android 基于recyclerview实现3D banner

package com.banner.recycler.recyclerviewpager; import android.content.Context; import android.content.res.TypedArray; import android.graphics.PointF; import android.os.Build; import android.os.Parcelable; import android.support.annotation.NonNull; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.LinearSmoothScroller; import android.support.v7.widget.RecyclerView; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.util.Log; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewTreeObserver; import java.lang.reflect.Field; import java.util.ArrayList; import java.util.List; /** * RecyclerViewPager * * @author Green */ public class RecyclerViewPager extends RecyclerView { public static final boolean DEBUG = BuildConfig.DEBUG; private RecyclerViewPagerAdapter<?> mViewPagerAdapter; private float mTriggerOffset = 0.25f; private float mFlingFactor = 0.15f; private float mMillisecondsPerInch = 25f; private float mTouchSpan; private List<OnPageChangedListener> mOnPageChangedListeners; private int mSmoothScrollTargetPosition = -1; private int mPositionBeforeScroll = -1; private boolean mSinglePageFling; boolean isInertia; // inertia slide state float minSlideDistance; PointF touchStartPoint; boolean mNeedAdjust; int mFisrtLeftWhenDragging; int mFirstTopWhenDragging; View mCurView; int mMaxLeftWhenDragging = Integer.MIN_VALUE; int mMinLeftWhenDragging = Integer.MAX_VALUE; int mMaxTopWhenDragging = Integer.MIN_VALUE; int mMinTopWhenDragging = Integer.MAX_VALUE; private int mPositionOnTouchDown = -1; private boolean mHasCalledOnPageChanged = true; private boolean reverseLayout = false; private float mLastY; public RecyclerViewPager(Context context) { this(context, null); } public RecyclerViewPager(Context context, AttributeSet attrs) { this(context, attrs, 0); } public RecyclerViewPager(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); initAttrs(context, attrs, defStyle); setNestedScrollingEnabled(false); ViewConfiguration viewConfiguration = ViewConfiguration.get(context); minSlideDistance = viewConfiguration.getScaledTouchSlop(); } private void initAttrs(Context context, AttributeSet attrs, int defStyle) { final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RecyclerViewPager, defStyle, 0); mFlingFactor = a.getFloat(R.styleable.RecyclerViewPager_rvp_flingFactor, 0.15f); mTriggerOffset = a.getFloat(R.styleable.RecyclerViewPager_rvp_triggerOffset, 0.25f); mSinglePageFling = a.getBoolean(R.styleable.RecyclerViewPager_rvp_singlePageFling, mSinglePageFling); isInertia = a.getBoolean(R.styleable.RecyclerViewPager_rvp_inertia, false); mMillisecondsPerInch = a.getFloat(R.styleable.RecyclerViewPager_rvp_millisecondsPerInch, 25f); a.recycle(); } public void setFlingFactor(float flingFactor) { mFlingFactor = flingFactor; } public float getFlingFactor() { return mFlingFactor; } public void setTriggerOffset(float triggerOffset) { mTriggerOffset = triggerOffset; } public float getTriggerOffset() { return mTriggerOffset; } public void setSinglePageFling(boolean singlePageFling) { mSinglePageFling = singlePageFling; } public boolean isSinglePageFling() { return mSinglePageFling; } public boolean isInertia() { return isInertia; } public void setInertia(boolean inertia) { isInertia = inertia; } @Override protected void onRestoreInstanceState(Parcelable state) { try { Field fLayoutState = state.getClass().getDeclaredField("mLayoutState"); fLayoutState.setAccessible(true); Object layoutState = fLayoutState.get(state); Field fAnchorOffset = layoutState.getClass().getDeclaredField("mAnchorOffset"); Field fAnchorPosition = layoutState.getClass().getDeclaredField("mAnchorPosition"); fAnchorPosition.setAccessible(true); fAnchorOffset.setAccessible(true); if (fAnchorOffset.getInt(layoutState) > 0) { fAnchorPosition.set(layoutState, fAnchorPosition.getInt(layoutState) - 1); } else if (fAnchorOffset.getInt(layoutState) < 0) { fAnchorPosition.set(layoutState, fAnchorPosition.getInt(layoutState) + 1); } fAnchorOffset.setInt(layoutState, 0); } catch (Throwable e) { e.printStackTrace(); } super.onRestoreInstanceState(state); } @Override public void setAdapter(Adapter adapter) { mViewPagerAdapter = ensureRecyclerViewPagerAdapter(adapter); super.setAdapter(mViewPagerAdapter); } @Override public void swapAdapter(Adapter adapter, boolean removeAndRecycleExistingViews) { mViewPagerAdapter = ensureRecyclerViewPagerAdapter(adapter); super.swapAdapter(mViewPagerAdapter, removeAndRecycleExistingViews); } @Override public Adapter getAdapter() { if (mViewPagerAdapter != null) { return mViewPagerAdapter.mAdapter; } return null; } public RecyclerViewPagerAdapter getWrapperAdapter() { return mViewPagerAdapter; } @Override public void setLayoutManager(LayoutManager layout) { super.setLayoutManager(layout); if (layout instanceof LinearLayoutManager) { reverseLayout = ((LinearLayoutManager) layout).getReverseLayout(); } } @Override public boolean fling(int velocityX, int velocityY) { boolean flinging = super.fling((int) (velocityX * mFlingFactor), (int) (velocityY * mFlingFactor)); if (flinging) { if (getLayoutManager().canScrollHorizontally()) { adjustPositionX(velocityX); } else { adjustPositionY(velocityY); } } if (DEBUG) { Log.d("@", "velocityX:" + velocityX); Log.d("@", "velocityY:" + velocityY); } return flinging; } @Override public void smoothScrollToPosition(int position) { if (DEBUG) { Log.d("@", "smoothScrollToPosition:" + position); } if (mPositionBeforeScroll < 0) { mPositionBeforeScroll = getCurrentPosition(); } mSmoothScrollTargetPosition = position; if (getLayoutManager() != null && getLayoutManager() instanceof LinearLayoutManager) { // exclude item decoration LinearSmoothScroller linearSmoothScroller = new LinearSmoothScroller(getContext()) { @Override public PointF computeScrollVectorForPosition(int targetPosition) { if (getLayoutManager() == null) { return null; } return ((LinearLayoutManager) getLayoutManager()) .computeScrollVectorForPosition(targetPosition); } @Override protected void onTargetFound(View targetView, State state, Action action) { if (getLayoutManager() == null) { return; } int dx = calculateDxToMakeVisible(targetView, getHorizontalSnapPreference()); int dy = calculateDyToMakeVisible(targetView, getVerticalSnapPreference());