Update canvas-helper.js

Shinerising · web-flow · commit 0e390f247e20 · 2017-07-19T10:07:10.000+08:00
diff --git a/src/lib/canvas-helper.js b/src/lib/canvas-helper.js
@@ -54,6 +54,48 @@ export default {
       callback(data);
     }
   },
+  
+  /**
+  * init image for reset size and rotation
+  **/
+  init(src, callback) {
+    console.log(src);
+      let image = new Image();
+      image.src = src;
+      var self = this;
+      image.onload = function() {
+        var mimeType = self._getImageType(image.src);
+        var cvs = self._getCanvas(image.naturalWidth, image.naturalHeight);
+        var ctx = cvs.getContext("2d");
+        ctx.drawImage(image, 0, 0);
+        var newImageData = cvs.toDataURL(mimeType, 100);
+        callback(newImageData);
+      }
+  },
+
+  /**
+  * rotate image via canvas
+  **/
+  rotate(imageData, direction, callback) {
+      let image = new Image();
+      image.src = imageData.src;
+      var self = this;
+      image.onload = function() {
+        var mimeType = self._getImageType(image.src);
+        var cvs = self._getCanvas(image.naturalHeight, image.naturalWidth);
+        var ctx = cvs.getContext("2d");
+        if (direction == 1) { 
+            ctx.rotate(90 * Math.PI / 180);
+            ctx.translate(0, -cvs.width);
+        } else {
+            ctx.rotate(-90 * Math.PI / 180);
+            ctx.translate(-cvs.height, 0);
+        }
+        ctx.drawImage(image, 0, 0);
+        var newImageData = cvs.toDataURL(mimeType, 100);
+        callback(newImageData);
+      }
+  },
 
   resize(image, options, callback) {
     const checkNumber = function(num) {
