Add ktlint check.

Signed-off-by: Yahor Berdnikau <egorr.berd@gmail.com>

build.gradle

@@ -1,15 +1,17 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
-apply from: 'dependencies.gradle'
-
 buildscript {
     apply from: 'dependencies.gradle'
 
     repositories {
         jcenter()
+        maven {
+            url "https://plugins.gradle.org/m2/"
+        }
     }
     dependencies {
         classpath gradlePlugins.androidTools
         classpath gradlePlugins.kotlin
+        classpath gradlePlugins.ktlintGradle
     }
 }
 

dependencies.gradle

@@ -5,6 +5,8 @@ ext.versions = [
 
         buildTools           : "25.0.3",
         androidTools         : "2.3.3",
+        ktlint               : "0.9.0",
+        ktlintGradle         : "2.1.0",
 
         androidSupport       : "22.2.1",
 
@@ -23,6 +25,7 @@ ext.versions = [
 ext.gradlePlugins = [
         androidTools : "com.android.tools.build:gradle:$versions.androidTools",
         kotlin       : "org.jetbrains.kotlin:kotlin-gradle-plugin:$versions.kotlin",
+        ktlintGradle : "gradle.plugin.org.jlleitschuh.gradle:ktlint-gradle:$versions.ktlintGradle",
 ]
 
 ext.androidSupport = [

gradle_scripts/code_quality.gradle

@@ -0,0 +1,10 @@
+// Applies code quality plugins when -Pqc is passed to the gradle
+def isCodeQualityEnabled = project.hasProperty('qc')
+
+if (isCodeQualityEnabled) {
+    apply plugin: "org.jlleitschuh.gradle.ktlint"
+
+    ktlint {
+        version = versions.ktlint
+    }
+}

subsonic-api/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'kotlin'
+apply from: '../gradle_scripts/code_quality.gradle'
 
 sourceSets {
     main.java.srcDirs += 'src/main/kotlin'

ultrasonic/build.gradle

@@ -1,5 +1,6 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
+apply from: "../gradle_scripts/code_quality.gradle"
 
 android {
     compileSdkVersion versions.compileSdk