Canvas Домашнее задание

app/build.gradle

@@ -1,16 +1,19 @@
 plugins {
     id 'com.android.application'
     id 'kotlin-android'
+    id 'kotlin-parcelize'
+    id 'kotlinx-serialization'
 }
 
 android {
     compileSdkVersion 30
     buildToolsVersion "30.0.3"
 
     defaultConfig {
+        namespace = "otus.homework.customview"
         applicationId "otus.homework.customview"
         minSdkVersion 23
-        targetSdkVersion 30
+        targetSdkVersion 34
         versionCode 1
         versionName "1.0"
 
@@ -30,10 +33,15 @@ android {
     kotlinOptions {
         jvmTarget = '1.8'
     }
+    buildFeatures {
+        viewBinding = true
+    }
 }
 
 dependencies {
-
+    implementation 'com.google.code.gson:gson:2.8.8'
+    implementation "org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.0"
+    implementation "org.jetbrains.kotlin:kotlin-serialization:1.9.24"
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
     implementation 'androidx.core:core-ktx:1.3.2'
     implementation 'androidx.appcompat:appcompat:1.2.0'

app/src/main/AndroidManifest.xml

@@ -10,7 +10,8 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.CustomView">
-        <activity android:name=".MainActivity">
+        <activity android:name=".MainActivity"
+            android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

app/src/main/java/otus/homework/customview/CategoryView.kt

@@ -0,0 +1,112 @@
+package otus.homework.customview
+
+import android.content.Context
+import android.graphics.Canvas
+import android.graphics.Paint
+import android.graphics.RectF
+import android.os.Bundle
+import android.os.Parcelable
+import android.util.AttributeSet
+import android.view.View
+import androidx.core.content.withStyledAttributes
+import kotlinx.serialization.decodeFromString
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+
+class CategoryView @JvmOverloads constructor(
+    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
+) : View(context, attrs, defStyleAttr) {
+
+    private val rectangle by lazy { RectF() }
+    private val paint by lazy { Paint() }
+
+    private var labelText: String? = null
+    private var overHead: Float? = null
+    private var maxValue: Double = 0.0
+
+    private var categoryWidth: Int = 0
+    private var categoryHeight: Int = 0
+
+    private var defaultBlockWidth = 30.px.toFloat()
+
+    private var categories: List<Category> = emptyList()
+
+    init {
+        initAttributes(attrs)
+        paint.apply {
+            style = Paint.Style.FILL
+        }
+    }
+
+    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+        val wMode = MeasureSpec.getMode(widthMeasureSpec)
+        val hMode = MeasureSpec.getMode(heightMeasureSpec)
+
+        when (wMode) {
+            MeasureSpec.AT_MOST, MeasureSpec.UNSPECIFIED -> {
+                categoryWidth = (defaultBlockWidth * categories.size).toInt()
+                categoryHeight = MeasureSpec.getSize(heightMeasureSpec)
+            }
+
+            MeasureSpec.EXACTLY -> {
+                categoryWidth = MeasureSpec.getSize(widthMeasureSpec)
+                categoryHeight = MeasureSpec.getSize(heightMeasureSpec)
+            }
+        }
+        setMeasuredDimension(categoryWidth, categoryHeight)
+    }
+
+    override fun onDraw(canvas: Canvas?) {
+        super.onDraw(canvas)
+        val blockWidth = categoryWidth / categories.size
+        val blockHeight = categoryHeight / maxValue
+
+        var currentValueX = 0.0
+        categories.forEach { category ->
+            paint.apply { color = category.color }
+            rectangle.set(
+                currentValueX.toFloat(),
+                (categoryHeight - blockHeight * category.value).toFloat(),
+                (currentValueX + blockWidth).toFloat(),
+                categoryHeight.toFloat()
+            )
+            canvas?.drawRect(rectangle, paint)
+            currentValueX += blockWidth
+        }
+    }
+
+    override fun onRestoreInstanceState(state: Parcelable?) {
+        val bundle = state as Bundle
+        val savedState = bundle.getString(SAVED_STATE_VIEW_KEY)
+        savedState?.let {
+            val viewState = Json.decodeFromString<SavedCategoryState>(it)
+            this@CategoryView.categories = viewState.charts
+        }
+        super.onRestoreInstanceState(bundle.getParcelable(INSTANCE_CATEGORY_KEY))
+    }
+
+    override fun onSaveInstanceState(): Parcelable {
+        val bundle = Bundle()
+        bundle.putString(SAVED_STATE_VIEW_KEY, Json.encodeToString(SavedCategoryState(categories)))
+        bundle.putParcelable(INSTANCE_CATEGORY_KEY, super.onSaveInstanceState())
+        return bundle
+    }
+
+    private fun initAttributes(attrs: AttributeSet?) {
+        context.withStyledAttributes(attrs, R.styleable.CategoryView, 0, 0) {
+            labelText = getString(R.styleable.CategoryView_chart_label)
+            overHead = getFloat(R.styleable.CategoryView_chart_sum_overhead, 0F)
+        }
+    }
+
+    fun setCharts(charts: List<Category>) {
+        this@CategoryView.categories = charts
+        maxValue = charts.maxOf { it.value }
+        requestLayout()
+    }
+
+    private companion object {
+        private const val SAVED_STATE_VIEW_KEY = "saved_state_view_key"
+        private const val INSTANCE_CATEGORY_KEY = "instance_category_key"
+    }
+}

