android-layout - 在滑动选项卡中水平滚动 : android

Question

我已经实现了一个水平滚动列表以及最近流行的滑动标签(如谷歌游戏商店)。但是，即使我尝试滚动水平列表(选项卡的一部分)，下一个选项卡也会出现。只有当我将手指放在列表以外的某个地方(以便按住当前选项卡)时，我才能滚动我的列表。

请建议我如何确保无论何时尝试滚动我的列表，选项卡都不会改变。在任何其他区域滑动应该会更改选项卡。

以下是我的水平列表适配器 View 的实现:

    public class HorizontalView extends AdapterView{

    public boolean mAlwaysOverrideTouch = true;
    protected ListAdapter mAdapter;
    private int mLeftViewIndex = -1;
    private int mRightViewIndex = 0;
    protected int mCurrentX;
    protected int mNextX;
    private int mMaxX = Integer.MAX_VALUE;
    private int mDisplayOffset = 0;
    protected Scroller mScroller;
    private GestureDetector mGesture;
    private Queue mRemovedViewQueue = new LinkedList();
    private OnItemSelectedListener mOnItemSelected;
    private OnItemClickListener mOnItemClicked;
    private OnItemLongClickListener mOnItemLongClicked;
    private boolean mDataChanged = false;

    public HorizontalView(Context context, AttributeSet attrs){
        super(context, attrs);
        initView();
    }

    private synchronized void initView(){
        mLeftViewIndex = -1;
        mRightViewIndex = 0;
        mDisplayOffset = 0;
        mCurrentX = 0;
        mNextX = 0;
        mMaxX = Integer.MAX_VALUE;
        mScroller = new Scroller(getContext());
        mGesture = new GestureDetector(getContext(), mOnGesture);       
    }

    @Override
    public void setOnItemSelectedListener(AdapterView.OnItemSelectedListener listener){
        mOnItemSelected = listener;
    }

    @Override
    public void setOnItemClickListener(AdapterView.OnItemClickListener listener){
        mOnItemClicked = listener;
    }

    @Override
    public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener listener) {
        mOnItemLongClicked = listener;
    }

    private DataSetObserver mDataObserver = new DataSetObserver() {
        @Override
        public void onChanged() {
            synchronized (HorizontalView.this) {
            mDataChanged = true;
            }
            invalidate();
            requestLayout();
        }

        @Override
        public void onInvalidated() {
            reset();
            invalidate();
            requestLayout();
        }
    };

    @Override
    public ListAdapter getAdapter() {
        return mAdapter;
    }


    @Override
    public View getSelectedView() {
        // TODO Auto-generated method stub
        return null;
    }


    public void setAdapter(ListAdapter adapter) {
        // TODO Auto-generated method stub
        if (mAdapter != null) {
            mAdapter.unregisterDataSetObserver(mDataObserver);
        }
        mAdapter = adapter;
        mAdapter.registerDataSetObserver(mDataObserver);
        reset();        
    }

    private synchronized void reset() {
          initView();
          removeAllViewsInLayout();
          requestLayout();
    }

    @Override
    public void setSelection(int position) {
        // TODO Auto-generated method stub

    }

    @SuppressWarnings("deprecation")
    private void addAndMeasureChild(final View child, int viewPos) {
        LayoutParams params = child.getLayoutParams();
        if (params == null) {
            params = new LayoutParams(LayoutParams.FILL_PARENT,
            LayoutParams.FILL_PARENT);
        }

        addViewInLayout(child, viewPos, params, true);
        child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST));
    }

    @Override
    protected synchronized void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);

        if (mAdapter == null) {
            return;
        }

        if (mDataChanged) {
            int oldCurrentX = mCurrentX;
            initView();
            removeAllViewsInLayout();
            mNextX = oldCurrentX;
            mDataChanged = false;
        }

        if (mScroller.computeScrollOffset()) {
            int scrollx = mScroller.getCurrX();
            mNextX = scrollx;
        }

        if (mNextX <= 0) {
            mNextX = 0;
            mScroller.forceFinished(true);
        }

        if (mNextX >= mMaxX) {
            mNextX = mMaxX;
            mScroller.forceFinished(true);
        }

        int dx = mCurrentX - mNextX;

