Booster

Resource Deredundancy

Resource Qualifier

Android defines a series of resource configuration qualifiers to facilitate adaptation for specific devices. Developers only need to name resources according to the qualifiers, and the Android Framework will complete the adaptation work based on the context. Common Configurations include:

  1. Language and region
  2. Screen size
  • small
  • normal
  • large
  • xlarge
  1. Screen orientation
  • port
  • land
  1. Screen pixel density
  • ldpi
  • mdpi
  • hdpi
  • xhdpi
  • xxhdpi
  • xxxhdpi
  • nodpi
  • tvdpi
  • anydpi
  • nnndpi
  1. Platform version (API Level)
  • v3
  • v4
  • v7
  • ...

Unnecessary Resource Removal

For APPs that are only published on domestic app stores, some configurations are not entirely necessary, such as: multiple languages, multiple screen densities, etc. We can remove unnecessary resources by configuring the following in build.gradle:

android {
    defaultConfig {
        resConfigs "zh"
    }
}
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Another approach is to build separate APKs for different Configurations. For example, to build an independent APK for each screen density:

android {
    splits {
        density {
            enable true
            exclude "ldpi", "xxhdpi", "xxxhdpi"
            compatibleScreens 'small', 'normal', 'large', 'xlarge'
        }
    }
}
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Since removing redundant resources is so simple, why do we need Booster?

Status of Apps From China

Most APPs in China don't handle screen density adaptation very well. Some may only adapt for xhdpi, while others adapt for both xhdpi and xxhdpi. In short, not all image resources are adapted consistently for all densities. If we use the "split APK" approach mentioned above, some resources won't be found. To solve this problem, Booster adopts a different deredundancy approach:

  1. First, group resources by type;
  2. Group resources of the same type by name;
  3. Sort resources with the same name by density from high to low
  4. For resources of the same type and name but different densities, keep the resource with the highest density and remove resources of other densities

The above process looks simple, but the actual situation is more complex. Is it possible to have resources of the same type, same name, and same density? Of course it is, since Configuration has many adaptation dimensions, such as: screen layout direction (ScreenConfig.layoutopen in new window).

Support RTL Layout

Most countries or regions use Left-To-Right layout direction for their languages. Languages like Arabic use Right-To-Left layout direction. In Android 4.1.1 (API Level 16) and below, the android:supportsRtl attribute was ignored. Starting from API Level 17, the android:supportsRtl attribute can be set in AndroidManifest.xml:

<manifest ... >
    ...
    <application ...
        android:supportsRtl="true">
    </application>
</manifest>
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Therefore, when removing redundant resources, it's also necessary to decide whether to keep resources with the same density but different layout directions based on the supportsRtl attribute.

Getting Started

To enable resource deredundancy, simply include booster-task-resource-deredundancyopen in new window, as shown below:

buildscript {
    ext {
        kotlin_version = "1.5.31"
        booster_version = "4.16.3"
    }
    repositories {
        mavenLocal()
        mavenCentral()
        google()
        jcenter()
        maven { url 'https://oss.sonatype.org/content/repositories/public/' }
        maven { url 'https://oss.sonatype.org/content/repositories/snapshots/' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath "com.didiglobal.booster:booster-gradle-plugin:$booster_version"

        /* Include this module */
        classpath "com.didiglobal.booster:booster-task-resource-deredundancy:$booster_version"
    }
}
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WARNING

For Android Gradle Plugin 3.6 and above, you need to set the following in gradle.properties:

android.precompileDependenciesResources=false
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