home.java

android 例子中的Home。很有代表意义

        if (resolveInfo == null) {
            return null;
        }

        final ApplicationInfo info = new ApplicationInfo();
        final ActivityInfo activityInfo = resolveInfo.activityInfo;
        info.icon = activityInfo.loadIcon(manager);
        if (info.title == null || info.title.length() == 0) {
            info.title = activityInfo.loadLabel(manager);
        }
        if (info.title == null) {
            info.title = "";
        }
        return info;
    }

    /**
     * When the notification that favorites have changed is received, requests
     * a favorites list refresh.
     */
    private void onFavoritesChanged() {
        bindFavorites(false);
    }

    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            switch (event.getKeyCode()) {
                case KeyEvent.KEYCODE_BACK:
                    return true;
                case KeyEvent.KEYCODE_HOME:
                    return true;
            }
        }

        return super.dispatchKeyEvent(event);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);

        menu.add(0, MENU_WALLPAPER_SETTINGS, 0, R.string.menu_wallpaper)
                 .setIcon(R.drawable.ic_menu_gallery)
                 .setAlphabeticShortcut('W');
        menu.add(0, MENU_SEARCH, 0, R.string.menu_search)
                .setIcon(android.R.drawable.ic_search_category_default)
                .setAlphabeticShortcut(SearchManager.MENU_KEY);
        menu.add(0, MENU_SETTINGS, 0, R.string.menu_settings)
                .setIcon(R.drawable.ic_menu_preferences)
                .setIntent(new Intent(android.provider.Settings.ACTION_SETTINGS));

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case MENU_WALLPAPER_SETTINGS:
                startWallpaper();
                return true;
            case MENU_SEARCH:
                onSearchRequested();
                return true;
        }

        return super.onOptionsItemSelected(item);
    }

    private void startWallpaper() {
        final Intent pickWallpaper = new Intent(Intent.ACTION_SET_WALLPAPER);
        startActivity(Intent.createChooser(pickWallpaper, getString(R.string.menu_wallpaper)));
    }

    /**
     * Loads the list of installed applications in mApplications.
     */
    private void loadApplications(boolean isLaunching) {
        if (isLaunching && mApplications != null) {
            return;
        }

        PackageManager manager = getPackageManager();

        Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
        mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);

        final List<ResolveInfo> apps = manager.queryIntentActivities(mainIntent, 0);
        Collections.sort(apps, new ResolveInfo.DisplayNameComparator(manager));

        if (apps != null) {
            final int count = apps.size();

            if (mApplications == null) {
                mApplications = new ArrayList<ApplicationInfo>(count);
            }
            mApplications.clear();

            for (int i = 0; i < count; i++) {
                ApplicationInfo application = new ApplicationInfo();
                ResolveInfo info = apps.get(i);

                application.title = info.loadLabel(manager);
                application.setActivity(new ComponentName(
                        info.activityInfo.applicationInfo.packageName,
                        info.activityInfo.name),
                        Intent.FLAG_ACTIVITY_NEW_TASK
                        | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
                application.icon = info.activityInfo.loadIcon(manager);

                mApplications.add(application);
            }
        }
    }

    /**
     * Shows all of the applications by playing an animation on the grid.
     */
    private void showApplications(boolean animate) {
        if (mBlockAnimation) {
            return;
        }
        mBlockAnimation = true;

        mShowApplicationsCheck.toggle();

        if (mShowLayoutAnimation == null) {
            mShowLayoutAnimation = AnimationUtils.loadLayoutAnimation(
                    this, R.anim.show_applications);
        }

        // This enables a layout animation; if you uncomment this code, you need to
        // comment the line mGrid.startAnimation() below
//        mGrid.setLayoutAnimationListener(new ShowGrid());
//        mGrid.setLayoutAnimation(mShowLayoutAnimation);
//        mGrid.startLayoutAnimation();

        if (animate) {
            mGridEntry.setAnimationListener(new ShowGrid());
            mGrid.startAnimation(mGridEntry);
        }

        mGrid.setVisibility(View.VISIBLE);

        if (!animate) {
            mBlockAnimation = false;
        }

        // ViewDebug.startHierarchyTracing("Home", mGrid);
    }

    /**
     * Hides all of the applications by playing an animation on the grid.
     */
    private void hideApplications() {
        if (mBlockAnimation) {
            return;
        }
        mBlockAnimation = true;

        mShowApplicationsCheck.toggle();

        if (mHideLayoutAnimation == null) {
            mHideLayoutAnimation = AnimationUtils.loadLayoutAnimation(
                    this, R.anim.hide_applications);
        }

        mGridExit.setAnimationListener(new HideGrid());
        mGrid.startAnimation(mGridExit);
        mGrid.setVisibility(View.INVISIBLE);
        mShowApplications.requestFocus();

