Refactor, reduce complexity and adding a "getImageSize_test" unit test

src/internal/getDefaultViewport.js

@@ -8,6 +8,8 @@ import getImageFitScale from './getImageFitScale.js';
  * @memberof Internal
  */
 function createViewport () {
+  const displayedArea = createDefaultDisplayedArea();
+
   return {
     scale: 1,
     translation: {
@@ -27,25 +29,34 @@ function createViewport () {
     voiLUT: undefined,
     colormap: undefined,
     labelmap: false,
+    displayedArea
+  };
+}
 
-    /**
-     * C.10.4 Displayed Area Module: This Module describes Attributes required to define a Specified Displayed Area space.
-     */
-    displayedArea: {
-      // Top Left Hand Corner
-      tlhc: {
-        x: 1,
-        y: 1
-      },
-      // Bottom Right Hand Corner
-      brhc: {
-        x: 1,
-        y: 1
-      },
-      rowPixelSpacing: 1,
-      columnPixelSpacing: 1,
-      presentationSizeMode: 'NONE'
-    }
+
+/**
+ * Creates the default displayed area.
+ * C.10.4 Displayed Area Module: This Module describes Attributes required to define a Specified Displayed Area space.
+ *
+ * @returns {tlhc: {x,y}, brhc: {x, y},rowPixelSpacing: Number, columnPixelSpacing: Number, presentationSizeMode: Number} displayedArea object
+ * @memberof Internal
+ */
+
+function createDefaultDisplayedArea () {
+  return {
+    // Top Left Hand Corner
+    tlhc: {
+      x: 1,
+      y: 1
+    },
+    // Bottom Right Hand Corner
+    brhc: {
+      x: 1,
+      y: 1
+    },
+    rowPixelSpacing: 1,
+    columnPixelSpacing: 1,
+    presentationSizeMode: 'NONE'
   };
 }
 

src/internal/getImageFitScale.js

@@ -1,21 +1,19 @@
+import { validateParameterUndefinedOrNull } from './validator.js';
 import getImageSize from './getImageSize.js';
 
+
 /**
  * Calculates the horizontal, vertical and minimum scale factor for an image
    @param {{width, height}} windowSize The window size where the image is displayed. This can be any HTML element or structure with a width, height fields (e.g. canvas).
  * @param {any} image The cornerstone image object
  * @param {Number} rotation Optional. The rotation angle of the image.
  * @return {{horizontalScale, verticalScale, scaleFactor}} The calculated horizontal, vertical and minimum scale factor
- * @memberof internal
+ * @memberof Internal
  */
 export default function (windowSize, image, rotation = null) {
-  if (windowSize === undefined) {
-    throw new Error('getImageScale: parameter windowSize must not be undefined');
-  }
 
-  if (image === undefined) {
-    throw new Error('getImageScale: parameter image must not be undefined');
-  }
+  validateParameterUndefinedOrNull(windowSize, 'getImageScale: parameter windowSize must not be undefined');
+  validateParameterUndefinedOrNull(image, 'getImageScale: parameter image must not be undefined');
 
   const imageSize = getImageSize(image, rotation);
   const rowPixelSpacing = image.rowPixelSpacing === undefined ? 1 : image.rowPixelSpacing;

src/internal/getImageSize.js

@@ -1,25 +1,39 @@
+import { validateParameterUndefinedOrNull } from './validator.js';
+
+/**
+ * Check if the angle is rotated
+ * @param {Number} rotation the rotation angle
+ * @returns {Boolean} true if the angle is rotated; Otherwise, false.
+ * @memberof Internal
+ */
+function isRotated (rotation) {
+  return !(rotation === null || rotation === undefined || rotation === 0 || rotation === 180);
+}
+
 /**
  * Retrieves the current image dimensions given an enabled element
  *
  * @param {any} image The Cornerstone image.
  * @param {Number} rotation Optional. The rotation angle of the image.
- * @return {{width, height}} The Image dimensions
+ * @return {{width:Number, height:Number}} The Image dimensions
+ * @memberof Internal
  */
 export default function (image, rotation = null) {
 
