android群英传笔记--第四章--ListView使用技巧（二）

自动显示、隐藏布局的ListView

public class ScrollHideListView extends Activity {

private Toolbar mToolbar;
private ListView mListView;
private String[] mStr = new String[20];
private int mTouchSlop;
private float mFirstY;
private float mCurrentY;
private int direction;
private ObjectAnimator mAnimator;
private boolean mShow = true;

View.OnTouchListener myTouchListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mFirstY = event.getY();
break;
case MotionEvent.ACTION_MOVE:
mCurrentY = event.getY();
if (mCurrentY - mFirstY > mTouchSlop) {
direction = 0;// down
} else if (mFirstY - mCurrentY > mTouchSlop) {
direction = 1;// up
}
if (direction == 1) {
if (mShow) {
toolbarAnim(1);//hide
mShow = !mShow;
}
} else if (direction == 0) {
if (!mShow) {
toolbarAnim(0);//show
mShow = !mShow;
}

4000
}
break;
case MotionEvent.ACTION_UP:
break;
}
return false;
}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.scroll_hide);
mTouchSlop = ViewConfiguration.get(this).getScaledTouchSlop();
mToolbar = (Toolbar) findViewById(R.id.toolbar);
mListView = (ListView) findViewById(R.id.listview);
for (int i = 0; i < mStr.length; i++) {
mStr[i] = "Item " + i;
}
View header = new View(this);
header.setLayoutParams(new AbsListView.LayoutParams(
AbsListView.LayoutParams.MATCH_PARENT,
(int) getResources().getDimension(
R.dimen.abc_action_bar_default_height_material)));
mListView.addHeaderView(header);
mListView.setAdapter(new ArrayAdapter<String>(
ScrollHideListView.this,
android.R.layout.simple_expandable_list_item_1,
mStr));
mListView.setOnTouchListener(myTouchListener);
}

private void toolbarAnim(int flag) {
if (mAnimator != null && mAnimator.isRunning()) {
mAnimator.cancel();
}
if (flag == 0) {
mAnimator = ObjectAnimator.ofFloat(mToolbar,
"translationY", mToolbar.getTranslationY(), 0);
} else {
mAnimator = ObjectAnimator.ofFloat(mToolbar,
"translationY", mToolbar.getTranslationY(),
-mToolbar.getHeight());
}
mAnimator.start();
}
}