add CropAgent for shape cropping with Paths

Author: SmartToolFactory

cropper/src/main/java/com/smarttoolfactory/cropper/crop/CropAgent.kt

@@ -0,0 +1,83 @@
+package com.smarttoolfactory.cropper.crop
+
+import android.graphics.Bitmap
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.geometry.Rect
+import androidx.compose.ui.graphics.*
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.LayoutDirection
+
+/**
+ * Crops imageBitmap based on path that is passed in [crop] function
+ */
+class CropAgent {
+
+    private val imagePaint = Paint().apply {
+        blendMode = BlendMode.SrcIn
+    }
+
+    private val paint = Paint()
+
+    fun crop(
+        imageBitmap: ImageBitmap,
+        cropRect: Rect,
+        shape: Shape,
+        layoutDirection: LayoutDirection,
+        density: Density,
+        onCropSuccess: (ImageBitmap) -> Unit
+    ) {
+
+        val croppedBitmap = Bitmap.createBitmap(
+            imageBitmap.asAndroidBitmap(),
+            cropRect.left.toInt(),
+            cropRect.top.toInt(),
+            cropRect.width.toInt(),
+            cropRect.height.toInt()
+        ).asImageBitmap()
+
+        val path = Path().apply {
+            val outline = shape.createOutline(cropRect.size, layoutDirection, density)
+            addOutline(outline)
+        }
+
+        Canvas(image = croppedBitmap).run {
+            saveLayer(nativeCanvas.clipBounds.toComposeRect(), imagePaint)
+            drawPath(path, paint)
+            drawImage(image = croppedBitmap, topLeftOffset = Offset.Zero, imagePaint)
+            onCropSuccess(croppedBitmap)
+            restore()
+        }
+    }
+
+    fun crop(
+        imageBitmap: ImageBitmap,
+        cropRect: Rect,
+        shape: Shape,
+        layoutDirection: LayoutDirection,
+        density: Density,
+    ): ImageBitmap {
+
+        val croppedBitmap = Bitmap.createBitmap(
+            imageBitmap.asAndroidBitmap(),
+            cropRect.left.toInt(),
+            cropRect.top.toInt(),
+            cropRect.width.toInt(),
+            cropRect.height.toInt()
+        ).asImageBitmap()
+
+        val path = Path().apply {
+            val outline = shape.createOutline(cropRect.size, layoutDirection, density)
+            addOutline(outline)
+        }
+
+        Canvas(image = croppedBitmap).run {
+            saveLayer(nativeCanvas.clipBounds.toComposeRect(), imagePaint)
+            drawPath(path, paint)
+            drawImage(image = croppedBitmap, topLeftOffset = Offset.Zero, imagePaint)
+            restore()
+        }
+
+        return croppedBitmap
+    }
+
+}