src/com/android/launcher2/WallpaperChooser.java

/*
 * Copyright (C) 2008 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.launcher2;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.app.FragmentTransaction;
import android.app.WallpaperManager;
import android.content.Context;
import android.content.DialogInterface;
import android.content.res.Resources;
import android.graphics.BitmapFactory;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.AsyncTask;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.SpinnerAdapter;

import java.io.IOException;
import java.util.ArrayList;

import com.android.launcher.R;

public class WallpaperChooser extends Activity {
    private static final String TAG = "Launcher.WallpaperChooser";

    private ViewGroup mWallpaperChooserBase;
    private ImageView mImageView = null;
    private Bitmap mBitmap = null;

    private ArrayList<Integer> mThumbs;
    private ArrayList<Integer> mImages;
    private WallpaperLoader mLoader;

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        /* We need some container to attach to in order for the fragment to be
         * considered embedded, so inflate an empty FrameLayout and use that
         * as the parent view
         */
        setContentView(R.layout.wallpaper_chooser_base);
        mWallpaperChooserBase = (ViewGroup) findViewById(R.id.wallpaper_chooser_base);

        findWallpapers();

        DialogFragment newFragment = new WallpaperDialogFragment(this);
        if (LauncherApplication.isScreenXLarge()) {
            // Display a dialog instead of embedding the view in the activity
            newFragment.show(getFragmentManager(), "dialog");
        } else {
            // Embed the fragment in the base view
            FragmentTransaction ft = getFragmentManager().openTransaction();
            ft.add(R.id.wallpaper_chooser_base, newFragment);
            ft.commit();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        if (mLoader != null && mLoader.getStatus() != WallpaperLoader.Status.FINISHED) {
            mLoader.cancel(true);
            mLoader = null;
        }
    }

    private void findWallpapers() {
        mThumbs = new ArrayList<Integer>(24);
        mImages = new ArrayList<Integer>(24);

        final Resources resources = getResources();
        // Context.getPackageName() may return the "original" package name,
        // com.android.launcher2; Resources needs the real package name,
        // com.android.launcher. So we ask Resources for what it thinks the
        // package name should be.
        final String packageName = resources.getResourcePackageName(R.array.wallpapers);

        addWallpapers(resources, packageName, R.array.wallpapers);
        addWallpapers(resources, packageName, R.array.extra_wallpapers);
    }

    private void addWallpapers(Resources resources, String packageName, int list) {
        final String[] extras = resources.getStringArray(list);
        for (String extra : extras) {
            int res = resources.getIdentifier(extra, "drawable", packageName);
            if (res != 0) {
                final int thumbRes = resources.getIdentifier(extra + "_small",
                        "drawable", packageName);

                if (thumbRes != 0) {
                    mThumbs.add(thumbRes);
                    mImages.add(res);
                    // Log.d(TAG, "addWallpapers: [" + packageName + "]: " + extra + " (" + res + ")");
                }
            }
        }
    }

    private void selectWallpaper(int position) {
        try {
            WallpaperManager wpm = (WallpaperManager)getSystemService(WALLPAPER_SERVICE);
            wpm.setResource(mImages.get(position));
            setResult(RESULT_OK);
            finish();
        } catch (IOException e) {
            Log.e(TAG, "Failed to set wallpaper: " + e);
        }
    }

    private class WallpaperDialogFragment extends DialogFragment implements
            AdapterView.OnItemSelectedListener, AdapterView.OnItemClickListener {
        private Context mContext;

        public WallpaperDialogFragment(Context context) {
            super();
            mContext = context;
            setCancelable(true);
        }

        @Override
        public void onDismiss(DialogInterface dialog) {
            WallpaperChooser.this.finish();
        }

        /* This will only be called when in XLarge mode, since this Fragment is invoked like
         * a dialog in that mode
         */
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            final View v = getLayoutInflater().inflate(
                    R.layout.wallpaper_chooser, mWallpaperChooserBase, false);

