Add reveal effect for gallery detail header on pre-L

app/src/main/java/com/hippo/ehviewer/ui/scene/GalleryDetailScene.java

@@ -36,6 +36,7 @@ import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentTransaction;
+import android.support.v4.view.ViewCompat;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.PopupMenu;
 import android.text.TextUtils;
@@ -45,7 +46,6 @@ import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.MenuItem;
 import android.view.View;
-import android.view.ViewAnimationUtils;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
@@ -79,6 +79,7 @@ import com.hippo.ehviewer.ui.CommonOperations;
 import com.hippo.ehviewer.ui.GalleryActivity;
 import com.hippo.ehviewer.ui.MainActivity;
 import com.hippo.ehviewer.ui.annotation.WholeLifeCircle;
+import com.hippo.reveal.ViewAnimationUtils;
 import com.hippo.rippleold.RippleSalon;
 import com.hippo.scene.Announcer;
 import com.hippo.scene.SceneFragment;
@@ -639,7 +640,6 @@ public class GalleryDetailScene extends BaseScene implements View.OnClickListene
         setActionDrawable(mSimilar, similar);
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     private boolean createCircularReveal() {
         if (mColorBg == null) {
             return false;
@@ -647,7 +647,7 @@ public class GalleryDetailScene extends BaseScene implements View.OnClickListene
 
         int w = mColorBg.getWidth();
         int h = mColorBg.getHeight();
-        if (mColorBg.isAttachedToWindow() && w != 0 && h != 0) {
+        if (ViewCompat.isAttachedToWindow(mColorBg) && w != 0 && h != 0) {
             ViewAnimationUtils.createCircularReveal(mColorBg, w / 2, h / 2, 0,
                     (float) Math.hypot(w / 2, h / 2)).setDuration(300).start();
             return true;
@@ -692,8 +692,7 @@ public class GalleryDetailScene extends BaseScene implements View.OnClickListene
                 break;
         }
 
-        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP &&
-                (oldState == STATE_INIT || oldState == STATE_FAILED || oldState == STATE_REFRESH) &&
+        if ((oldState == STATE_INIT || oldState == STATE_FAILED || oldState == STATE_REFRESH) &&
                 (state == STATE_NORMAL || state == STATE_REFRESH_HEADER)) {
             if (!createCircularReveal()) {
                 SimpleHandler.getInstance().post(new Runnable() {

app/src/main/java/com/hippo/reveal/RevealView.java

@@ -0,0 +1,78 @@
+/*
+ * 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.reveal;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Path;
+import android.util.AttributeSet;
+import android.view.View;
+
+public class RevealView extends View implements Reveal {
+
+    private final Path mRevealPath = new Path();
+    private boolean mReveal;
+    private int mCenterX;
+    private int mCenterY;
+    private float mRadius;
+
+    public RevealView(Context context) {
+        super(context);
+    }
+
+    public RevealView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public RevealView(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    @Override
+    public void setRevealEnable(boolean enable) {
+        mReveal = enable;
+        invalidate();
+    }
+
+    @Override
+    public void setReveal(int centerX, int centerY, float radius) {
+        mCenterX = centerX;
+        mCenterY = centerY;
+        mRadius = radius;
+        invalidate();
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        boolean reveal = mReveal;
+        int saveCount = 0;
+
+        if (reveal) {
+            saveCount = canvas.save();
+            Path path = mRevealPath;
+            path.reset();
+            path.addCircle(mCenterX, mCenterY, mRadius, Path.Direction.CW);
+            canvas.clipPath(path);
+        }
+
+        super.draw(canvas);
+
+        if (reveal) {
+            canvas.restoreToCount(saveCount);
+        }
+    }
+}