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.animation.ValueAnimator; import android.app.Activity; import android.app.ActivityOptions; import android.content.Intent; import android.content.res.TypedArray; import android.graphics.Color; import android.graphics.ColorMatrixColorFilter; import android.graphics.drawable.ColorDrawable; import android.graphics.drawable.Drawable; import android.graphics.drawable.TransitionDrawable; import android.net.Uri; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.customtabs.CustomTabsIntent; import android.support.v4.content.ContextCompat; import android.support.v7.widget.RecyclerView; import android.transition.Transition; import android.transition.TransitionInflater; import android.util.Pair; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.animation.AnimationUtils; import android.widget.ImageButton; import android.widget.ProgressBar; import android.widget.TextView; import com.bumptech.glide.Glide; import com.bumptech.glide.load.engine.DiskCacheStrategy; import com.bumptech.glide.load.resource.drawable.GlideDrawable; import com.bumptech.glide.load.resource.gif.GifDrawable; import com.bumptech.glide.request.RequestListener; import com.bumptech.glide.request.target.Target; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.List; import butterknife.Bind; import butterknife.ButterKnife; import io.plaidapp.R; import io.plaidapp.data.DataLoadingSubject; import io.plaidapp.data.PlaidItem; import io.plaidapp.data.PlaidItemComparator; import io.plaidapp.data.api.designernews.model.Story; import io.plaidapp.data.api.dribbble.model.Shot; import io.plaidapp.data.api.producthunt.model.Post; import io.plaidapp.data.pocket.PocketUtils; import io.plaidapp.ui.widget.BadgedFourThreeImageView; import io.plaidapp.util.AnimUtils; import io.plaidapp.util.ObservableColorMatrix; import io.plaidapp.util.ViewUtils; import io.plaidapp.util.customtabs.CustomTabActivityHelper; import io.plaidapp.util.glide.DribbbleTarget; /** * Adapter for the main screen grid of items */ public class FeedAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> { public static final float DUPE_WEIGHT_BOOST = 0.4f; private static final int TYPE_DESIGNER_NEWS_STORY = 0; private static final int TYPE_DRIBBBLE_SHOT = 1; private static final int TYPE_PRODUCT_HUNT_POST = 2; private static final int TYPE_LOADING_MORE = -1; // we need to hold on to an activity ref for the shared element transitions :/ private final Activity host; private final LayoutInflater layoutInflater; private final PlaidItemComparator comparator; private final boolean pocketIsInstalled; private @Nullable DataLoadingSubject dataLoading; private final int columns; private final ColorDrawable[] shotLoadingPlaceholders; private List<PlaidItem> items; public FeedAdapter(Activity hostActivity, DataLoadingSubject dataLoading, int columns, boolean pocketInstalled) { this.host = hostActivity; this.dataLoading = dataLoading; this.columns = columns; this.pocketIsInstalled = pocketInstalled; layoutInflater = LayoutInflater.from(host); comparator = new PlaidItemComparator(); items = new ArrayList<>(); setHasStableIds(true); TypedArray placeholderColors = hostActivity.getResources().obtainTypedArray(R.array.loading_placeholders); shotLoadingPlaceholders = new ColorDrawable[placeholderColors.length()]; for (int i = 0; i < placeholderColors.length(); i++) { shotLoadingPlaceholders[i] = new ColorDrawable(placeholderColors.getColor(i, Color.DKGRAY)); } } @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { switch (viewType) { case TYPE_DESIGNER_NEWS_STORY: return createDesignerNewsStoryHolder(parent); case TYPE_DRIBBBLE_SHOT: return createDribbbleShotHolder(parent); case TYPE_PRODUCT_HUNT_POST: return createProductHuntStoryHolder(parent); case TYPE_LOADING_MORE: return new LoadingMoreHolder(layoutInflater.inflate(R.layout.infinite_loading, parent, false)); } return null; } @Override public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { switch (getItemViewType(position)) { case TYPE_DESIGNER_NEWS_STORY: bindDesignerNewsStory((Story) getItem(position), (DesignerNewsStoryHolder) holder); break; case TYPE_DRIBBBLE_SHOT: bindDribbbleShotHolder((Shot) getItem(position), (DribbbleShotHolder) holder); break; case TYPE_PRODUCT_HUNT_POST: bindProductHuntPostView((Post) getItem(position), (ProductHuntStoryHolder) holder); break; case TYPE_LOADING_MORE: bindLoadingViewHolder((LoadingMoreHolder) holder); break; } } @Override public void onViewRecycled(RecyclerView.ViewHolder holder) { if (holder instanceof DribbbleShotHolder) { // reset the badge & ripple which are dynamically determined DribbbleShotHolder shotHolder = (DribbbleShotHolder) holder; shotHolder.image.showBadge(false); shotHolder.image.setForeground(ContextCompat.getDrawable(host, R.drawable.mid_grey_ripple)); } } @NonNull private DesignerNewsStoryHolder createDesignerNewsStoryHolder(ViewGroup parent) { final DesignerNewsStoryHolder holder = new DesignerNewsStoryHolder( layoutInflater.inflate(R.layout.designer_news_story_item, parent, false), pocketIsInstalled); holder.