/
FadeableViewPager.java
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/
FadeableViewPager.java
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/*
* MIT License
*
* Copyright (c) 2017 Jan Heinrich Reimer
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.heinrichreimersoftware.materialintro.view;
import android.content.Context;
import android.database.DataSetObserver;
import android.os.Parcelable;
import androidx.annotation.NonNull;
import androidx.viewpager.widget.PagerAdapter;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
public class FadeableViewPager extends SwipeBlockableViewPager {
public FadeableViewPager(Context context) {
super(context);
}
public FadeableViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public void setAdapter(PagerAdapter adapter) {
super.setAdapter(new PagerAdapterWrapper(adapter));
}
@Override
public PagerAdapter getAdapter() {
PagerAdapterWrapper wrapper = (PagerAdapterWrapper) super.getAdapter();
return wrapper == null ? null : wrapper.getAdapter();
}
@SuppressWarnings("deprecation")
@Deprecated
@Override
public void setOnPageChangeListener(OnPageChangeListener listener) {
super.setOnPageChangeListener(new OnPageChangeListenerWrapper(listener));
}
@Override
public void addOnPageChangeListener(@NonNull OnPageChangeListener listener) {
super.addOnPageChangeListener(new OnPageChangeListenerWrapper(listener));
}
@Override
public void removeOnPageChangeListener(@NonNull OnPageChangeListener listener) {
super.removeOnPageChangeListener(new OnPageChangeListenerWrapper(listener));
}
@Override
public void setPageTransformer(boolean reverseDrawingOrder, PageTransformer transformer) {
super.setPageTransformer(reverseDrawingOrder, new PageTransformerWrapper(transformer, getAdapter()));
}
private class OnPageChangeListenerWrapper implements OnPageChangeListener {
private final OnPageChangeListener listener;
private OnPageChangeListenerWrapper(OnPageChangeListener listener) {
this.listener = listener;
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
int count = listener instanceof OnOverscrollPageChangeListener ?
FadeableViewPager.super.getAdapter().getCount() : getAdapter().getCount();
listener.onPageScrolled(Math.min(position, count - 1),
position < count ? positionOffset : 0,
position < count ? positionOffsetPixels : 0);
}
@Override
public void onPageSelected(int position) {
int count = listener instanceof OnOverscrollPageChangeListener ?
FadeableViewPager.super.getAdapter().getCount() : getAdapter().getCount();
listener.onPageSelected(Math.min(position, count - 1));
}
@Override
public void onPageScrollStateChanged(int state) {
listener.onPageScrollStateChanged(state);
}
}
private class PagerAdapterWrapper extends PagerAdapter {
private final PagerAdapter adapter;
private PagerAdapterWrapper(PagerAdapter adapter) {
this.adapter = adapter;
adapter.registerDataSetObserver(new DataSetObserver() {
@Override
public void onChanged() {
notifyDataSetChanged();
}
@Override
public void onInvalidated() {
notifyDataSetChanged();
}
});
}
public PagerAdapter getAdapter() {
return adapter;
}
@Override
public int getCount() {
return adapter.getCount() + 1;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return object != null && adapter.isViewFromObject(view, object);
}
@Override
public void startUpdate(ViewGroup container) {
adapter.startUpdate(container);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
if (position < adapter.getCount())
return adapter.instantiateItem(container, position);
return null;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
if (position < adapter.getCount())
adapter.destroyItem(container, position, object);
}
@Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
if (position < adapter.getCount())
adapter.setPrimaryItem(container, position, object);
}
@Override
public void finishUpdate(ViewGroup container) {
adapter.finishUpdate(container);
}
@SuppressWarnings("deprecation")
@Deprecated
@Override
public void startUpdate(View container) {
adapter.startUpdate(container);
}
@SuppressWarnings("deprecation")
@Deprecated
@Override
public Object instantiateItem(View container, int position) {
if (position < adapter.getCount())
return adapter.instantiateItem(container, position);
return null;
}
@SuppressWarnings("deprecation")
@Deprecated
@Override
public void destroyItem(View container, int position, Object object) {
if (position < adapter.getCount())
adapter.destroyItem(container, position, object);
}
@SuppressWarnings("deprecation")
@Deprecated
@Override
public void setPrimaryItem(View container, int position, Object object) {
if (position < adapter.getCount())
adapter.setPrimaryItem(container, position, object);
}
@SuppressWarnings("deprecation")
@Deprecated
@Override
public void finishUpdate(View container) {
adapter.finishUpdate(container);
}
@Override
public Parcelable saveState() {
return adapter.saveState();
}
@Override
public void restoreState(Parcelable state, ClassLoader loader) {
adapter.restoreState(state, loader);
}
@Override
public int getItemPosition(Object object) {
int position = adapter.getItemPosition(object);
if (position < adapter.getCount()) return position;
return POSITION_NONE;
}
@Override
public void registerDataSetObserver(DataSetObserver observer) {
adapter.registerDataSetObserver(observer);
}
@Override
public void unregisterDataSetObserver(DataSetObserver observer) {
adapter.unregisterDataSetObserver(observer);
}
@Override
public CharSequence getPageTitle(int position) {
if (position < adapter.getCount())
return adapter.getPageTitle(position);
return null;
}
@Override
public float getPageWidth(int position) {
if (position < adapter.getCount())
return adapter.getPageWidth(position);
return 1f;
}
}
private class PageTransformerWrapper implements PageTransformer {
private final PageTransformer pageTransformer;
private final PagerAdapter adapter;
private PageTransformerWrapper(PageTransformer pageTransformer, PagerAdapter adapter) {
this.pageTransformer = pageTransformer;
this.adapter = adapter;
}
@Override
public void transformPage(View page, float position) {
pageTransformer.transformPage(page, Math.min(position, adapter.getCount() - 1));
}
}
public interface OnOverscrollPageChangeListener extends OnPageChangeListener {
}
public static class SimpleOnOverscrollPageChangeListener implements OnOverscrollPageChangeListener {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
}
@Override
public void onPageScrollStateChanged(int state) {
}
}
}