Cleanup resize complexity (#7439)

Cleanup resize complexity

diff --git a/src/core/core.controller.js b/src/core/core.controller.js
index c31e92a9423f334a66b9d26fab16b9f3f3126bf1..8567895827164a50f89f322d138e9af7bc516d7b 100644 (file)
--- a/src/core/core.controller.js
+++ b/src/core/core.controller.js
@@ -172,8 +172,25 @@ function getCanvas(item) {
        return item;
 }
 
+function computeNewSize(canvas, width, height, aspectRatio) {
+       if (width === undefined || height === undefined) {
+               width = getMaximumWidth(canvas);
+               height = getMaximumHeight(canvas);
+       }
+       // the canvas render width and height will be casted to integers so make sure that
+       // the canvas display style uses the same integer values to avoid blurring effect.
+
+       // Minimum values set to 0 instead of canvas.size because the size defaults to 300x150 if the element is collapsed
+       width = Math.max(0, Math.floor(width));
+       return {
+               width,
+               height: Math.max(0, Math.floor(aspectRatio ? width / aspectRatio : height))
+       };
+}
+
 class Chart {
 
+       // eslint-disable-next-line max-statements
        constructor(item, config) {
                const me = this;
 
@@ -297,38 +314,27 @@ class Chart {
                const options = me.options;
                const canvas = me.canvas;
                const aspectRatio = options.maintainAspectRatio && me.aspectRatio;
-
-               if (width === undefined || height === undefined) {
-                       width = getMaximumWidth(canvas);
-                       height = getMaximumHeight(canvas);
-               }
-               // the canvas render width and height will be casted to integers so make sure that
-               // the canvas display style uses the same integer values to avoid blurring effect.
-
-               // Set to 0 instead of canvas.size because the size defaults to 300x150 if the element is collapsed
-               const newWidth = Math.max(0, Math.floor(width));
-               const newHeight = Math.max(0, Math.floor(aspectRatio ? newWidth / aspectRatio : height));
+               const newSize = computeNewSize(canvas, width, height, aspectRatio);
 
                // detect devicePixelRation changes
                const oldRatio = me.currentDevicePixelRatio;
                const newRatio = options.devicePixelRatio || me.platform.getDevicePixelRatio();
 
-               if (me.width === newWidth && me.height === newHeight && oldRatio === newRatio) {
+               if (me.width === newSize.width && me.height === newSize.height && oldRatio === newRatio) {
                        return;
                }
 
-               canvas.width = me.width = newWidth;
-               canvas.height = me.height = newHeight;
+               canvas.width = me.width = newSize.width;
+               canvas.height = me.height = newSize.height;
                if (canvas.style) {
-                       canvas.style.width = newWidth + 'px';
-                       canvas.style.height = newHeight + 'px';
+                       canvas.style.width = newSize.width + 'px';
+                       canvas.style.height = newSize.height + 'px';
                }
 
                retinaScale(me, newRatio);
 
                if (!silent) {
                        // Notify any plugins about the resize
-                       const newSize = {width: newWidth, height: newHeight};
                        plugins.notify(me, 'resize', [newSize]);
 
                        // Notify of resize