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final Story story = (Story) getItem(holder.getAdapterPosition()); CustomTabActivityHelper.openCustomTab(host, DesignerNewsStory.getCustomTabIntent(host, story, null).build(), Uri.parse(story.url)); } }); holder.comments.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View commentsView) { final Intent intent = new Intent(); intent.setClass(host, DesignerNewsStory.class); intent.putExtra(DesignerNewsStory.EXTRA_STORY, (Story) getItem(holder.getAdapterPosition())); setGridItemContentTransitions(holder.itemView); final ActivityOptions options = ActivityOptions.makeSceneTransitionAnimation(host, Pair.create(holder.itemView, host.getString(R.string.transition_story_title_background)), Pair.create(holder.itemView, host.getString(R.string.transition_story_background))); host.startActivity(intent, options.toBundle()); } }); if (pocketIsInstalled) { holder.pocket.setImageAlpha(178); // grumble... no xml setter, grumble... holder.pocket.setOnClickListener(new View.OnClickListener() { @Override public void onClick(final View view) { PocketUtils.addToPocket(host, ((Story) getItem(holder.getAdapterPosition())).url); // notify changed with a payload asking RV to run the anim notifyItemChanged(holder.getAdapterPosition(), HomeGridItemAnimator.ANIMATE_ADD_POCKET); } }); } return holder; } private void bindDesignerNewsStory(final Story story, final DesignerNewsStoryHolder holder) { holder.title.setText(story.title); holder.comments.setText(String.valueOf(story.comment_count)); } @NonNull private DribbbleShotHolder createDribbbleShotHolder(ViewGroup parent) { final DribbbleShotHolder holder = new DribbbleShotHolder( layoutInflater.inflate(R.layout.dribbble_shot_item, parent, false)); holder.image.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { holder.itemView .setTransitionName(holder.itemView.getResources().getString(R.string.transition_shot)); holder.itemView.setBackgroundColor(ContextCompat.getColor(host, R.color.background_light)); Intent intent = new Intent(); intent.setClass(host, DribbbleShot.class); intent.putExtra(DribbbleShot.EXTRA_SHOT, (Shot) getItem(holder.getAdapterPosition())); setGridItemContentTransitions(holder.itemView); ActivityOptions options = ActivityOptions.makeSceneTransitionAnimation(host, Pair.create(view, host.getString(R.string.transition_shot)), Pair.create(view, host.getString(R.string.transition_shot_background))); host.startActivity(intent, options.toBundle()); } }); // play animated GIFs whilst touched holder.image.setOnTouchListener(new View.OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { // get the image and check if it's an animated GIF final Drawable drawable = holder.image.getDrawable(); if (drawable == null) return false; GifDrawable gif = null; if (drawable instanceof GifDrawable) { gif = (GifDrawable) drawable; } else if (drawable instanceof TransitionDrawable) { // we fade in images on load which uses a TransitionDrawable; check its layers TransitionDrawable fadingIn = (TransitionDrawable) drawable; for (int i = 0; i < fadingIn.getNumberOfLayers(); i++) { if (fadingIn.getDrawable(i) instanceof GifDrawable) { gif = (GifDrawable) fadingIn.getDrawable(i); break; } } } if (gif == null) return false; // GIF found, start/stop it on press/lift switch (event.getAction()) { case MotionEvent.ACTION_DOWN: gif.start(); break; case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: gif.stop(); break; } return false; } }); return holder; } private void bindDribbbleShotHolder(final Shot shot, final DribbbleShotHolder holder) { final int[] imageSize = shot.images.bestSize(); Glide.with(host).load(shot.images.best()).listener(new RequestListener<String, GlideDrawable>() { @Override public boolean onResourceReady(GlideDrawable resource, String model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) { if (!shot.hasFadedIn) { holder.image.setHasTransientState(true); final ObservableColorMatrix cm = new ObservableColorMatrix(); ObjectAnimator saturation = ObjectAnimator.ofFloat(cm, ObservableColorMatrix.SATURATION, 0f, 1f); saturation.