[android, ios, macos] Generate symbol-placement: line-center wrappers

7 files changed, 68 insertions, 32 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Property.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Property.java
index c264d773c5..ba3619567d 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Property.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Property.java
@@ -92,6 +92,10 @@ public final class Property {
    * The label is placed along the line of the geometry. Can only be used on LineString and Polygon geometries.
    */
   public static final String SYMBOL_PLACEMENT_LINE = "line";
+  /**
+   * The label is placed at the center of the line of the geometry. Can only be used on LineString and Polygon geometries. Note that a single feature in a vector tile may contain multiple line geometries.
+   */
+  public static final String SYMBOL_PLACEMENT_LINE_CENTER = "line-center";
 
   /**
    * Label placement relative to its geometry.
@@ -99,6 +103,7 @@ public final class Property {
   @StringDef({
       SYMBOL_PLACEMENT_POINT,
       SYMBOL_PLACEMENT_LINE,
+      SYMBOL_PLACEMENT_LINE_CENTER,
     })
   @Retention(RetentionPolicy.SOURCE)
   public @interface SYMBOL_PLACEMENT {}
@@ -106,7 +111,7 @@ public final class Property {
   // ICON_ROTATION_ALIGNMENT: In combination with `symbol-placement`, determines the rotation behavior of icons.
 
   /**
-   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, aligns icons east-west. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE}, aligns icon x-axes with the line.
+   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, aligns icons east-west. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE} or {@link Property#SYMBOL_PLACEMENT_LINE_CENTER}, aligns icon x-axes with the line.
    */
   public static final String ICON_ROTATION_ALIGNMENT_MAP = "map";
   /**
@@ -114,7 +119,7 @@ public final class Property {
    */
   public static final String ICON_ROTATION_ALIGNMENT_VIEWPORT = "viewport";
   /**
-   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, this is equivalent to {@link Property#ICON_ROTATION_ALIGNMENT_VIEWPORT}. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE}, this is equivalent to {@link Property#ICON_ROTATION_ALIGNMENT_MAP}.
+   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, this is equivalent to {@link Property#ICON_ROTATION_ALIGNMENT_VIEWPORT}. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE} or {@link Property#SYMBOL_PLACEMENT_LINE_CENTER}, this is equivalent to {@link Property#ICON_ROTATION_ALIGNMENT_MAP}.
    */
   public static final String ICON_ROTATION_ALIGNMENT_AUTO = "auto";
 
@@ -271,7 +276,7 @@ public final class Property {
   // TEXT_ROTATION_ALIGNMENT: In combination with `symbol-placement`, determines the rotation behavior of the individual glyphs forming the text.
 
   /**
-   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, aligns text east-west. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE}, aligns text x-axes with the line.
+   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, aligns text east-west. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE} or {@link Property#SYMBOL_PLACEMENT_LINE_CENTER}, aligns text x-axes with the line.
    */
   public static final String TEXT_ROTATION_ALIGNMENT_MAP = "map";
   /**
@@ -279,7 +284,7 @@ public final class Property {
    */
   public static final String TEXT_ROTATION_ALIGNMENT_VIEWPORT = "viewport";
   /**
-   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, this is equivalent to {@link Property#TEXT_ROTATION_ALIGNMENT_VIEWPORT}. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE}, this is equivalent to {@link Property#TEXT_ROTATION_ALIGNMENT_MAP}.
+   * When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_POINT}, this is equivalent to {@link Property#TEXT_ROTATION_ALIGNMENT_VIEWPORT}. When {@link SYMBOL_PLACEMENT} is set to {@link Property#SYMBOL_PLACEMENT_LINE} or {@link Property#SYMBOL_PLACEMENT_LINE_CENTER}, this is equivalent to {@link Property#TEXT_ROTATION_ALIGNMENT_MAP}.
    */
   public static final String TEXT_ROTATION_ALIGNMENT_AUTO = "auto";
 
diff --git a/platform/android/scripts/generate-style-code.js b/platform/android/scripts/generate-style-code.js
index 05ca957974..b435351df5 100755
--- a/platform/android/scripts/generate-style-code.js
+++ b/platform/android/scripts/generate-style-code.js
@@ -235,10 +235,15 @@ global.propertyValueDoc = function (property, value) {
 
