src/com/android/mms/ui/SearchActivity.java

/**
 * Copyright (c) 2009, 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 com.android.mms.ui;

import com.android.mms.MmsApp;
import com.android.mms.R;
import android.app.ListActivity;
import android.app.SearchManager;
import android.content.AsyncQueryHandler;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Color;
import android.graphics.Typeface;
import android.net.Uri;
import android.os.Bundle;
import android.provider.Telephony;
import android.text.SpannableString;
import android.text.TextPaint;
import android.text.style.ForegroundColorSpan;
import android.text.style.StyleSpan;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.ListView;
import android.widget.TextView;

import com.android.mms.data.Contact;
import com.android.mms.ui.ComposeMessageActivity;

/***
 * Presents a List of search results.  Each item in the list represents a thread which
 * matches.  The item contains the contact (or phone number) as the "title" and a
 * snippet of what matches, below.  The snippet is taken from the most recent part of
 * the conversation that has a match.  Each match within the visible portion of the
 * snippet is highlighted.
 */

public class SearchActivity extends ListActivity
{
    AsyncQueryHandler mQueryHandler;

    /*
     * Subclass of TextView which displays a snippet of text which matches the full text and
     * highlights the matches within the snippet.
     */
    public static class TextViewSnippet extends TextView {
        private static String sEllipsis = "\u2026";

        private static int sTypefaceHighlight = Typeface.BOLD;

        private String mFullText;
        private String mTargetString;

        public TextViewSnippet(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        public TextViewSnippet(Context context) {
            super(context);
        }

        public TextViewSnippet(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
        }

        /**
         * We have to know our width before we can compute the snippet string.  Do that
         * here and then defer to super for whatever work is normally done.
         */
        @Override
        protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
            String fullTextLower = mFullText.toLowerCase();
            String targetStringLower = mTargetString.toLowerCase();

            int startPos = fullTextLower.indexOf(targetStringLower);
            int searchStringLength = targetStringLower.length();
            int bodyLength = fullTextLower.length();

            TextPaint tp = getPaint();

            float searchStringWidth = tp.measureText(mTargetString);
            float textFieldWidth = getWidth();

            String snippetString = null;
            if (searchStringWidth > textFieldWidth) {
                snippetString = mFullText.substring(startPos, startPos + searchStringLength);
            } else {
                float ellipsisWidth = tp.measureText(sEllipsis);
                textFieldWidth -= (2F * ellipsisWidth); // assume we'll need one on both ends

                int offset = -1;
                int start = -1;
                int end = -1;
                /* TODO: this code could be made more efficient by only measuring the additional
                 * characters as we widen the string rather than measuring the whole new
                 * string each time.
                 */
                while (true) {
                    offset += 1;

                    int newstart = Math.max(0, startPos - offset);
                    int newend = Math.min(bodyLength, startPos + searchStringLength + offset);

                    if (newstart == start && newend == end) {
                        // if we couldn't expand out any further then we're done
                        break;
                    }
                    start = newstart;
                    end = newend;

                    // pull the candidate string out of the full text rather than body
                    // because body has been toLower()'ed
                    String candidate = mFullText.substring(start, end);
                    if (tp.measureText(candidate) > textFieldWidth) {
                        // if the newly computed width would exceed our bounds then we're done
                        // do not use this "candidate"
                        break;
                    }

                    snippetString = String.format(
                            "%s%s%s",
                            start == 0 ? "" : sEllipsis,
                            candidate,
                            end == bodyLength ? "" : sEllipsis);
                }
            }

            String snippetStringLower = snippetString.toLowerCase();
            SpannableString spannable = new SpannableString(snippetString);
            int start = 0;
            while (true) {
                int index = snippetStringLower.indexOf(targetStringLower, start);
                if (index == -1) {
                    break;
                }
//              spannable.setSpan(new ForegroundColorSpan(sHighlightColor), index, index+searchStringLength, 0);
                spannable.setSpan(new StyleSpan(sTypefaceHighlight), index, index+searchStringLength, 0);
                start = index + searchStringLength;
            }
            setText(spannable);

