从外部读取预置桌面布局

private static final String external_workspace = "/system/default_workspace.xml";

//。。。。。

        if(mOpenHelper.loadFavoritesFromExternal(mOpenHelper.getWritableDatabase()) == 0){
              mOpenHelper.loadFavorites(mOpenHelper.getWritableDatabase(), R.xml.default_workspace);

//。。。。DatabaseHelper增加常量
        private static final String TAG_OUT_SHORTCUT = "out-shortcut";
        private static final String TAG_OUT_FOLDER = "out-folder";

//....

    private int loadFavoritesFromExternal(SQLiteDatabase db) {
            Intent intent = new Intent(Intent.ACTION_MAIN, null);
            intent.addCategory(Intent.CATEGORY_LAUNCHER);
            ContentValues values = new ContentValues();

            PackageManager packageManager = mContext.getPackageManager();
/*
            int rid = -1;
            Resources dwRes = null;
            Context dwCxt = null;
            try {
                ArrayList<PackageInfo> list = (ArrayList<PackageInfo>) packageManager.getInstalledPackages(PackageManager.GET_ACTIVITIES);
//                for(int z = 0;z<list.size();z++) {Log.v(TAG, list.get(z).packageName);}
                dwCxt = mContext.createPackageContext("com.letou.dw", Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY);
                dwRes = packageManager.getResourcesForApplication("com.letou.dw");
                rid = dwRes.getIdentifier("default_workspace", "xml", "com.letou.dw");
            } catch (Exception e) {
                e.printStackTrace();
            }
*/
            int i = 0;

                boolean hasOutDw = false;
                try {
                    File f = new File(external_workspace);
//System.out.println(" dw " + f.exists());
                    hasOutDw = f.exists();
                } catch(Exception e) {
                    Log.w(TAG, "Got exception parsing favorites.", e);
                }
            if(!hasOutDw) return i;

            try {
//System.out.println(" dw "+rid +" " + dwRes);
//                if(rid != -1 && dwRes != null) parser = dwRes.getXml(rid);
                    XmlPullParser parserOut = Xml.newPullParser();
                    parserOut.setInput(new FileInputStream("/system/default_workspace.xml"), "UTF-8");
                    int event = parserOut.getEventType();// 产生第一个事件
                    while (event != XmlPullParser.END_DOCUMENT) {
                        switch (event) {
                        case XmlPullParser.START_DOCUMENT:// 判断当前事件是否是文档开始事件
                            break;
                        case XmlPullParser.START_TAG:// 判断当前事件是否是标签元素开始事件
                            String name = parserOut.getName();
                            int attributeCount = parserOut.getAttributeCount();

                            long container = LauncherSettings.Favorites.CONTAINER_DESKTOP;
                            int type;

                            String screen = null;
                            String x = null;
                            String y = null;
                            String packName = null;
                            String clzName = null;
                            String spanX = null;
                            String spanY = null;
                            String title = null;
                            String icon = null;
                            String uri = null;

                            boolean added = false;
                            for (int z = 0; z < attributeCount; z++) {
//System.out.println(" attribute "+ parserOut.getAttributeName(z) + " "+ parserOut.getAttributeValue(z));

                                String key = parserOut.getAttributeName(z);
                                String value = parserOut.getAttributeValue(z);

                                if("container".equals(key)) {
                                    container = Long.valueOf(value);
                                } else if ("screen".equals(key)) {
                                    screen = value;
                                } else if ("x".equals(key)) {
                                    x = value;
                                } else if ("y".equals(key)) {
                                    y = value;
                                } else if ("packageName".equals(key)) {
                                    packName = value;
                                } else if ("className".equals(key)) {
                                    clzName = value;
                                } else if ("spanX".equals(key)) {
                                    spanX = value;
                                } else if ("spanY".equals(key)) {
                                    spanY = value;
                                } else if ("title".equals(key)) {
                                    title = value;
                                } else if ("icon".equals(key)) {
                                    icon = value;
                                } else if ("uri".equals(key)) {
                                    uri = value;
                                }

