OpenLayers v9.1.0 API - Module: ol/style/flat

Vector layers can be styled with an object literal containing properties for stroke, fill, image, and text styles. The types below can be composed into a single object. For example, a style with both stroke and fill properties could look like this:

const style = {
  'stroke-color': 'yellow',
  'stroke-width': 1.5,
  'fill-color': 'orange',
};

See details about the available properties depending on what type of symbolizer should be applied:

Stroke - properties for applying a stroke to lines and polygons
Fill - properties for filling polygons
Text - properties for labeling points, lines, and polygons
Icon - properties for rendering points with an icon
Circle - properties for rendering points with a circle
Shape - properties for rendering points with a regular shape

To conditionally apply styles based on a filter, a list of rules can be used. For example, to style points with a big orange circle if the population is greater than 1 million and a smaller blue circle otherwise:

const rules = [
  {
    filter: ['>', ['get', 'population'], 1_000_000],
    style: {
      'circle-radius': 10,
      'circle-fill-color': 'red',
    }
  },
  {
    else: true,
    style: {
      'circle-radius': 5,
      'circle-fill-color': 'blue',
    },
  },
];

Type Definitions

BooleanExpression{boolean} {Array}

A literal boolean (e.g. true) or an expression that evaluates to a boolean (e.g. ['>', ['get', 'population'], 1_000_000]).

ColorExpression{Color} {string} {Array}

A CSS named color (e.g. 'blue'), an array of 3 RGB values (e.g. [0, 255, 0]), an array of 4 RGBA values (e.g. [0, 255, 0, 0.5]), or an expression that evaluates to one of these color types (e.g. ['get', 'color']).

DefaultStyle{Object}

These default style properties are applied when no other style is given.

Properties:

Name	Type	Description
`fill-color`	string	`'rgba(255,255,255,0.4)'`
`stroke-color`	string	`'#3399CC'`
`stroke-width`	number	`1.25`
`circle-radius`	number	`5`
`circle-fill-color`	string	`'rgba(255,255,255,0.4)'`
`circle-stroke-width`	number	`1.25`
`circle-stroke-color`	string	`'#3399CC'`

FlatCircle{Object}

Circle style properties for rendering point features. At least circle-radius must be provided.

Properties:

Name	Type	Description
`circle-radius`	number \| undefined	Circle radius.
`circle-fill-color`	ColorExpression \| undefined	The fill color.
`circle-stroke-color`	ColorExpression \| undefined	The stroke color.
`circle-stroke-width`	NumberExpression \| undefined	Stroke pixel width.
`circle-stroke-line-cap`	StringExpression (defaults to 'round')	Line cap style: `butt`, `round`, or `square`.
`circle-stroke-line-join`	StringExpression (defaults to 'round')	Line join style: `bevel`, `round`, or `miter`.
`circle-stroke-line-dash`	NumberArrayExpression \| undefined	Line dash pattern.
`circle-stroke-line-dash-offset`	NumberExpression (defaults to 0)	Line dash offset.
`circle-stroke-miter-limit`	NumberExpression (defaults to 10)	Miter limit.
`circle-displacement`	NumberArrayExpression (defaults to [0,0])	displacement
`circle-scale`	SizeExpression (defaults to 1)	Scale. A two dimensional scale will produce an ellipse. Unless two dimensional scaling is required a better result may be obtained with an appropriate setting for `circle-radius`.
`circle-rotation`	NumberExpression (defaults to 0)	Rotation in radians (positive rotation clockwise, meaningful only when used in conjunction with a two dimensional scale).
`circle-rotate-with-view`	BooleanExpression (defaults to false)	Whether to rotate the shape with the view (meaningful only when used in conjunction with a two dimensional scale).
`circle-declutter-mode`	DeclutterMode \| undefined	Declutter mode
`z-index`	NumberExpression \| undefined	The zIndex of the style.

FlatFill{Object}

Fill style properties applied to polygon features.

