import android.animation.Animator; import android.content.Context; import android.support.design.widget.CoordinatorLayout; import android.support.v4.view.ViewCompat; import android.support.v4.view.animation.FastOutSlowInInterpolator; import android.util.AttributeSet; import android.view.View; import android.view.ViewPropertyAnimator; import android.view.animation.Interpolator; /** * CoordinatorLayout Behavior for a quick return footer * * When a nested ScrollView is scrolled down, the quick return view will disappear. * When the ScrollView is scrolled back up, the quick return view will reappear. * * @author bherbst */ @SuppressWarnings("unused") public class QuickReturnFooterBehavior extends CoordinatorLayout.Behavior<View> { private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator(); private int mDySinceDirectionChange; public QuickReturnFooterBehavior(Context context, AttributeSet attrs) { super(context, attrs); } @Override public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild, View target, int nestedScrollAxes) { return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0; } @Override public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dx, int dy, int[] consumed) { if (dy > 0 && mDySinceDirectionChange < 0 || dy < 0 && mDySinceDirectionChange > 0) { // We detected a direction change- cancel existing animations and reset our cumulative delta Y child.animate().cancel(); mDySinceDirectionChange = 0; } mDySinceDirectionChange += dy; if (mDySinceDirectionChange > child.getHeight() && child.getVisibility() == View.VISIBLE) { hide(child); } else if (mDySinceDirectionChange < 0 && child.getVisibility() == View.GONE) { show(child); } } /** * Hide the quick return view. * * Animates hiding the view, with the view sliding down and out of the screen. * After the view has disappeared, its visibility will change to GONE. * * @param view The quick return view */ private void hide(final View view) { ViewPropertyAnimator animator = view.animate() .translationY(view.getHeight()) .setInterpolator(INTERPOLATOR) .setDuration(200); animator.setListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animator) {} @Override public void onAnimationEnd(Animator animator) { // Prevent drawing the View after it is gone view.setVisibility(View.GONE); } @Override public void onAnimationCancel(Animator animator) { // Canceling a hide should show the view show(view); } @Override public void onAnimationRepeat(Animator animator) {} }); animator.start(); } /** * Show the quick return view. * * Animates showing the view, with the view sliding up from the bottom of the screen. * After the view has reappeared, its visibility will change to VISIBLE. * * @param view The quick return view */ private void show(final View view) { ViewPropertyAnimator animator = view.animate() .translationY(0) .setInterpolator(INTERPOLATOR) .setDuration(200); animator.setListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animator) { view.setVisibility(View.VISIBLE); } @Override public void onAnimationEnd(Animator animator) {} @Override public void onAnimationCancel(Animator animator) { // Canceling a show should hide the view hide(view); } @Override public void onAnimationRepeat(Animator animator) {} }); animator.start(); } }
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" > <android.support.v7.widget.RecyclerView android:id="@+id/recyclerview" android:layout_width="match_parent" android:layout_height="match_parent" /> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_gravity="bottom" app:layout_behavior="com.mb.widget.QuickReturnFooterBehavior" android:background="@color/quickreturn_background" android:gravity="center" android:padding="16dp" android:text="QuickReturn Footer" android:textAppearance="@style/TextAppearance.AppCompat.Headline" android:textColor="@android:color/white" /> </android.support.design.widget.CoordinatorLayout>
public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview); recyclerView.setAdapter(new SimpleStringRecyclerViewAdapter(this,Arrays.asList(Cheeses.sCheeseStrings))); recyclerView.setLayoutManager(new LinearLayoutManager(this)); } }
SwipeDismissBehavior用法及实现原理
http://www.open-open.com/lib/view/open1446609550545.html
https://github.com/hugeterry/CoordinatorTabLayout