                            }
                            // If we are adding to the hotseat, the screen is used as the position in the
                            // hotseat. This screen can't be at position 0 because AllApps is in the
                            // zeroth position.
                            if (container == LauncherSettings.Favorites.CONTAINER_HOTSEAT &&
                                    Hotseat.isAllAppsButtonRank(Integer.valueOf(screen))) {
                                throw new RuntimeException("Invalid screen position for hotseat item");
                            }

                            values.clear();
                            values.put(LauncherSettings.Favorites.CONTAINER, container);
                            values.put(LauncherSettings.Favorites.SCREEN, screen);
                            values.put(LauncherSettings.Favorites.CELLX, x);
                            values.put(LauncherSettings.Favorites.CELLY, y);

                            if (TAG_FAVORITE.equals(name)) {
                                long id = addAppShortcut(db, values, packName, clzName, packageManager, intent);
                                added = id >= 0;
                            } else if (TAG_SEARCH.equals(name)) {
                                added = addSearchWidget(db, values);
                            } else if (TAG_CLOCK.equals(name)) {
                                added = addClockWidget(db, values);
                            } else if (TAG_APPWIDGET.equals(name)) {
                                added = addAppWidget(db, values, new ComponentName(packName, clzName), Integer.valueOf(spanX.trim()), Integer.valueOf(spanY.trim()));
                            } else if (TAG_OUT_SHORTCUT.equals(name)) {
                                long id = addUriShortcut(db, values, uri , title, icon);
                                added = id >= 0;
                            } else if (TAG_OUT_FOLDER.equals(name)) {
                                values.put(LauncherSettings.Favorites.TITLE, title);
                                long folderId = addFolder(db, values);
                                added = folderId >= 0;

                                ArrayList<Long> folderItems = new ArrayList<Long>();

                                int folderDepth = parserOut.getDepth();
                                while ((type = parserOut.next()) != XmlPullParser.END_TAG || parserOut.getDepth() > folderDepth) {
                                    if (type != XmlPullParser.START_TAG) {
                                        continue;
                                    }

                                    String packNameItem = null;
                                    String clzNameItem = null;
                                    String titleItem = null;
                                    String iconItem = null;
                                    String uriItem = null;

                                    int itemCount = parserOut.getAttributeCount();
                                    for (int z = 0; z < itemCount; z++) {

                                        String key = parserOut.getAttributeName(z);
                                        String value = parserOut.getAttributeValue(z);
//System.out.println(" ITEM " + key + " " + value);

                                        if ("packageName".equals(key)) {
                                            packNameItem = value;
                                        } else if ("className".equals(key)) {
                                            clzNameItem = value;
                                        } else if ("title".equals(key)) {
                                            titleItem = value;
                                        } else if ("icon".equals(key)) {
                                            iconItem = value;
                                        } else if ("uri".equals(key)) {
                                            uriItem = value;
                                        }

                                    }

                                    final String folder_item_name = parserOut.getName();

                                    values.clear();
                                    values.put(LauncherSettings.Favorites.CONTAINER, folderId);

                                    if (TAG_FAVORITE.equals(folder_item_name) && folderId >= 0) {
                                        long id = addAppShortcut(db, values, packNameItem, clzNameItem, packageManager, intent);
                                        if (id >= 0) {
                                            folderItems.add(id);
                                        }
                                    } else if (TAG_OUT_SHORTCUT.equals(folder_item_name) && folderId >= 0) {
                                        long id = addUriShortcut(db, values, uriItem, titleItem, iconItem);
                                        if (id >= 0) {
                                            folderItems.add(id);
                                        }
                                    } else {
                                        throw new RuntimeException("Folders can " + "contain only shortcuts");
                                    }
                                }
                            }
                            if (added) i++;
                            break;
                        case XmlPullParser.END_TAG:// 判断当前事件是否是标签元素结束事件
                            if (TAG_FAVORITE.equals(parserOut.getName())) {// 判断结束标签元素
                            }
                            break;
                        }
                        event = parserOut.next();// 进入下一个元素并触发相应事件
                    }// end while

