解决的问题有两个:
1)实现水平滑动的ListView。重写AdapterView,上代码:
- package com.liucanwen.horizontallistview.view;
- import java.util.LinkedList;
- import java.util.Queue;
- import android.content.Context;
- import android.database.DataSetObserver;
- import android.graphics.Rect;
- import android.util.AttributeSet;
- import android.view.GestureDetector;
- import android.view.GestureDetector.OnGestureListener;
- import android.view.View.MeasureSpec;
- import android.view.MotionEvent;
- import android.view.View;
- import android.widget.AdapterView;
- import android.widget.ListAdapter;
- import android.widget.Scroller;
- /**
- * 重写ListView,以达到水平滑动
- */
- public class HorizontalListView extends AdapterView<ListAdapter>
- {
- 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<View> mRemovedViewQueue = new LinkedList<View>();
- private OnItemSelectedListener mOnItemSelected;
- private OnItemClickListener mOnItemClicked;
- private OnItemLongClickListener mOnItemLongClicked;
- private boolean mDataChanged = false;
- public HorizontalListView(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 (HorizontalListView.this)
- {
- mDataChanged = true;
- }
- invalidate();
- requestLayout();
- }
- @Override
- public void onInvalidated()
- {
- reset();
- invalidate();
- requestLayout();
- }
- };
- @Override
- public ListAdapter getAdapter()
- {
- return mAdapter;
- }
- @Override
- public View getSelectedView()
- {
- // TODO: implement
- return null;
- }
- @Override
- public void setAdapter(ListAdapter adapter)
- {
- 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: implement
- }
- 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,
- 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,
- mRemovedViewQueue.poll(), this);
- addAndMeasureChild(child, 0);
- leftEdge -= child.getMeasuredWidth();
- mLeftViewIndex--;
- mDisplayOffset -= child.getMeasuredWidth();
- }
- }
- private void removeNonVisibleItems(final int dx)
- {
- View child = getChildAt(0);
- while (child != null && child.getRight() + dx <= 0)
- {
- mDisplayOffset += child.getMeasuredWidth();
- mRemovedViewQueue.offer(child);
- removeViewInLayout(child);
- mLeftViewIndex++;
- child = getChildAt(0);
- }
- child = getChildAt(getChildCount() - 1);
- while (child != null && child.getLeft() + dx >= getWidth())
- {
- mRemovedViewQueue.offer(child);
- removeViewInLayout(child);
- mRightViewIndex--;
- child = getChildAt(getChildCount() - 1);
- }
- }
- 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 + child.getPaddingRight();
- }
- }
- }
- 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 (HorizontalListView.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 HorizontalListView.this.onDown(e);
- }
- @Override
- public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
- float velocityY)
- {
- return HorizontalListView.this
- .onFling(e1, e2, velocityX, velocityY);
- }
- @Override
- public boolean onScroll(MotionEvent e1, MotionEvent e2,
- float distanceX, float distanceY)
- {
- synchronized (HorizontalListView.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(HorizontalListView.this,
- child, mLeftViewIndex + 1 + i,
- mAdapter.getItemId(mLeftViewIndex + 1 + i));
- }
- if (mOnItemSelected != null)
- {
- mOnItemSelected.onItemSelected(HorizontalListView.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(
- HorizontalListView.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());
- }
- };
- }
2)第一步实现了水平滑动,往往我们会把这个水平ListView放到ScrollView里面(见截图实现),而这两个控件恰好滑动会有冲突,滑动水平ListView时会有卡顿,因此重写ScrollView,以达到流畅滑动:
- package com.liucanwen.horizontallistview.view;
- import android.content.Context;
- import android.util.AttributeSet;
- import android.view.GestureDetector;
- import android.view.GestureDetector.SimpleOnGestureListener;
- import android.view.MotionEvent;
- import android.view.View;
- import android.widget.ScrollView;
- /**
- * 重写ScrollView,以解决ScrollView与水平listView滑动时冲突
- */
- public class MyScrollView extends ScrollView
- {
- private GestureDetector mGestureDetector;
- View.OnTouchListener mGestureListener;
- public MyScrollView(Context context, AttributeSet attrs)
- {
- super(context, attrs);
- mGestureDetector = new GestureDetector(new YScrollDetector());
- setFadingEdgeLength(0);
- }
- @Override
- public boolean onInterceptTouchEvent(MotionEvent ev)
- {
- return super.onInterceptTouchEvent(ev)
- && mGestureDetector.onTouchEvent(ev);
- }
- class YScrollDetector extends SimpleOnGestureListener
- {
- @Override
- public boolean onScroll(MotionEvent e1, MotionEvent e2,
- float distanceX, float distanceY)
- {
- if (Math.abs(distanceY) > Math.abs(distanceX))
- {
- return true;
- }
- return false;
- }
- }
- }
好了,大功告成!
以下系项目的源代码下载地址:
http://download.csdn.net/detail/qq15989177612/6943633