Android Application Info Flags

This documentation covers Android Application Info flags, which provide detailed information about installed applications on Android devices. These flags are part of the ApplicationInfo class and can be accessed through the Package Manager.

Overview

Application Info flags are bitwise flags that describe various properties and capabilities of an Android application. They are stored as integer values where each bit position represents a specific application characteristic.

Getting Application Info

To retrieve application information and flags, use the Package Manager:

// To use the `global` variable you require the WXU Plugin
const pm = global.require("pm")
const info = JSON.parse(pm.getApplicationInfo("com.goolag.pif"))

let number = info.flags;
// flag for system apps
let flag = 1<<0;

if ((number & flag) != 0) {
    console.log("This app is a system app");
} else {
    console.log("This app is not a system app");
}

Understanding Bit Shifting

Before diving into the flags, it's important to understand bit shifting operations:

What is Bit Shifting?

Bit shifting is a bitwise operation that moves bits to the left or right. In the context of Android flags:

• 1<<0 means shift the bit 1 zero positions to the left, resulting in: 00000001 (decimal 1)
• 1<<1 means shift the bit 1 one position to the left, resulting in: 00000010 (decimal 2)
• 1<<2 means shift the bit 1 two positions to the left, resulting in: 00000100 (decimal 4)

Why Use Bit Shifting for Flags?

1. Memory Efficiency: Multiple boolean values can be stored in a single integer
2. Performance: Bitwise operations are very fast
3. Compatibility: Allows for easy addition of new flags without breaking existing code

Checking if a Flag is Set

To check if a specific flag is set, use the bitwise AND operator (&):

const FLAG_SYSTEM = 1<<0;  // Value: 1
const FLAG_DEBUGGABLE = 1<<1;  // Value: 2

// Check if app is a system app
if ((info.flags & FLAG_SYSTEM) != 0) {
    console.log("System app");
}

// Check if app is debuggable
if ((info.flags & FLAG_DEBUGGABLE) != 0) {
    console.log("Debuggable app");
}

Complete Application Info Flags Reference

Here are all the available Application Info flags with their descriptions:

Core Application Flags

Flag	Value	Description
FLAG_SYSTEM	1<<0 (1)	Application is installed in the device's system image
FLAG_DEBUGGABLE	1<<1 (2)	Application allows debugging of its code
FLAG_HAS_CODE	1<<2 (4)	Application has code associated with it
FLAG_PERSISTENT	1<<3 (8)	Application is persistent
FLAG_FACTORY_TEST	1<<4 (16)	Application holds FACTORY_TEST permission
FLAG_ALLOW_TASK_REPARENTING	1<<5 (32)	Allows task reparenting
FLAG_ALLOW_CLEAR_USER_DATA	1<<6 (64)	Allows clearing user data
FLAG_UPDATED_SYSTEM_APP	1<<7 (128)	System app that has been updated
FLAG_TEST_ONLY	1<<8 (256)	Application is for testing only

Screen Support Flags

Flag	Value	Description
FLAG_SUPPORTS_SMALL_SCREENS	1<<9 (512)	Supports small screens
FLAG_SUPPORTS_NORMAL_SCREENS	1<<10 (1024)	Supports normal screens
FLAG_SUPPORTS_LARGE_SCREENS	1<<11 (2048)	Supports large screens
FLAG_RESIZEABLE_FOR_SCREENS	1<<12 (4096)	UI can adjust for different screen sizes
FLAG_SUPPORTS_SCREEN_DENSITIES	1<<13 (8192)	Supports different screen densities (deprecated)
FLAG_SUPPORTS_XLARGE_SCREENS	1<<19 (524288)	Supports extra large screens

System and Security Flags

Flag	Value	Description
FLAG_VM_SAFE_MODE	1<<14 (16384)	VM operates in safe mode
FLAG_ALLOW_BACKUP	1<<15 (32768)	Allows OS-driven backups
FLAG_KILL_AFTER_RESTORE	1<<16 (65536)	Killed after restore operation
FLAG_RESTORE_ANY_VERSION	1<<17 (131072)	Can restore from future versions
FLAG_EXTERNAL_STORAGE	1<<18 (262144)	Installed on external storage
FLAG_LARGE_HEAP	1<<20 (1048576)	Requests large heap
FLAG_STOPPED	1<<21 (2097152)	Package is in stopped state
FLAG_SUPPORTS_RTL	1<<22 (4194304)	Supports right-to-left layouts
FLAG_INSTALLED	1<<23 (8388608)	Currently installed for calling user
FLAG_IS_DATA_ONLY	1<<24 (16777216)	Only data is installed
FLAG_FULL_BACKUP_ONLY	1<<26 (67108864)	Uses full-data streaming backups
FLAG_USES_CLEARTEXT_TRAFFIC	1<<27 (134217728)	May use cleartext network traffic
FLAG_EXTRACT_NATIVE_LIBS	1<<28 (268435456)	Extracts native libraries
FLAG_HARDWARE_ACCELERATED	1<<29 (536870912)	Hardware accelerated rendering
FLAG_SUSPENDED	1<<30 (1073741824)	Package is suspended
FLAG_MULTIARCH	1<<31 (2147483648)	Code may be loaded into other processes

Deprecated Flags

Flag	Value	Description
FLAG_IS_GAME	1<<25 (33554432)	Application is a game (deprecated, use CATEGORY_GAME instead)

Practical Examples

Example 1: Checking Multiple Flags

const info = JSON.parse(pm.getApplicationInfo("com.example.app"));
const flags = info.flags;

// Define flag constants
const FLAG_SYSTEM = 1<<0;
const FLAG_DEBUGGABLE = 1<<1;
const FLAG_ALLOW_BACKUP = 1<<15;

// Check multiple flags
const isSystem = (flags & FLAG_SYSTEM) != 0;
const isDebuggable = (flags & FLAG_DEBUGGABLE) != 0;
const allowsBackup = (flags & FLAG_ALLOW_BACKUP) != 0;

console.log(`System app: ${isSystem}`);
console.log(`Debuggable: ${isDebuggable}`);
console.log(`Allows backup: ${allowsBackup}`);

Example 2: Creating a Flag Checker Function

function checkAppFlags(packageName) {
    const info = JSON.parse(pm.getApplicationInfo(packageName));
    const flags = info.flags;
    
    const flagChecks = {
        'System App': (flags & (1<<0)) != 0,
        'Debuggable': (flags & (1<<1)) != 0,
        'Has Code': (flags & (1<<2)) != 0,
        'Persistent': (flags & (1<<3)) != 0,
        'Updated System App': (flags & (1<<7)) != 0,
        'Test Only': (flags & (1<<8)) != 0,
        'External Storage': (flags & (1<<18)) != 0,
        'Large Heap': (flags & (1<<20)) != 0,
        'Stopped': (flags & (1<<21)) != 0,
        'Suspended': (flags & (1<<30)) != 0
    };
    
    console.log(`Flags for ${packageName}:`);
    for (const [flagName, isSet] of Object.entries(flagChecks)) {
        console.log(`  ${flagName}: ${isSet}`);
    }
}

// Usage
checkAppFlags("com.android.settings");

Important Notes

1. Security Warning: Don't use FLAG_SYSTEM for security decisions. Use signature checks or permissions instead.

2. API Level Considerations: Some flags may behave differently or be ignored on certain Android API levels.

3. Performance: Bitwise operations are very efficient, making flag checking fast even for multiple flags.

4. Future Compatibility: New flags may be added in future Android versions, so always check documentation for the target API level.

See Also

• Android Developer Documentation - ApplicationInfo
• Bitwise Operations in Programming
• Package Manager API Reference