recycleview.zip

package cn.xxx.view.recycleview; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Rect; import android.os.Build; import android.support.v4.view.ViewCompat; import android.support.v7.widget.GridLayoutManager; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.util.AttributeSet; import android.util.Log; import android.view.FocusFinder; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; import cn.xxx.R; public class TvRecyclerView extends RecyclerView { private static final String TAG = "TvRecyclerView"; private int position; //焦点是否居中 private boolean mSelectedItemCentered; private int mSelectedItemOffsetStart; private int mSelectedItemOffsetEnd; //分页的时候使用 private int mLoadMoreBeforehandCount = 0; public TvRecyclerView(Context context) { this(context, null); } public TvRecyclerView(Context context, AttributeSet attrs) { this(context, attrs, -1); } public TvRecyclerView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(context, attrs, defStyle); } private void init(Context context, AttributeSet attrs, int defStyle) { initView(); initAttr(context, attrs); } private void initView() { setDescendantFocusability(FOCUS_AFTER_DESCENDANTS); setHasFixedSize(true); setWillNotDraw(true); setOverScrollMode(View.OVER_SCROLL_NEVER); setChildrenDrawingOrderEnabled(true); setClipChildren(false); setClipToPadding(false); setClickable(false); setFocusable(true); setFocusableInTouchMode(true); /** 防止RecyclerView刷新时焦点不错乱bug的步骤如下: (1)adapter执行setHasStableIds(true)方法 (2)重写getItemId()方法,让每个view都有各自的id (3)RecyclerView的动画必须去掉 */ setItemAnimator(null); } private void initAttr(Context context, AttributeSet attrs) { if (attrs != null) { final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TvRecyclerView); /** * 如果是towWayView的layoutManager */ final String name = a.getString(R.styleable.TvRecyclerView_tv_layoutManager); mSelectedItemCentered = a.getBoolean(R.styleable.TvRecyclerView_tv_selectedItemCentered, false); mLoadMoreBeforehandCount = a.getInteger(R.styleable.TvRecyclerView_tv_loadMoreBeforehandCount, 0); mSelectedItemOffsetStart = a.getDimensionPixelSize(R.styleable.TvRecyclerView_tv_selectedItemOffsetStart, 0); mSelectedItemOffsetEnd = a.getDimensionPixelSize(R.styleable.TvRecyclerView_tv_selectedItemOffsetEnd, 0); a.recycle(); } } private int getFreeWidth() { return getWidth() - getPaddingLeft() - getPaddingRight(); } private int getFreeHeight() { return getHeight() - getPaddingTop() - getPaddingBottom(); } @Override protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); } @Override public boolean hasFocus() { return super.hasFocus(); } @Override public boolean isInTouchMode() { // 解决4.4版本抢焦点的问题 if (Build.VERSION.SDK_INT == 19) { return !(hasFocus() && !super.isInTouchMode()); } else { return super.isInTouchMode(); } //return super.isInTouchMode(); } @Override public void requestChildFocus(View child, View focused) { if (null != child) { if (mSelectedItemCentered) { mSelectedItemOffsetStart = !isVertical() ? (getFreeWidth() - child.getWidth()) : (getFreeHeight() - child.getHeight()); mSelectedItemOffsetStart /= 2; mSelectedItemOffsetEnd = mSelectedItemOffsetStart; } } super.requestChildFocus(child, focused); } @Override public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { final int parentLeft = getPaddingLeft(); final int parentRight = getWidth() - getPaddingRight(); final int parentTop = getPaddingTop(); final int parentBottom = getHeight() - getPaddingBottom(); final int childLeft = child.getLeft() + rect.left; final int childTop = child.getTop() + rect.top; final int childRight = childLeft + rect.width(); final int childBottom = childTop + rect.height(); final int offScreenLeft = Math.min(0, childLeft - parentLeft - mSelectedItemOffsetStart); final int offScreenRight = Math.max(0, childRight - parentRight + mSelectedItemOffsetEnd); final int offScreenTop = Math.min(0, childTop - parentTop - mSelectedItemOffsetStart); final int offScreenBottom = Math.max(0, childBottom - parentBottom + mSelectedItemOffsetEnd); final boolean canScrollHorizontal = getLayoutManager().canScrollHorizontally(); final boolean canScrollVertical = getLayoutManager().canScrollVertically(); // Favor the "start" layout direction over the end when bringing one side or the other // of a large rect into view. If we decide to bring in end because start is already // visible, limit the scroll such that start won't go out of bounds. final int dx; if (canScrollHorizontal) { if (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL) { dx = offScreenRight != 0 ? offScreenRight : Math.max(offScreenLeft, childRight - parentRight); } else { dx = offScreenLeft != 0 ? offScreenLeft : Math.min(childLeft - parentLeft, offScreenRight); } } else { dx = 0; } // Favor bringing the top into view over the bottom. If top is already visible and // we should scroll to make bottom visible, make sure top does not go out of bounds. final int dy; if (canScrollVertical) { dy = offScreenTop != 0 ? offScreenTop : Math.min(childTop - parentTop, offScreenBottom); } else { dy = 0; } if (dx != 0 || dy != 0) { if (immediate) { scrollBy(dx, dy); } else { smoothScrollBy(dx, dy); } // 重绘是为了选中item置顶，具体请参考getChildDrawingOrder方法 postInvalidate(); return true; } return false; } @Override public int getBaseline() { return -1; } public int getSelectedItemOffsetStart() { return mSelectedItemOffsetStart; } public int getSelectedItemOffsetEnd() { return mSelectedItemOffsetEnd; } @Override public void setLayoutManager(LayoutManager layout) { super.setLayoutManager(layout); } /** * 判断是垂直，还是横向. */ private boolean isVertical() { LayoutManager manager = getLayoutManager(); if (manager != null) { LinearLayoutManager layout = (LinearLayoutManager) getLayoutManager(); return layout.getOrientation() == LinearLayoutManager.VERTICAL; } return false; } /** * 设置选中的Item距离开始或结束的偏移量； * 与滚动方向有关； * 与setSelectedItemAtCentered()方法二选一 * * @param offsetStart * @param offsetEnd 从结尾到你移动的位置. */ public void setSelectedItemOffset(int offset