AppWidget命令分析

1, 概述

AppWidget是窗口小部件， appwidget命令主要是设置apk是否有放在窗口的权限。

2, AppWidget命令

命令格式：

appwidget

 

命令列表：

命令	功能	实现方法
grantbind	允许 权限	appWidgetService.setBindAppWidgetPermission
revokebind	拒绝	appWidgetService.setBindAppWidgetPermission

 

3, 详细流程

所有adb命令的appwidget方法最后都会通过AppWidget.java执行,然后通过跨进程

调用AppWidgetService的方法完成,至于android系统中的AppWidget原理在此就不论述了。

   AppWidget的main方法如下,

public static void main(String[] args) {
        Parser parser = new Parser(args);
        Runnable command = parser.parseCommand();
        if (command != null) {
            command.run();
        }
    }

Parser是一个内部类, parseCommand方法如下,

public Runnable parseCommand() {
            try {
                String operation = mTokenizer.nextArg();
                if (ARGUMENT_GRANT_BIND.equals(operation)) {
                    return parseSetGrantBindAppWidgetPermissionCommand(true);
                } else if (ARGUMENT_REVOKE_BIND.equals(operation)) {
                    return parseSetGrantBindAppWidgetPermissionCommand(false);
                } else {
               throw new IllegalArgumentException("Unsupported operation: " + operation);
                }
            } catch (IllegalArgumentException iae) {
                System.out.println(USAGE);
                System.out.println("[ERROR] " + iae.getMessage());
                return null;
            }
        } 

2个指令分别对应同一个方法,都是parseSetGrantBindAppWidgetPermissionCommand,只是参数不一样而已。

private SetBindAppWidgetPermissionCommand parseSetGrantBindAppWidgetPermissionCommand(
                boolean granted) {
            String packageName = null;
            int userId = UserHandle.USER_OWNER;
            for (String argument; (argument = mTokenizer.nextArg()) != null;) {
                if (ARGUMENT_PACKAGE.equals(argument)) {
                    packageName = argumentValueRequired(argument);
                } else if (ARGUMENT_USER.equals(argument)) {
                    String user = argumentValueRequired(argument);
                    if (VALUE_USER_CURRENT.equals(user)) {
                        userId = UserHandle.USER_CURRENT;
                    } else {
                        userId = Integer.parseInt(user);
                    }
                } else {
                    throw new IllegalArgumentException("Unsupported argument: " + argument);
                }
            }
            if (packageName == null) {
                throw new IllegalArgumentException("Package name not specified."
                        + " Did you specify --package argument?");
            }
            return new SetBindAppWidgetPermissionCommand(packageName, granted, userId);
        }

返回的是SetBindAppWidgetPermissionCommand对象,该对象的run方法如下,

@Override
        public void run() {
            IBinder binder = ServiceManager.getService(Context.APPWIDGET_SERVICE);
            IAppWidgetService appWidgetService = IAppWidgetService.Stub.asInterface(binder);
            try {
         appWidgetService.setBindAppWidgetPermission(mPackageName, mUserId, mGranted);
            } catch (RemoteException re) {
                re.printStackTrace();
            }
        }

2个命令最后都是调用appWidgetService 的setBindAppWidgetPermission完成,只是mGranted参数不一样。