mask-size
CSS
property specifies the sizes of the mask images. The size of the image can be fully or partially constrained in order to preserve its intrinsic ratio.
/* Keywords syntax */ mask-size: cover; mask-size: contain; /* One-value syntax */ /* the width of the image (height set to 'auto') */ mask-size: 50%; mask-size: 3em; mask-size: 12px; mask-size: auto; /* Two-value syntax */ /* first value: width of the image, second value: height */ mask-size: 50% auto; mask-size: 3em 25%; mask-size: auto 6px; mask-size: auto auto; /* Multiple values */ /* Do not confuse this with mask-size: auto auto */ mask-size: auto, auto; mask-size: 50%, 25%, 25%; mask-size: 6px, auto, contain; /* Global values */ mask-size: inherit; mask-size: initial; mask-size: unset;注意： If the value of this property is not set in a
mask
shorthand property that is applied to the element after the
mask-size
CSS property, the value of this property is then reset to its initial value by the shorthand property.
One or more
<bg-size>
values, separated by commas.
A
<bg-size>
can be specified in one of three ways:
To specify a size using width and height, you can supply one or two values:
auto
.
Each value can be a
<length>
，
<percentage>
，或
auto
.
<length>
<length>
value scales the mask image to the specified length in the corresponding dimension. Negative lengths are not allowed.
<percentage>
<percentage>
value scales the mask image in the corresponding dimension to the specified percentage of the mask positioning area, which is determined by the value of
mask-origin
. The mask positioning area is, by default, the area containing the content of the box and its padding; the area may also be changed to just the content or to the area containing borders, padding and content. Negative percentages are not allowed.
auto
A keyword that scales the mask image in the corresponding directions in order to maintain its intrinsic proportion.
contain
mask-position
.
cover
contain
. Scales the image as large as possible and maintains image aspect ratio (image doesn't get squished). The image "covers" the entire width or height of the container. When the image and container have different dimensions,
the image is clipped
either on left/right or at top/bottom.
The interpretation of possible values depends on the image's intrinsic dimensions (width and height) and intrinsic proportion (ratio of width and height). A bitmap image always has intrinsic dimensions and an intrinsic proportion. A vector image may have both intrinsic dimensions and thus it has an intrinsic proportion too. It also may have one or no intrinsic dimensions and in either case it might or might not have an intrinsic proportion. Gradients are treated as images with no intrinsic dimensions or intrinsic proportion.
The rendered size of the mask image is then computed as follows:
mask-size
are specified and are not
auto
:
The mask image renders at the specified size.
mask-size
is
contain
or
cover
:
The image is rendered by preserving its intrinsic proportion at the largest size contained within or covering the mask positioning area. If the image has no intrinsic proportion, then it is rendered at the size of the mask positioning area.
mask-size
is
auto
or
auto auto
:
contain
had been specified instead. If the image has one intrinsic dimension and a proportion, it's rendered at the size determined by that one dimension and the proportion. If the image has one intrinsic dimension but no proportion, it's rendered using the intrinsic dimension and the corresponding dimension of the mask positioning area.
mask-size
has one
auto
component and one non-
auto
component:
If the image has an intrinsic proportion, then render it using the specified dimension and compute the other dimension from the specified dimension and the intrinsic proportion. If the image has no intrinsic proportion, use the specified dimension for that dimension. For the other dimension, use the image's corresponding intrinsic dimension if there is one. If there is no such intrinsic dimension, use the corresponding dimension of the mask positioning area.
| 初始值 |
auto
|
|---|---|
| 适用于 |
all elements; In SVG, it applies to container elements excluding the
defs
element and all graphics elements
|
| 继承 | no |
| 计算值 | as specified, but with relative lengths converted into absolute lengths |
| 动画类型 | repeatable list of simple list of length, percentage, or calc |
<bg-size>#where
<bg-size> = [ <length-percentage> | auto ]{1,2} | cover | containwhere
<length-percentage> = <length> | <percentage>
#masked {
width: 200px;
height: 200px;
background: blue linear-gradient(red, blue);
-webkit-mask-image: url(https://mdn.mozillademos.org/files/12668/MDN.svg);
mask-image: url(https://mdn.mozillademos.org/files/12668/MDN.svg);
-webkit-mask-size: 50%;
mask-size: 50%; /* Can be changed in the live sample */
margin-bottom: 10px;
}
<div id="masked"> </div> <select id="maskSize"> <option value="auto">auto</option> <option value="40% 80%">40% 80%</option> <option value="50%" selected>50%</option> <option value="200px 100px">200px 100px</option> <option value="cover">cover</option> <option value="contain">contain</option> </select>
var maskSize = document.getElementById("maskSize");
maskSize.addEventListener("change", function (evt) {
document.getElementById("masked").style.maskSize = evt.target.value;
});
| 规范 | 状态 | 注释 |
|---|---|---|
|
CSS Masking Module Level 1
The definition of 'mask-size' in that specification. |
候选推荐 | 初始定义 |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
mask-size
|
Chrome
完整支持
4
Prefixed
|
Edge 完整支持 18 |
Firefox
完整支持
53
|
IE 不支持 No |
Opera
完整支持
15
Prefixed
|
Safari
完整支持
4
Prefixed
|
WebView Android
完整支持
4.4
Prefixed
|
Chrome Android
完整支持
18
Prefixed
|
Firefox Android
完整支持
53
|
Opera Android
完整支持
14
Prefixed
|
Safari iOS
完整支持
2
Prefixed
|
Samsung Internet Android
完整支持
1.0
Prefixed
|
完整支持
不支持
用户必须明确启用此特征。
要求使用供应商前缀或不同名称。