org.thomnichols.android.gmarks.ThreadIterator.java Source code

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Here is the source code for org.thomnichols.android.gmarks.ThreadIterator.java

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/* This file is part of GMarks. Copyright 2011 Thom Nichols
 *
 * GMarks is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GMarks is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GMarks.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.thomnichols.android.gmarks;

import java.io.IOException;
import java.util.Iterator;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.thomnichols.android.gmarks.BookmarksQueryService.AuthException;

import android.util.Log;

public abstract class ThreadIterator<T> implements Iterator<T>, Iterable<T> {
    static final String TAG = "BOOKMARK THREAD ITERATOR";
    protected final BookmarksQueryService bookmarksQueryService;
    private static final String uriTemplate = "https://www.google.com/bookmarks/api/threadsearch?fo=%s&g=Time&nr=25&start=";
    private final String uriBase;

    private JSONObject currentBatch = null;
    private int currentQueryIndex = 0;
    private int totalItems = -1;
    private int sectionIndex = 0;
    protected int currentItemIndex = 0;
    protected JSONArray currentSection = null;

    public ThreadIterator(BookmarksQueryService bookmarksQueryService, String threadParam)
            throws AuthException, IOException {
        this.bookmarksQueryService = bookmarksQueryService;
        this.bookmarksQueryService.getXtParam(); // ensures we're logged in & have the default thread ID
        this.uriBase = String.format(uriTemplate, threadParam);
    }

    private boolean getNextSection() {
        if (currentBatch == null)
            return false;
        try {
            JSONArray allSections = currentBatch.getJSONArray("threadTitles");
            if (this.sectionIndex >= allSections.length())
                return false;

            this.currentSection = allSections.getJSONObject(sectionIndex++).getJSONArray("sectionContent");
            this.currentItemIndex = 0;
            this.currentQueryIndex += currentSection.length();
            return true;
        } catch (JSONException ex) {
            Log.w(TAG, "JSON iterator error", ex);
        }
        return false;
    }

    private boolean queryNext() throws IteratorException {
        try {
            this.currentBatch = this.bookmarksQueryService.queryJSON(uriBase + currentQueryIndex);
            this.currentItemIndex = 0;
            this.sectionIndex = 0;

            if (this.totalItems < 0)
                this.totalItems = currentBatch.getInt("nr");

            JSONArray sectionList = currentBatch.getJSONArray("threadTitles");
            if (sectionList.length() < 1) {
                Log.w(TAG, "JSON response has 0 items!");
                return false;
            }

            this.currentSection = sectionList.getJSONObject(sectionIndex++).getJSONArray("sectionContent");
            this.currentQueryIndex += currentSection.length();
            return this.currentSection.length() > 0;
        } catch (IOException ex) {
            Log.w(TAG, "IO error in query all bookmarks", ex);
            throw new IteratorException(ex);
            //            return false;
        } catch (JSONException ex) {
            Log.w(TAG, "JSON error in query all bookmarks", ex);
            throw new IteratorException(ex);
            //            return false;
        }
    }

    public boolean hasNext() throws IteratorException {
        return this.currentSection != null && this.currentItemIndex < this.currentSection.length()
                || getNextSection() || queryNext();
    }

    public void remove() {
        throw new UnsupportedOperationException();
    }

    public Iterator<T> iterator() {
        return this;
    }
}