            GridView gridView = (GridView) v.findViewById(R.id.gallery);
            gridView.setOnItemClickListener(this);
            gridView.setAdapter(new ImageAdapter(WallpaperChooser.this));

            final int viewInset =
                    getResources().getDimensionPixelSize(R.dimen.alert_dialog_content_inset);

            AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
            builder.setCancelable(true);
            builder.setNegativeButton(R.string.wallpaper_cancel, null);
            builder.setTitle(R.string.pick_wallpaper);
            builder.setView(gridView, viewInset, viewInset, viewInset, viewInset);
            return builder.create();
        }

        /* This will be called on both XLarge and small screens, but since the dialog
         * is already created on XLarge, we want to skip this view creation
         */
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            /* Only generate a custom view if this fragment is being embedded in a view,
             * i.e: on a small screen
             */
            if (!LauncherApplication.isScreenXLarge()) {
                View view = inflater.inflate(R.layout.wallpaper_chooser, container, false);

                final Gallery gallery = (Gallery) view.findViewById(R.id.gallery);
                gallery.setCallbackDuringFling(false);
                gallery.setOnItemSelectedListener(this);
                gallery.setAdapter(new ImageAdapter(WallpaperChooser.this));

                View setButton = view.findViewById(R.id.set);
                setButton.setOnClickListener(new OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        selectWallpaper(gallery.getSelectedItemPosition());
                    }
                });
                mImageView = (ImageView) view.findViewById(R.id.wallpaper);
                return view;
            }
            return super.onCreateView(inflater, container, savedInstanceState);
        }

        // Click handler for the Dialog's GridView
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectWallpaper(position);
        }

        // Selection handler for the embedded Gallery view
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if (mLoader != null && mLoader.getStatus() != WallpaperLoader.Status.FINISHED) {
                mLoader.cancel();
            }
            mLoader = (WallpaperLoader) new WallpaperLoader().execute(position);
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
        }
    }

    private class ImageAdapter extends BaseAdapter implements ListAdapter, SpinnerAdapter {
        private LayoutInflater mLayoutInflater;

        ImageAdapter(WallpaperChooser context) {
            mLayoutInflater = context.getLayoutInflater();
        }

        public int getCount() {
            return mThumbs.size();
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView image;

            if (convertView == null) {
                image = (ImageView) mLayoutInflater.inflate(R.layout.wallpaper_item, parent, false);
            } else {
                image = (ImageView) convertView;
            }

            int thumbRes = mThumbs.get(position);
            image.setImageResource(thumbRes);
            Drawable thumbDrawable = image.getDrawable();
            if (thumbDrawable != null) {
                thumbDrawable.setDither(true);
            } else {
                Log.e(TAG, "Error decoding thumbnail resId=" + thumbRes + " for wallpaper #"
                        + position);
            }

            return image;
        }
    }

    class WallpaperLoader extends AsyncTask<Integer, Void, Bitmap> {
        BitmapFactory.Options mOptions;

        WallpaperLoader() {
            mOptions = new BitmapFactory.Options();
            mOptions.inDither = false;
            mOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;            
        }

        @Override
        protected Bitmap doInBackground(Integer... params) {
            if (isCancelled()) return null;
            try {
                return BitmapFactory.decodeResource(getResources(),
                        mImages.get(params[0]), mOptions);
            } catch (OutOfMemoryError e) {
                return null;
            }
        }

        @Override
        protected void onPostExecute(Bitmap b) {
            if (b == null) return;

            if (!isCancelled() && !mOptions.mCancel) {
                // Help the GC
                if (mBitmap != null) {
                    mBitmap.recycle();
                }

                // This should always be the case, but check anyways
                final ImageView view = mImageView;
                if (view != null) {
                    view.setImageBitmap(b);

                    mBitmap = b;

                    final Drawable drawable = view.getDrawable();
                    drawable.setFilterBitmap(true);
                    drawable.setDither(true);

                    view.postInvalidate();
                }

                mLoader = null;
            } else {
               b.recycle(); 
            }
        }

        void cancel() {
            mOptions.requestCancelDecode();
            super.cancel(true);
        }
    }
}