am 3059dbb6: am 04c0f415: Merge "Update alpha documentation" into mnc-dev
* commit '3059dbb65ac77e663fb4e89317fcafa3d2f6d9e2':
Update alpha documentation
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 81ad5ad..ed0ceb2 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -11091,25 +11091,34 @@
}
/**
- * <p>Sets the opacity of the view. This is a value from 0 to 1, where 0 means the view is
- * completely transparent and 1 means the view is completely opaque.</p>
+ * Sets the opacity of the view to a value from 0 to 1, where 0 means the view is
+ * completely transparent and 1 means the view is completely opaque.
*
- * <p> Note that setting alpha to a translucent value (0 < alpha < 1) can have significant
- * performance implications, especially for large views. It is best to use the alpha property
- * sparingly and transiently, as in the case of fading animations.</p>
+ * <p class="note"><strong>Note:</strong> setting alpha to a translucent value (0 < alpha < 1)
+ * can have significant performance implications, especially for large views. It is best to use
+ * the alpha property sparingly and transiently, as in the case of fading animations.</p>
*
* <p>For a view with a frequently changing alpha, such as during a fading animation, it is
* strongly recommended for performance reasons to either override
- * {@link #hasOverlappingRendering()} to return false if appropriate, or setting a
- * {@link #setLayerType(int, android.graphics.Paint) layer type} on the view.</p>
+ * {@link #hasOverlappingRendering()} to return <code>false</code> if appropriate, or setting a
+ * {@link #setLayerType(int, android.graphics.Paint) layer type} on the view for the duration
+ * of the animation. On versions {@link android.os.Build.VERSION_CODES#MNC} and below,
+ * the default path for rendering an unlayered View with alpha could add multiple milliseconds
+ * of rendering cost, even for simple or small views. Starting with
+ * {@link android.os.Build.VERSION_CODES#MNC}, {@link #LAYER_TYPE_HARDWARE} is automatically
+ * applied to the view at the rendering level.</p>
*
* <p>If this view overrides {@link #onSetAlpha(int)} to return true, then this view is
* responsible for applying the opacity itself.</p>
*
- * <p>Note that if the view is backed by a
- * {@link #setLayerType(int, android.graphics.Paint) layer} and is associated with a
- * {@link #setLayerPaint(android.graphics.Paint) layer paint}, setting an alpha value less than
- * 1.0 will supersede the alpha of the layer paint.</p>
+ * <p>On versions {@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1} and below, note that if
+ * the view is backed by a {@link #setLayerType(int, android.graphics.Paint) layer} and is
+ * associated with a {@link #setLayerPaint(android.graphics.Paint) layer paint}, setting an
+ * alpha value less than 1.0 will supersede the alpha of the layer paint.</p>
+ *
+ * <p>Starting with {@link android.os.Build.VERSION_CODES#MNC}, setting a translucent alpha
+ * value will clip a View to its bounds, unless the View returns <code>false</code> from
+ * {@link #hasOverlappingRendering}.</p>
*
* @param alpha The opacity of the view.
*