Merge "Only call saveLayerAlpha when alpha is not at max or min values" into udc-dev

packages/SystemUI/src/com/android/keyguard/KeyguardClockFrame.kt

@@ -18,14 +18,24 @@ class KeyguardClockFrame(
     }
 
     protected override fun dispatchDraw(canvas: Canvas) {
-        val restoreTo = saveCanvasAlpha(this, canvas, drawAlpha)
+        saveCanvasAlpha(this, canvas, drawAlpha) { super.dispatchDraw(it) }
-        super.dispatchDraw(canvas)
-        canvas.restoreToCount(restoreTo)
     }
 
     companion object {
         @JvmStatic
-        fun saveCanvasAlpha(view: View, canvas: Canvas, alpha: Int): Int {
+        fun saveCanvasAlpha(view: View, canvas: Canvas, alpha: Int, drawFunc: (Canvas) -> Unit) {
+            if (alpha <= 0) {
+                // Zero Alpha -> skip drawing phase
+                return
+            }
+
+            if (alpha >= 255) {
+                // Max alpha -> no need for layer
+                drawFunc(canvas)
+                return
+            }
+
+            // Find x & y of view on screen
             var (x, y) =
                 run {
                     val locationOnScreen = IntArray(2)
@@ -33,7 +43,10 @@ class KeyguardClockFrame(
                     Pair(locationOnScreen[0].toFloat(), locationOnScreen[1].toFloat())
                 }
 
-            return canvas.saveLayerAlpha(-1f * x, -1f * y, x + view.width, y + view.height, alpha)
+            val restoreTo =
+                canvas.saveLayerAlpha(-1f * x, -1f * y, x + view.width, y + view.height, alpha)
+            drawFunc(canvas)
+            canvas.restoreToCount(restoreTo)
         }
     }
 }

packages/SystemUI/src/com/android/keyguard/KeyguardClockSwitch.java

@@ -130,9 +130,12 @@ public class KeyguardClockSwitch extends RelativeLayout {
 
     @Override
     protected void dispatchDraw(Canvas canvas) {
-        int restoreTo = KeyguardClockFrame.saveCanvasAlpha(this, canvas, mDrawAlpha);
+        KeyguardClockFrame.saveCanvasAlpha(
-        super.dispatchDraw(canvas);
+                this, canvas, mDrawAlpha,
-        canvas.restoreToCount(restoreTo);
+                c -> {
+                    super.dispatchDraw(c);
+                    return kotlin.Unit.INSTANCE;
+                });
     }
 
     public void setLogBuffer(LogBuffer logBuffer) {

packages/SystemUI/src/com/android/keyguard/KeyguardStatusContainer.kt

@@ -17,8 +17,6 @@ class KeyguardStatusContainer(
     }
 
     protected override fun dispatchDraw(canvas: Canvas) {
-        val restoreTo = KeyguardClockFrame.saveCanvasAlpha(this, canvas, drawAlpha)
+        KeyguardClockFrame.saveCanvasAlpha(this, canvas, drawAlpha) { super.dispatchDraw(canvas) }
-        super.dispatchDraw(canvas)
-        canvas.restoreToCount(restoreTo)
     }
 }

packages/SystemUI/src/com/android/keyguard/KeyguardStatusView.java

@@ -146,8 +146,11 @@ public class KeyguardStatusView extends GridLayout {
 
     @Override
     protected void dispatchDraw(Canvas canvas) {
-        int restoreTo = KeyguardClockFrame.saveCanvasAlpha(this, canvas, mDrawAlpha);
+        KeyguardClockFrame.saveCanvasAlpha(
-        super.dispatchDraw(canvas);
+                this, canvas, mDrawAlpha,
-        canvas.restoreToCount(restoreTo);
+                c -> {
+                    super.dispatchDraw(c);
+                    return kotlin.Unit.INSTANCE;
+                });
     }
 }