[Dock Defend] Cache the density in the drawable so we don't re-fetch it

constantly.

Bug: 255625888
Test: verified density got updated each time display size changed
Change-Id: I8cbb9ffe0e3ef18dc43fe13749b7584eb83640e1

packages/SystemUI/src/com/android/systemui/battery/AccessorizedBatteryDrawable.kt

@@ -57,6 +57,8 @@ class AccessorizedBatteryDrawable(
     private var shieldLeftOffsetScaled = SHIELD_LEFT_OFFSET
     private var shieldTopOffsetScaled = SHIELD_TOP_OFFSET
 
+    private var density = context.resources.displayMetrics.density
+
     private val dualTone =
         context.resources.getBoolean(com.android.internal.R.bool.config_batterymeterDualTone)
 
@@ -126,8 +128,7 @@ class AccessorizedBatteryDrawable(
             } else {
                 BATTERY_HEIGHT
             }
-        // TODO(b/255625888): Cache the density so we don't have to re-fetch.
-        return (height * context.resources.displayMetrics.density).toInt()
+        return (height * density).toInt()
     }
 
     override fun getIntrinsicWidth(): Int {
@@ -137,8 +138,7 @@ class AccessorizedBatteryDrawable(
             } else {
                 BATTERY_WIDTH
             }
-        // TODO(b/255625888): Cache the density so we don't have to re-fetch.
-        return (width * context.resources.displayMetrics.density).toInt()
+        return (width * density).toInt()
     }
 
     override fun draw(c: Canvas) {
@@ -195,6 +195,11 @@ class AccessorizedBatteryDrawable(
         mainBatteryDrawable.setColors(fgColor, bgColor, singleToneColor)
     }
 
+    /** Notifies this drawable that the density might have changed. */
+    fun notifyDensityChanged() {
+        density = context.resources.displayMetrics.density
+    }
+
     private fun loadPaths() {
         val shieldPathString = context.resources.getString(R.string.config_batterymeterShieldPath)
         shieldPath.set(PathParser.createPathFromPathData(shieldPathString))

packages/SystemUI/src/com/android/systemui/battery/BatteryMeterView.java

@@ -179,6 +179,7 @@ public class BatteryMeterView extends LinearLayout implements DarkReceiver {
     protected void onConfigurationChanged(Configuration newConfig) {
         super.onConfigurationChanged(newConfig);
         updatePercentView();
+        mDrawable.notifyDensityChanged();
     }
 
     public void setColorsFromContext(Context context) {