Android Open Source - campus Search Suggestion Adapter

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License

The source code is released under:

GNU General Public License

Java Source Code

package lecho.app.campus.adapter;
/*from   w  ww.j a v  a 2  s  .c o m*/
import lecho.app.campus.R;
import lecho.app.campus.dao.PlaceDao;
import android.app.SearchManager;
import android.app.SearchableInfo;
import android.content.ContentResolver;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.support.v4.widget.ResourceCursorAdapter;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.actionbarsherlock.widget.SearchView;

public class SearchSuggestionAdapter extends ResourceCursorAdapter {
  private static final String TAG = "SearchSuggestionAdapter";
  private SearchableInfo mSearchableInfo;
  private SearchView mSearchView;

  static final int INVALID_INDEX = -1;
  // Cached column indexes, updated when the cursor changes.
  private int mSymbolCol = INVALID_INDEX;
  private int mNameCol = INVALID_INDEX;
  private int mDescriptionCol = INVALID_INDEX;

  public SearchSuggestionAdapter(Context context, SearchView searchView, SearchableInfo searchableInfo) {
    super(context, R.layout.search_dropdown_item, null, FLAG_REGISTER_CONTENT_OBSERVER);
    mSearchableInfo = searchableInfo;
    mSearchView = searchView;
  }

  /**
   * Tags the view with cached child view look-ups.
   */
  @Override
  public View newView(Context context, Cursor cursor, ViewGroup parent) {
    View v = super.newView(context, cursor, parent);
    v.setTag(new ChildViewCache(v));
    return v;
  }

  @Override
  public void bindView(View view, Context context, Cursor cursor) {
    if (mSymbolCol < 0 | mNameCol < 0 | mDescriptionCol < 0) {
      Log.w(TAG, "Bind viw called with invalid column indexes");
      return;
    }
    ChildViewCache views = (ChildViewCache) view.getTag();

    String symbol = cursor.getString(mSymbolCol);
    String name = cursor.getString(mNameCol);
    String description = cursor.getString(mDescriptionCol);

    views.mSymbol.setText(symbol);

    if (TextUtils.isEmpty(description)) {
      views.mName.setSingleLine(false);
      views.mName.setMaxLines(2);
      views.mName.setText(name);
      views.mDescription.setVisibility(View.GONE);
    } else {
      views.mName.setSingleLine(true);
      views.mName.setMaxLines(1);
      views.mName.setText(name);
      views.mDescription.setVisibility(View.VISIBLE);
      views.mDescription.setText(description);
    }
  }

  @Override
  public Cursor runQueryOnBackgroundThread(CharSequence constraint) {
    String query = (constraint == null) ? "" : constraint.toString();
    /**
     * for in app search we show the progress spinner until the cursor is
     * returned with the results.
     */
    Cursor cursor = null;
    if (mSearchView.getVisibility() != View.VISIBLE || mSearchView.getWindowVisibility() != View.VISIBLE) {
      return null;
    }
    // mSearchView.getWindow().getDecorView().post(mStartSpinnerRunnable);
    // // TODO:
    try {
      cursor = getSuggestions(query);
      // trigger fill window so the spinner stays up until the results
      // are copied over and
      // closer to being ready
      if (cursor != null) {
        return cursor;
      }
    } catch (RuntimeException e) {
      Log.w(TAG, "Search suggestions query threw an exception.", e);
    }
    // If cursor is null or an exception was thrown, stop the spinner
    // and return null.
    // changeCursor doesn't get called if cursor is null
    // mSearchView.getWindow().getDecorView().post(mStopSpinnerRunnable);
    return null;
  }

  public Cursor getSuggestions(String query) {
    if (mSearchableInfo == null) {
      return null;
    }

    String authority = mSearchableInfo.getSuggestAuthority();
    if (authority == null) {
      return null;
    }

    Uri.Builder uriBuilder = new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority)
        .query("") // TODO: Remove, workaround for a bug in
              // Uri.writeToParcel()
        .fragment(""); // TODO: Remove, workaround for a bug in
                // Uri.writeToParcel()

    // if content path provided, insert it now
    final String contentPath = mSearchableInfo.getSuggestPath();
    if (contentPath != null) {
      uriBuilder.appendEncodedPath(contentPath);
    }

    // append standard suggestion query path
    uriBuilder.appendPath(SearchManager.SUGGEST_URI_PATH_QUERY);

    // get the query selection, may be null
    String selection = mSearchableInfo.getSuggestSelection();
    // inject query, either as selection args or inline
    String[] selArgs = null;
    if (selection != null) { // use selection if provided
      selArgs = new String[] { query };
    } else { // no selection, use REST pattern
      uriBuilder.appendPath(query);
    }

    Uri uri = uriBuilder.build();

    // finally, make the query
    return mContext.getContentResolver().query(uri, null, selection, selArgs, null);
  }

  /**
   * Cache columns.
   */
  @Override
  public void changeCursor(Cursor c) {
    try {
      super.changeCursor(c);

      if (c != null) {
        mSymbolCol = c.getColumnIndex(PlaceDao.Properties.Symbol.columnName);
        mNameCol = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_1);
        mDescriptionCol = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_2);
      }
    } catch (Exception e) {
      Log.e(TAG, "error changing cursor and caching columns", e);
    }
  }

  /**
   * Cache of the child views of drop-drown list items, to avoid looking up
   * the children each time the contents of a list item are changed.
   */
  private final static class ChildViewCache {
    public final TextView mSymbol;
    public final TextView mName;
    public final TextView mDescription;

    public ChildViewCache(View v) {
      mSymbol = (TextView) v.findViewById(R.id.symbol);
      mName = (TextView) v.findViewById(R.id.name);
      mDescription = (TextView) v.findViewById(R.id.description);
    }
  }
}

Java Source Code List

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