Feat: modify the attributes of scale

README.md

@@ -154,10 +154,20 @@ p, q, r, s, t
 #### Scale
 
 ```dart
-ScaleOption(width, height, keepRatio: keepRatio);
+ScaleOption(width, height, keepRatio: keepRatio, keepWidthFirst: keepWidthFirst);
 ```
 
-After specifying the width and height, it is not clipped, but stretched to the specified width and height (Does maintain the aspect ratio of the image if wanted).
+`keepRatio` and `keepWidthFirst` are optional parameters used to maintain the aspect ratio of the original image to prevent image deformation.
+
+`keepWidthFirst` takes effect only when `keepRatio` is true.
+
+The following is a brief description:
+
+| width | height | keepRatio | keepWidthFirst | src size  | dest size |
+| ----- | ------ | --------- | -------------- | --------- | --------- |
+| 500   | 300    | false     | true/false     | 1920x1920 | 500x300   |
+| 500   | 300    | true      | true           | 1920x1920 | 500x500   |
+| 500   | 300    | true      | false          | 1920x1920 | 300x300   |
 
 #### AddText
 
@@ -230,8 +240,8 @@ Support next `BlendMode`, other will be ignored. You can also see [the document
 | iOS/macOS                   | android(PorterDuff.Mode) | flutter(BlendMode) |
 | --------------------------- | ------------------------ | ------------------ |
 | kCGBlendModeClear           | CLEAR                    | clear              |
-|                             | SRC                      | src                |
-|                             | DST                      | dst                |
+|                             | SRC                      | src                |
+|                             | DST                      | dst                |
 | kCGBlendModeNormal          | SRC_OVER                 | srcOver            |
 | kCGBlendModeDestinationOver | DST_OVER                 | dstOver            |
 | kCGBlendModeSourceIn        | SRC_IN                   | srcIn              |

android/src/main/kotlin/com/fluttercandies/image_editor/core/ImageHandler.kt

@@ -41,15 +41,14 @@ class ImageHandler(private var bitmap: Bitmap) {
     }
 
     private fun handleScale(option: ScaleOption): Bitmap {
-        val bitmapRatio = bitmap.width.toFloat() / bitmap.height.toFloat()
-        val optionRatio = option.width.toFloat() / option.height.toFloat()
         var w = option.width
         var h = option.height
         if (option.keepRatio) {
-            if (bitmapRatio < optionRatio) {
-                w = (option.height * bitmapRatio).toInt()
-            } else if (bitmapRatio > optionRatio) {
-                h = (option.width / bitmapRatio).toInt()
+            val srcRatio = bitmap.width.toFloat() / bitmap.height.toFloat()
+            if (option.keepWidthFirst) {
+                h = (w / srcRatio).toInt()
+            } else {
+                w = (srcRatio * h).toInt()
             }
         }
         val newBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)

android/src/main/kotlin/com/fluttercandies/image_editor/option/ScaleOption.kt

@@ -1,3 +1,3 @@
 package com.fluttercandies.image_editor.option
 
-data class ScaleOption(val width: Int, val height: Int, val keepRatio: Boolean) : Option
+data class ScaleOption(val width: Int, val height: Int, val keepRatio: Boolean, val keepWidthFirst: Boolean) : Option

android/src/main/kotlin/com/fluttercandies/image_editor/util/ConvertUtils.kt

@@ -104,7 +104,8 @@ object ConvertUtils {
         val w = optionMap["width"] as Int
         val h = optionMap["height"] as Int
         val keepRatio = optionMap["keepRatio"] as Boolean
-        return ScaleOption(w, h, keepRatio)
+        val keepWidthFirst = optionMap["keepWidthFirst"] as Boolean
+        return ScaleOption(w, h, keepRatio, keepWidthFirst)
     }
 
     private fun getColorOption(optionMap: Any?): ColorOption {

example/lib/home_page.dart

@@ -16,6 +16,7 @@ import 'package:image_editor/image_editor.dart'
         Option,
         OutputFormat,
         RotateOption;
+import 'package:image_size_getter/image_size_getter.dart';
 
 import 'const/resource.dart';
 import 'widget/clip_widget.dart';
@@ -137,6 +138,8 @@ class _SimpleExamplePageState extends State<SimpleExamplePage> {
 
     final Uint8List assetImage = await getAssetImage();
 
+    final srcSize = ImageSizeGetter.getSize(MemoryInput(assetImage));
+
     print(const JsonEncoder.withIndent('  ').convert(option.toJson()));
     final Uint8List? result = await ImageEditor.editImage(
       image: assetImage,
@@ -148,6 +151,10 @@ class _SimpleExamplePageState extends State<SimpleExamplePage> {
       return;
     }
 
