Add Search to the Settings App (initial release)

- add basic UI for search
- build the search Index thru sqlite FTS4 (faster than FTS3)
- create the search Index on the fly depending on the locale
- re-index if there is a configuration change
- re-index too if the Android build version has changed (usefull
for an Android OTA or when a new Android version is pushed as
we need to recompute the Index)
- search thru "title" and "summary" Preference's data
- group results in the same order of the Settings categories
into the Drawer
- rewrite "title" and/or "summary" if they are containing
an hyphen "\u2011"
- add Preference Keywords (only for the Settings App) in the
Index and allow search on them (Wi-Fi network preference is
used as an example)

Known restrictions:

- we cannot yet search for "dynamic settings"
- ... nor we cannot search for settings coming from an external App
(like the Phone App and its related settings that are surfacing
into the Settings App).
- will need a few other CLs to add more keywords (and have them translated)

Change-Id: I017a4d6c433f28c257c08cacc1bed98c4c517039

1 files changed, 259 insertions, 0 deletions

diff --git a/src/com/android/settings/dashboard/DashboardSummary.java b/src/com/android/settings/dashboard/DashboardSummary.java
index f5b47ae..ce3b0c0 100644
--- a/src/com/android/settings/dashboard/DashboardSummary.java
+++ b/src/com/android/settings/dashboard/DashboardSummary.java
@@ -17,17 +17,97 @@
 package com.android.settings.dashboard;
 
 import android.app.Fragment;
+import android.content.Context;
+import android.database.Cursor;
+import android.os.AsyncTask;
 import android.os.Bundle;
+import android.text.Editable;
+import android.text.TextUtils;
+import android.text.TextWatcher;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.inputmethod.InputMethodManager;
+import android.widget.AdapterView;
+import android.widget.BaseAdapter;
+import android.widget.EditText;
+import android.widget.ImageView;
+import android.widget.ListView;
+import android.widget.TextView;
 import com.android.settings.R;
+import com.android.settings.SettingsActivity;
+import com.android.settings.indexer.Index;
 
 public class DashboardSummary extends Fragment {
 
+    private static final String SAVE_KEY_QUERY = ":settings:query";
+
+    private EditText mEditText;
+    private ListView mListView;
+
+    private SearchResultsAdapter mAdapter;
+    private Index mIndex;
+    private UpdateSearchResultsTask mUpdateSearchResultsTask;
+
+    /**
+     * A basic AsyncTask for updating the query results cursor
+     */
+    private class UpdateSearchResultsTask extends AsyncTask<String, Void, Cursor> {
+        @Override
+        protected Cursor doInBackground(String... params) {
+            return mIndex.search(params[0]);
+        }
+
+        @Override
+        protected void onPostExecute(Cursor cursor) {
+            if (!isCancelled()) {
+                setCursor(cursor);
+            } else if (cursor != null) {
+                cursor.close();
+            }
+        }
+    }
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+
+        mIndex = Index.getInstance(getActivity());
+        mAdapter = new SearchResultsAdapter(getActivity());
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+
+        clearResults();
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+
+        updateSearchResults();
+    }
+
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        if (outState != null) {
+            outState.putString(SAVE_KEY_QUERY, mEditText.getText().toString());
+        }
+    }
+
+    @Override
+    public void onActivityCreated(Bundle savedInstanceState) {
+        super.onActivityCreated(savedInstanceState);
+
+        if (savedInstanceState != null) {
+            final String query = savedInstanceState.getString(SAVE_KEY_QUERY);
+            if (query != null && !TextUtils.isEmpty(query)) {
+                mEditText.setText(query);
+            }
+        }
     }
 
     @Override
@@ -36,6 +116,185 @@ public class DashboardSummary extends Fragment {
 
         final View view = inflater.inflate(R.layout.dashboard, container, false);
 
