Different level of APK compression (#947)

* Different level of APK compression
- can reduce from 200mb to 50mb with level 5 of compression. Supports Intellij IDEA and command line gradle invocation
- by default, this feature is disabled. To enable create a file local.properties in `apps/android` and paste this line: `compression_level=5`
- level can be from 0 (no compression) to 9 (slowest and the must effective)
- automatically enables `extractNativeLibs` AndroidManifest's flag since it's required in this case. Feel free to find an alternative that works with compression of .so libs and without enabling this flag
- Windows is not suppored, of course. Only Unix-like OSes

* script corrections

* Missing JAVA_HOME in some environments

* Rename release apk made by IDEA to simplex.apk

* Enhancements

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

apps/android/app/build.gradle

@@ -28,6 +28,7 @@ android {
         }
         manifestPlaceholders.app_name = "@string/app_name"
         manifestPlaceholders.provider_authorities = "chat.simplex.app.provider"
+        manifestPlaceholders.extract_native_libs = compression_level != "0"
     }
 
     buildTypes {
@@ -73,6 +74,7 @@ android {
         resources {
             excludes += '/META-INF/{AL2.0,LGPL2.1}'
         }
+        jniLibs.useLegacyPackaging = compression_level != "0"
     }
 }
 
@@ -122,3 +124,70 @@ dependencies {
     androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_version"
     debugImplementation "androidx.compose.ui:ui-tooling:$compose_version"
 }
+
+def buildType = "unknown"
+// Don't do anything if no compression is needed
+if (compression_level != "0") {
+    tasks.whenTaskAdded { task ->
+        if (task.name == 'packageDebug') {
+            task.doLast {
+                buildType = "debug"
+            }
+            task.finalizedBy compressApk
+        } else if (task.name == 'packageRelease') {
+            task.doLast {
+                buildType = "release"
+            }
+            task.finalizedBy compressApk
+        }
+    }
+}
+
+tasks.register("compressApk") {
+    doLast {
+        def javaHome = System.properties['java.home'] ?: org.gradle.internal.jvm.Jvm.current().getJavaHome()
+        def sdkDir = android.getSdkDirectory().getAbsolutePath()
+        def keyAlias = ""
+        def keyPassword = ""
+        def storeFile = ""
+        def storePassword = ""
+        if (project.properties['android.injected.signing.key.alias'] != null) {
+            keyAlias = project.properties['android.injected.signing.key.alias']
+            keyPassword = project.properties['android.injected.signing.key.password']
+            storeFile = project.properties['android.injected.signing.store.file']
+            storePassword = project.properties['android.injected.signing.store.password']
+        } else if (android.signingConfigs.hasProperty(buildType)) {
+            def gradleConfig = android.signingConfigs[buildType]
+            keyAlias = gradleConfig.keyAlias
+            keyPassword = gradleConfig.keyPassword
+            storeFile = gradleConfig.storeFile
+            storePassword = gradleConfig.storePassword
+        } else {
+            // There is no signing config for current build type, can't sign the apk
+            println("No signing configs for this build type: $buildType")
+            return
+        }
+
+        def outputDir = tasks["package${buildType.capitalize()}"].outputs.files.last()
+
+        exec {
+            workingDir '../../../scripts/android'
+            setEnvironment(['JAVA_HOME': "$javaHome"])
+            commandLine './compress-and-sign-apk.sh',  \
+                     "$compression_level",  \
+                     "$outputDir",  \
+                     "$sdkDir",  \
+                     "$storeFile",  \
+                     "$storePassword",  \
+                     "$keyAlias",  \
+                     "$keyPassword"
+        }
+
+        if (project.properties['android.injected.signing.key.alias'] != null && buildType == 'release') {
+            new File(outputDir, "app-release.apk").renameTo(new File(outputDir, "simplex.apk"))
+        }
+
+        // View all gradle properties set
+        // project.properties.each { k, v -> println "$k -> $v" }
+    }
+}

apps/android/app/src/main/AndroidManifest.xml

@@ -26,6 +26,7 @@
       android:allowBackup="true"
       android:icon="@mipmap/icon"
       android:label="${app_name}"
+      android:extractNativeLibs="${extract_native_libs}"
       android:supportsRtl="true"
       android:theme="@style/Theme.SimpleX">
 

apps/android/build.gradle

@@ -18,6 +18,9 @@ buildscript {
         // to allow debug & release versions to coexist
         application_id_suffix = localProperties['application_id_suffix'] ?: ''
 
+        // Compression level for debug AND release apk. 0 = disable compression. Max is 9
+        compression_level = localProperties['compression_level'] ?: '0'
+
         // NOTE: If you need a different version of something, provide it in `local.properties`
         // like so: compose_version=123, or gradle_plugin_version=1.2.3, etc
     }

scripts/android/compress-and-sign-apk.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+
+# Fail fast in case any command fails
+set -e
+
+level=$1
+apk_parent_dir=$2
+sdk_dir=$3
+
+store_file=$4
+store_password=$5
+key_alias=$6
+key_password=$7
+
+if [ -z ${7} ]; then echo "You didn't enter all required params:
+compress-and-sign-apk.sh level apk_parent_dir sdk_dir store_file store_password key_alias key_password"
+fi
+
+cd $apk_parent_dir
+
+ORIG_NAME=$(echo app*.apk)
+unzip -o -q -d apk $ORIG_NAME
+
+rm $ORIG_NAME
+
+(cd apk && zip -r -q -$level ../$ORIG_NAME .)
+# Shouldn't be compressed because of Android requirement
+(cd apk && zip -r -q -0 ../$ORIG_NAME resources.arsc)
+#(cd apk && 7z a -r -mx=$level -tzip -x!resources.arsc ../$ORIG_NAME .)
+#(cd apk && 7z a -r -mx=0 -tzip ../$ORIG_NAME resources.arsc)
+
+ALL_TOOLS=($sdk_dir/build-tools/*/)
+BIN_DIR="${ALL_TOOLS[1]}"
+
+$BIN_DIR/zipalign -p -f 4 $ORIG_NAME $ORIG_NAME-2
+
+mv $ORIG_NAME{-2,}
+
+$BIN_DIR/apksigner sign \
+  --ks "$store_file" --ks-key-alias "$key_alias" --ks-pass "pass:$store_password" \
+  --key-pass "pass:$key_password" $ORIG_NAME
+
+# cleanup
+rm -rf apk || true
+rm ${ORIG_NAME}.idsig 2> /dev/null || true