library/src/main/ets/ImageKnifeLoader.ets

@@ -39,16 +39,6 @@ class RequestData {
 /**
  * ImageKnifeDispatcher 抽取出来的方法，因@Concurrent只能import方法，故抽取到另一个类
  */
-interface GeneratedObjectLiteralInterface_1 {
-  height: number;
-  width: number;
-}
-
-interface Generated {
-  editable: boolean;
-  desiredSize: Size;
-}
-
 export class ImageKnifeLoader {
   static async parseImage(resBuf: ArrayBuffer, typeValue: string, fileKey: string,
     request: RequestJobRequest): Promise<RequestJobResult> {
@@ -85,15 +75,19 @@ export class ImageKnifeLoader {
     }
 
     let size = (await imageSource.getImageInfo()).size
-    try{
-      if ((request.downsampType !== DownsampleStrategy.NONE) &&
-        request.requestSource == ImageKnifeRequestSource.SRC ) {
-        decodingOptions =await ImageKnifeLoader.downsamplerReqSize(typeValue,request,size,ImageKnifeRequestSource.SRC)
+    if ((request.downsampType !== undefined && request.downsampType !== DownsampleStrategy.NONE) &&
+      request.requestSource == ImageKnifeRequestSource.SRC) {
+      let reqSize =
+        new Downsampler().calculateScaling(typeValue, size.width, size.height, request.targetWidth,
+          request.targetHeight, request.downsampType)
+      decodingOptions = {
+        editable: request.requestSource === ImageKnifeRequestSource.SRC && request.transformation !== undefined ? true : false,
+        desiredSize: {
+          width: reqSize.targetWidth,
+          height: reqSize.targetHeight
+        }
       }
-    }catch(err){
-      return ImageKnifeLoader.makeEmptyResult("image.createImageSource failed")
     }
-
     await imageSource.createPixelMap(decodingOptions)
       .then((pixelmap: PixelMap) => {
         resPixelmap = pixelmap
@@ -131,13 +125,18 @@ export class ImageKnifeLoader {
       editable: true,
       desiredSize: defaultSize
     };
-    try{
-      if ((request.downsampType !== DownsampleStrategy.NONE) &&
-        request.requestSource == ImageKnifeRequestSource.SRC ) {
-        opts =await ImageKnifeLoader.downsamplerReqSize(typeValue,request,size)
+    if ((request.downsampType !== DownsampleStrategy.NONE && request.downsampType !== undefined) &&
+      request.requestSource == ImageKnifeRequestSource.SRC) {
+      let reqSize =
+        new Downsampler().calculateScaling(typeValue, size.width, size.height, request.targetWidth,
+          request.targetHeight, request.downsampType)
+      opts = {
+        editable: true,
+        desiredSize: {
+          height: vp2px(reqSize.targetHeight),
+          width: vp2px(reqSize.targetWidth)
+        }
       }
-    }catch(err){
-      return ImageKnifeLoader.makeEmptyResult("image.createImageSource failed")
     }
     await imageSource.createPixelMap(opts)
       .then((pixelmap: PixelMap) => {
@@ -383,25 +382,4 @@ export class ImageKnifeLoader {
     }
     return resBuf
   }
-  static async downsamplerReqSize(typeValue:string,request:RequestJobRequest ,size:Size,SRC?:ImageKnifeRequestSource): Promise<image.DecodingOptions>{
-    let reqSize = new Downsampler().calculateScaling(typeValue, size.width, size.height, request.targetWidth, request.targetHeight, request.downsampType)
-    if(typeValue=="svg") {
-      return ({
-        editable: true,
-        desiredSize: ({
-          height: vp2px(reqSize.targetHeight),
-          width: vp2px(reqSize.targetWidth)
-        } as Size)
-      } as  image.DecodingOptions )
-    }else {
-       return( {
-          editable: request.requestSource ===SRC && request.transformation !== undefined ? true : false,
-          desiredSize: ({
-            width: reqSize.targetWidth,
-            height: reqSize.targetHeight
-          }as Size)
-        }as  image.DecodingOptions)
-      }
-  }
-}
-
+}

library/src/main/ets/downsampling/Downsampler.ets

@@ -27,58 +27,55 @@ export interface calculateScaleType {
   targetHeight: number
 }
 