+        mEditText = (EditText)view.findViewById(R.id.edittext_query);
+        mEditText.addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+                updateSearchResults();
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+            }
+        });
+        mEditText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
+            @Override
+            public void onFocusChange(View v, boolean hasFocus) {
+                if (!hasFocus) {
+                    closeSoftKeyboard();
+                }
+            }
+        });
+
+        mListView = (ListView) view.findViewById(R.id.list_results);
+        mListView.setAdapter(mAdapter);
+        mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
+            @Override
+            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+                closeSoftKeyboard();
+                final Cursor cursor = mAdapter.mCursor;
+                cursor.moveToPosition(position);
+                final String fragmentName = cursor.getString(Index.COLUMN_INDEX_FRAGMENT_NAME);
+                final String fragmentTitle = cursor.getString(Index.COLUMN_INDEX_FRAGMENT_TITLE);
+
+                ((SettingsActivity) getActivity()).startPreferencePanel(fragmentName, null, 0,
+                        fragmentTitle, null, 0);
+            }
+        });
+
         return view;
     }
+
+    private void closeSoftKeyboard() {
+        InputMethodManager imm = InputMethodManager.peekInstance();
+        if (imm != null && imm.isActive(mEditText)) {
+            imm.hideSoftInputFromWindow(mEditText.getWindowToken(), 0);
+        }
+    }
+
+    private void clearResults() {
+        if (mUpdateSearchResultsTask != null) {
+            mUpdateSearchResultsTask.cancel(false);
+            mUpdateSearchResultsTask = null;
+        }
+        setCursor(null);
+    }
+
+    private void setCursor(Cursor cursor) {
+        Cursor oldCursor = mAdapter.swapCursor(cursor);
+        if (oldCursor != null) {
+            oldCursor.close();
+        }
+    }
+
+    private void updateSearchResults() {
+        if (mUpdateSearchResultsTask != null) {
+            mUpdateSearchResultsTask.cancel(false);
+            mUpdateSearchResultsTask = null;
+        }
+        final String query = mEditText.getText().toString();
+        if (TextUtils.isEmpty(query)) {
+            setCursor(null);
+        } else {
+            mUpdateSearchResultsTask = new UpdateSearchResultsTask();
+            mUpdateSearchResultsTask.execute(query);
+        }
+    }
+
+    private static class SearchResult {
+        public String title;
+        public String summary;
+        public int iconResId;
+
+        public SearchResult(String title, String summary, int iconResId) {
+            this.title = title;
+            this.summary = summary;
+            this.iconResId = iconResId;
+        }
+    }
+
+    private static class SearchResultsAdapter extends BaseAdapter {
+
+        private Cursor mCursor;
+        private LayoutInflater mInflater;
+        private boolean mDataValid;
+
+        public SearchResultsAdapter(Context context) {
+            mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+            mDataValid = false;
+        }
+
+        public Cursor swapCursor(Cursor newCursor) {
+            if (newCursor == mCursor) {
+                return null;
+            }
+            Cursor oldCursor = mCursor;
+            mCursor = newCursor;
+            if (newCursor != null) {
+                mDataValid = true;
+                notifyDataSetChanged();
+            } else {
+                mDataValid = false;
+                notifyDataSetInvalidated();
+            }
+            return oldCursor;
+        }
+
+        @Override
+        public int getCount() {
+            if (!mDataValid || mCursor == null || mCursor.isClosed()) return 0;
+            return mCursor.getCount();
+        }
+
+        @Override
+        public Object getItem(int position) {
+            if (mDataValid && mCursor.moveToPosition(position)) {
+                final String title = mCursor.getString(Index.COLUMN_INDEX_TITLE);
+                final String summary = mCursor.getString(Index.COLUMN_INDEX_SUMMARY);
+                final String iconResStr = mCursor.getString(Index.COLUMN_INDEX_ICON);
+                final int iconResId =
+                        TextUtils.isEmpty(iconResStr) ? 0 : Integer.parseInt(iconResStr);
+                return new SearchResult(title, summary, iconResId);
+            }
+            return null;
+        }
+
+        @Override
+        public long getItemId(int position) {
+            return 0;
+        }
+
+        @Override
+        public View getView(int position, View convertView, ViewGroup parent) {
+            if (!mDataValid && convertView == null) {
+                throw new IllegalStateException(
+                        "this should only be called when the cursor is valid");
+            }
+            if (!mCursor.moveToPosition(position)) {
+                throw new IllegalStateException("couldn't move cursor to position " + position);
+            }
+
+            View view;
+            TextView textTitle;
+            TextView textSummary;
+            ImageView imageView;
+
+            if (convertView == null) {
+                view = mInflater.inflate(R.layout.search_result, parent, false);
+            } else {
+                view = convertView;
+            }
+            textTitle = (TextView) view.findViewById(R.id.title);
+            textSummary = (TextView) view.findViewById(R.id.summary);
+            imageView = (ImageView) view.findViewById(R.id.icon);
+
+            SearchResult result = (SearchResult) getItem(position);
+
+            textTitle.setText(result.title);
+            textSummary.setText(result.summary);
+            if (result.iconResId != R.drawable.empty_icon) {
+                imageView.setImageResource(result.iconResId);
+                imageView.setBackgroundResource(R.color.background_search_result_icon);
+            } else {
+                imageView.setImageDrawable(null);
+                imageView.setBackgroundResource(R.drawable.empty_icon);
+            }
+
+            return view;
+        }
+    }
 }