        // This enables a layout animation; if you uncomment this code, you need to
        // comment the line mGrid.startAnimation() above
//        mGrid.setLayoutAnimationListener(new HideGrid());
//        mGrid.setLayoutAnimation(mHideLayoutAnimation);
//        mGrid.startLayoutAnimation();
    }

    /**
     * Receives intents from other applications to change the wallpaper.
     */
    private class WallpaperIntentReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            getWindow().setBackgroundDrawable(getWallpaper());
        }
    }

    /**
     * Receives notifications when applications are added/removed.
     */
    private class ApplicationsIntentReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            loadApplications(false);
            bindApplications();
            bindRecents();
            bindFavorites(false);
        }
    }

    /**
     * Receives notifications whenever the user favorites have changed.
     */
    private class FavoritesChangeObserver extends ContentObserver {
        public FavoritesChangeObserver() {
            super(mHandler);
        }

        @Override
        public void onChange(boolean selfChange) {
            onFavoritesChanged();
        }
    }

    /**
     * GridView adapter to show the list of all installed applications.
     */
    private class ApplicationsAdapter extends ArrayAdapter<ApplicationInfo> {
        private Rect mOldBounds = new Rect();

        public ApplicationsAdapter(Context context, ArrayList<ApplicationInfo> apps) {
            super(context, 0, apps);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            final ApplicationInfo info = mApplications.get(position);

            if (convertView == null) {
                final LayoutInflater inflater = getLayoutInflater();
                convertView = inflater.inflate(R.layout.application, parent, false);
            }

            //final ImageView imageView = (ImageView) convertView.findViewById(R.id.icon);
            Drawable icon = info.icon;

            if (!info.filtered) {
                final Resources resources = getContext().getResources();
                int width = (int) resources.getDimension(android.R.dimen.app_icon_size);
                int height = (int) resources.getDimension(android.R.dimen.app_icon_size);

                final int iconWidth = icon.getIntrinsicWidth();
                final int iconHeight = icon.getIntrinsicHeight();

                if (icon instanceof PaintDrawable) {
                    PaintDrawable painter = (PaintDrawable) icon;
                    painter.setIntrinsicWidth(width);
                    painter.setIntrinsicHeight(height);
                }

                if (width > 0 && height > 0 && (width < iconWidth || height < iconHeight)) {
                    final float ratio = (float) iconWidth / iconHeight;

                    if (iconWidth > iconHeight) {
                        height = (int) (width / ratio);
                    } else if (iconHeight > iconWidth) {
                        width = (int) (height * ratio);
                    }

                    final Bitmap.Config c =
                            icon.getOpacity() != PixelFormat.OPAQUE ?
                                Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
                    final Bitmap thumb = Bitmap.createBitmap(width, height, c);
                    final Canvas canvas = new Canvas(thumb);
                    canvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG, 0));
                    // Copy the old bounds to restore them later
                    // If we were to do oldBounds = icon.getBounds(),
                    // the call to setBounds() that follows would
                    // change the same instance and we would lose the
                    // old bounds
                    mOldBounds.set(icon.getBounds());
                    icon.setBounds(0, 0, width, height);
                    icon.draw(canvas);
                    icon.setBounds(mOldBounds);
                    icon = info.icon = new BitmapDrawable(thumb);
                    info.filtered = true;
                }
            }

            final TextView textView = (TextView) convertView.findViewById(R.id.label);
            textView.setCompoundDrawablesWithIntrinsicBounds(null, icon, null, null);
            textView.setText(info.title);

            return convertView;
        }
    }

    /**
     * Shows and hides the applications grid view.
     */
    private class ShowApplications implements View.OnClickListener {
        public void onClick(View v) {
            if (mGrid.getVisibility() != View.VISIBLE) {
                showApplications(true);
            } else {
                hideApplications();
            }
        }
    }

    /**
     * Hides the applications grid when the layout animation is over.
     */
    private class HideGrid implements Animation.AnimationListener {
        public void onAnimationStart(Animation animation) {
        }

        public void onAnimationEnd(Animation animation) {
            mBlockAnimation = false;
        }

        public void onAnimationRepeat(Animation animation) {
        }
    }

    /**
     * Shows the applications grid when the layout animation is over.
     */
    private class ShowGrid implements Animation.AnimationListener {
        public void onAnimationStart(Animation animation) {
        }

        public void onAnimationEnd(Animation animation) {
            mBlockAnimation = false;
            // ViewDebug.stopHierarchyTracing();
        }

        public void onAnimationRepeat(Animation animation) {
        }
    }

    /**
     * Starts the selected activity/application in the grid view.
     */
    private class ApplicationLauncher implements AdapterView.OnItemClickListener {
        public void onItemClick(AdapterView parent, View v, int position, long id) {
            ApplicationInfo app = (ApplicationInfo) parent.getItemAtPosition(position);
            startActivity(app.intent);
        }
    }
}