src/com/android/launcher3/SavedWallpaperImages.java

/*
 * Copyright (C) 2013 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.launcher3;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.util.Pair;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;


public class SavedWallpaperImages {
    private static String TAG = "Launcher3.SavedWallpaperImages";
    private ImageDb mDb;
    ArrayList<Integer> mIds;
    ArrayList<Drawable> mThumbs;
    Context mContext;

    public SavedWallpaperImages(Context context) {
        mDb = new ImageDb(context);
        mContext = context;
    }

    public void loadThumbnailsAndImageIdList() {
        mIds = new ArrayList<Integer>();
        mThumbs = new ArrayList<Drawable>();
        SQLiteDatabase db = mDb.getReadableDatabase();
        Cursor result = db.query(ImageDb.TABLE_NAME,
                new String[] { ImageDb.COLUMN_ID,
                    ImageDb.COLUMN_IMAGE_THUMBNAIL_FILENAME }, // cols to return
                null, // select query
                null, // args to select query
                null,
                null,
                null,
                null);

        while (result.moveToNext()) {
            String filename = result.getString(1);
            File file = new File(mContext.getFilesDir(), filename);
            Bitmap thumb = BitmapFactory.decodeFile(file.getAbsolutePath());
            if (thumb != null) {
                mIds.add(result.getInt(0));
                mThumbs.add(new BitmapDrawable(thumb));
            }
        }
        result.close();
    }

    public ArrayList<Drawable> getThumbnails() {
        return mThumbs;
    }

    public ArrayList<Integer> getImageIds() {
        return mIds;
    }

    public String getImageFilename(int id) {
        Pair<String, String> filenames = getImageFilenames(id);
        if (filenames != null) {
            return filenames.second;
        }
        return null;
    }

    private Pair<String, String> getImageFilenames(int id) {
        SQLiteDatabase db = mDb.getReadableDatabase();
        Cursor result = db.query(ImageDb.TABLE_NAME,
                new String[] { ImageDb.COLUMN_IMAGE_THUMBNAIL_FILENAME,
                    ImageDb.COLUMN_IMAGE_FILENAME }, // cols to return
                ImageDb.COLUMN_ID + " = ?", // select query
                new String[] { Integer.toString(id) }, // args to select query
                null,
                null,
                null,
                null);
        if (result.getCount() > 0) {
            result.moveToFirst();
            String thumbFilename = result.getString(0);
            String imageFilename = result.getString(1);
            result.close();
            return new Pair<String, String>(thumbFilename, imageFilename);
        } else {
            return null;
        }
    }

    public void deleteImage(int id) {
        Pair<String, String> filenames = getImageFilenames(id);
        File imageFile = new File(mContext.getFilesDir(), filenames.first);
        imageFile.delete();
        File thumbFile = new File(mContext.getFilesDir(), filenames.second);
        thumbFile.delete();
        SQLiteDatabase db = mDb.getWritableDatabase();
        db.delete(ImageDb.TABLE_NAME,
                ImageDb.COLUMN_ID + " = ?", // SELECT query
                new String[] {
                    Integer.toString(id) // args to SELECT query
                });
    }

    public void writeImage(Bitmap thumbnail, byte[] imageBytes) {
        try {
            File imageFile = File.createTempFile("wallpaper", "", mContext.getFilesDir());
            FileOutputStream imageFileStream =
                    mContext.openFileOutput(imageFile.getName(), Context.MODE_PRIVATE);
            imageFileStream.write(imageBytes);
            imageFileStream.close();

            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            thumbnail.compress(Bitmap.CompressFormat.JPEG, 95, stream);
            File thumbFile = File.createTempFile("wallpaperthumb", "", mContext.getFilesDir());
            FileOutputStream thumbFileStream =
                    mContext.openFileOutput(thumbFile.getName(), Context.MODE_PRIVATE);
            thumbFileStream.write(stream.toByteArray());

            SQLiteDatabase db = mDb.getWritableDatabase();
            ContentValues values = new ContentValues();
            values.put(ImageDb.COLUMN_IMAGE_THUMBNAIL_FILENAME, thumbFile.getName());
            values.put(ImageDb.COLUMN_IMAGE_FILENAME, imageFile.getName());
            db.insert(ImageDb.TABLE_NAME, null, values);
        } catch (IOException e) {
            Log.e(TAG, "Failed writing images to storage " + e);
        }
    }

    static class ImageDb extends SQLiteOpenHelper {
        final static int DB_VERSION = 1;
        final static String DB_NAME = "saved_wallpaper_images.db";
        final static String TABLE_NAME = "saved_wallpaper_images";
        final static String COLUMN_ID = "id";
        final static String COLUMN_IMAGE_THUMBNAIL_FILENAME = "image_thumbnail";
        final static String COLUMN_IMAGE_FILENAME = "image";

        Context mContext;

        public ImageDb(Context context) {
            super(context, new File(context.getCacheDir(), DB_NAME).getPath(), null, DB_VERSION);
            // Store the context for later use
            mContext = context;
        }

        @Override
        public void onCreate(SQLiteDatabase database) {
            database.execSQL("CREATE TABLE IF NOT EXISTS " + TABLE_NAME + " (" +
                    COLUMN_ID + " INTEGER NOT NULL, " +
                    COLUMN_IMAGE_THUMBNAIL_FILENAME + " TEXT NOT NULL, " +
                    COLUMN_IMAGE_FILENAME + " TEXT NOT NULL, " +
                    "PRIMARY KEY (" + COLUMN_ID + " ASC) " +
                    ");");
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            if (oldVersion != newVersion) {
                // Delete all the records; they'll be repopulated as this is a cache
                db.execSQL("DELETE FROM " + TABLE_NAME);
            }
        }
    }
}