app/src/main/java/otus/homework/customview/MainActivity.kt

@@ -2,10 +2,29 @@ package otus.homework.customview
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import otus.homework.customview.databinding.ActivityMainBinding
 
 class MainActivity : AppCompatActivity() {
+
+    private val payloads by lazy { this.readData() }
+
+    private lateinit var binding: ActivityMainBinding
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_main)
+        binding = ActivityMainBinding.inflate(layoutInflater)
+        val view = binding.root
+        setContentView(view)
+        initCategory()
+    }
+
+    private fun initPieChart() {
+        val pieces = payloads.mapPieces()
+        /* binding.pieChart.setPieces(pieces) */
+    }
+
+    private fun initCategory() {
+        val charts = payloads.mapCategories()
+        binding.view.setCharts(charts)
     }
 }

app/src/main/java/otus/homework/customview/PayloadData.kt

@@ -0,0 +1,90 @@
+package otus.homework.customview
+
+import android.content.Context
+import android.content.res.Resources
+import android.graphics.Color
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import kotlinx.serialization.Serializable
+import java.util.Random
+
+const val DEFAULT_ANGLE = 0.0
+const val MAX_SWEEP_ANGLE = 360
+
+data class PayloadData(
+    val id: Int,
+    val time: Long,
+    val name: String,
+    val amount: Double,
+    val category: String,
+)
+
+@Serializable
+data class PieData(
+    val color: Int,
+    val name: String,
+    val startAngle: Double,
+    val sweepAngle: Double
+)
+
+@Serializable
+data class Category(
+    val color: Int,
+    val value: Double,
+    val name: String
+)
+
+@Serializable
+data class SavedPiecesState(
+    val pieces: List<PieData>
+)
+
+@Serializable
+data class SavedCategoryState(
+    val charts: List<Category>
+)
+
+fun List<PayloadData>.mapPieces(): List<PieData> {
+    val totalSum = this.sumOf { it.amount }
+    var startAngle = DEFAULT_ANGLE
+
+    return this.map { payload ->
+        val sweepAngle = payload.amount.calculateSweepAngle(totalSum)
+        val data = PieData(
+            name = payload.name,
+            color = generateColor(),
+            startAngle = startAngle,
+            sweepAngle = sweepAngle
+        )
+        startAngle += sweepAngle
+        data
+    }
+}
+
+fun List<PayloadData>.mapCategories(): List<Category> = this.map {
+    Category(
+        name = it.name,
+        value = it.amount,
+        color = generateColor()
+    )
+}
+
+private fun generateColor(): Int {
+    val rnd = Random()
+    return Color.argb(255, rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256))
+}
+
+private fun Double.calculateSweepAngle(total: Double): Double = this / total * MAX_SWEEP_ANGLE
+
+fun Context.readData(): List<PayloadData> {
+    val data = this.resources.openRawResource(R.raw.payload)
+    val str = data.bufferedReader().use { it.readText() }
+    val gson = Gson()
+
+    val listType = object : TypeToken<List<PayloadData>>() {}.type
+    val itemList: List<PayloadData> = gson.fromJson(str, listType)
+    return itemList
+}
+
+val Int.px: Int
+    get() = (this * Resources.getSystem().displayMetrics.density).toInt()