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator valueAnimator) { // just animating the color matrix does not invalidate the // drawable so need this update listener. Also have to create a // new CMCF as the matrix is immutable :( if (holder.image.getDrawable() != null) { holder.image.getDrawable().setColorFilter(new ColorMatrixColorFilter(cm)); } } }); saturation.setDuration(2000); saturation.setInterpolator( AnimationUtils.loadInterpolator(host, android.R.interpolator.fast_out_slow_in)); saturation.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { holder.image.setHasTransientState(false); } }); saturation.start(); shot.hasFadedIn = true; } return false; } @Override public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) { return false; } }).placeholder(shotLoadingPlaceholders[holder.getAdapterPosition() % shotLoadingPlaceholders.length]) .diskCacheStrategy(DiskCacheStrategy.SOURCE).fitCenter().override(imageSize[0], imageSize[1]) .into(new DribbbleTarget(holder.image, false)); } @NonNull private ProductHuntStoryHolder createProductHuntStoryHolder(ViewGroup parent) { final ProductHuntStoryHolder holder = new ProductHuntStoryHolder( layoutInflater.inflate(R.layout.product_hunt_item, parent, false)); holder.comments.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { CustomTabActivityHelper.openCustomTab(host, new CustomTabsIntent.Builder() .setToolbarColor(ContextCompat.getColor(host, R.color.product_hunt)).build(), Uri.parse(((Post) getItem(holder.getAdapterPosition())).discussion_url)); } }); holder.itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { CustomTabActivityHelper.openCustomTab(host, new CustomTabsIntent.Builder() .setToolbarColor(ContextCompat.getColor(host, R.color.product_hunt)).build(), Uri.parse(((Post) getItem(holder.getAdapterPosition())).redirect_url)); } }); return holder; } private void bindProductHuntPostView(final Post item, ProductHuntStoryHolder holder) { holder.title.setText(item.name); holder.tagline.setText(item.tagline); holder.comments.setText(String.valueOf(item.comments_count)); } private void bindLoadingViewHolder(LoadingMoreHolder holder) { // only show the infinite load progress spinner if there are already items in the // grid i.e. it's not the first item & data is being loaded holder.progress.setVisibility( (holder.getAdapterPosition() > 0 && dataLoading.isDataLoading()) ? View.VISIBLE : View.INVISIBLE); } @Override public int getItemViewType(int position) { if (position < getDataItemCount() && getDataItemCount() > 0) { PlaidItem item = getItem(position); if (item instanceof Story) { return TYPE_DESIGNER_NEWS_STORY; } else if (item instanceof Shot) { return TYPE_DRIBBBLE_SHOT; } else if (item instanceof Post) { return TYPE_PRODUCT_HUNT_POST; } } return TYPE_LOADING_MORE; } private PlaidItem getItem(int position) { return items.get(position); } public int getItemColumnSpan(int position) { switch (getItemViewType(position)) { case TYPE_LOADING_MORE: return columns; default: return getItem(position).colspan; } } private void add(PlaidItem item) { items.add(item); } public void clear() { items.clear(); notifyDataSetChanged(); } public void addAndResort(Collection<? extends PlaidItem> newItems) { // de-dupe results as the same item can be returned by multiple feeds boolean add = true; for (PlaidItem newItem : newItems) { int count = getDataItemCount(); for (int i = 0; i < count; i++) { PlaidItem existingItem = getItem(i); if (existingItem.equals(newItem)) { // if we find a dupe mark the weight boost field on the first-in, but don't add // the dupe. We use the fact that an item comes from multiple sources to indicate it // is more important and sort it higher existingItem.weightBoost = DUPE_WEIGHT_BOOST; add = false; break; } } if (add) { add(newItem); add = true; } } sort(); expandPopularItems(); } private void expandPopularItems() { // for now just expand the first dribbble image per page which should be // the most popular according to #sort. // TODO make this smarter & handle other item types List<Integer> expandedPositions = new ArrayList<>(); int page = -1; final int count = items.size(); for (int i = 0; i < count; i++) { PlaidItem item = getItem(i); if (item instanceof Shot && item.page > page) { item.colspan = columns; page = item.page; expandedPositions.add(i); } else { item.colspan = 1; } } // make sure that any expanded items are at the start of a row // so that we don't leave any gaps in the grid for (int expandedPos = 0; expandedPos < expandedPositions.size(); expandedPos++) { int pos = expandedPositions.get(expandedPos); int extraSpannedSpaces = expandedPos * (columns - 1); int rowPosition = (pos + extraSpannedSpaces) % columns; if (rowPosition != 