feat: Add crop(...) (#8)

* feat: Add `crop(...)`

* feat: Implement `crop(...)` on iOS

* Update HybridImage.swift

* feat: Implement `crop(...)` for Android

* fix: Update react-native-nitro-modules to 0.26.3

* docs

* Update README.md

Author: mrousavy

README.md

@@ -63,9 +63,18 @@ const resourceImage = loadImageFromResources('my-resource.jpg')
 const symbolImage   = loadImageFromSymbol('star')
 ```
 
+#### Load with Options
+
+When loading from a remote URL, you can tweak options such as `priority`:
+
+```ts
+const image1 = await loadImageFromURLAsync(URL1, { priority: 'low' })
+const image2 = await loadImageFromURLAsync(URL2, { priority: 'high' })
+```
+
 #### `ArrayBuffer`
 
-The `Image` type can be converted to- and from- an `ArrayBuffer`:
+The `Image` type can be converted to- and from- an `ArrayBuffer`, which gives you access to the raw pixel data in ARGB format:
 
 ```ts
 const webImage        = await loadImageFromURLAsync('https://picsum.photos/seed/123/400')
@@ -82,6 +91,15 @@ const webImage = await loadImageFromURLAsync('https://picsum.photos/seed/123/400
 const smaller  = await webImage.resizeAsync(200, 200)
 ```
 
+#### Cropping
+
+An `Image` can be cropped entirely in-memory, without ever writing to- or reading from- a file:
+
+```ts
+const webImage = await loadImageFromURLAsync('https://picsum.photos/seed/123/400')
+const smaller  = await webImage.cropAsync(100, 100, 50, 50)
+```
+
 #### Saving
 
 An in-memory `Image` object can also be written/saved to a file:

android/src/main/java/com/margelo/nitro/image/HybridImage.kt

@@ -61,14 +61,41 @@ class HybridImage: HybridImageSpec {
     }
 
     override fun resize(width: Double, height: Double): HybridImageSpec {
+        if (width < 0) {
+            throw Error("Width cannot be less than 0! (width: $width)")
+        }
+        if (height < 0) {
+            throw Error("Height cannot be less than 0! (height: $height)")
+        }
         val resizedBitmap = Bitmap.createScaledBitmap(bitmap, width.toInt(), height.toInt(), true)
         return HybridImage(resizedBitmap)
     }
-
     override fun resizeAsync(width: Double, height: Double): Promise<HybridImageSpec> {
         return Promise.async { resize(width, height) }
     }
 
+    override fun crop(startX: Double, startY: Double, endX: Double, endY: Double): HybridImageSpec {
+        val width = endX - startX
+        val height = endY - startY
+        if (width < 0) {
+            throw Error("Width cannot be less than 0! (startX: $startX - endX: $endX = $width)")
+        }
+        if (height < 0) {
+            throw Error("Height cannot be less than 0! (startY: $startY - endY: $endY = $height)")
+        }
+        val croppedBitmap = Bitmap.createBitmap(bitmap, startX.toInt(), startY.toInt(), width.toInt(), height.toInt())
+        return HybridImage(croppedBitmap)
+    }
+
+    override fun cropAsync(
+        startX: Double,
+        startY: Double,
+        endX: Double,
+        endY: Double
+    ): Promise<HybridImageSpec> {
+        return Promise.async { crop(startX, startY, endX, endY) }
+    }
+
     override fun saveToFileAsync(
         path: String,
         format: ImageFormat,

bun.lock

@@ -36,6 +36,12 @@ class HybridImage: HybridImageSpec {
   }
 
   func resize(width: Double, height: Double) throws -> any HybridImageSpec {
+    guard width > 0 else {
+      throw RuntimeError.error(withMessage: "Width cannot be less than 0! (width: \(width))")
+    }
+    guard height > 0 else {
+      throw RuntimeError.error(withMessage: "Height cannot be less than 0! (height: \(height))")
+    }
     let targetSize = CGSize(width: width, height: height)
 
     let renderer = UIGraphicsImageRenderer(size: targetSize)
@@ -52,6 +58,34 @@ class HybridImage: HybridImageSpec {
     }
   }
 
+  func crop(startX: Double, startY: Double, endX: Double, endY: Double) throws -> any HybridImageSpec {
+    let targetWidth = endX - startX
+    let targetHeight = endY - startY
+    guard targetWidth > 0 else {
+      throw RuntimeError.error(withMessage: "Width cannot be less than 0! (startX: \(startX) - endX: \(endX) = \(targetWidth))")
+    }
+    guard targetHeight > 0 else {
+      throw RuntimeError.error(withMessage: "Height cannot be less than 0! (startY: \(startY) - endY: \(endY) = \(targetHeight))")
+    }
+    guard let cgImage = uiImage.cgImage else {
+      throw RuntimeError.error(withMessage: "This image does not have an underlying .cgImage!")
+    }
+    
+    let targetRect = CGRect(origin: CGPoint(x: startX, y: startY),
+                            size: CGSize(width: width, height: height))
+    guard let croppedCgImage = cgImage.cropping(to: targetRect) else {
+      throw RuntimeError.error(withMessage: "Failed to crop CGImage to \(targetRect)!")
+    }
+    let croppedUiImage = UIImage(cgImage: croppedCgImage)
+    return HybridImage(uiImage: croppedUiImage)
+  }
+  
+  func cropAsync(startX: Double, startY: Double, endX: Double, endY: Double) throws -> Promise<any HybridImageSpec> {
+    return Promise.async {
+      return try self.crop(startX: startX, startY: startY, endX: endX, endY: endY)
+    }
+  }
+  
   private func saveImage(to path: String, format: ImageFormat, quality: Double) throws {
     guard let data = uiImage.getData(in: format, quality: quality) else {
       throw RuntimeError.error(withMessage: "Failed to get Image data in format \(format.stringValue) with quality \(quality)!")