Introduce self-written SectionedAdapter

app/src/main/java/com/topjohnwu/magisk/adapters/ReposAdapter.java

@@ -6,6 +6,7 @@ import android.database.Cursor;
 import android.net.Uri;
 import android.support.v7.widget.RecyclerView;
 import android.text.TextUtils;
+import android.util.Pair;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -30,116 +31,103 @@ import java.util.Map;
 import butterknife.BindView;
 import butterknife.ButterKnife;
 
-public class ReposAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
+public class ReposAdapter extends SectionedAdapter<ReposAdapter.SectionHolder, ReposAdapter.RepoHolder> {
 
-    private static final int SECTION_TYPE = 0;
+    private static final int UPDATES = 0;
-    private static final int REPO_TYPE = 1;
+    private static final int INSTALLED = 1;
+    private static final int OTHERS = 2;
 
-    private List<Repo> mUpdateRepos, mInstalledRepos, mOthersRepos;
-    private int[] sectionList;
-    private int size;
     private Cursor repoCursor = null;
     private Map<String, Module> moduleMap;
     private RepoDatabaseHelper repoDB;
+    private List<Pair<Integer, List<Repo>>> repoPairs;
 
     public ReposAdapter(RepoDatabaseHelper db, Map<String, Module> map) {
         repoDB = db;
         moduleMap = map;
-        mUpdateRepos = new ArrayList<>();
+        repoPairs = new ArrayList<>();
-        mInstalledRepos = new ArrayList<>();
+    }
-        mOthersRepos = new ArrayList<>();
+
-        sectionList = new int[3];
+
-        size = 0;
+    @Override
+    public int getSectionCount() {
+        return repoPairs.size();
     }
 
     @Override
-    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    public int getItemCount(int section) {
-        Context context = parent.getContext();
+        return repoPairs.get(section).second.size();
-        View v;
+    }
-        RecyclerView.ViewHolder holder = null;
+
-        switch (viewType) {
+    @Override
-            case SECTION_TYPE:
+    public SectionHolder onCreateSectionViewHolder(ViewGroup parent) {
-                v = LayoutInflater.from(context).inflate(R.layout.section, parent, false);
+        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.section, parent, false);
-                holder = new SectionHolder(v);
+        return new SectionHolder(v);
+    }
+
+    @Override
+    public RepoHolder onCreateItemViewHolder(ViewGroup parent, int viewType) {
+        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_repo, parent, false);
+        return new RepoHolder(v);
+    }
+
+    @Override
+    public void onBindSectionViewHolder(SectionHolder holder, int section) {
+        switch (repoPairs.get(section).first) {
+            case UPDATES:
+                holder.sectionText.setText(R.string.update_available);
                 break;
-            case REPO_TYPE:
+            case INSTALLED:
-                v = LayoutInflater.from(context).inflate(R.layout.list_item_repo, parent, false);
+                holder.sectionText.setText(R.string.installed);
-                holder = new RepoHolder(v);
+                break;
+            case OTHERS:
+                holder.sectionText.setText(R.string.not_installed);
                 break;
         }
-        return holder;
     }
 
     @Override
-    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
+    public void onBindItemViewHolder(RepoHolder holder, int section, int position) {
+        Repo repo = repoPairs.get(section).second.get(position);
         Context context = holder.itemView.getContext();
-        switch (getItemViewType(position)) {
-            case SECTION_TYPE:
-                SectionHolder section = (SectionHolder) holder;
-                if (position == sectionList[0]) {
-                    section.sectionText.setText(context.getString(R.string.update_available));
-                } else if (position == sectionList[1]) {
-                    section.sectionText.setText(context.getString(R.string.installed));
-                } else {
-                    section.sectionText.setText(context.getString(R.string.not_installed));
-                }
-                break;
-            case REPO_TYPE:
-                RepoHolder repoHolder = (RepoHolder) holder;
-                Repo repo = getRepo(position);
-                repoHolder.title.setText(repo.getName());
-                repoHolder.versionName.setText(repo.getVersion());
-                String author = repo.getAuthor();
-                repoHolder.author.setText(TextUtils.isEmpty(author) ? null : context.getString(R.string.author, author));
-                repoHolder.description.setText(repo.getDescription());
 
