50 lines
1.5 KiB
JavaScript
50 lines
1.5 KiB
JavaScript
/**
|
||
* @fileOverview Fix android canvas.toDataUrl bug.
|
||
*/
|
||
define([
|
||
'./util',
|
||
'./jpegencoder',
|
||
'../../base'
|
||
], function( Util, encoder, Base ) {
|
||
var origin = Util.canvasToDataUrl,
|
||
supportJpeg;
|
||
|
||
Util.canvasToDataUrl = function( canvas, type, quality ) {
|
||
var ctx, w, h, fragement, parts;
|
||
|
||
// 非android手机直接跳过。
|
||
if ( !Base.os.android ) {
|
||
return origin.apply( null, arguments );
|
||
}
|
||
|
||
// 检测是否canvas支持jpeg导出，根据数据格式来判断。
|
||
// JPEG 前两位分别是：255, 216
|
||
if ( type === 'image/jpeg' && typeof supportJpeg === 'undefined' ) {
|
||
fragement = origin.apply( null, arguments );
|
||
|
||
parts = fragement.split(',');
|
||
|
||
if ( ~parts[ 0 ].indexOf('base64') ) {
|
||
fragement = atob( parts[ 1 ] );
|
||
} else {
|
||
fragement = decodeURIComponent( parts[ 1 ] );
|
||
}
|
||
|
||
fragement = fragement.substring( 0, 2 );
|
||
|
||
supportJpeg = fragement.charCodeAt( 0 ) === 255 &&
|
||
fragement.charCodeAt( 1 ) === 216;
|
||
}
|
||
|
||
// 只有在android环境下才修复
|
||
if ( type === 'image/jpeg' && !supportJpeg ) {
|
||
w = canvas.width;
|
||
h = canvas.height;
|
||
ctx = canvas.getContext('2d');
|
||
|
||
return encoder.encode( ctx.getImageData( 0, 0, w, h ), quality );
|
||
}
|
||
|
||
return origin.apply( null, arguments );
|
||
};
|
||
}); |