* [android] Add flag in WXCell to decide whether enable flatGUI.

android/sdk/src/main/java/com/taobao/weex/WXSDKInstance.java

@@ -118,7 +118,8 @@ public class WXSDKInstance implements IWXActivityStateListener,DomContext, View.
   private boolean mNeedValidate = false;
   private static volatile int mViewPortWidth = 750;
   private int mInstanceViewPortWidth = 750;
-  private final  @NonNull FlatUIIImplementation mUIImp = new FlatGUIIContext();
+  private final  @NonNull
+  FlatGUIIContext mUIImp =new FlatGUIIContext();
 
   public long mRenderStartNanos;
   public int mExecJSTraceId = WXTracing.nextId();
@@ -200,7 +201,7 @@ public void enableLayerType(boolean enable) {
   }
 
   public @NonNull
-  FlatGUIIContext getFlatUIImp(){
+  FlatGUIIContext getFlatUIContext(){
     return mUIImp;
   }
 
@@ -248,7 +249,7 @@ public WXSDKInstance(Context context) {
   /**
    * For unittest only.
    */
-  @RestrictTo(Scope.LIBRARY)
+  @RestrictTo(Scope.TESTS)
   WXSDKInstance(Context context,String id) {
     mInstanceId = id;
     init(context);

android/sdk/src/main/java/com/taobao/weex/common/Constants.java

@@ -180,6 +180,8 @@ public interface Name {
     String NORMAL = "normal";
     String ARIA_LABEL = "ariaLabel";
     String ARIA_HIDDEN = "ariaHidden";
+
+    String FLAT = "flat";
   }
 
   public interface Value {

android/sdk/src/main/java/com/taobao/weex/ui/component/WXComponent.java

@@ -465,7 +465,7 @@ public final void setLayout(ImmutableDomObject domObject) {
 
   private void setComponentLayoutParams(int realWidth, int realHeight, int realLeft, int realTop,
       int realRight, int realBottom, Point rawOffset) {
-    FlatGUIIContext UIImp = getInstance().getFlatUIImp();
+    FlatGUIIContext UIImp = getInstance().getFlatUIContext();
     WidgetContainer ancestor;
     Widget widget;
     if ((ancestor = UIImp.getFlatComponentAncestor(this)) != null) {

android/sdk/src/main/java/com/taobao/weex/ui/component/WXDiv.java

@@ -67,7 +67,7 @@ protected WXFrameLayout initComponentHostView(@NonNull Context context) {
   @Override
   public boolean promoteToView(boolean checkAncestor) {
     return !intendToBeFlatContainer() ||
-        getInstance().getFlatUIImp().promoteToView(this, checkAncestor, WXDiv.class);
+        getInstance().getFlatUIContext().promoteToView(this, checkAncestor, WXDiv.class);
   }
 
   /**
@@ -78,7 +78,7 @@ public boolean promoteToView(boolean checkAncestor) {
   @NonNull
   public WidgetGroup getOrCreateFlatWidget() {
     if (mWidgetGroup == null) {
-      mWidgetGroup = new WidgetGroup(getInstance().getFlatUIImp().getFlatComponentAncestor(this).getHostView());
+      mWidgetGroup = new WidgetGroup(getInstance().getFlatUIContext().getFlatComponentAncestor(this).getHostView());
       for (int i = 0; i < getChildCount(); i++) {
         createChildViewAt(i);
       }
@@ -103,7 +103,7 @@ public void unmountFlatGUI() {
 
   @Override
   public boolean intendToBeFlatContainer() {
-    return getInstance().getFlatUIImp().isFlatUIEnabled() && WXDiv.class.equals(getClass());
+    return getInstance().getFlatUIContext().isFlatUIEnabled() && WXDiv.class.equals(getClass());
   }
 
   @Override

android/sdk/src/main/java/com/taobao/weex/ui/component/WXImage.java

@@ -88,13 +88,13 @@ public Integer map(String raw) {
 
   @Override
   public boolean promoteToView(boolean checkAncestor) {
-    return getInstance().getFlatUIImp().promoteToView(this, checkAncestor, WXImage.class);
+    return getInstance().getFlatUIContext().promoteToView(this, checkAncestor, WXImage.class);
   }
 
