Do trick to draw disappearing children first

app/src/main/java/com/hippo/scene/SceneFragment.java

@@ -19,8 +19,12 @@ package com.hippo.scene;
 import android.os.Bundle;
 import android.support.annotation.IntDef;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentActivity;
+import android.view.View;
+
+import com.hippo.ehviewer.R;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -97,4 +101,12 @@ public class SceneFragment extends Fragment {
     public boolean onBackPressed() {
         return false;
     }
+
+    @Override
+    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+
+        view.setTag(R.id.fragment_tag, getTag());
+        view.setBackgroundColor(getContext().getResources().getColor(R.color.background_light));
+    }
 }

app/src/main/java/com/hippo/scene/StageActivity.java

@@ -28,7 +28,6 @@ import com.hippo.ehviewer.R;
 import com.hippo.yorozuya.IntIdGenerator;
 
 import java.util.ArrayList;
-import java.util.Collections;
 
 public abstract class StageActivity extends AppCompatActivity {
 
@@ -148,7 +147,14 @@ public abstract class StageActivity extends AppCompatActivity {
     }
 
     int getStackIndex(String tag) {
-        return Collections.binarySearch(mSceneTagList, tag);
+        return mSceneTagList.indexOf(tag); // Collections.binarySearch(mSceneTagList, tag);
+    }
+
+    // TODO What about id is negative
+    int compareScene(String tag1, String tag2) throws NumberFormatException {
+        int int1 = Integer.parseInt(tag1);
+        int int2 = Integer.parseInt(tag2);
+        return int1 - int2;
     }
 
     public void finishScene(SceneFragment scene) {

app/src/main/java/com/hippo/scene/StageLayout.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2016 Hippo Seven
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hippo.scene;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+
+import com.hippo.ehviewer.R;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+
+public class StageLayout extends FrameLayout {
+
+    private Field mDisappearingChildrenField;
+    private ArrayList<View> mSuperDisappearingChildren;
+    private View mDumpView;
+    private boolean mDoTrick;
+
+    public StageLayout(Context context) {
+        super(context);
+        init(context);
+    }
+
+    public StageLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init(context);
+    }
+
+    public StageLayout(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init(context);
+    }
+
+    private void init(Context context) {
+        try {
+            mDisappearingChildrenField = ViewGroup.class.getDeclaredField("mDisappearingChildren");
+            mDisappearingChildrenField.setAccessible(true);
+        } catch (NoSuchFieldException e) {
+            e.printStackTrace();
+        }
+
+        if (mDisappearingChildrenField != null) {
+            mDumpView = new View(context);
+            addView(mDumpView, LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private void getSuperDisappearingChildren() {
+        if (mDisappearingChildrenField == null || mSuperDisappearingChildren != null) {
+            return;
+        }
+
+        try {
+            mSuperDisappearingChildren = (ArrayList<View>) mDisappearingChildrenField.get(this);
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private String getViewTag(View view) {
+        Object tag = view.getTag(R.id.fragment_tag);
+        if (tag instanceof String) {
+            return (String) tag;
+        } else {
+            return null;
+        }
+    }
+
+    private boolean beforeDispatchDraw() {
+        getSuperDisappearingChildren();
+
+        if (mSuperDisappearingChildren == null ||
+                mSuperDisappearingChildren.size() <= 0 || getChildCount() <= 1) { // dump view
+            return false;
+        }
+
+        StageActivity stage = null;
+        Context context = getContext();
+        if (context instanceof StageActivity) {
+            stage = (StageActivity) context;
+        }
+        if (stage == null) {
+            return false;
+        }
+
+        View view1 = mSuperDisappearingChildren.get(0);
+        View view2 = getChildAt(1); // dump view
+        String tag1 = getViewTag(view1);
+        String tag2 = getViewTag(view2);
+        try {
+            return stage.compareScene(tag1, tag2) < 0;
+        } catch (NumberFormatException e) {
+            return false;
+        }
+    }
+
+    @Override
+    protected void dispatchDraw(Canvas canvas) {
+        mDoTrick = beforeDispatchDraw();
+        super.dispatchDraw(canvas);
+        mDoTrick = false;
+    }
+
+    @Override
+    protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
+        ArrayList<View> disappearingChildren = mSuperDisappearingChildren;
+
+        if (mDoTrick && disappearingChildren != null && disappearingChildren.size() > 0) {
+            if (child == mDumpView) {
+                boolean more = false;
+                for (int i = disappearingChildren.size() - 1; i >= 0; i--) {
+                    more |= super.drawChild(canvas, disappearingChildren.get(i), drawingTime);
+                }
+                return more;
+            } else if (disappearingChildren.contains(child)) {
+                // Skip
+                return false;
+            }
+        }
+
+        return super.drawChild(canvas, child, drawingTime);
+    }
+}

