Example of sliding ListView to automatically hide the head and bottom elements of the page_html/css_WEB-ITnose

The complete engineering code is here: https://github.com/NashLegend/Auto-Hide-ListView

Many software now have this kind of sliding The function of automatically hiding the head and bottom elements of the page when listing, such as Google. When you first enter the Activity, the page is a list with a view at the bottom and a view at the head. When the list slides up, the head and tail elements are hidden to show more content. When the list slides down, the Pull out the head and tail elements. Such as Google.

This is what it looked like when you first entered:

Pull the list over again, hiding the head and tail, and it’s done It looks like this:

If you scroll down, it will change back to the first picture.

This example implements this function

In this example, the layout of MainActivity is as follows, and ToolBar is the top element , Button is the bottom element.

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity">     <listview android:id="@+id/list_view" android:layout_width="match_parent" android:layout_height="match_parent" android:headerdividersenabled="false"></listview>     <android.support.v7.widget.toolbar android:id="@+id/action_bar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" android:background="@android:color/holo_blue_light"></android.support.v7.widget.toolbar>     <button android:id="@+id/footer" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignparentbottom="true" android:text="@string/ScrollDown"></button></relativelayout>

public class MainActivity extends ActionBarActivity {     ListView listView;    Toolbar toolbar;    View header;    View footer;    int touchSlop = 10;     @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        touchSlop = (int) (ViewConfiguration.get(MainActivity.this).getScaledTouchSlop() * 0.9);//滚动过多少距离后才开始计算是否隐藏/显示头尾元素。这里用了默认touchslop的0.9倍。        listView = (ListView) findViewById(R.id.list_view);        footer = findViewById(R.id.footer);        toolbar = (Toolbar) findViewById(R.id.action_bar);        // 下面这句将这个ToolBar设置为ActionBar,在这个例子里面，这句其实用不着，但是如果用了这句，就得把Theme设置为NoActionBar了，无关这里要说的，具体见上面的链接中的Style        setSupportActionBar(toolbar);                 //为这个ListView填充元素。        String[] str = new String[64];        for (int i = 0; i  adapter = new ArrayAdapter(MainActivity.this, R.layout.simple_layout, str);        listView.setAdapter(adapter);                 //为ListView添加一个Header，这个Header与ToolBar一样高。这样我们可以正确的看到列表中的第一个元素而不被遮住。        header = new View(MainActivity.this);        header.setLayoutParams(new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, (int) getResources().getDimension(R.dimen.abc_action_bar_default_height_material)));        header.setBackgroundColor(Color.parseColor("#00000000"));        listView.addHeaderView(header);                 //为ListView设置触摸事件和滚动事件，这是核心        listView.setOnTouchListener(onTouchListener);        listView.setOnScrollListener(onScrollListener);        footer.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                //为button设置点击事件，点击一次滚动10个item                listView.smoothScrollByOffset(10);            }        });    }     @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.menu_main, menu);        return true;    }     @Override    public boolean onOptionsItemSelected(MenuItem item) {        int id = item.getItemId();        if (id == R.id.action_settings) {            return true;        }        return super.onOptionsItemSelected(item);    }     AnimatorSet backAnimatorSet;//这是显示头尾元素使用的动画     private void animateBack() {        //先清除其他动画        if (hideAnimatorSet != null && hideAnimatorSet.isRunning()) {            hideAnimatorSet.cancel();        }        if (backAnimatorSet != null && backAnimatorSet.isRunning()) {            //如果这个动画已经在运行了，就不管它        } else {            backAnimatorSet = new AnimatorSet();            //下面两句是将头尾元素放回初始位置。            ObjectAnimator headerAnimator = ObjectAnimator.ofFloat(toolbar, "translationY", toolbar.getTranslationY(), 0f);            ObjectAnimator footerAnimator = ObjectAnimator.ofFloat(footer, "translationY", footer.getTranslationY(), 0f);            ArrayList<animator> animators = new ArrayList();            animators.add(headerAnimator);            animators.add(footerAnimator);            backAnimatorSet.setDuration(300);            backAnimatorSet.playTogether(animators);            backAnimatorSet.start();        }    }     AnimatorSet hideAnimatorSet;//这是隐藏头尾元素使用的动画     private void animateHide() {        //先清除其他动画        if (backAnimatorSet != null && backAnimatorSet.isRunning()) {            backAnimatorSet.cancel();        }        if (hideAnimatorSet != null && hideAnimatorSet.isRunning()) {            //如果这个动画已经在运行了，就不管它        } else {            hideAnimatorSet = new AnimatorSet();            ObjectAnimator headerAnimator = ObjectAnimator.ofFloat(toolbar, "translationY", toolbar.getTranslationY(), -toolbar.getHeight());//将ToolBar隐藏到上面            ObjectAnimator footerAnimator = ObjectAnimator.ofFloat(footer, "translationY", footer.getTranslationY(), footer.getHeight());//将Button隐藏到下面            ArrayList<animator> animators = new ArrayList();            animators.add(headerAnimator);            animators.add(footerAnimator);            hideAnimatorSet.setDuration(200);            hideAnimatorSet.playTogether(animators);            hideAnimatorSet.start();        }    }     View.OnTouchListener onTouchListener = new View.OnTouchListener() {          float lastY = 0f;        float currentY = 0f;        //下面两个表示滑动的方向，大于0表示向下滑动，小于0表示向上滑动，等于0表示未滑动        int lastDirection = 0;        int currentDirection = 0;         @Override        public boolean onTouch(View v, MotionEvent event) {            switch (event.getAction()) {                case MotionEvent.ACTION_DOWN:                    lastY = event.getY();                    currentY = event.getY();                    currentDirection = 0;                    lastDirection = 0;                    break;                case MotionEvent.ACTION_MOVE:                    if (listView.getFirstVisiblePosition() > 0) {                        //只有在listView.getFirstVisiblePosition()>0的时候才判断是否进行显隐动画。因为listView.getFirstVisiblePosition()==0时，                        //ToolBar??也就是头部元素必须是可见的，如果这时候隐藏了起来，那么占位置用了headerview就被用户发现了                        //但是当用户将列表向下拉露出列表的headerview的时候，应该要让头尾元素再次出现才对??这个判断写在了后面onScrollListener里面……                        float tmpCurrentY = event.getY();                        if (Math.abs(tmpCurrentY - lastY) > touchSlop) {//滑动距离大于touchslop时才进行判断                            currentY = tmpCurrentY;                            currentDirection = (int) (currentY - lastY);                            if (lastDirection != currentDirection) {                                //如果与上次方向不同，则执行显/隐动画                                if (currentDirection  0) {                if (firstVisibleItem > lastPosition && state == SCROLL_STATE_FLING) {                    //如果上次的位置小于当前位置，那么隐藏头尾元素                    animateHide();                }                                 //================================                if (firstVisibleItem  <br> <br> <p></p> </animator></animator>