0) { int swapWith = pos + (columns - rowPosition); if (swapWith < items.size()) { Collections.swap(items, pos, swapWith); } } } } protected void sort() { // calculate the 'weight' for each data type and then sort by that. Each data type has a // different metric for weighing it e.g. Dribbble uses likes etc. Weights are 'scoped' to // the page they belong to and lower weights are sorted higher in the grid. int count = getDataItemCount(); int maxDesignNewsVotes = 0; int maxDesignNewsComments = 0; long maxDribbleLikes = 0; int maxProductHuntVotes = 0; int maxProductHuntComments = 0; // work out some maximum values to weigh individual items against for (int i = 0; i < count; i++) { PlaidItem item = getItem(i); if (item instanceof Story) { maxDesignNewsComments = Math.max(((Story) item).comment_count, maxDesignNewsComments); maxDesignNewsVotes = Math.max(((Story) item).vote_count, maxDesignNewsVotes); } else if (item instanceof Shot) { maxDribbleLikes = Math.max(((Shot) item).likes_count, maxDribbleLikes); } else if (item instanceof Post) { maxProductHuntComments = Math.max(((Post) item).comments_count, maxProductHuntComments); maxProductHuntVotes = Math.max(((Post) item).votes_count, maxProductHuntVotes); } } // now go through and set the weight of each item for (int i = 0; i < count; i++) { PlaidItem item = getItem(i); if (item instanceof Story) { ((Story) item).weigh(maxDesignNewsComments, maxDesignNewsVotes); } else if (item instanceof Shot) { ((Shot) item).weigh(maxDribbleLikes); } else if (item instanceof Post) { ((Post) item).weigh(maxProductHuntComments, maxProductHuntVotes); } // scope it to the page it came from item.weight += item.page; } // sort by weight Collections.sort(items, comparator); notifyDataSetChanged(); // TODO call the more specific RV variants } public void removeDataSource(String dataSource) { int i = items.size() - 1; while (i >= 0) { PlaidItem item = items.get(i); if (dataSource.equals(item.dataSource)) { items.remove(i); } i--; } notifyDataSetChanged(); } @Override public long getItemId(int position) { if (getItemViewType(position) == TYPE_LOADING_MORE) { return -1L; } return getItem(position).id; } @Override public int getItemCount() { // include loading footer return getDataItemCount() + 1; } /** * The shared element transition to dribbble shots & dn stories can intersect with the FAB. * This can cause a strange layers-passing-through-each-other effect, especially on return. * In this situation, hide the FAB on exit and re-show it on return. */ private void setGridItemContentTransitions(View gridItem) { if (!ViewUtils.viewsIntersect(gridItem, host.findViewById(R.id.fab))) return; final TransitionInflater ti = TransitionInflater.from(host); host.getWindow().setExitTransition(ti.inflateTransition(R.transition.home_content_item_exit)); final Transition reenter = ti.inflateTransition(R.transition.home_content_item_reenter); // we only want this content transition in certain cases so clear it out after it's done. reenter.addListener(new AnimUtils.TransitionListenerAdapter() { @Override public void onTransitionEnd(Transition transition) { host.getWindow().setExitTransition(null); host.getWindow().setReenterTransition(null); } }); host.getWindow().setReenterTransition(reenter); } public int getDataItemCount() { return items.size(); } /** * Which ViewHolder types require a divider decoration */ public Class[] getDividedViewHolderClasses() { return new Class[] { DesignerNewsStoryHolder.class, ProductHuntStoryHolder.class }; } /* protected */ class DribbbleShotHolder extends RecyclerView.ViewHolder { BadgedFourThreeImageView image; public DribbbleShotHolder(View itemView) { super(itemView); image = (BadgedFourThreeImageView) itemView; } } /* protected */ class DesignerNewsStoryHolder extends RecyclerView.ViewHolder { @Bind(R.id.story_title) TextView title; @Bind(R.id.story_comments) TextView comments; @Bind(R.id.pocket) ImageButton pocket; public DesignerNewsStoryHolder(View itemView, boolean pocketIsInstalled) { super(itemView); ButterKnife.bind(this, itemView); pocket.setVisibility(pocketIsInstalled ? View.VISIBLE : View.GONE); } } /* protected */ class ProductHuntStoryHolder extends RecyclerView.ViewHolder { @Bind(R.id.hunt_title) TextView title; @Bind(R.id.tagline) TextView tagline; @Bind(R.id.story_comments) TextView comments; public ProductHuntStoryHolder(View itemView) { super(itemView); ButterKnife.bind(this, itemView); } } /* protected */ class LoadingMoreHolder extends RecyclerView.ViewHolder { ProgressBar progress; public LoadingMoreHolder(View itemView) { super(itemView); progress = (ProgressBar) itemView; } } }