Proguard Meaning

Proguard.java

android {
    defaultConfig {
        multiDexEnabled true // Multiple dex enable only for Android Version >21 (prior v21 see more at: https://developer.android.com/studio/build/multidex.html)
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        // Keep file into main dex
        multiDexKeepFile file('multidex-config.txt')
        multiDexKeepProguard file('multidex-config.pro')
    }
  
    buildTypes {
        debug {
            minifyEnabled false 
            signingConfig signingConfigs.debug

        release {
            shrinkResources true // Shrink resource 
            minifyEnabled true // Shrink code (default useProguard == true -> obfocus and optimize)
            ext.set("dexprotector.configFile", "${projectDir}/dexprotector.xml") // Deprotector
            signingConfig signingConfigs.release
        }
    }
}
The getDefaultProguardFile('proguard-android.txt') method gets the default ProGuard settings file that is packaged with the Android plugin. When you build your project, the plugin creates a copy of the settings file in project-dir/build/intermediates/proguard-files/.
Tip: For even more code shrinking, try the proguard-android-optimize.txt file located in the same directory. It includes the same ProGuard rules, but with other optimizations that perform analysis at the bytecode level—inside and across methods—to reduce your APK size further and help it run faster.
The proguard-rules.pro file is where you can add custom ProGuard rules. By default, this file is located at the root of the module (next to the build.gradle file).


dump.txt
  Describes the internal structure of all the class files in the APK.
mapping.txt
  Provides a translation between the original and obfuscated class, method, and field names.
seeds.txt
  Lists the classes and members that were not obfuscated.
usage.txt
  Lists the code that was removed from the APK. 
    
### Customize which resources to keep
Create keep.xml at res/raw/keep.xml
<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@layout/l_used*_c,@layout/l_used_a,@layout/l_used_b*"
    tools:discard="@layout/unused2" />

      
### Remove unused alternative resources
android {
    defaultConfig {
        ...
        resConfigs "en", "fr"
    }
}