解决滑动到顶部后无法下滑复位只能靠重写返回键复位的逻辑问题

app/src/main/java/github/hellocsl/ucmainpager/behavior/uc/UcNewsHeaderPagerBehavior.java

@@ -3,6 +3,8 @@
 import android.content.Context;
 import android.support.design.widget.CoordinatorLayout;
 import android.support.v4.view.ViewCompat;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.MotionEvent;
@@ -68,7 +70,7 @@ public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View chi
         if (BuildConfig.DEBUG) {
             Log.d(TAG, "onStartNestedScroll: ");
         }
-        return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0 && canScroll(child, 0) && !isClosed(child);
+        return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0 && canScroll(child, 0) && isOnRVTop(child, target);
     }
 
 
@@ -88,6 +90,21 @@ public boolean isClosed() {
         return mCurState == STATE_CLOSED;
     }
 
+    /**
+     * to judge whether current recyclerview'item is at the top of recyclerview
+     *
+     * @param child
+     * @param target
+     * @return
+     */
+    private boolean isOnRVTop(View child, View target) {
+        if (target instanceof RecyclerView) {
+            boolean isRVTop = ((LinearLayoutManager) ((RecyclerView) target)
+                    .getLayoutManager()).findFirstCompletelyVisibleItemPosition() == 0;
+            return isRVTop;
+        }
+        return true;
+    }
 
     private void changeState(int newState) {
         if (mCurState != newState) {
@@ -113,6 +130,8 @@ private boolean canScroll(View child, float pendingDy) {
     public boolean onInterceptTouchEvent(CoordinatorLayout parent, final View child, MotionEvent ev) {
         if (ev.getAction() == MotionEvent.ACTION_UP && !isClosed()) {
             handleActionUp(parent, child);
+        } else if (ev.getAction() == MotionEvent.ACTION_UP && isClosed()) {
+            handleActionDown(parent, child);
         }
         return super.onInterceptTouchEvent(parent, child, ev);
     }
@@ -151,6 +170,22 @@ private void handleActionUp(CoordinatorLayout parent, final View child) {
         } else {
             mFlingRunnable.scrollToOpen(DURATION_SHORT);
         }
+    }
+
+    private void handleActionDown(CoordinatorLayout parent, final View child) {
+        if (BuildConfig.DEBUG) {
+            Log.d(TAG, "handleActionUp: ");
+        }
+        if (mFlingRunnable != null) {
+            child.removeCallbacks(mFlingRunnable);
+            mFlingRunnable = null;
+        }
+        mFlingRunnable = new FlingRunnable(parent, child);
+        if (child.getTranslationY() > getHeaderOffsetRange() / 3 * 2) {
+            mFlingRunnable.scrollToOpen(DURATION_SHORT);
+        } else {
+            mFlingRunnable.scrollToClosed(DURATION_SHORT);
+        }
 
     }
 

build.gradle

@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.0.0'
+        classpath 'com.android.tools.build:gradle:2.1.2'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

gradle.properties

@@ -1,18 +1,17 @@
-# Project-wide Gradle settings.
-
-# IDE (e.g. Android Studio) users:
-# Gradle settings configured through the IDE *will override*
-# any settings specified in this file.
-
+## Project-wide Gradle settings.
+#
 # For more details on how to configure your build environment visit
 # http://www.gradle.org/docs/current/userguide/build_environment.html
-
+#
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
 # Default value: -Xmx10248m -XX:MaxPermSize=256m
 # org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
-
+#
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
+# org.gradle.parallel=true
+#Fri Sep 16 22:38:01 CST 2016
+systemProp.http.proxyHost=127.0.0.1
+systemProp.http.proxyPort=1080

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Mon Dec 28 10:00:20 PST 2015
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip