Raphael.js函数getBBox在IE8中返回NAN / NAN / NAN [英] Raphael.js function getBBox give back NAN/NAN/NAN in IE8

问题描述

使用Raphaël2.1.4 - JavaScript矢量库
执行类似的操作：

using Raphaël 2.1.4 - JavaScript Vector Library do something like that:

var textDummy = paper.text(50,500, 'hello world').attr({fill: 'transparent', 'font-size': 14});
var textBox = textDummy.getBBox();

使用chrome和firefox一切都很好，
但在IE8中它会回馈NaN / NaN / NaN，
par例如textBox.height是NaN。

with chrome and firefox everything is fine, but in IE8 it give back NaN/NaN/NaN, par exemple textBox.height is NaN.

我如何解决这个问题？

推荐答案

我在Rapahel 2.2.0和2.2.1中遇到了同样的问题，使用 ._ getBBox（）没有修复它为了我。

I had the same problem in Rapahel 2.2.0 and 2.2.1, and using ._getBBox() didn't fix it for me.

为我修复的是回退到 .auxGetBBox（）如果已定义且常规 .getBBox（）不起作用，如下所示：

What did fix it for me is falling back to .auxGetBBox() if it's defined and regular .getBBox() doesn't work, like this:

var bbox = path.getBBox( );

// Workaround for apparent bug in Raphael's VML module's getBBox() override
if( isNaN( bbox.x ) && path.auxGetBBox ){
  bbox = path.auxGetBBox();
}

---

我没有修复了底层错误，但我找到了它的来源。

---

I don't have a fix for the underlying bug, but I have found the source of it.

在VML模式下，Raphael采用初始 getBBox（）函数，在元素原型上将其保存为 auxGetBBox（），然后将其替换为看似已损坏的函数。

In VML mode, Raphael takes the initial getBBox() function, saves it as auxGetBBox() on the element prototype, then replaces it with a function that appears to be broken.

它的计算基于一个定义为的变量var z = 1 / this.paper._viewBoxShift.scale; ，显然希望_viewBoxShift.scale是当前视图框与初始视图框相比规模的一些因素，但实际上 _viewBoxShift.scale 是这样的对象，看起来像来自 paperproto.getSize（）：

It has calculations based on a variable defined as var z = 1/this.paper._viewBoxShift.scale;, which clearly expects _viewBoxShift.scale to be some factor of the scale of the current viewbox compared to the initial viewbox , but actually _viewBoxShift.scale is an object like this which appears to come from paperproto.getSize():

{height：someNumber，width：someNumber }

这是所有 NaN 的来源。 Cannae除以一个对象。

This is where all the NaNs are coming from. Cannae divide by an object.

因此，如果使用视图框不应用缩放，这种解决方法可以正常工作，但如果应用了缩放，可能会给出不正确的结果（我能做的事情）在VML模式的raphael最新版本中完全可以工作，但这是一个单独的问题。修复 将深入挖掘Raphael的VML模块，将适当的缩放因子输入到 z 变量中。

So this workaround works fine if no zoom is applied using a viewbox, but may give incorrect results if a zoom has been applied (something I can't get to work at all in recent versions of raphael in VML mode, but that's a seperate question). Fixing that will involve digging deep into Raphael's VML module to pipe a proper zoom factor into this z variable.

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