-                repoHolder.infoLayout.setOnClickListener(v -> new MarkDownWindow(null, repo.getDetailUrl(), context));
+        holder.title.setText(repo.getName());
+        holder.versionName.setText(repo.getVersion());
+        String author = repo.getAuthor();
+        holder.author.setText(TextUtils.isEmpty(author) ? null : context.getString(R.string.author, author));
+        holder.description.setText(repo.getDescription());
 
-                repoHolder.downloadImage.setOnClickListener(v -> {
+        holder.infoLayout.setOnClickListener(v -> new MarkDownWindow(null, repo.getDetailUrl(), context));
-                    String filename = repo.getName() + "-" + repo.getVersion() + ".zip";
-                    new AlertDialogBuilder(context)
-                            .setTitle(context.getString(R.string.repo_install_title, repo.getName()))
-                            .setMessage(context.getString(R.string.repo_install_msg, filename))
-                            .setCancelable(true)
-                            .setPositiveButton(R.string.install, (d, i) -> Utils.dlAndReceive(
-                                    context,
-                                    new DownloadReceiver() {
-                                        @Override
-                                        public void onDownloadDone(Uri uri) {
-                                            new ProcessRepoZip((Activity) context, uri, true).exec();
-                                        }
-                                    },
-                                    repo.getZipUrl(),
-                                    Utils.getLegalFilename(filename)))
-                            .setNeutralButton(R.string.download, (d, i) -> Utils.dlAndReceive(
-                                    context,
-                                    new DownloadReceiver() {
-                                        @Override
-                                        public void onDownloadDone(Uri uri) {
-                                            new ProcessRepoZip((Activity) context, uri, false).exec();
-                                        }
-                                    },
-                                    repo.getZipUrl(),
-                                    Utils.getLegalFilename(filename)))
-                            .setNegativeButton(R.string.no_thanks, null)
-                            .show();
-                });
-                break;
-        }
-    }
 
-    @Override
+        holder.downloadImage.setOnClickListener(v -> {
-    public int getItemViewType(int position) {
+            String filename = repo.getName() + "-" + repo.getVersion() + ".zip";
-        for (int i : sectionList) {
+            new AlertDialogBuilder(context)
-            if (position == i)
+                    .setTitle(context.getString(R.string.repo_install_title, repo.getName()))
-                return SECTION_TYPE;
+                    .setMessage(context.getString(R.string.repo_install_msg, filename))
-        }
+                    .setCancelable(true)
-        return REPO_TYPE;
+                    .setPositiveButton(R.string.install, (d, i) -> Utils.dlAndReceive(
-    }
+                            context,
-
+                            new DownloadReceiver() {
-    @Override
+                                @Override
-    public int getItemCount() {
+                                public void onDownloadDone(Uri uri) {
-        return size;
+                                    new ProcessRepoZip((Activity) context, uri, true).exec();
+                                }
+                            },
+                            repo.getZipUrl(),
+                            Utils.getLegalFilename(filename)))
+                    .setNeutralButton(R.string.download, (d, i) -> Utils.dlAndReceive(
+                            context,
+                            new DownloadReceiver() {
+                                @Override
+                                public void onDownloadDone(Uri uri) {
+                                    new ProcessRepoZip((Activity) context, uri, false).exec();
+                                }
+                            },
+                            repo.getZipUrl(),
+                            Utils.getLegalFilename(filename)))
+                    .setNegativeButton(R.string.no_thanks, null)
+                    .show();
+        });
     }
 
     public void notifyDBChanged() {
@@ -150,53 +138,43 @@ public class ReposAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>
     }
 
     public void filter(String s) {
-        mUpdateRepos.clear();
+        List<Repo> updates = new ArrayList<>();
-        mInstalledRepos.clear();
+        List<Repo> installed = new ArrayList<>();
-        mOthersRepos.clear();
+        List<Repo> others = new ArrayList<>();
-        sectionList[0] = sectionList[1] = sectionList[2] = 0;
+
+        repoPairs.clear();
         while (repoCursor.moveToNext()) {
             Repo repo = new Repo(repoCursor);
             if (repo.getName().toLowerCase().contains(s.toLowerCase())
                     || repo.getAuthor().toLowerCase().contains(s.toLowerCase())
                     || repo.getDescription().toLowerCase().contains(s.toLowerCase())
                     ) {
-                // Passed the filter
+                // Passed the repoFilter
                 Module module = moduleMap.get(repo.getId());
                 if (module != null) {
                     if (repo.getVersionCode() > module.getVersionCode()) {
                         // Updates
-                        mUpdateRepos.add(repo);
+                        updates.add(repo);
                     } else {
-                        mInstalledRepos.add(repo);
+                        installed.add(repo);
                     }
                 } else {
-                    mOthersRepos.add(repo);
+                    others.add(repo);
                 }
             }
         }
         repoCursor.moveToFirst();
 