        // removeNonVisibleItems(dx);
        fillList(dx);
        positionItems(dx);

        mCurrentX = mNextX;

        if (!mScroller.isFinished()) {
            post(new Runnable() {
                @Override
                public void run() {
                    requestLayout();
                }
            });
        }
     }

    private void fillList(final int dx) {
        int edge = 0;
        View child = getChildAt(getChildCount() - 1);
        if (child != null) {
            edge = child.getRight();
        }
        fillListRight(edge, dx);

        edge = 0;
        child = getChildAt(0);
        if (child != null) {
            edge = child.getLeft();
        }
        fillListLeft(edge, dx);
    }

    private void fillListRight(int rightEdge, final int dx) {
        while (rightEdge + dx < getWidth() && mRightViewIndex < mAdapter.getCount()) {
            View child = mAdapter.getView(mRightViewIndex, (View) mRemovedViewQueue.poll(), this);
            addAndMeasureChild(child, -1);
            rightEdge += child.getMeasuredWidth();

            if (mRightViewIndex == mAdapter.getCount() - 1) {
                mMaxX = mCurrentX + rightEdge - getWidth();
            }

            if (mMaxX < 0) {
                mMaxX = 0;
            }
            mRightViewIndex++;
        }
    }

    private void fillListLeft(int leftEdge, final int dx) {
        while (leftEdge + dx > 0 && mLeftViewIndex >= 0) {
        View child = mAdapter.getView(mLeftViewIndex, (View) mRemovedViewQueue.poll(), this);
        addAndMeasureChild(child, 0);
        leftEdge -= child.getMeasuredWidth();
        mLeftViewIndex--;
        mDisplayOffset -= child.getMeasuredWidth();
        }
    }

    private void positionItems(final int dx) {
        if (getChildCount() > 0) {
        mDisplayOffset += dx;
        int left = mDisplayOffset;
        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            int childWidth = child.getMeasuredWidth();
            child.layout(left, 0, left + childWidth,child.getMeasuredHeight());
            left += childWidth;
        }
        }
    }

    public synchronized void scrollTo(int x) {
        mScroller.startScroll(mNextX, 0, x - mNextX, 0);
        requestLayout();
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        boolean handled = super.dispatchTouchEvent(ev);
        handled |= mGesture.onTouchEvent(ev);
        return handled;
    }

    protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        synchronized (HorizontalView.this) {
            mScroller.fling(mNextX, 0, (int) -velocityX, 0, 0, mMaxX, 0, 0);
        }
        requestLayout();

        return true;
    }

    protected boolean onDown(MotionEvent e) {
        mScroller.forceFinished(true);
        return true;
    }

    private OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener(){

        @Override
        public boolean onDown(MotionEvent e) {
            return HorizontalView.this.onDown(e);
        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY) {
            return HorizontalView.this.onFling(e1, e2, velocityX, velocityY);
        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {

            synchronized (HorizontalView.this) {
            mNextX += (int) distanceX;
            }
            requestLayout();

            return true;
        }

        @Override
        public boolean onSingleTapConfirmed(MotionEvent e) {
            for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            if (isEventWithinView(e, child)) {
                if (mOnItemClicked != null) {
                    mOnItemClicked.onItemClick(HorizontalView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
                }
                if (mOnItemSelected != null) {
                    mOnItemSelected.onItemSelected(HorizontalView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
                }
                break;
            }
            }
            return true;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            int childCount = getChildCount();
            for (int i = 0; i < childCount; i++) {
                View child = getChildAt(i);
                if (isEventWithinView(e, child)) {
                    if (mOnItemLongClicked != null) {
                mOnItemLongClicked.onItemLongClick(HorizontalView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
                    }
                    break;
                }