            } catch (XmlPullParserException e) {
                Log.w(TAG, "Got exception parsing favorites.", e);
            } catch (IOException e) {
                Log.w(TAG, "Got exception parsing favorites.", e);
            } catch (RuntimeException e) {
                Log.w(TAG, "Got exception parsing favorites.", e);
            }

            return i;
    }


        private long addAppShortcut(SQLiteDatabase db, ContentValues values, String packName, String clzName,
                PackageManager packageManager, Intent intent) {
            long id = -1;
            ActivityInfo info;
            String packageName = packName;
            String className = clzName;
            try {
                ComponentName cn;
                try {
                    cn = new ComponentName(packageName, className);
                    info = packageManager.getActivityInfo(cn, 0);
                } catch (PackageManager.NameNotFoundException nnfe) {
                    String[] packages = packageManager.currentToCanonicalPackageNames(
                        new String[] { packageName });
                    cn = new ComponentName(packages[0], className);
                    info = packageManager.getActivityInfo(cn, 0);
                }
                id = generateNewId();
                intent.setComponent(cn);
                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
                        Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
                values.put(Favorites.INTENT, intent.toUri(0));
                values.put(Favorites.TITLE, info.loadLabel(packageManager).toString());
                values.put(Favorites.ITEM_TYPE, Favorites.ITEM_TYPE_APPLICATION);
                values.put(Favorites.SPANX, 1);
                values.put(Favorites.SPANY, 1);
                values.put(Favorites._ID, generateNewId());
                if (dbInsertAndCheck(this, db, TABLE_FAVORITES, null, values) < 0) {
                    return -1;
                }
            } catch (PackageManager.NameNotFoundException e) {
                Log.w(TAG, "Unable to add favorite: " + packageName +
                        "/" + className, e);
            }
            return id;
        }


        private boolean addAppWidget(SQLiteDatabase db, ContentValues values, ComponentName cn,
                int spanX, int spanY) {
            boolean allocatedAppWidgets = false;
            final AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(mContext);

            try {
                int appWidgetId = mAppWidgetHost.allocateAppWidgetId();

                values.put(Favorites.ITEM_TYPE, Favorites.ITEM_TYPE_APPWIDGET);
                values.put(Favorites.SPANX, spanX);
                values.put(Favorites.SPANY, spanY);
                values.put(Favorites.APPWIDGET_ID, appWidgetId);
                values.put(Favorites._ID, generateNewId());
                dbInsertAndCheck(this, db, TABLE_FAVORITES, null, values);

                allocatedAppWidgets = true;

                appWidgetManager.bindAppWidgetId(appWidgetId, cn);
            } catch (RuntimeException ex) {
                Log.e(TAG, "Problem allocating appWidgetId", ex);
            }

            return allocatedAppWidgets;
        }


private long addUriShortcut(SQLiteDatabase db, ContentValues values, String uri, String title, String icon) {
            Resources r = mContext.getResources();

            final int iconResId = R.drawable.ic_launcher_shortcut_browser_bookmark;
            // final int titleResId =
            // a.getResourceId(R.styleable.Favorite_title, 0);

            Intent intent;
            try {
                intent = Intent.parseUri(uri, 0);
            } catch (URISyntaxException e) {
                Log.w(TAG, "Shortcut has malformed uri: " + uri);
                return -1; // Oh well
            }

            if (iconResId == 0) { // || titleResId == 0) {
                Log.w(TAG, "Shortcut is missing icon resource ID");
                return -1;
            }

            long id = generateNewId();
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            values.put(Favorites.INTENT, intent.toUri(0));
            values.put(Favorites.TITLE, title);
            values.put(Favorites.ITEM_TYPE, Favorites.ITEM_TYPE_SHORTCUT);
            values.put(Favorites.SPANX, 1);
            values.put(Favorites.SPANY, 1);
            values.put(Favorites.ICON_TYPE, Favorites.ICON_TYPE_RESOURCE);
            values.put(Favorites.ICON_PACKAGE, mContext.getPackageName());
            values.put(Favorites.ICON_RESOURCE, r.getResourceName(iconResId));
            values.put(Favorites._ID, id);

            if (dbInsertAndCheck(this, db, TABLE_FAVORITES, null, values) < 0) {
                return -1;
            }
            return id;
        }

    }