            // do this after the call to setText() above
            super.onLayout(changed, left, top, right, bottom);
        }

        public void setText(String fullText, String target) {
            mFullText = fullText;
            mTargetString = target;
            requestLayout();
        }
    }

    public void onCreate(Bundle icicle)
    {
        super.onCreate(icicle);
        setContentView(R.layout.search_activity);

        String searchStringParameter = getIntent().getStringExtra(SearchManager.QUERY).trim();
        final String searchString =
        	searchStringParameter != null ? searchStringParameter.trim() : searchStringParameter;
        ContentResolver cr = getContentResolver();

        final ListView listView = getListView();
        listView.setSelector(android.R.drawable.list_selector_background);
        listView.setItemsCanFocus(true);
        listView.setFocusable(true);
        listView.setClickable(true);

        // I considered something like "searching..." but typically it will
        // flash on the screen briefly which I found to be more distracting
        // than beneficial.
        // This gets updated when the query completes.
        setTitle("");

        // When the query completes cons up a new adapter and set our list adapter to that.
        mQueryHandler = new AsyncQueryHandler(cr) {
            protected void onQueryComplete(int token, Object cookie, Cursor c) {
                final int threadIdPos = c.getColumnIndex("thread_id");
                final int addressPos  = c.getColumnIndex("address");
                final int bodyPos     = c.getColumnIndex("body");
                final int rowidPos    = c.getColumnIndex("_id");

                int cursorCount = c.getCount();
                setTitle(getResources().getQuantityString(
                        R.plurals.search_results_title,
                        cursorCount,
                        cursorCount,
                        searchString));

                setListAdapter(new CursorAdapter(SearchActivity.this, c) {
                    @Override
                    public void bindView(View view, Context context, Cursor cursor) {
                        final TextView title = (TextView)(view.findViewById(R.id.title));
                        final TextViewSnippet snippet = (TextViewSnippet)(view.findViewById(R.id.subtitle));

                        String address = cursor.getString(addressPos);
                        Contact contact = Contact.get(address, false);

                        contact.addListener(new Contact.UpdateListener() {
                            public void onUpdate(final Contact updated) {
                                runOnUiThread(new Runnable() {
                                    public void run() {
                                        title.setText(updated.getNameAndNumber());
                                    }
                                });
                            }
                        });

                        String titleString = contact.getNameAndNumber();
                        title.setText(titleString);

                        snippet.setText(cursor.getString(bodyPos), searchString);

                        // if the user touches the item then launch the compose message
                        // activity with some extra parameters to highlight the search
                        // results and scroll to the latest part of the conversation
                        // that has a match.
                        final long threadId = cursor.getLong(threadIdPos);
                        final long rowid = cursor.getLong(rowidPos);

                        view.setOnClickListener(new View.OnClickListener() {
                            public void onClick(View v) {
                                final Intent onClickIntent = new Intent(SearchActivity.this, ComposeMessageActivity.class);
                                onClickIntent.putExtra("thread_id", threadId);
                                onClickIntent.putExtra("highlight", searchString);
                                onClickIntent.putExtra("select_id", rowid);
                                startActivity(onClickIntent);
                            }
                        });
                    }

                    @Override
                    public View newView(Context context, Cursor cursor, ViewGroup parent) {
                        LayoutInflater inflater = LayoutInflater.from(context);
                        View v = inflater.inflate(R.layout.search_item, parent, false);
                        return v;
                    }

                });

                // ListView seems to want to reject the setFocusable until such time
                // as the list is not empty.  Set it here and request focus.  Without
                // this the arrow keys (and trackball) fail to move the selection.
                listView.setFocusable(true);
                listView.setFocusableInTouchMode(true);
                listView.requestFocus();

                // Remember the query if there are actual results
                if (cursorCount > 0) {
                    MmsApp mmsApp = (MmsApp)getApplication();
                    mmsApp.getRecentSuggestions().saveRecentQuery(
                            searchString,
                            getString(R.string.search_history,
                                    cursorCount, searchString));
                }
            }
        };

        // don't pass a projection since the search uri ignores it
        Uri uri = Telephony.MmsSms.SEARCH_URI.buildUpon().appendQueryParameter("pattern", searchString).build();

        // kick off a query for the threads which match the search string
        mQueryHandler.startQuery(0, null, uri, null, null, null, null);

    }
}