            }
         }

         private boolean isEventWithinView(MotionEvent e, View child) {
             Rect viewRect = new Rect();
             int[] childPosition = new int[2];
             child.getLocationOnScreen(childPosition);
             int left = childPosition[0];
             int right = left + child.getWidth();
             int top = childPosition[1];
             int bottom = top + child.getHeight();
             viewRect.set(left, top, right, bottom);
             return viewRect.contains((int) e.getRawX(), (int) e.getRawY());
         }
    };

    @Override
    public void setAdapter(Adapter adapter) {
        // TODO Auto-generated method stub

    }
    }

包含水平列表的片段还有其他 View 。以下是它的布局文件:

    <?xml version="1.0" encoding="UTF-8"?>

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/photo"
    android:orientation="vertical">

    <LinearLayout 
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center_vertical">

        <ImageView
            android:id="@+id/main_image"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:gravity="left"
            android:contentDescription="@string/sunny_desc"
            android:src="@drawable/sun5" />

        <LinearLayout 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:gravity="center">

            <TextView
                android:id="@+id/temp"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                style="@android:style/TextAppearance.Large"
                android:textStyle="bold"
                android:gravity="right"
                android:textColor="#FFFFFF"
                android:text="@string/temp" />

            <TextView
                android:id="@+id/type"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                style="@android:style/TextAppearance.Medium"
                android:textStyle="italic"
                android:gravity="right"
                android:textColor="#FFFFFF"
                android:text="@string/type" />

        </LinearLayout>    

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:baselineAligned="false"
        android:gravity="center_vertical">

        <LinearLayout
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="vertical"
            android:gravity="center_vertical">

            <TextView
                android:id="@+id/humdity"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="5dp"
                android:layout_marginLeft="10dp"
                android:layout_marginBottom="5dp"
                android:gravity="left"
                android:textColor="#FFFFFF"
                android:text="@string/humidity" />

            <TextView
                android:id="@+id/wind"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_marginBottom="2dp"
                android:gravity="left"
                android:textColor="#FFFFFF"
                android:text="@string/wind" />

        </LinearLayout>

        <LinearLayout 
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:gravity="center_vertical">

            <TextView
                android:id="@+id/sunrise"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="5dp"
                android:layout_marginRight="10dp"
                android:layout_marginBottom="5dp"
                android:gravity="right"
                android:layout_weight="1"
                android:textColor="#FFFFFF"
                android:text="@string/sunrise" />

            <TextView
                android:id="@+id/sunset"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginRight="10dp"
                android:layout_marginBottom="2dp"
                android:gravity="right"
                android:textColor="#FFFFFF"
                android:layout_weight="1"
                android:text="@string/sunset" />
        </LinearLayout>

    </LinearLayout>



    <LinearLayout 
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <com.sparktg.weather.HorizontalView
            android:id="@+id/item"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:layout_marginTop="10dp"
            android:smoothScrollbar="true"
            android:spacing="20dp"
            android:cacheColorHint="#FFFFFF">
        </com.sparktg.weather.HorizontalView>

    </LinearLayout> 

   <LinearLayout 
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <ListView  android:id="@id/android:list"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical
                android:drawSelectorOnTop="false"/>

    </LinearLayout>

    </LinearLayout>

我应该尝试在单个选项卡中实现多个片段吗？如果是，我应该怎么做？我已经使用以下教程实现了我的滑动选项卡:

http://davidjkelley.net/?p=34

请帮忙。

Answer 1

经过更多研究，我发现了以下针对我的问题的解决方案。以下方法将添加到我的适配器 View 中，之后滚动负责滚动哪个 View 。

// Following is the method to ensure that when the view ontaing this
// horizontal list is touched, rather than swiping between adjacent tabs
// (using left and right swipe), the list can be scrolled.
@Override
public boolean onTouchEvent(MotionEvent p_event) {
    if (p_event.getAction() == MotionEvent.ACTION_MOVE
            && getParent() != null) {
        getParent().requestDisallowInterceptTouchEvent(true);
    }

    return super.onTouchEvent(p_event);
}