feat:support alpha

Android/doric/src/main/java/pub/doric/shader/ViewNode.java

@@ -203,6 +203,17 @@ public abstract class ViewNode<T extends View> extends DoricContextHolder {
                             prop.asObject().getProperty("color").asNumber().toInt());
                 }
                 break;
+            case "alpha":
+                if (isAnimating()) {
+                    addAnimator(ObjectAnimator.ofFloat(
+                            this,
+                            name,
+                            getAlpha(),
+                            prop.asNumber().toFloat()));
+                } else {
+                    setAlpha(prop.asNumber().toFloat());
+                }
+                break;
             case "corners":
                 if (prop.isNumber()) {
                     if (isAnimating()) {
@@ -518,6 +529,16 @@ public abstract class ViewNode<T extends View> extends DoricContextHolder {
         mView.setBackgroundColor(color);
     }
 
+    @DoricMethod
+    public void setAlpha(float alpha) {
+        getNodeView().setAlpha(alpha);
+    }
+
+    @DoricMethod
+    public float getAlpha() {
+        return getNodeView().getAlpha();
+    }
+
     @DoricMethod
     public void setCorners(float corner) {
         requireDoricLayer().setCornerRadius(DoricUtils.dp2px(corner));