From 017320d15f5a9de25d2723234ef124f3c8c95839 Mon Sep 17 00:00:00 2001
From: MoyuScript <i@moyu.moe>
Date: Tue, 1 Aug 2017 23:27:12 +0800
Subject: [PATCH] Calculate correct bounds for text/elements under nested
 transforms

---
 src/Bounds.js        | 16 ++--------------
 src/NodeContainer.js |  7 ++++++-
 src/NodeParser.js    |  5 +++--
 src/TextBounds.js    | 29 +++++++++++++++++++++--------
 src/index.js         | 11 ++++++-----
 5 files changed, 38 insertions(+), 30 deletions(-)

diff --git a/src/Bounds.js b/src/Bounds.js
index 25f81e2..aaba24c 100644
--- a/src/Bounds.js
+++ b/src/Bounds.js
@@ -44,20 +44,8 @@ export class Bounds {
     }
 }
 
-export const parseBounds = (node: HTMLElement, isTransformed: boolean): Bounds => {
-    return isTransformed ? offsetBounds(node) : Bounds.fromClientRect(node.getBoundingClientRect());
-};
-
-const offsetBounds = (node: HTMLElement): Bounds => {
-    // //$FlowFixMe
-    const parent = node.offsetParent ? offsetBounds(node.offsetParent) : {top: 0, left: 0};
-
-    return new Bounds(
-        node.offsetLeft + parent.left,
-        node.offsetTop + parent.top,
-        node.offsetWidth,
-        node.offsetHeight
-    );
+export const parseBounds = (node: HTMLElement): Bounds => {
+    return Bounds.fromClientRect(node.getBoundingClientRect());
 };
 
 export const calculatePaddingBox = (bounds: Bounds, borders: Array<Border>): Bounds => {
diff --git a/src/NodeContainer.js b/src/NodeContainer.js
index 83773f6..8e22718 100644
--- a/src/NodeContainer.js
+++ b/src/NodeContainer.js
@@ -88,10 +88,15 @@ export default class NodeContainer {
             zIndex: parseZIndex(style.zIndex)
         };
 
+        if (this.isTransformed()) {
+            // getBoundingClientRect provides values post-transform, we want them without the transformation
+            node.style.transform = 'matrix(1,0,0,1,0,0)';
+        }
+
         this.image =
             // $FlowFixMe
             node.tagName === 'IMG' ? imageLoader.loadImage(node.currentSrc || node.src) : null;
-        this.bounds = parseBounds(node, this.isTransformed());
+        this.bounds = parseBounds(node);
         if (__DEV__) {
             this.name = `${node.tagName.toLowerCase()}${node.id
                 ? `#${node.id}`
diff --git a/src/NodeParser.js b/src/NodeParser.js
index 6079264..6e23be0 100644
--- a/src/NodeParser.js
+++ b/src/NodeParser.js
@@ -35,7 +35,8 @@ const parseNodeTree = (
     stack: StackingContext,
     imageLoader: ImageLoader
 ): void => {
-    node.childNodes.forEach((childNode: Node) => {
+    for (let childNode = node.firstChild, nextNode; childNode; childNode = nextNode) {
+        nextNode = childNode.nextSibling;
         if (childNode.nodeType === Node.TEXT_NODE) {
             //$FlowFixMe
             if (childNode.data.trim().length > 0) {
@@ -72,7 +73,7 @@ const parseNodeTree = (
                 }
             }
         }
-    });
+    }
 };
 
 const createsRealStackingContext = (container: NodeContainer, node: HTMLElement): boolean => {
diff --git a/src/TextBounds.js b/src/TextBounds.js
index 05e9acf..4073fb0 100644
--- a/src/TextBounds.js
+++ b/src/TextBounds.js
@@ -3,7 +3,7 @@
 
 import {ucs2} from 'punycode';
 import type TextContainer from './TextContainer';
-import {Bounds} from './Bounds';
+import {Bounds, parseBounds} from './Bounds';
 import {TEXT_DECORATION} from './parsing/textDecoration';
 
 import FEATURES from './Feature';
@@ -40,19 +40,32 @@ export const parseTextBounds = (textContainer: TextContainer, node: Text): Array
         ) {
             if (FEATURES.SUPPORT_RANGE_BOUNDS) {
                 textBounds.push(new TextBounds(text, getRangeBounds(node, offset, text.length)));
+            } else {
+                const replacementNode = node.splitText(text.length);
+                textBounds.push(new TextBounds(text, getWrapperBounds(node)));
+                node = replacementNode;
             }
+        } else if (!FEATURES.SUPPORT_RANGE_BOUNDS) {
+            node = node.splitText(text.length);
         }
         offset += text.length;
     }
     return textBounds;
+};
 
-    /*
-     else if (container.node && typeof container.node.data === 'string') {
-     var replacementNode = container.node.splitText(text.length);
-     var bounds = this.getWrapperBounds(container.node, container.parent.hasTransform());
-     container.node = replacementNode;
-     return bounds;
-     }*/
+const getWrapperBounds = (node: Text): Bounds => {
+    const wrapper = node.ownerDocument.createElement('html2canvaswrapper');
+    wrapper.appendChild(node.cloneNode(true));
+    const parentNode = node.parentNode;
+    if (parentNode) {
+        parentNode.replaceChild(wrapper, node);
+        const bounds = parseBounds(wrapper);
+        if (wrapper.firstChild) {
+            parentNode.replaceChild(wrapper.firstChild, wrapper);
+        }
+        return bounds;
+    }
+    return new Bounds(0, 0, 0, 0);
 };
 
 const getRangeBounds = (node: Text, offset: number, length: number): Bounds => {
diff --git a/src/index.js b/src/index.js
index e87b03b..1104a62 100644
--- a/src/index.js
+++ b/src/index.js
@@ -19,10 +19,7 @@ export type Options = {
     type: ?string
 };
 
-const html2canvas = (
-    element: HTMLElement,
-    config: Options
-): Promise<HTMLCanvasElement> => {
+const html2canvas = (element: HTMLElement, config: Options): Promise<HTMLCanvasElement> => {
     const logger = new Logger();
 
     const ownerDocument = element.ownerDocument;
@@ -91,7 +88,11 @@ const html2canvas = (
                 }
             }
 
-            const renderer = new CanvasRenderer(canvas, {scale: options.scale, backgroundColor, imageStore});
+            const renderer = new CanvasRenderer(canvas, {
+                scale: options.scale,
+                backgroundColor,
+                imageStore
+            });
             return renderer.render(stack);
         });
     });