Properties:

Name	Type	Description
`fill-color`	ColorExpression \| undefined	The fill color.
`fill-pattern-src`	StringExpression \| undefined	Fill pattern image URL.
`fill-pattern-size`	SizeExpression \| undefined	Fill pattern image size in pixels. Can be used together with `fill-pattern-offset` to define the sub-rectangle to use from a fill pattern image sprite sheet.
`fill-pattern-offset`	SizeExpression \| undefined	Fill pattern image offset in pixels.

FlatIcon{Object}

Icon style properties applied to point features. icon-src must be provided to render points with an icon.

Properties:

Name	Type	Description
`icon-src`	string \| undefined	Image source URI.
`icon-anchor`	NumberArrayExpression (defaults to [0.5, 0.5])	Anchor. Default value is the icon center.
`icon-anchor-origin`	IconOrigin (defaults to 'top-left')	Origin of the anchor: `bottom-left`, `bottom-right`, `top-left` or `top-right`.
`icon-anchor-x-units`	IconAnchorUnits (defaults to 'fraction')	Units in which the anchor x value is specified. A value of `'fraction'` indicates the x value is a fraction of the icon. A value of `'pixels'` indicates the x value in pixels.
`icon-anchor-y-units`	IconAnchorUnits (defaults to 'fraction')	Units in which the anchor y value is specified. A value of `'fraction'` indicates the y value is a fraction of the icon. A value of `'pixels'` indicates the y value in pixels.
`icon-color`	Color \| string \| undefined	Color to tint the icon. If not specified, the icon will be left as is.
`icon-cross-origin`	null \| string \| undefined	The `crossOrigin` attribute for loaded images. Note that you must provide a `icon-cross-origin` value if you want to access pixel data with the Canvas renderer. See https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image for more detail.
`icon-offset`	Array.<number> (defaults to [0, 0])	Offset, which, together with the size and the offset origin, define the sub-rectangle to use from the original icon image.
`icon-displacement`	NumberArrayExpression (defaults to [0,0])	Displacement of the icon.
`icon-offset-origin`	IconOrigin (defaults to 'top-left')	Origin of the offset: `bottom-left`, `bottom-right`, `top-left` or `top-right`.
`icon-opacity`	NumberExpression (defaults to 1)	Opacity of the icon.
`icon-scale`	SizeExpression (defaults to 1)	Scale.
`icon-width`	number \| undefined	Width of the icon. If not specified, the actual image width will be used. Cannot be combined with `scale`.
`icon-height`	number \| undefined	Height of the icon. If not specified, the actual image height will be used. Cannot be combined with `scale`.
`icon-rotation`	NumberExpression (defaults to 0)	Rotation in radians (positive rotation clockwise).
`icon-rotate-with-view`	BooleanExpression (defaults to false)	Whether to rotate the icon with the view.
`icon-size`	Size \| undefined	Icon size in pixel. Can be used together with `icon-offset` to define the sub-rectangle to use from the origin (sprite) icon image.
`icon-declutter-mode`	DeclutterMode \| undefined	Declutter mode
`z-index`	NumberExpression \| undefined	The zIndex of the style.

FlatShape{Object}

Regular shape style properties for rendering point features. At least shape-points must be provided.

Properties:

Name	Type	Description
`shape-points`	number \| undefined	Number of points for stars and regular polygons. In case of a polygon, the number of points is the number of sides.
`shape-fill-color`	ColorExpression \| undefined	The fill color.
`shape-stroke-color`	ColorExpression \| undefined	The stroke color.
`shape-stroke-width`	NumberExpression \| undefined	Stroke pixel width.
`shape-stroke-line-cap`	StringExpression (defaults to 'round')	Line cap style: `butt`, `round`, or `square`.
`shape-stroke-line-join`	StringExpression (defaults to 'round')	Line join style: `bevel`, `round`, or `miter`.
`shape-stroke-line-dash`	NumberArrayExpression \| undefined	Line dash pattern.
`shape-stroke-line-dash-offset`	NumberExpression (defaults to 0)	Line dash offset.
`shape-stroke-miter-limit`	NumberExpression (defaults to 10)	Miter limit.
`shape-radius`	number \| undefined	Radius of a regular polygon.
`shape-radius2`	number \| undefined	Second radius to make a star instead of a regular polygon.
`shape-angle`	number (defaults to 0)	Shape's angle in radians. A value of 0 will have one of the shape's point facing up.
`shape-displacement`	NumberArrayExpression (defaults to [0,0])	Displacement of the shape
`shape-rotation`	NumberExpression (defaults to 0)	Rotation in radians (positive rotation clockwise).
`shape-rotate-with-view`	BooleanExpression (defaults to false)	Whether to rotate the shape with the view.
`shape-scale`	SizeExpression (defaults to 1)	Scale. Unless two dimensional scaling is required a better result may be obtained with appropriate settings for `shape-radius` and `shape-radius2`.
`shape-declutter-mode`	DeclutterMode \| undefined	Declutter mode.
`z-index`	NumberExpression \| undefined	The zIndex of the style.

FlatStroke{Object}

Stroke style properties applied to line strings and polygon boundaries. To apply a stroke, at least one of stroke-color or stroke-width must be provided.

Properties:

Name	Type	Description
`stroke-color`	ColorExpression \| undefined	The stroke color.
`stroke-width`	NumberExpression \| undefined	Stroke pixel width.
`stroke-line-cap`	StringExpression (defaults to 'round')	Line cap style: `butt`, `round`, or `square`.
`stroke-line-join`	StringExpression (defaults to 'round')	Line join style: `bevel`, `round`, or `miter`.
`stroke-line-dash`	NumberArrayExpression \| undefined	Line dash pattern.
`stroke-line-dash-offset`	NumberExpression (defaults to 0)	Line dash offset.
`stroke-miter-limit`	NumberExpression (defaults to 10)	Miter limit.
`z-index`	NumberExpression \| undefined	The zIndex of the style.

FlatStyle{FlatFill} {FlatStroke} {FlatText} {FlatIcon} {FlatShape} {FlatCircle}

For static styling, the layer.setStyle() method can be called with an object literal that has fill, stroke, text, icon, regular shape, and/or circle properties.

FlatStyleLike{FlatStyle} {Array<FlatStyle>} {Array<Rule>}

A flat style literal or an array of the same.

FlatText{Object}

Label style properties applied to all features. At a minimum, a text-value must be provided.

Properties:

Name	Type	Description
`text-value`	StringExpression \| undefined	Text content (with `\n` for line breaks).
`text-font`	StringExpression (defaults to '10px sans-serif')	Font style as CSS `font` value.
`text-max-angle`	NumberExpression (defaults to Math.PI/4)	When `text-placement` is set to `'line'`, allow a maximum angle between adjacent characters. The expected value is in radians, and the default is 45° (`Math.PI / 4`).
`text-offset-x`	NumberExpression (defaults to 0)	Horizontal text offset in pixels. A positive will shift the text right.
`text-offset-y`	NumberExpression (defaults to 0)	Vertical text offset in pixels. A positive will shift the text down.
`text-overflow`	BooleanExpression (defaults to false)	For polygon labels or when `placement` is set to `'line'`, allow text to exceed the width of the polygon at the label position or the length of the path that it follows.
`text-placement`	StringExpression (defaults to 'point')	Text placement.
`text-repeat`	NumberExpression \| undefined	Repeat interval in pixels. When set, the text will be repeated at this interval. Only available when `text-placement` is set to `'line'`. Overrides `text-align`.
`text-scale`	SizeExpression \| undefined	Scale.
`text-rotate-with-view`	BooleanExpression (defaults to false)	Whether to rotate the text with the view.
`text-rotation`	NumberExpression (defaults to 0)	Rotation in radians (positive rotation clockwise).
`text-align`	StringExpression \| undefined	Text alignment. Possible values: `'left'`, `'right'`, `'center'`, `'end'` or `'start'`. Default is `'center'` for `'text-placement': 'point'`. For `'text-placement': 'line'`, the default is to let the renderer choose a placement where `text-max-angle` is not exceeded.
`text-justify`	StringExpression \| undefined	Text justification within the text box. If not set, text is justified towards the `textAlign` anchor. Otherwise, use options `'left'`, `'center'`, or `'right'` to justify the text within the text box. Note: `text-justify` is ignored for immediate rendering and also for `'text-placement': 'line'`.
`text-baseline`	StringExpression (defaults to 'middle')	Text base line. Possible values: `'bottom'`, `'top'`, `'middle'`, `'alphabetic'`, `'hanging'`, `'ideographic'`.
`text-padding`	NumberArrayExpression (defaults to [0, 0, 0, 0])	Padding in pixels around the text for decluttering and background. The order of values in the array is `[top, right, bottom, left]`.
`text-fill-color`	ColorExpression \| undefined	The fill color. Specify `'none'` to avoid hit detection on the fill.
`text-background-fill-color`	ColorExpression \| undefined	The fill color.
`text-stroke-color`	ColorExpression \| undefined	The stroke color.
`text-stroke-line-cap`	StringExpression (defaults to 'round')	Line cap style: `butt`, `round`, or `square`.
`text-stroke-line-join`	StringExpression (defaults to 'round')	Line join style: `bevel`, `round`, or `miter`.
`text-stroke-line-dash`	NumberArrayExpression \| undefined	Line dash pattern.
`text-stroke-line-dash-offset`	NumberExpression (defaults to 0)	Line dash offset.
`text-stroke-miter-limit`	NumberExpression (defaults to 10)	Miter limit.
`text-stroke-width`	NumberExpression \| undefined	Stroke pixel width.
`text-background-stroke-color`	ColorExpression \| undefined	The stroke color.
`text-background-stroke-line-cap`	StringExpression (defaults to 'round')	Line cap style: `butt`, `round`, or `square`.
`text-background-stroke-line-join`	StringExpression (defaults to 'round')	Line join style: `bevel`, `round`, or `miter`.
`text-background-stroke-line-dash`	NumberArrayExpression \| undefined	Line dash pattern.
`text-background-stroke-line-dash-offset`	NumberExpression (defaults to 0)	Line dash offset.
`text-background-stroke-miter-limit`	NumberExpression (defaults to 10)	Miter limit.
`text-background-stroke-width`	NumberExpression \| undefined	Stroke pixel width.
`text-declutter-mode`	DeclutterMode \| undefined	Declutter mode
`z-index`	NumberExpression \| undefined	The zIndex of the style.

NumberArrayExpression{Array.<number>} {Array}

An array of numbers (e.g. [1, 2, 3]) or an expression that evaluates to the same (e.g. ['get', 'values']).

NumberExpression{number} {Array}

A literal number (e.g. 42) or an expression that evaluates to a number (e.g. ['+', 40, 2]).

Rule{Object}

A rule is used to conditionally apply a style. If the rule's filter evaluates to true, the style will be applied.

Properties:

Name	Type	Description
`style`	FlatStyle \| Array<FlatStyle>	The style to be applied if the filter matches.
`filter`	EncodedExpression \| undefined	The filter used to determine if a style applies. If no filter is included, the rule always applies (unless it is an else rule).
`else`	boolean \| undefined	If true, the rule applies only if no other previous rule applies. If the else rule also has a filter, the rule will not apply if the filter does not match.

SizeExpression{number} {Array.<number>} {Array}

An array of two numbers (e.g. [10, 20]) or an expression that evaluates to the same (e.g. ['get', 'size']).

StringExpression{string} {Array}

A literal string (e.g. 'hello') or an expression that evaluates to a string (e.g. ['get', 'greeting']).