     // Match references to other property names & values.
     // Requires the format 'When `foo` is set to `bar`,'.
-    let doc = property.values[value].doc.replace(/When `(.+?)` is set to `(.+?)`,/g, function (m, peerPropertyName, propertyValue, offset, str) {
+    let doc = property.values[value].doc.replace(/When `(.+?)` is set to `(.+?)`(?: or `([^`]+?)`)?,/g, function (m, peerPropertyName, propertyValue, secondPropertyValue, offset, str) {
         let otherProperty = snakeCaseUpper(peerPropertyName);
         let otherValue = snakeCaseUpper(peerPropertyName) + '_' + snakeCaseUpper(propertyValue);
-        return 'When {@link ' + `${otherProperty}` + '} is set to {@link Property#' + `${otherValue}` + '},';
+        const firstPropertyValue = 'When {@link ' + `${otherProperty}` + '} is set to {@link Property#' + `${otherValue}` + '}';
+        if (secondPropertyValue) {
+            return firstPropertyValue + ` or {@link Property#${snakeCaseUpper(peerPropertyName) + '_' + snakeCaseUpper(secondPropertyValue)}},`;
+        } else {
+            return firstPropertyValue + ',';
+        }
     });
 
     // Match references to our own property values.
diff --git a/platform/android/src/style/conversion/types_string_values.hpp b/platform/android/src/style/conversion/types_string_values.hpp
index ff79fa4f1c..9f6696d181 100644
--- a/platform/android/src/style/conversion/types_string_values.hpp
+++ b/platform/android/src/style/conversion/types_string_values.hpp
@@ -67,6 +67,9 @@ namespace conversion {
           case mbgl::style::SymbolPlacementType::Line:
             return "line";
             break;
+          case mbgl::style::SymbolPlacementType::LineCenter:
+            return "line-center";
+            break;
           default:
             throw std::runtime_error("Not implemented");
         }
diff --git a/platform/darwin/scripts/generate-style-code.js b/platform/darwin/scripts/generate-style-code.js
index 3809e9c636..0e5bf89fd4 100755
--- a/platform/darwin/scripts/generate-style-code.js
+++ b/platform/darwin/scripts/generate-style-code.js
@@ -248,13 +248,20 @@ global.testHelperMessage = function (property, layerType, isFunction) {
 global.propertyDoc = function (propertyName, property, layerType, kind) {
     // Match references to other property names & values.
     // Requires the format 'When `foo` is set to `bar`,'.
-    let doc = property.doc.replace(/`([^`]+?)` is set to `([^`]+?)`/g, function (m, peerPropertyName, propertyValue, offset, str) {
+    let doc = property.doc.replace(/`([^`]+?)` is set to `([^`]+?)`(?: or `([^`]+?)`)?/g, function (m, peerPropertyName, propertyValue, secondPropertyValue, offset, str) {
         let otherProperty = camelizeWithLeadingLowercase(peerPropertyName);
         let otherValue = objCType(layerType, peerPropertyName) + camelize(propertyValue);
         if (property.type == 'array' && kind == 'light') {
             otherValue = propertyValue;
         }
-        return '`' + `${otherProperty}` + '` is set to `' + `${otherValue}` + '`';
+        const firstPropertyValue = '`' + `${otherProperty}` + '` is set to `' + `${otherValue}` + '`';
+        if (secondPropertyValue) {
+            return firstPropertyValue + ' or `' +
+                objCType(layerType, peerPropertyName) + camelize(secondPropertyValue) +
+                '`';
+        } else {
+            return firstPropertyValue;
+        }
     });
     // Match references to our own property values.
     // Requires the format 'is equivalent to `bar`'.
diff --git a/platform/darwin/src/MGLSymbolStyleLayer.h b/platform/darwin/src/MGLSymbolStyleLayer.h
index 2c899fe76f..afaea9a74f 100644
--- a/platform/darwin/src/MGLSymbolStyleLayer.h
+++ b/platform/darwin/src/MGLSymbolStyleLayer.h
@@ -83,8 +83,8 @@ typedef NS_ENUM(NSUInteger, MGLIconPitchAlignment) {
 typedef NS_ENUM(NSUInteger, MGLIconRotationAlignment) {
     /**
      When `symbolPlacement` is set to `MGLSymbolPlacementPoint`, aligns icons
-     east-west. When `symbolPlacement` is set to `MGLSymbolPlacementLine`,
-     aligns icon x-axes with the line.
+     east-west. When `symbolPlacement` is set to `MGLSymbolPlacementLine` or
+     `MGLSymbolPlacementLineCenter`, aligns icon x-axes with the line.
      */
     MGLIconRotationAlignmentMap,
     /**
@@ -95,8 +95,8 @@ typedef NS_ENUM(NSUInteger, MGLIconRotationAlignment) {
     /**
      When `symbolPlacement` is set to `MGLSymbolPlacementPoint`, this is
      equivalent to `MGLIconRotationAlignmentViewport`. When `symbolPlacement` is
-     set to `MGLSymbolPlacementLine`, this is equivalent to
-     `MGLIconRotationAlignmentMap`.
+     set to `MGLSymbolPlacementLine` or `MGLSymbolPlacementLineCenter`, this is
+     equivalent to `MGLIconRotationAlignmentMap`.
      */
     MGLIconRotationAlignmentAuto,
 };
@@ -142,6 +142,12 @@ typedef NS_ENUM(NSUInteger, MGLSymbolPlacement) {
      `LineString` and `Polygon` geometries.
      */
     MGLSymbolPlacementLine,
+    /**
+     The label is placed at the center of the line of the geometry. Can only be
+     used on `LineString` and `Polygon` geometries. Note that a single feature
+     in a vector tile may contain multiple line geometries.
+     */
+    MGLSymbolPlacementLineCenter,
 };
 