app/src/main/res/anim/decelerate_terz.xml

@@ -15,6 +15,6 @@
   ~ limitations under the License.
   -->
 
-<accelerateInterpolator
+<decelerateInterpolator
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:factor="1.5"/>

app/src/main/res/anim/scene_close_enter.xml

@@ -19,12 +19,12 @@
     xmlns:android="http://schemas.android.com/apk/res/android">
 
     <alpha
-        android:fromAlpha="0.0"
+        android:fromAlpha="0.7"
         android:toAlpha="1.0"
         android:fillEnabled="true"
         android:fillBefore="true"
         android:fillAfter="true"
-        android:interpolator="@anim/accelerate_terz"
+        android:interpolator="@anim/decelerate_terz"
         android:duration="250"/>
 
 </set>

app/src/main/res/anim/scene_open_exit.xml

@@ -16,16 +16,15 @@
   -->
 
 <set
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:background="#ff000000">
+    xmlns:android="http://schemas.android.com/apk/res/android">
 
     <alpha
         android:fromAlpha="1.0"
-        android:toAlpha="0.0"
+        android:toAlpha="0.7"
         android:fillEnabled="true"
-        android:fillBefore="true"
+        android:fillBefore="false"
         android:fillAfter="true"
         android:interpolator="@android:interpolator/accelerate_decelerate"
-        android:duration="350"/>
+        android:duration="217"/>
 
 </set>

app/src/main/res/layout/activity_main.xml

@@ -22,7 +22,7 @@
     android:layout_height="match_parent"
     android:fitsSystemWindows="true">
 
-    <FrameLayout
+    <com.hippo.scene.StageLayout
         android:id="@+id/fragment_container"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
@@ -34,6 +34,7 @@
         android:layout_width="wrap_content"
         android:layout_height="match_parent"
         android:layout_gravity="left"
+        android:background="@color/background_light"
         android:fitsSystemWindows="true"
         app:headerLayout="@layout/nav_header_main"
         app:menu="@menu/nav_drawer_main"/>

app/src/main/res/values-v21/themes.xml

@@ -17,7 +17,7 @@
 
 <resources>
 
-    <style name="AppTheme.Main" parent="AppTheme.NoActionBar">
+    <style name="AppTheme.Main" parent="AppTheme.Translucent.NoActionBar">
         <item name="android:windowDrawsSystemBarBackgrounds">true</item>
         <item name="android:statusBarColor">@android:color/transparent</item>
     </style>

app/src/main/res/values/colors.xml

@@ -36,6 +36,9 @@
     <color name="secondary_text_default_dark">#61ffffff</color>
     <color name="secondary_text_disabled_light">#24000000</color>
 
+    <color name="background_dark">#ff303030</color>
+    <color name="background_light">#fffafafa</color>
+
     <color name="red_500">#fff44336</color>
     <color name="teal_500">#ff009688</color>
     <color name="teal_700">#ff00796b</color>

app/src/main/res/values/ids.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2016 Hippo Seven
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<resources>
+
+    <item name="fragment_tag" type="id"/>
+
+</resources>

app/src/main/res/values/themes.xml

@@ -24,12 +24,22 @@
         <item name="colorAccent">@color/colorAccent</item>
     </style>
 
-    <style name="AppTheme.NoActionBar">
+    <style name="AppTheme.Translucent">
+        <item name="android:windowBackground">@android:color/transparent</item>
+        <item name="android:colorBackgroundCacheHint">@null</item>
+        <item name="android:windowIsTranslucent">true</item>
+        <!-- Note that we use the base animation style here (that is no
+             animations) because we really have no idea how this kind of
+             activity will be used. -->
+        <item name="android:windowAnimationStyle">@android:style/Animation</item>
+    </style>
+
+    <style name="AppTheme.Translucent.NoActionBar">
         <item name="windowActionBar">false</item>
         <item name="windowNoTitle">true</item>
     </style>
 
-    <style name="AppTheme.Main" parent="AppTheme.NoActionBar">
+    <style name="AppTheme.Main" parent="AppTheme.Translucent.NoActionBar">
     </style>
 
 </resources>