedCornerProgressDrawable @JvmOverloads constructor(
     drawable: Drawable? = null
@@ -54,9 +59,16 @@ class RoundedCornerProgressDrawable @JvmOverloads constructor(
 
     override fun onLevelChange(level: Int): Boolean {
         val db = drawable?.bounds!!
+
+        // The thumb offset shifts the sun icon directly under the user's thumb
+        val thumbOffset = bounds.height() / 2
+        val width = bounds.width() * level / MAX_LEVEL + thumbOffset
+
         // On 0, the width is bounds.height (a circle), and on MAX_LEVEL, the width is bounds.width
-        val width = bounds.height() + (bounds.width() - bounds.height()) * level / MAX_LEVEL
-        drawable?.setBounds(bounds.left, db.top, bounds.left + width, db.bottom)
+        drawable?.setBounds(
+            bounds.left, db.top,
+            width.coerceAtMost(bounds.width()).coerceAtLeast(bounds.height()), db.bottom
+        )
         return super.onLevelChange(level)
     }
 
@@ -91,4 +103,4 @@ class RoundedCornerProgressDrawable @JvmOverloads constructor(
             return true
         }
     }
-}
+}