-        sectionList[0] = mUpdateRepos.isEmpty() ? -1 : 0;
+        if (!updates.isEmpty())
-        size = mUpdateRepos.isEmpty() ? 0 : mUpdateRepos.size() + 1;
+            repoPairs.add(new Pair<>(UPDATES, updates));
-        sectionList[1] = mInstalledRepos.isEmpty() ? -1 : size;
+        if (!installed.isEmpty())
-        size += mInstalledRepos.isEmpty() ? 0 : mInstalledRepos.size() + 1;
+            repoPairs.add(new Pair<>(INSTALLED, installed));
-        sectionList[2] = mOthersRepos.isEmpty() ? -1 : size;
+        if (!others.isEmpty())
-        size += mOthersRepos.isEmpty() ? 0 : mOthersRepos.size() + 1;
+            repoPairs.add(new Pair<>(OTHERS, others));
 
         notifyDataSetChanged();
     }
 
-    private Repo getRepo(int position) {
-        if (!mUpdateRepos.isEmpty()) position -= 1;
-        if (position < mUpdateRepos.size()) return mUpdateRepos.get(position);
-        position -= mUpdateRepos.size();
-        if (!mInstalledRepos.isEmpty()) position -= 1;
-        if (position < mInstalledRepos.size()) return mInstalledRepos.get(position);
-        position -= mInstalledRepos.size();
-        if (!mOthersRepos.isEmpty()) position -= 1;
-        return mOthersRepos.get(position);
-    }
-
     static class SectionHolder extends RecyclerView.ViewHolder {
 
         @BindView(R.id.section_text) TextView sectionText;

app/src/main/java/com/topjohnwu/magisk/adapters/SectionedAdapter.java

@@ -0,0 +1,78 @@
+package com.topjohnwu.magisk.adapters;
+
+import android.support.v7.widget.RecyclerView;
+import android.view.ViewGroup;
+
+public abstract class SectionedAdapter<S extends RecyclerView.ViewHolder, C extends RecyclerView.ViewHolder>
+        extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
+
+    private static final int SECTION_TYPE = Integer.MIN_VALUE;
+
+    @Override
+    final public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+        if (viewType == SECTION_TYPE)
+            return onCreateSectionViewHolder(parent);
+        return onCreateItemViewHolder(parent, viewType);
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    final public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
+        PositionInfo info = getPositionInfo(position);
+        if (info.position == -1)
+            onBindSectionViewHolder((S) holder, info.section);
+        else
+            onBindItemViewHolder((C) holder, info.section, info.position);
+    }
+
+    @Override
+    final public int getItemCount() {
+        int size, sec;
+        size = sec = getSectionCount();
+        for (int i = 0; i < sec; ++i){
+            size += getItemCount(i);
+        }
+        return size;
+    }
+
+    @Override
+    final public int getItemViewType(int position) {
+        PositionInfo info = getPositionInfo(position);
+        if (info.position == -1)
+            return SECTION_TYPE;
+        else
+            return  getItemViewType(info.section, info.position);
+    }
+
+    public int getItemViewType(int section, int position) {
+        return 0;
+    }
+
+    private PositionInfo getPositionInfo(int position) {
+        int section = 0;
+        while (true) {
+            if (position == 0)
+                return new PositionInfo(section, -1);
+            position -= 1;
+            if (position < getItemCount(section))
+                return new PositionInfo(section, position);
+            position -= getItemCount(section++);
+        }
+    }
+
+    private static class PositionInfo {
+        int section;
+        int position;
+        PositionInfo(int section, int position) {
+            this.section = section;
+            this.position = position;
+        }
+    }
+
+    public abstract int getSectionCount();
+    public abstract int getItemCount(int section);
+    public abstract S onCreateSectionViewHolder(ViewGroup parent);
+    public abstract C onCreateItemViewHolder(ViewGroup parent, int viewType);
+    public abstract void onBindSectionViewHolder(S holder, int section);
+    public abstract void onBindItemViewHolder(C holder, int section, int position);
+}