src/com/android/browser/BrowserSnapshotPage.java

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * 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.browser;

import android.app.Fragment;
import android.app.LoaderManager.LoaderCallbacks;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.content.CursorLoader;
import android.content.Loader;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.LayoutInflater;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.MeasureSpec;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.AdapterContextMenuInfo;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ResourceCursorAdapter;
import android.widget.TextView;

import com.android.browser.CombinedBookmarkHistoryView.CombinedBookmarksCallbacks;
import com.android.browser.provider.SnapshotProvider.Snapshots;

import java.text.DateFormat;
import java.util.Date;

public class BrowserSnapshotPage extends Fragment implements
        LoaderCallbacks<Cursor>, OnItemClickListener {

    public static final String EXTRA_ANIMATE_ID = "animate_id";

    private static final int LOADER_SNAPSHOTS = 1;
    private static final String[] PROJECTION = new String[] {
        Snapshots._ID,
        Snapshots.TITLE,
        "length(" + Snapshots.VIEWSTATE + ")",
        Snapshots.THUMBNAIL,
        Snapshots.FAVICON,
        Snapshots.URL,
        Snapshots.DATE_CREATED,
    };
    private static final int SNAPSHOT_TITLE = 1;
    private static final int SNAPSHOT_VIEWSTATE_LENGTH = 2;
    private static final int SNAPSHOT_THUMBNAIL = 3;
    private static final int SNAPSHOT_FAVICON = 4;
    private static final int SNAPSHOT_URL = 5;
    private static final int SNAPSHOT_DATE_CREATED = 6;

    GridView mGrid;
    View mEmpty;
    SnapshotAdapter mAdapter;
    CombinedBookmarksCallbacks mCallback;

    public static BrowserSnapshotPage newInstance(CombinedBookmarksCallbacks cb,
            Bundle extras) {
        BrowserSnapshotPage instance = new BrowserSnapshotPage();
        instance.mCallback = cb;
        instance.setArguments(extras);
        return instance;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.snapshots, container, false);
        mEmpty = view.findViewById(android.R.id.empty);
        mGrid = (GridView) view.findViewById(R.id.grid);
        setupGrid(inflater);
        getLoaderManager().initLoader(LOADER_SNAPSHOTS, null, this);
        return view;
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        getLoaderManager().destroyLoader(LOADER_SNAPSHOTS);
        if (mAdapter != null) {
            mAdapter.changeCursor(null);
            mAdapter = null;
        }
    }

    void setupGrid(LayoutInflater inflater) {
        View item = inflater.inflate(R.layout.snapshot_item, mGrid, false);
        int mspec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        item.measure(mspec, mspec);
        int width = item.getMeasuredWidth();
        mGrid.setColumnWidth(width);
        mGrid.setOnItemClickListener(this);
        mGrid.setOnCreateContextMenuListener(this);
    }

    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
        if (id == LOADER_SNAPSHOTS) {
            return new CursorLoader(getActivity(),
                    Snapshots.CONTENT_URI, PROJECTION,
                    null, null, Snapshots.DATE_CREATED + " DESC");
        }
        return null;
    }

    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        if (loader.getId() == LOADER_SNAPSHOTS) {
            if (mAdapter == null) {
                mAdapter = new SnapshotAdapter(getActivity(), data);
                mGrid.setAdapter(mAdapter);
            } else {
                mAdapter.changeCursor(data);
            }
            boolean empty = mAdapter.isEmpty();
            mGrid.setVisibility(empty ? View.GONE : View.VISIBLE);
            mEmpty.setVisibility(empty ? View.VISIBLE : View.GONE);
        }
    }

    @Override
    public void onLoaderReset(Loader<Cursor> loader) {
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,
            ContextMenuInfo menuInfo) {
        MenuInflater inflater = getActivity().getMenuInflater();
        inflater.inflate(R.menu.snapshots_context, menu);
        // Create the header, re-use BookmarkItem (has the layout we want)
        BookmarkItem header = new BookmarkItem(getActivity());
        AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo;
        populateBookmarkItem(mAdapter.getItem(info.position), header);
        menu.setHeaderView(header);
    }

    private void populateBookmarkItem(Cursor cursor, BookmarkItem item) {
        item.setName(cursor.getString(SNAPSHOT_TITLE));
        item.setUrl(cursor.getString(SNAPSHOT_URL));
        item.setFavicon(getBitmap(cursor, SNAPSHOT_FAVICON));
    }

    static Bitmap getBitmap(Cursor cursor, int columnIndex) {
        byte[] data = cursor.getBlob(columnIndex);
        if (data == null) {
            return null;
        }
        return BitmapFactory.decodeByteArray(data, 0, data.length);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.delete_context_menu_id) {
            AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
            deleteSnapshot(info.id);
            return true;
        }
        return super.onContextItemSelected(item);
    }

    void deleteSnapshot(long id) {
        final Uri uri = ContentUris.withAppendedId(Snapshots.CONTENT_URI, id);
        final ContentResolver cr = getActivity().getContentResolver();
        new Thread() {
            @Override
            public void run() {
                cr.delete(uri, null, null);
            }
        }.start();

    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        mCallback.openSnapshot(id);
    }

    private static class SnapshotAdapter extends ResourceCursorAdapter {

        public SnapshotAdapter(Context context, Cursor c) {
            super(context, R.layout.snapshot_item, c, 0);
        }

        @Override
        public void bindView(View view, Context context, Cursor cursor) {
            ImageView thumbnail = (ImageView) view.findViewById(R.id.thumb);
            byte[] thumbBlob = cursor.getBlob(SNAPSHOT_THUMBNAIL);
            if (thumbBlob == null) {
                thumbnail.setImageResource(R.drawable.browser_thumbnail);
            } else {
                Bitmap thumbBitmap = BitmapFactory.decodeByteArray(
                        thumbBlob, 0, thumbBlob.length);
                thumbnail.setImageBitmap(thumbBitmap);
            }
            TextView title = (TextView) view.findViewById(R.id.title);
            title.setText(cursor.getString(SNAPSHOT_TITLE));
            TextView size = (TextView) view.findViewById(R.id.size);
            int stateLen = cursor.getInt(SNAPSHOT_VIEWSTATE_LENGTH);
            size.setText(String.format("%.2fMB", stateLen / 1024f / 1024f));
            long timestamp = cursor.getLong(SNAPSHOT_DATE_CREATED);
            TextView date = (TextView) view.findViewById(R.id.date);
            DateFormat dateFormat = DateFormat.getDateInstance(DateFormat.SHORT);
            date.setText(dateFormat.format(new Date(timestamp)));
        }

        @Override
        public Cursor getItem(int position) {
            return (Cursor) super.getItem(position);
        }
    }

}