buildscript {
    ext.kotlin_version = '1.2.40'
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.2'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        maven { url 'https://jitpack.io' }
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.brotandos.dictionary"
        minSdkVersion 19
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.android.support:appcompat-v7:27.1.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
    implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"

    implementation 'com.github.Brotandos:koatl:v0.1.1'
}

import android.annotation.SuppressLint
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.v4.app.Fragment
import android.support.v4.app.FragmentManager
import org.jetbrains.anko.frameLayout

class MainActivity : AppCompatActivity() {
    private val fragManager = supportFragmentManager
    private val container = 1

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        frameLayout { id = container }
        // If there are any instances saved, return
        if (savedInstanceState != null) return
        // else run default fragment
        changeFragment(DictionaryFragment())
    }


    @SuppressLint("PrivateResource")
    private fun changeFragment(f: Fragment, needToCleanStack: Boolean = false) {
        if (needToCleanStack) clearBackStack()
        fragManager.beginTransaction()
                .setCustomAnimations(
                        R.anim.abc_fade_in,
                        R.anim.abc_fade_out,
                        R.anim.abc_popup_enter,
                        R.anim.abc_popup_exit)
                .replace(container, f)
                .addToBackStack(f::class.simpleName)
                .commit()
    }

    
    private fun clearBackStack() {
        if (fragManager.backStackEntryCount == 0) return
        val first = fragManager.getBackStackEntryAt(0)
        fragManager.popBackStack(first.id, FragmentManager.POP_BACK_STACK_INCLUSIVE)
    }
    
    
    override fun onBackPressed() {
        if (fragManager.backStackEntryCount > 1) fragManager.popBackStack()
        else finish()
    }
}

<resources>
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>
</resources>

data class Dictionary(var title: String, val items: MutableList<DictionaryItem>)
data class DictionaryItem(val key: String, val value: String)

object G {
    object Color {
        const val CARD_SHADOW_1: Int = 0xFFEEEEEE.toInt()
        const val CARD_SHADOW_2: Int = 0xFFDDDDDD.toInt()
        const val CARD: Int = 0xFFFEFEFE.toInt()
        const val PRIMARY: Int = 0xFF3F51B5.toInt()
    }
}

import android.content.Context
import android.graphics.drawable.GradientDrawable
import android.graphics.drawable.LayerDrawable
import android.view.View
import com.brotandos.koatlib.times
import org.jetbrains.anko.dip

fun Context.cardBg(color: Int, radius: Int = dip(2)) = GradientDrawable() * {
    shape = GradientDrawable.RECTANGLE
    cornerRadius = radius.toFloat()
    setColor(color)
}

fun View.layerCard(color: Int = G.Color.CARD) = LayerDrawable(arrayOf(
        context.cardBg(G.Color.CARD_SHADOW_1, dip(4)),
        context.cardBg(G.Color.CARD_SHADOW_2, dip(3)),
        context.cardBg(color)
)) * {
    setLayerInset(0, 0, 0, 0, 0)
    setLayerInset(1, 0, 0, 0, dip(1))
    setLayerInset(2, dip(1), dip(1), dip(1), dip(2))
}

val bgLayerCard: View.() -> Unit = {
    background = layerCard()
}