Java tutorial
/* * Copyright 2015 Google Inc. * * 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 io.plaidapp.ui; import android.animation.Animator; import android.animation.AnimatorListenerAdapter; import android.animation.ObjectAnimator; import android.content.Context; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.v4.content.ContextCompat; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.animation.AnimationUtils; import android.widget.ImageView; import android.widget.TextView; import java.util.ArrayList; import java.util.Collections; import java.util.List; import io.plaidapp.R; import io.plaidapp.data.Source; import io.plaidapp.data.prefs.DribbblePrefs; import io.plaidapp.data.prefs.SourceManager; import io.plaidapp.ui.recyclerview.ItemTouchHelperAdapter; import io.plaidapp.util.ColorUtils; import io.plaidapp.util.ViewUtils; /** * Adapter for showing the list of data sources used as filters for the home grid. */ public class FilterAdapter extends RecyclerView.Adapter<FilterAdapter.FilterViewHolder> implements ItemTouchHelperAdapter, DribbblePrefs.DribbbleLoginStatusListener { public interface FilterAuthoriser { void requestDribbbleAuthorisation(View sharedElement, Source forSource); } private static final int FILTER_ICON_ENABLED_ALPHA = 179; // 70% private static final int FILTER_ICON_DISABLED_ALPHA = 51; // 20% private final List<Source> filters; private final FilterAuthoriser authoriser; private final Context context; private @Nullable List<FiltersChangedListener> listeners; public FilterAdapter(@NonNull Context context, @NonNull List<Source> filters, @NonNull FilterAuthoriser authoriser) { this.context = context.getApplicationContext(); this.filters = filters; this.authoriser = authoriser; setHasStableIds(true); } public List<Source> getFilters() { return filters; } /** * Adds a new data source to the list of filters. If the source already exists then it is simply * activated. * * @param toAdd the source to add * @return whether the filter was added (i.e. if it did not already exist) */ public boolean addFilter(Source toAdd) { // first check if it already exists final int count = filters.size(); for (int i = 0; i < count; i++) { Source existing = filters.get(i); if (existing.getClass() == toAdd.getClass() && existing.key.equalsIgnoreCase(toAdd.key)) { // already exists, just ensure it's active if (!existing.active) { existing.active = true; dispatchFiltersChanged(existing); notifyItemChanged(i); SourceManager.updateSource(existing, context); } return false; } } // didn't already exist, so add it filters.add(toAdd); Collections.sort(filters, new Source.SourceComparator()); dispatchFiltersChanged(toAdd); notifyDataSetChanged(); SourceManager.addSource(toAdd, context); return true; } public void removeFilter(Source removing) { int position = filters.indexOf(removing); filters.remove(position); notifyItemRemoved(position); dispatchFilterRemoved(removing); SourceManager.removeSource(removing, context); } public int getFilterPosition(Source filter) { return filters.indexOf(filter); } public void enableFilterByKey(@NonNull String key, @NonNull Context context) { final int count = filters.size(); for (int i = 0; i < count; i++) { Source filter = filters.get(i); if (filter.key.equals(key)) { if (!filter.active) { filter.active = true; notifyItemChanged(i); dispatchFiltersChanged(filter); SourceManager.updateSource(filter, context); return; } } } } @Override public FilterViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) { final FilterViewHolder holder = new FilterViewHolder( LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.filter_item, viewGroup, false)); holder.