Java tutorial
/* * Copyright (C) 2011 The Android Open Source Project * Copyright (C) 2012 Jake Wharton * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.viewpagerindicator.as.library.indicator; import android.content.Context; import android.support.v4.view.ViewPager.OnPageChangeListener; import android.support.v7.widget.RecyclerView; import android.util.AttributeSet; import android.view.Gravity; import android.view.View; import android.widget.HorizontalScrollView; import android.widget.ImageView; import com.viewpagerindicator.as.R; import com.viewpagerindicator.as.library.pageview.RecyclerViewPager; import static android.view.ViewGroup.LayoutParams.FILL_PARENT; import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT; /** * This widget implements the dynamic action bar tab behavior that can change * across different configurations or circumstances. */ public class RecyclerIconPageIndicator extends HorizontalScrollView implements RecyclerPageIndicator { private final IcsLinearLayout mIconsLayout; private RecyclerView mRecyclerView; private OnPageChangeListener mListener; private Runnable mIconSelector; private int mSelectedIndex; public RecyclerIconPageIndicator(Context context) { this(context, null); } public RecyclerIconPageIndicator(Context context, AttributeSet attrs) { super(context, attrs); setHorizontalScrollBarEnabled(false); mIconsLayout = new IcsLinearLayout(context, R.attr.vpiIconPageIndicatorStyle); addView(mIconsLayout, new LayoutParams(WRAP_CONTENT, FILL_PARENT, Gravity.CENTER)); } private void animateToIcon(final int position) { final View iconView = mIconsLayout.getChildAt(position); if (mIconSelector != null) { removeCallbacks(mIconSelector); } mIconSelector = new Runnable() { public void run() { final int scrollPos = iconView.getLeft() - (getWidth() - iconView.getWidth()) / 2; smoothScrollTo(scrollPos, 0); mIconSelector = null; } }; post(mIconSelector); } @Override public void onAttachedToWindow() { super.onAttachedToWindow(); if (mIconSelector != null) { // Re-post the selector we saved post(mIconSelector); } } @Override public void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mIconSelector != null) { removeCallbacks(mIconSelector); } } // @Override // public void onPageScrollStateChanged(int arg0) { // if (mListener != null) { // mListener.onPageScrollStateChanged(arg0); // } // } // // @Override // public void onPageScrolled(int arg0, float arg1, int arg2) { // if (mListener != null) { // mListener.onPageScrolled(arg0, arg1, arg2); // } // } // // @Override // public void onPageSelected(int arg0) { // setCurrentItem(arg0); // if (mListener != null) { // mListener.onPageSelected(arg0); // } // } // @Override // public void setViewPager(ViewPager view) { // if (mRecyclerView == view) { // return; // } // if (mRecyclerView != null) { // mRecyclerView.setOnPageChangeListener(null); // } // PagerAdapter adapter = view.getAdapter(); // if (adapter == null) { // throw new IllegalStateException("ViewPager does not have adapter instance."); // } // mRecyclerView = view; // view.setOnPageChangeListener(this); // notifyDataSetChanged(); // } public void notifyDataSetChanged() { mIconsLayout.removeAllViews(); IconPagerAdapter iconAdapter = (IconPagerAdapter) mRecyclerView.getAdapter(); int count = mRecyclerView.getAdapter().getItemCount(); for (int i = 0; i < count; i++) { ImageView view = new ImageView(getContext(), null, R.attr.vpiIconPageIndicatorStyle); view.setImageResource(iconAdapter.getIconResId(i)); mIconsLayout.addView(view); } if (mSelectedIndex > count) { mSelectedIndex = count - 1; } requestLayout(); } @Override public void setViewPager(RecyclerView view) { if (mRecyclerView == view) { return; } if (mRecyclerView != null) { wrapViewPager(mRecyclerView).clearOnPageChangedListeners(); ; wrapViewPager(mRecyclerView).clearOnScrollListeners(); } if (view.getAdapter() == null) { throw new IllegalStateException("ViewPager does not have adapter instance."); } mRecyclerView = view; notifyDataSetChanged(); animateIcon(mSelectedIndex); wrapViewPager(mRecyclerView).addOnPageChangedListener(new RecyclerViewPager.OnPageChangedListener() { @Override public void OnPageChanged(int oldPosition, int newPosition) { mSelectedIndex = newPosition; invalidate(); animateIcon(newPosition); if (mListener != null) { mListener.onPageSelected(newPosition); } } }); wrapViewPager(mRecyclerView).addOnScrollListener(new RecyclerView.OnScrollListener() { @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) { super.onScrollStateChanged(recyclerView, newState); if (mListener != null) { mListener.onPageScrollStateChanged(newState); } } @Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) { super.onScrolled(recyclerView, dx, dy); if (mListener != null) { mListener.onPageScrolled(wrapViewPager(mRecyclerView).getCurrentPosition(), 0f, dx); } } }); } @Override public void setViewPager(RecyclerView view, int initialPosition) { setViewPager(view); setCurrentItem(initialPosition); } @Override public void setCurrentItem(int item) { if (mRecyclerView == null) { throw new IllegalStateException("ViewPager has not been bound."); } mSelectedIndex = item; mRecyclerView.scrollToPosition(item); animateIcon(item); } private void animateIcon(int item) { int tabCount = mIconsLayout.getChildCount(); for (int i = 0; i < tabCount; i++) { View child = mIconsLayout.getChildAt(i); boolean isSelected = (i == item); System.out.println(i + ", isSelected:" + isSelected); child.setSelected(isSelected); if (isSelected) { animateToIcon(item); } } } public void setmListener(OnPageChangeListener mListener) { this.mListener = mListener; } private RecyclerViewPager wrapViewPager(RecyclerView view) { if (view instanceof RecyclerViewPager) { return (RecyclerViewPager) view; } throw new IllegalArgumentException("this view is not RecyclerViewPager type"); } }