+    final resultSize = ImageSizeGetter.getSize(MemoryInput(result));
+
+    print('srcSize: $srcSize, resultSize: $resultSize');
+
     final MemoryImage img = MemoryImage(result);
     setProvider(img);
   }

example/lib/widget/scale_widget.dart

@@ -17,38 +17,59 @@ class _ScaleWidgetState extends State<ScaleWidget> {
   int width = 1920;
   int height = 1920;
 
+  bool keepRatio = false;
+  bool keepWidthFirst = true;
+
   @override
   Widget build(BuildContext context) {
     return ExpandContainer(
-      title: 'width: $width, height: $height',
+      title: 'scale',
       child: Column(
         children: <Widget>[
           Slider(
             onChanged: (double v) => setState(() => width = v.toInt()),
             value: width.toDouble(),
             min: 1,
             max: 1920,
+            label: 'width',
           ),
           Slider(
             onChanged: (double v) => setState(() => height = v.toInt()),
             value: height.toDouble(),
             min: 1,
             max: 1920,
           ),
+          CheckboxListTile(
+            title: Text('keep ratio'),
+            value: keepRatio,
+            onChanged: (bool? v) => setState(() => keepRatio = v == true),
+          ),
+          CheckboxListTile(
+            title: Text(
+              keepWidthFirst ? 'keep width first' : 'keep height first',
+            ),
+            value: keepWidthFirst,
+            onChanged: (bool? v) => setState(() => keepWidthFirst = v == true),
+          ),
           SizedBox(
             width: double.infinity,
             child: TextButton(
               child: const Text('scale'),
-              onPressed: _rotate,
+              onPressed: _scale,
             ),
           ),
         ],
       ),
     );
   }
 
-  void _rotate() {
-    final ScaleOption opt = ScaleOption(width, height);
+  void _scale() {
+    final ScaleOption opt = ScaleOption(
+      width,
+      height,
+      keepRatio: keepRatio,
+      keepWidthFirst: keepWidthFirst,
+    );
     widget.onTap?.call(opt);
   }
 }

ios/Classes/EditorUIImageHandler.m

@@ -8,6 +8,68 @@
 #import "EditorUIImageHandler.h"
 #import <CoreImage/CIFilterBuiltins.h>
 
+
+void releaseCGContext(CGContextRef ref) {
+    char *bitmapData = CGBitmapContextGetData(ref);
+    if (bitmapData) free(bitmapData);
+    CGContextRelease(ref);
+}
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnonnull"
+CGContextRef createCGContext(size_t pixelsWide, size_t pixelsHigh) {
+    CGContextRef context = NULL;
+    CGColorSpaceRef colorSpace;
+    void *bitmapData;
+    size_t bitmapByteCount;
+    size_t bitmapBytesPerRow;
+
+    bitmapBytesPerRow = (pixelsWide * 4);// 1
+    bitmapByteCount = (bitmapBytesPerRow * pixelsHigh);
+
+    colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);// 2
+    bitmapData = calloc(bitmapByteCount, sizeof(uint8_t));// 3
+    if (bitmapData == NULL) {
+        fprintf(stderr, "Memory not allocated!");
+        return NULL;
+    }
+    context = CGBitmapContextCreate(bitmapData,// 4
+        pixelsWide,
+        pixelsHigh,
+        8,      // bits per component
+        bitmapBytesPerRow,
+        colorSpace,
+        kCGImageAlphaPremultipliedLast);
+    if (context == NULL) {
+        free(bitmapData);// 5
+        fprintf(stderr, "Context not created!");
+        return NULL;
+    }
+    CGColorSpaceRelease(colorSpace);// 6
+
+    return context;// 7
+}
+
+#pragma clang diagnostic pop
+
+CGSize CGImageGetSize(CGImageRef ref) {
+    size_t w = CGImageGetWidth(ref);
+    size_t h = CGImageGetHeight(ref);
+    return CGSizeMake(w, h);
+}
+
+UIImage *getImageFromCGContext(CGContextRef context) {
+    size_t h = CGBitmapContextGetHeight(context);
+    size_t w = CGBitmapContextGetWidth(context);
+
+    CGImageRef pImage = CGBitmapContextCreateImage(context);
+
+    UIImage *image = [[UIImage alloc] initWithCGImage:pImage];
+    CGImageRelease(pImage);
+    return image;
+}
+
+
 @implementation EditorUIImageHandler {
     UIImage *outImage;
 }
@@ -211,29 +273,31 @@ - (void)scale:(FIScaleOption *)option {
     if (!outImage) {
         return;
     }
-    float imageRatio = outImage.size.width / outImage.size.height;
-    float optionRatio = option.width / option.height;
-    int w = option.width;
-    int h = option.height;
+
+    CGImageRef srcImage = outImage.CGImage;
+
+    double width = option.width;
+    double height = option.height;
+
     if (option.keepRatio) {
-        if (imageRatio < optionRatio) {
-            w = option.height * imageRatio;
-        } else if (imageRatio > optionRatio) {
-            h = option.width / imageRatio;
+        CGSize srcSize = CGImageGetSize(srcImage);
+
+        double srcRatio = srcSize.width / srcSize.height;
+
+        if (option.keepWidthFirst) {
+            height = width / srcRatio;
+        } else {
+            width = srcRatio * height;
         }
     }
-    UIGraphicsBeginImageContext(CGSizeMake(w, h));
-    CGContextRef ctx = UIGraphicsGetCurrentContext();
-    if (!ctx) {
-        return;
-    }
-    [outImage drawInRect:CGRectMake(0, 0, w, h)];
-    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
-    UIGraphicsEndImageContext();
-    if (!newImage) {
-        return;
-    }
-    outImage = newImage;
+
+    CGContextRef context = createCGContext((size_t) width, (size_t) height);
+
+    CGContextDrawImage(context, CGRectMake(0, 0, width, height), srcImage);
+
+    outImage = getImageFromCGContext(context);
+
+    releaseCGContext(context);
 }
 