   @Override
   @NonNull public ImageWidget getOrCreateFlatWidget() {
     if(imageWidget == null){
-      imageWidget = new ImageWidget(getInstance().getFlatUIImp().getFlatComponentAncestor(this).getHostView());
+      imageWidget = new ImageWidget(getInstance().getFlatUIContext().getFlatComponentAncestor(this).getHostView());
     }
     return imageWidget;
   }

android/sdk/src/main/java/com/taobao/weex/ui/component/WXText.java

@@ -56,14 +56,14 @@ public class WXText extends WXComponent<WXTextView> implements FlatComponent<Tex
 
   @Override
   public boolean promoteToView(boolean checkAncestor) {
-    return getInstance().getFlatUIImp().promoteToView(this, checkAncestor, WXText.class);
+    return getInstance().getFlatUIContext().promoteToView(this, checkAncestor, WXText.class);
   }
 
   @Override
   @NonNull
   public TextWidget getOrCreateFlatWidget() {
     if (mTextWidget == null) {
-      mTextWidget = new TextWidget(getInstance().getFlatUIImp().getFlatComponentAncestor(this).getHostView());
+      mTextWidget = new TextWidget(getInstance().getFlatUIContext().getFlatComponentAncestor(this).getHostView());
     }
     return mTextWidget;
   }

android/sdk/src/main/java/com/taobao/weex/ui/component/list/WXCell.java

@@ -20,15 +20,18 @@
 
 import android.content.Context;
 import android.support.annotation.NonNull;
+import android.text.TextUtils;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 import com.taobao.weex.WXSDKInstance;
 import com.taobao.weex.annotation.Component;
+import com.taobao.weex.common.Constants.Name;
 import com.taobao.weex.dom.WXDomObject;
 import com.taobao.weex.ui.component.WXVContainer;
 import com.taobao.weex.ui.flat.WidgetContainer;
 import com.taobao.weex.ui.view.WXFrameLayout;
+import com.taobao.weex.utils.WXUtils;
 
 /**
  * Root component for components in {@link WXListComponent}
@@ -82,6 +85,17 @@ protected WXFrameLayout initComponentHostView(@NonNull Context context) {
         }
     }
 
+    @Override
+    protected boolean setProperty(String key, Object param) {
+        if(TextUtils.equals(Name.FLAT, key)){
+            getInstance().getFlatUIContext().setFlatUIEnabled(WXUtils.getBoolean(param, false));
+            return true;
+        }
+        else {
+            return super.setProperty(key, param);
+        }
+    }
+
     public int getLocationFromStart(){
         return mLastLocationY;
     }
@@ -141,6 +155,6 @@ public void unmountFlatGUI() {
     @Override
     public boolean intendToBeFlatContainer() {
         //TODO Is it possible to remove the cell class judge
-        return getInstance().getFlatUIImp().isFlatUIEnabled() && WXCell.class.equals(getClass());
+        return getInstance().getFlatUIContext().isFlatUIEnabled() && WXCell.class.equals(getClass());
     }
 }

android/sdk/src/main/java/com/taobao/weex/ui/flat/FlatGUIIContext.java

@@ -36,18 +36,18 @@
 
 //TODO when Weex instance is destroyed, there is a work of garbage collection.
 //TODO !!!!The index of weex playground show empty cell sometimes.
+//TODO The constructor of FlatGUIContext should have a flag decide whether to enable flagGUI.
 
 @RestrictTo(Scope.LIBRARY)
 public class FlatGUIIContext {
 
   private boolean mFlatUIEnabled;
-
-  //TODO a union-find should be used to achieve quick merge and find. Map is O(n) for merge, while union-find is O(1).
   private Map<WXComponent, WidgetContainer> mWidgetRegistry = new ArrayMap<>();
   private Map<WXComponent, AndroidViewWidget> mViewWidgetRegistry = new ArrayMap<>();
 
-  public FlatGUIIContext(boolean flatUIEnabled) {
-    this.mFlatUIEnabled = flatUIEnabled;
+  @RestrictTo(Scope.LIBRARY)
+  public void setFlatUIEnabled(boolean flag){
+    mFlatUIEnabled = flag;
   }
 
   public boolean isFlatUIEnabled() {

android/sdk/src/main/java/com/taobao/weex/ui/flat/WidgetContainer.java

@@ -56,7 +56,7 @@ public void createChildViewAt(int index) {
       if (ret.first != null) {
         WXComponent child = ret.first;
         Widget flatChild;
-        FlatGUIIContext uiImp = getInstance().getFlatUIImp();
+        FlatGUIIContext uiImp = getInstance().getFlatUIContext();
         WidgetContainer parent = uiImp.getFlatComponentAncestor(this);
         if (parent == null || uiImp.getAndroidViewWidget(this) != null) {
           parent = this;