-
 export class Downsampler {
   calculateScaling(
-    typeValue: string |null,
-    sourceWidth: number, //原始宽高
+    typeValue: string | null,
+    sourceWidth: number | undefined, //原始宽高
     sourceHeight: number, //原始宽高
     requestWidth: number, //请求宽高
     requestHeight: number, //请求宽高
-    downsampType: DownsampleStrategy,
+    downsampType: DownsampleStrategy | undefined,
   ): calculateScaleType {
-
-    if (sourceHeight <= 0 || sourceWidth <= 0) {
-        throw new Error(`Invalid width and height, sourceHeight:${sourceHeight}+ sourceWidth:${sourceWidth}`)
+    const fileType = typeValue //获取图片类型
+    let targetWidth: number | null = null;//降采样之后的宽
+    let targetHeight: number | null = null;//降采样之后的高
+    if (sourceHeight <= 0 || sourceWidth == undefined || sourceWidth == null || sourceWidth <= 0) {
+      throw new Error("Cannot found width or height")
+    }
+    if(downsampType===undefined){
+      throw new Error("Cannot found downsampType");
     }
     let downsampler = this.getDownsampler(downsampType);
-    let exactScaleFactor: number =
-      downsampler.getScaleFactor(sourceWidth, sourceHeight, requestWidth, requestHeight, downsampType);
-    let rounding: SampleSizeRounding =
-      downsampler.getSampleSizeRounding(sourceWidth, sourceHeight, requestWidth, requestHeight, downsampType); //采样类型
-    //原始宽高和缩放系数的乘积
-    let outSize:Size = {
-      width: this.round(exactScaleFactor * sourceWidth),
-      height: this.round(exactScaleFactor * sourceHeight)
+    let exactScaleFactor : number = downsampler.getScaleFactor(sourceWidth, sourceHeight, requestWidth, requestHeight, downsampType);
+    let rounding: SampleSizeRounding= downsampler.getSampleSizeRounding(sourceWidth, sourceHeight, requestWidth, requestHeight, downsampType);//采样类型
+    if (exactScaleFactor==undefined|| exactScaleFactor <= 0 ) {
+      throw new Error("Cannot round with exactScaleFactor");
     }
-    let scaleFactor =
-      rounding == SampleSizeRounding.QUALITY ? Math.max(sourceWidth / outSize.width, sourceHeight / outSize.height) :
-      Math.min(sourceWidth / outSize.width, sourceHeight / outSize.height) //将整型的缩放因子转换为2的次幂采样大小
-    scaleFactor = Math.max(1, highestOneBit(scaleFactor))
-    if (rounding == 0 && (scaleFactor < (1 / exactScaleFactor))) {
-      scaleFactor = scaleFactor << 1;
+    let outWidth: number = this.round(exactScaleFactor * sourceWidth);//原始宽和缩放系数的乘积
+    let outHeight: number = this.round(exactScaleFactor * sourceHeight);//原始高和缩放系数的乘积
+    let widthScaleFactor = sourceWidth / outWidth;//计算的缩放因子
+    let heightScaleFactor = sourceHeight / outHeight;//计算的缩放因子
+    let scaleFactor = rounding ==SampleSizeRounding.QUALITY ? Math.max(widthScaleFactor, heightScaleFactor) :
+    Math.min(widthScaleFactor, heightScaleFactor) //将整型的缩放因子转换为2的次幂采样大小
+    let powerOfTwoSampleSize: number = scaleFactor;
+    powerOfTwoSampleSize = Math.max(1, highestOneBit(scaleFactor))
+    if (rounding == 0 && (powerOfTwoSampleSize < (1 / exactScaleFactor))) {
+      powerOfTwoSampleSize = powerOfTwoSampleSize << 1;
     }
     //基于上一步得出的采样大小，根据不同的图片类型，计算采样后的图片尺寸
-    if (typeValue === "png") {
-      return {
-        targetWidth: Math.floor(sourceWidth / scaleFactor),
-        targetHeight: Math.floor(sourceHeight / scaleFactor)
-      }
-    } else if (typeValue === "webp") {
-      return {
-        targetWidth: Math.round(sourceWidth / scaleFactor),
-        targetHeight: Math.round(sourceHeight / scaleFactor)
-      }
+    if (fileType === "png") {
+      targetWidth = Math.floor(sourceWidth / powerOfTwoSampleSize);
+      targetHeight = Math.floor(sourceHeight / powerOfTwoSampleSize);
+    } else if (fileType === "webp") {
+      targetWidth = Math.round(sourceWidth / powerOfTwoSampleSize);
+      targetHeight = Math.round(sourceHeight / powerOfTwoSampleSize);
     } else {
-      return {
-        targetWidth: sourceWidth / scaleFactor,
-        targetHeight: sourceHeight / scaleFactor
-
-      }
+      targetWidth = sourceWidth / powerOfTwoSampleSize;
+      targetHeight = sourceHeight / powerOfTwoSampleSize;
     }
+    return  { targetWidth, targetHeight }
   }
-
-  getDownsampler(downsampType: DownsampleStrategy) {
+  getDownsampler(downsampType:DownsampleStrategy) {
     switch (downsampType) {
       case DownsampleStrategy.FIT_CENTER_MEMORY:
       case DownsampleStrategy.FIT_CENTER_QUALITY:
@@ -96,7 +93,6 @@ export class Downsampler {
         throw new Error('Unsupported downsampling strategy');
     }
   }
-
   round(value: number): number {
     return Math.floor(value + 0.5);
   }

library/src/main/ets/model/ImageKnifeOption.ets

@@ -124,7 +124,7 @@ export class ImageKnifeOption {
   onComplete?:(event:EventImage | undefined) => void
   drawingColorFilter?: ColorFilter | drawing.ColorFilter
   // 下采样
-  @Trace downsampleOf: DownsampleStrategy = DownsampleStrategy.NONE
+  @Trace downsampleOf?: DownsampleStrategy = DownsampleStrategy.NONE
   constructor(option?:ImageOption) {
     this.loadSrc = option?.loadSrc == undefined ? "" : option?.loadSrc
     this.placeholderSrc = option?.placeholderSrc
@@ -145,7 +145,7 @@ export class ImageKnifeOption {
     this.onLoadListener = option?.onLoadListener
     this.onComplete = option?.onComplete
     this.drawingColorFilter = option?.drawingColorFilter
-    this.downsampleOf = option?.downsampleOf==undefined?DownsampleStrategy.NONE:option?.downsampleOf
+    this.downsampleOf = option?.downsampleOf
   }
 }