 #pragma mark add text

ios/Classes/FIConvertUtils.h

@@ -66,6 +66,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property(assign, nonatomic) int width;
 @property(assign, nonatomic) int height;
 @property(assign, nonatomic) BOOL keepRatio;
+@property(assign, nonatomic) BOOL keepWidthFirst;
 
 @end
 

ios/Classes/FIConvertUtils.m

@@ -108,6 +108,7 @@ + (id)createFromDict:(NSDictionary *)dict {
     option.width = [dict[@"width"] intValue];
     option.height = [dict[@"height"] intValue];
     option.keepRatio = [dict[@"keepRatio"] boolValue];
+    option.keepWidthFirst = [dict[@"keepWidthFirst"] boolValue];
     return option;
 }
 

lib/src/option/scale.dart

@@ -5,11 +5,13 @@ class ScaleOption implements Option {
     this.width,
     this.height, {
     this.keepRatio = false,
+    this.keepWidthFirst = true,
   }) : assert(width > 0 && height > 0);
 
   final int width;
   final int height;
   final bool keepRatio;
+  final bool keepWidthFirst;
 
   @override
   bool get canIgnore => false;
@@ -23,6 +25,7 @@ class ScaleOption implements Option {
       'width': width,
       'height': height,
       'keepRatio': keepRatio,
+      'keepWidthFirst': keepWidthFirst,
     };
   }
 }

macos/Classes/FIConvertUtils.h

@@ -54,6 +54,8 @@ NS_ASSUME_NONNULL_BEGIN
 @interface FIScaleOption : NSObject <FIOption>
 @property(assign, nonatomic) int width;
 @property(assign, nonatomic) int height;
+@property(assign, nonatomic) BOOL keepRatio;
+@property(assign, nonatomic) BOOL keepWidthFirst;
 @end
 
 @interface FIAddText : NSObject <FIOption>

macos/Classes/FIConvertUtils.m

@@ -106,6 +106,8 @@ + (id)createFromDict:(NSDictionary *)dict {
   FIScaleOption *option = [FIScaleOption new];
   option.width = [dict[@"width"] intValue];
   option.height = [dict[@"height"] intValue];
+  option.keepRatio = [dict[@"keepRatio"] boolValue];
+  option.keepWidthFirst = [dict[@"keepWidthFirst"] boolValue];
   return option;
 }
 

macos/Classes/FIUIImageHandler.m

@@ -52,8 +52,15 @@ CGContextRef createCGContext(size_t pixelsWide, size_t pixelsHigh) {
 
     return context;// 7
 }
+
 #pragma clang diagnostic pop
 
+CGSize CGImageGetSize(CGImageRef ref) {
+    size_t w = CGImageGetWidth(ref);
+    size_t h = CGImageGetHeight(ref);
+    return CGSizeMake(w, h);
+}
+
 FIImage *getImageFromCGContext(CGContextRef context) {
     size_t h = CGBitmapContextGetHeight(context);
     size_t w = CGBitmapContextGetWidth(context);
@@ -345,12 +352,26 @@ - (void)scale:(FIScaleOption *)option {
         return;
     }
 
+    CGImageRef srcImage = outImage.CGImage;
+
     double width = option.width;
     double height = option.height;
 
+    if (option.keepRatio) {
+        CGSize srcSize = CGImageGetSize(srcImage);
+
+        double srcRatio = srcSize.width / srcSize.height;
+
+        if (option.keepWidthFirst) {
+            height = width / srcRatio;
+        } else {
+            width = srcRatio * height;
+        }
+    }
+
     CGContextRef context = createCGContext((size_t) width, (size_t) height);
 
-    CGContextDrawImage(context, CGRectMake(0, 0, width, height), [outImage CGImage]);
+    CGContextDrawImage(context, CGRectMake(0, 0, width, height), srcImage);
 
     outImage = [self getImageWith:context];