流画布到imgITools使ico [英] Stream canvas to imgITools to make ico

问题描述

所以在WinXP我一直很难把一个PNG文件转换为带画布的ICO。我发现这个方法 encodeImage 。我不知道它是否工作，但它看起来很有希望，但我不知道如何喂给我的画在 imgITools.decodeData 。 >

我应该使用 aImageStream 和/或 aMimeType ？ / p>

  imgTools.decodeImageData（aImageStream，aMimeType，imgContainer）; 
  

这是我的代码更多：

  img ['asdf']。file = new FileUtils.File（myPathHere）; 
 
 let iconStream; 
 try {
 let imgTools = Cc [@ mozilla.org/image/tools;1] 
 .createInstance（Ci.imgITools）; 
 let imgContainer = {value：null}; 
 
 imgTools.decodeImageData（aImageStream，aMimeType，imgContainer）; 
 iconStream = imgTools.encodeImage（imgContainer.value，
image / vnd.microsoft.icon，
format = bmp; bpp = 32）; 
} catch（e）{
 alert（'failed converting icon'+ e）
 throw（processIcon  -  Failure converting icon（+ e +））; 
} 
 
 let outputStream = FileUtils.openSafeFileOutputStream（img ['asdf']。file）; 
 NetUtil.asyncCopy（iconStream，outStream，netutilCallback）; 
  

解决方案

，可能更容易使用以下canvas方法：

• toDataURI / toDataURIHD


• toBlob /


• mozFetchAsStream

还有未记录的 -moz-parse-options：，例如 -moz-parse-options：format = bmp; bpp = 32 。 （ref-tests似乎依赖于它，所以它不会很快消失，我会想）。

所以，这里是一个例子， a ArrayBuffer 。

 （canvas.toBlobHD || canvas.toBlob） .call（canvas，function（b）{
 var r = new FileReader（）; 
 r.onloadend = function（）{
 // r.result包含ArrayBuffer。
; 
 r.readAsArrayBuffer（b）; 
}，image / vnd.microsoft.icon，-moz-parse-options：format = bmp; bpp = 32 
  

这里有一个更完整的 example fiddle 创建一个256x256的BMP图标。

由于您可能想将数据提供给js-ctypes，因此ArrayBuffer非常好，因为您可以直接从中创建指针，或使用 OS.File将其写入文件。

So on WinXP I have been having a hard time converting a PNG file to an ICO with canvas. I found this method encodeImage. I don't know if it works but it looks promising but I can't figure out how to feed the image I drew on a canvas into imgITools.decodeData.

What should I use for aImageStream and/or aMimeType?

imgTools.decodeImageData(aImageStream, aMimeType, imgContainer);

This is more of my code:

 img['asdf'].file = new FileUtils.File(myPathHere);

let iconStream;
try {
  let imgTools = Cc["@mozilla.org/image/tools;1"]
                    .createInstance(Ci.imgITools);
  let imgContainer = { value: null };

  imgTools.decodeImageData(aImageStream, aMimeType, imgContainer);
  iconStream = imgTools.encodeImage(imgContainer.value,
                                    "image/vnd.microsoft.icon",
                                    "format=bmp;bpp=32");
} catch (e) {
  alert('failure converting icon ' + e)
  throw("processIcon - Failure converting icon (" + e + ")");
}

let outputStream = FileUtils.openSafeFileOutputStream(img['asdf'].file);
NetUtil.asyncCopy(iconStream, outStream, netutilCallback);

解决方案

Since you're having a canvas already(?), it would be probably easier to use either on of the following canvas methods:

• toDataURI/toDataURIHD
• toBlob/toBlobHD
• mozFetchAsStream

There is also the undocumented -moz-parse-options:, e.g -moz-parse-options:format=bmp;bpp=32. (ref-tests seem to depend on it, so it isn't going away anytime soon I'd think).

So, here is an example for loading stuff into an ArrayBuffer.

(canvas.toBlobHD || canvas.toBlob).call(canvas, function (b) {
    var r = new FileReader();
    r.onloadend = function () {
        // r.result contains the ArrayBuffer.
    };
    r.readAsArrayBuffer(b);
}, "image/vnd.microsoft.icon", "-moz-parse-options:format=bmp;bpp=32");

Here is a more complete example fiddle creating a 256x256 BMP icon.

Since you likely want to feed that data into js-ctypes, having an ArrayBuffer is great because you can create pointers from it directly, or write it to a file using OS.File.

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