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ДЗ: Custom View #132

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19 changes: 19 additions & 0 deletions app/src/main/java/otus/homework/customview/Expense.kt
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@@ -0,0 +1,19 @@
package otus.homework.customview

import android.content.Context
import com.google.gson.Gson

data class Expense(
val id: Int,
val name: String,
val amount: Float,
val category: String,
val time: Long
)

fun Context.loadExpenses(): List<Expense> {
val input = resources.openRawResource(R.raw.payload)
val json = input.bufferedReader().use { it.readText() }
return Gson().fromJson(json, Array<Expense>::class.java).toList()
}

10 changes: 10 additions & 0 deletions app/src/main/java/otus/homework/customview/MainActivity.kt
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Expand Up @@ -2,10 +2,20 @@ package otus.homework.customview

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast

class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)

val pie = findViewById<PieChartView>(R.id.pieChart)
pie.setExpenses(loadExpenses())

pie.listener = object : PieChartView.OnSliceClickListener {
override fun onCategoryClick(category: String) {
Toast.makeText(this@MainActivity, category, Toast.LENGTH_SHORT).show()
}
}
}
}
113 changes: 113 additions & 0 deletions app/src/main/java/otus/homework/customview/PieChartView.kt
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package otus.homework.customview

import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.graphics.RectF
import android.os.Bundle
import android.os.Parcelable
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.View
import kotlin.math.atan2
import kotlin.math.min

class PieChartView @JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null
) : View(context, attrs) {

interface OnSliceClickListener {
fun onCategoryClick(category: String)
}

var listener: OnSliceClickListener? = null

private val paint = Paint(Paint.ANTI_ALIAS_FLAG)
private val rect = RectF()

private val colors = listOf(
Color.RED, Color.BLUE, Color.GREEN, Color.CYAN, Color.MAGENTA,
Color.YELLOW, Color.DKGRAY, Color.GRAY, Color.LTGRAY, Color.BLACK
)

private var data: Map<String, Float> = emptyMap()
private var angles = mutableListOf<Pair<String, Float>>()

fun setExpenses(expenses: List<Expense>) {
data = expenses.groupBy { it.category }
.mapValues { it.value.sumOf { e -> e.amount.toDouble() }.toFloat() }
calculateAngles()
invalidate()
}

private fun calculateAngles() {
angles.clear()
val total = data.values.sum()
data.forEach { (cat, value) ->
angles += cat to (value / total * 360f)
}
}

// --- onMeasure (учтены все MeasureSpec) ---
override fun onMeasure(w: Int, h: Int) {
val size = min(
MeasureSpec.getSize(w),
MeasureSpec.getSize(h)
)

val finalSize = when {
MeasureSpec.getMode(w) == MeasureSpec.EXACTLY -> MeasureSpec.getSize(w)
MeasureSpec.getMode(h) == MeasureSpec.EXACTLY -> MeasureSpec.getSize(h)
else -> size
}
setMeasuredDimension(finalSize, finalSize)
}

override fun onDraw(canvas: Canvas) {
var startAngle = -90f
rect.set(0f, 0f, width.toFloat(), height.toFloat())

angles.forEachIndexed { i, (cat, sweep) ->
paint.color = colors[i % colors.size]
canvas.drawArc(rect, startAngle, sweep, true, paint)
startAngle += sweep
}
}

// --- обработка клика ---
override fun onTouchEvent(e: MotionEvent): Boolean {
if (e.action != MotionEvent.ACTION_DOWN) return true

val cx = width / 2f
val cy = height / 2f
val angle = (Math.toDegrees(
atan2(e.y - cy, e.x - cx).toDouble()
) + 360 + 90) % 360

var acc = 0f
for ((cat, sweep) in angles) {
acc += sweep
if (angle <= acc) {
listener?.onCategoryClick(cat)
break
}
}
return true
}

// --- сохранение состояния ---
override fun onSaveInstanceState(): Parcelable =
Bundle().apply {
putParcelable("super", super.onSaveInstanceState())
putSerializable("data", HashMap(data))
}

override fun onRestoreInstanceState(state: Parcelable) {
val b = state as Bundle
super.onRestoreInstanceState(b.getParcelable("super"))
data = (b.getSerializable("data") as HashMap<String, Float>)
calculateAngles()
}
}
16 changes: 8 additions & 8 deletions app/src/main/res/layout/activity_main.xml
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Expand Up @@ -7,13 +7,13 @@
android:layout_height="match_parent"
tools:context=".MainActivity">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
<otus.homework.customview.PieChartView
android:id="@+id/pieChart"
android:layout_width="300dp"
android:layout_height="300dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
Binary file added art/Screenshot_20260202_230456.png
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