-  if (image.width === undefined || image.height === undefined) {
-    throw new Error('getImageSize: parameter image must have width/height');
-  }
+  validateParameterUndefinedOrNull(image, 'getImageSize: parameter image must not be undefined');
+  validateParameterUndefinedOrNull(image.width, 'getImageSize: parameter image must have width');
+  validateParameterUndefinedOrNull(image.height, 'getImageSize: parameter image must have height');
+
 
-  if (rotation === undefined || rotation === 0 || rotation === 180) {
+  if (isRotated(rotation)) {
     return {
-      width: image.width,
-      height: image.height
+      height: image.width,
+      width: image.height
     };
   }
 
   return {
-    width: image.height,
-    height: image.width
+    width: image.width,
+    height: image.height
   };
 }

src/internal/validator.js

@@ -0,0 +1,27 @@
+
+/**
+ * Check if the supplied parameter is undefined and throws and error
+ * @param {any} checkParam the parameter to validate for undefined
+ * @param {any} errorMsg the error message to be thrown
+ * @returns {void}
+ * @memberof internal
+ */
+export function validateParameterUndefined (checkParam, errorMsg) {
+  if (checkParam === undefined) {
+    throw new Error(errorMsg);
+  }
+}
+
+
+/**
+ * Check if the supplied parameter is undefined or null and throws and error
+ * @param {any} checkParam the parameter to validate for undefined
+ * @param {any} errorMsg the error message to be thrown
+ * @returns {void}
+ * @memberof internal
+ */
+export function validateParameterUndefinedOrNull (checkParam, errorMsg) {
+  if (checkParam === undefined || checkParam === null) {
+    throw new Error(errorMsg);
+  }
+}

src/resize.js

@@ -110,13 +110,7 @@ export default function (element, forceFitToWindow) {
     return;
   }
 
-  if (forceFitToWindow === true) {
-    fitToWindow(element);
-
-    return;
-  }
-
-  if (wasFitToWindow(enabledElement, oldCanvasWidth, oldCanvasHeight)) {
+  if (forceFitToWindow || wasFitToWindow(enabledElement, oldCanvasWidth, oldCanvasHeight)) {
     // Fit the image to the window again if it fitted before the resize
     fitToWindow(element);
   } else {

test/internal/getImageSize_test.js

@@ -0,0 +1,59 @@
+import { should, expect } from 'chai';
+
+import getImageSize from '../../src/internal/getImageSize.js';
+
+should();
+
+describe('getImageSize', function () {
+
+  describe('when image parameters is not passed', function () {
+    it('should throw an error', function () {
+
+      expect(function () {
+        getImageSize();
+      }).to.throw('getImageSize: parameter image must not be undefined');
+
+      expect(function () {
+        getImageSize({ width: 50 });
+      }).to.throw('getImageSize: parameter image must have height');
+
+      expect(function () {
+        getImageSize({ height: 100 });
+      }).to.throw('getImageSize: parameter image must have width');
+    });
+  });
+
+  describe('when an image is passed with no rotation', function () {
+    it('should return the image width/height', function () {
+      const image = {
+        width: 50,
+        height:100
+      };
+
+      const imageSizeNoRotationParameter = getImageSize(image);
+      const imageSize0RotationParameter = getImageSize(image, 0);
+      const imageSize180RotationParameter = getImageSize(image, 180);
+
+      imageSizeNoRotationParameter.should.be.deep.equal(image);
+      imageSize0RotationParameter.should.be.deep.equal(image);
+      imageSize180RotationParameter.should.be.deep.equal(image);
+    });
+  });
+
+  describe('when an image is passed rotated', function () {
+    it('should return the image width/height rotated', function () {
+      let image = {
+        width: 50,
+        height:100
+      };
+
+      const returnedImageSize = getImageSize(image, 90);
+
+      // rotate
+      image.width = 100;
+      image.height = 50;
+
+      returnedImageSize.should.be.deep.equal(image);
+    });
+  });
+});