-moz-image-region

Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.

For certain XUL elements and pseudo-elements that use an image from the list-style-image property, this property specifies a region of the image that is used in place of the whole image. This allows elements to use different pieces of the same image to improve performance.

The syntax is similar to the clip property. All four values are relative to the upper left corner of the image.

Syntax

css

/* Keyword value */
-moz-image-region: auto;

/* <shape> value */
-moz-image-region: rect(0, 8px, 4px, 4px);

/* Global values */
-moz-image-region: inherit;
-moz-image-region: initial;
-moz-image-region: unset;

Values

auto: Automatically defines the region of the image to use.
<shape>: A shape defining the part of the image to use. The rect() function defines a rectangle to use as shape. Its parameters define the top, right, bottom, and left offsets of the edges of the image, in this order.

Formal definition

Initial value	`auto`
Applies to	XUL elements and `:-moz-tree-image`, `:-moz-tree-twisty`, and `:-moz-tree-checkbox` pseudo-elements. Note: `-moz-image-region` only works with elements where the icon is specified using `list-style-image`. It will not work with XUL `<image src="url" />`.
Inherited	yes
Computed value	as specified
Animation type	discrete

Formal syntax

-moz-image-region = 
  <shape>  |
  auto

Examples

Clipping an image

css

#example-button {
  /* display only the 4x4 area from the top left of this image */
  list-style-image: url("chrome://example/skin/example.png");
  -moz-image-region: rect(0px, 4px, 4px, 0px);
}
#example-button:hover {
  /* use the 4x4 area to the right of the first for the hovered button */
  -moz-image-region: rect(0px, 8px, 4px, 4px);
}

Specifications

Not part of any standard.