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Diffstat (limited to 'platform/darwin/docs/guides/For Style Authors.md.ejs')
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1 files changed, 37 insertions, 25 deletions
diff --git a/platform/darwin/docs/guides/For Style Authors.md.ejs b/platform/darwin/docs/guides/For Style Authors.md.ejs index 92ce4c1594..93ca7014a3 100644 --- a/platform/darwin/docs/guides/For Style Authors.md.ejs +++ b/platform/darwin/docs/guides/For Style Authors.md.ejs @@ -240,30 +240,6 @@ whose names differ from the style specification are listed below: <% for (const type in renamedProperties) { -%> <% if (renamedProperties.hasOwnProperty(type)) { -%> -### <%- camelize(type) %> style functions - -The runtime styling API introduces `MGLStyleFunction` to the <%- os %> SDK. -[Data-driven styling](data-driven-styling.html) expands `MGLStyleFunction`. -Individual style property documentation includes which subclasses of -`MGLStyleFunction` are enabled for that property. You can use `MGLStyleValue` -methods to create a `MGLStyleFunction`. - -In style specification | In the SDK | [MGLStyleValue valueWithInterpolationMode:...] ------------------------|-------------------------------|------------- -`zoom function` | `MGLCameraStyleFunction` | `cameraStops:options:` -`property function` | `MGLSourceStyleFunction` | `sourceStops:attributeName:options:` -`zoom-and-property functions`| `MGLCompositeStyleFunction` | `compositeStops:attributeName:options:` - -Data-driven styling also introduces interpolation mode, which defines the -relationship between style values and attributes or zoom levels. - -In style specification | In the SDK ------------------------------|----------- -`exponential` | `MGLInterpolationModeExponential` -`interval` | `MGLInterpolationModeInterval` -`categorical` | `MGLInterpolationModeCategorical` -`identity` | `MGLInterpolationModeIdentity` - ### <%- camelize(type) %> style layers In style JSON | In Objective-C | In Swift @@ -280,10 +256,12 @@ In style JSON | In Objective-C | In Swift Each property representing a layout or paint attribute is set to an `MGLStyleValue` object, which is either an `MGLConstantStyleValue` object (for -constant values) or an `MGLStyleFunction` object (for zoom level functions). The +constant values) or an `MGLStyleFunction` object (for style functions). The style value object is a container for the raw value or function parameters that you want the attribute to be set to. +### Constant style values + In contrast to the JSON type that the style specification defines for each layout or paint property, the style value object often contains a more specific Foundation or Cocoa type. General rules for attribute types are listed below. @@ -326,6 +304,40 @@ translation downward. This is the reverse of how `CGVector` is interpreted on iOS. <% } -%> +### Style functions + +A _style function_ allows you to vary the value of a layout or paint attribute +based on the zoom level, data provided by content sources, or both. For more +information about style functions that incorporate data from sources, see +“[Data-Driven Styling](data-driven-styling.html)”. + +Each kind of style function is represented by a distinct class, but you +typically create style functions as you create any other style value, using +class methods on `MGLStyleValue`: + +In style specification | SDK class | SDK factory method +---------------------------|-----------------------------|------------------- +zoom function | `MGLCameraStyleFunction` | `+[MGLStyleValue valueWithInterpolationMode:cameraStops:options:]` +property function | `MGLSourceStyleFunction` | `+[MGLStyleValue valueWithInterpolationMode:sourceStops:attributeName:options:]` +zoom-and-property function | `MGLCompositeStyleFunction` | `+[MGLStyleValue valueWithInterpolationMode:compositeStops:attributeName:options:]` + +The documentation for each individual style layer property indicates the kinds +of style functions that are enabled for that property. + +When you create a style function, you specify an _interpolation mode_ and a +series of _stops_. Each stop determines the effective value displayed at a +particular zoom level (for camera functions) or the effective value on features +with a particular attribute value in the content source (for source functions). +The interpolation mode tells the SDK how to calculate the effective value +between any two stops: + +In style specification | In the SDK +-----------------------------|----------- +`exponential` | `MGLInterpolationModeExponential` +`interval` | `MGLInterpolationModeInterval` +`categorical` | `MGLInterpolationModeCategorical` +`identity` | `MGLInterpolationModeIdentity` + ## Filtering sources You can filter a shape or vector source by setting the |