메모장 줌 기능 추가

presentation/src/main/java/com/nextroom/nextroom/presentation/customview/PainterView.kt

@@ -43,41 +43,46 @@ class PainterView @JvmOverloads constructor(
     }
 
     override fun onTouchEvent(event: MotionEvent): Boolean {
-        val x = event.x
-        val y = event.y
-
-        when (event.action) {
-            MotionEvent.ACTION_DOWN -> {
-                if (tool == PEN) {
-                    path = Path().apply {
-                        moveTo(x, y)
-                        paths.add(this)
-                        listener?.onPainted(paths)
+        if (event.pointerCount == 1) {
+            val x = event.x
+            val y = event.y
+
+            when (event.action) {
+                MotionEvent.ACTION_DOWN -> {
+                    if (tool == PEN) {
+                        path = Path().apply {
+                            moveTo(x, y)
+                            paths.add(this)
+                            listener?.onPainted(paths)
+                        }
+                    } else {
+                        erase(x, y)
                     }
-                } else {
-                    erase(x, y)
                 }
-            }
 
-            MotionEvent.ACTION_MOVE -> {
-                if (tool == PEN) {
-                    path?.lineTo(x, y)
-                } else {
-                    erase(x, y)
+                MotionEvent.ACTION_MOVE -> {
+                    if (tool == PEN) {
+                        path?.lineTo(x, y)
+                    } else {
+                        erase(x, y)
+                    }
                 }
-            }
 
-            MotionEvent.ACTION_UP -> {
-                path?.let {
-                    paths.add(it)
-                    listener?.onPainted(paths)
+                MotionEvent.ACTION_UP -> {
+                    path?.let {
+                        paths.add(it)
+                        listener?.onPainted(paths)
+                    }
+                    path = null
                 }
-                path = null
-            }
 
-            else -> return false
+                else -> return false
+            }
+            invalidate()
+        } else if (event.pointerCount == 2) {
+            return false
         }
-        invalidate()
+
         return true
     }
 

presentation/src/main/java/com/nextroom/nextroom/presentation/customview/ZoomLayout.kt

@@ -0,0 +1,63 @@
+package com.nextroom.nextroom.presentation.customview
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.MotionEvent
+import android.view.ScaleGestureDetector
+import android.view.ScaleGestureDetector.OnScaleGestureListener
+import android.view.View
+import android.widget.FrameLayout
+import kotlin.math.max
+import kotlin.math.min
+import kotlin.math.sign
+
+
+class ZoomLayout @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyle: Int = 0
+) : FrameLayout(context, attrs, defStyle), OnScaleGestureListener {
+
+    private var scale = 1.0f
+    private var lastScaleFactor = 0f
+    private val scaleDetector by lazy { ScaleGestureDetector(context, this) }
+
+    override fun onInterceptTouchEvent(ev: MotionEvent): Boolean {
+        scaleDetector.onTouchEvent(ev)
+        applyScaleAndTranslation()
+        return false
+    }
+
+    override fun onScale(scaleDetector: ScaleGestureDetector): Boolean {
+        val scaleFactor = scaleDetector.scaleFactor
+        if (lastScaleFactor == 0f || (sign(scaleFactor.toDouble()) == sign(lastScaleFactor.toDouble()))) {
+            scale *= scaleFactor
+            scale = max(MIN_ZOOM.toDouble(), min(scale.toDouble(), MAX_ZOOM.toDouble())).toFloat()
+            lastScaleFactor = scaleFactor
+        } else {
+            lastScaleFactor = 0f
+        }
+
+        return true
+    }
+
+    override fun onScaleBegin(detector: ScaleGestureDetector): Boolean {
+        return true
+    }
+
+    override fun onScaleEnd(scaleDetector: ScaleGestureDetector) {}
+
+    private fun applyScaleAndTranslation() {
+        child().scaleX = scale
+        child().scaleY = scale
+    }
+
+    private fun child(): View {
+        return getChildAt(0)
+    }
+
+    companion object {
+        private const val MIN_ZOOM = 1.0f
+        private const val MAX_ZOOM = 8.0f
+    }
+}

presentation/src/main/res/layout/fragment_memo.xml

@@ -9,14 +9,19 @@
         android:id="@+id/tb_memo"
         layout="@layout/common_toolbar" />
 
-    <com.nextroom.nextroom.presentation.customview.PainterView
-        android:id="@+id/custom_painter_view"
+    <com.nextroom.nextroom.presentation.customview.ZoomLayout
         android:layout_width="0dp"
         android:layout_height="0dp"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@id/tb_memo" />
+        app:layout_constraintTop_toBottomOf="@id/tb_memo">
+
+        <com.nextroom.nextroom.presentation.customview.PainterView
+            android:id="@+id/custom_painter_view"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent" />
+    </com.nextroom.nextroom.presentation.customview.ZoomLayout>
 
     <androidx.constraintlayout.widget.Guideline
         android:id="@+id/guide_end"