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final int position = holder.getAdapterPosition(); if (position == RecyclerView.NO_POSITION) return; final Source filter = filters.get(position); if (isAuthorisedDribbbleSource(filter) && !DribbblePrefs.get(holder.itemView.getContext()).isLoggedIn()) { authoriser.requestDribbbleAuthorisation(holder.filterIcon, filter); } else { holder.itemView.setHasTransientState(true); ObjectAnimator fade = ObjectAnimator.ofInt(holder.filterIcon, ViewUtils.IMAGE_ALPHA, filter.active ? FILTER_ICON_DISABLED_ALPHA : FILTER_ICON_ENABLED_ALPHA); fade.setDuration(300); fade.setInterpolator(AnimationUtils.loadInterpolator(holder.itemView.getContext(), android.R.interpolator.fast_out_slow_in)); fade.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { holder.itemView.setHasTransientState(false); } }); fade.start(); filter.active = !filter.active; holder.filterName.setEnabled(filter.active); notifyItemChanged(position); SourceManager.updateSource(filter, holder.itemView.getContext()); dispatchFiltersChanged(filter); } } }); return holder; } @Override public void onBindViewHolder(final FilterViewHolder vh, int position) { final Source filter = filters.get(position); vh.isSwipeable = filter.isSwipeDismissable(); vh.filterName.setText(filter.name); vh.filterName.setEnabled(filter.active); if (filter.iconRes > 0) { vh.filterIcon.setImageDrawable(vh.itemView.getContext().getDrawable(filter.iconRes)); } vh.filterIcon.setImageAlpha(filter.active ? FILTER_ICON_ENABLED_ALPHA : FILTER_ICON_DISABLED_ALPHA); } @Override public int getItemCount() { return filters.size(); } @Override public long getItemId(int position) { return filters.get(position).key.hashCode(); } private boolean isAuthorisedDribbbleSource(Source source) { return source.key.equals(SourceManager.SOURCE_DRIBBBLE_FOLLOWING) || source.key.equals(SourceManager.SOURCE_DRIBBBLE_USER_LIKES) || source.key.equals(SourceManager.SOURCE_DRIBBBLE_USER_SHOTS); } @Override public void onItemDismiss(int position) { Source removing = filters.get(position); if (removing.isSwipeDismissable()) { removeFilter(removing); } } public int getEnabledSourcesCount() { int count = 0; for (Source source : filters) { if (source.active) { count++; } } return count; } public void addFilterChangedListener(FiltersChangedListener listener) { if (listeners == null) { listeners = new ArrayList<>(); } listeners.add(listener); } public void removeFilterChangedListener(FiltersChangedListener listener) { if (listeners != null) { listeners.remove(listener); } } private void dispatchFiltersChanged(Source filter) { if (listeners != null) { for (FiltersChangedListener listener : listeners) { listener.onFiltersChanged(filter); } } } private void dispatchFilterRemoved(Source filter) { if (listeners != null) { for (FiltersChangedListener listener : listeners) { listener.onFilterRemoved(filter); } } } public interface FiltersChangedListener { void onFiltersChanged(Source changedFilter); void onFilterRemoved(Source removed); } public static class FilterViewHolder extends RecyclerView.ViewHolder { public TextView filterName; public ImageView filterIcon; public boolean isSwipeable; public FilterViewHolder(View itemView) { super(itemView); filterName = (TextView) itemView.findViewById(R.id.filter_name); filterIcon = (ImageView) itemView.findViewById(R.id.filter_icon); } public void highlightFilter() { itemView.setHasTransientState(true); int highlightColor = ContextCompat.getColor(itemView.getContext(), R.color.accent); int fadeFromTo = ColorUtils.modifyAlpha(highlightColor, 0); ObjectAnimator background = ObjectAnimator.ofArgb(itemView, ViewUtils.BACKGROUND_COLOR, fadeFromTo, highlightColor, fadeFromTo); background.setDuration(1000L); background.setInterpolator( AnimationUtils.loadInterpolator(itemView.getContext(), android.R.interpolator.linear)); background.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { itemView.setBackground(null); itemView.setHasTransientState(false); } }); background.start(); } } @Override public void onDribbbleLogin() { // no-op } @Override public void onDribbbleLogout() { boolean changed = false; for (Source filter : filters) { if (filter.active && isAuthorisedDribbbleSource(filter)) { filter.active = false; SourceManager.updateSource(filter, context); dispatchFiltersChanged(filter); changed = true; } } if (changed) { notifyDataSetChanged(); } } }