 /**
@@ -242,8 +248,8 @@ typedef NS_ENUM(NSUInteger, MGLTextPitchAlignment) {
 typedef NS_ENUM(NSUInteger, MGLTextRotationAlignment) {
     /**
      When `symbolPlacement` is set to `MGLSymbolPlacementPoint`, aligns text
-     east-west. When `symbolPlacement` is set to `MGLSymbolPlacementLine`,
-     aligns text x-axes with the line.
+     east-west. When `symbolPlacement` is set to `MGLSymbolPlacementLine` or
+     `MGLSymbolPlacementLineCenter`, aligns text x-axes with the line.
      */
     MGLTextRotationAlignmentMap,
     /**
@@ -254,8 +260,8 @@ typedef NS_ENUM(NSUInteger, MGLTextRotationAlignment) {
     /**
      When `symbolPlacement` is set to `MGLSymbolPlacementPoint`, this is
      equivalent to `MGLTextRotationAlignmentViewport`. When `symbolPlacement` is
-     set to `MGLSymbolPlacementLine`, this is equivalent to
-     `MGLTextRotationAlignmentMap`.
+     set to `MGLSymbolPlacementLine` or `MGLSymbolPlacementLineCenter`, this is
+     equivalent to `MGLTextRotationAlignmentMap`.
      */
     MGLTextRotationAlignmentAuto,
 };
@@ -653,12 +659,13 @@ MGL_EXPORT
  * Constant `MGLIconRotationAlignment` values
  * Any of the following constant string values:
    * `map`: When `symbol-placement` is set to `point`, aligns icons east-west.
- When `symbol-placement` is set to `line`, aligns icon x-axes with the line.
+ When `symbol-placement` is set to `line` or `line-center`, aligns icon x-axes
+ with the line.
    * `viewport`: Produces icons whose x-axes are aligned with the x-axis of the
  viewport, regardless of the value of `symbol-placement`.
    * `auto`: When `symbol-placement` is set to `point`, this is equivalent to
- `viewport`. When `symbol-placement` is set to `line`, this is equivalent to
- `map`.
+ `viewport`. When `symbol-placement` is set to `line` or `line-center`, this is
+ equivalent to `map`.
  * Predefined functions, including mathematical and string operators
  * Conditional expressions
  * Variable assignments and references to assigned variables
@@ -795,8 +802,9 @@ MGL_EXPORT
  
  This property is only applied to the style if `iconImageName` is non-`nil`, and
  `iconRotationAlignment` is set to an expression that evaluates to `map`, and
- `symbolPlacement` is set to an expression that evaluates to `line`. Otherwise,
- it is ignored.
+ `symbolPlacement` is set to an expression that evaluates to either
+ `MGLSymbolPlacementLine` or `MGLSymbolPlacementLineCenter`. Otherwise, it is
+ ignored.
  
  This attribute corresponds to the <a
  href="https://www.mapbox.com/mapbox-gl-style-spec/#layout-symbol-icon-keep-upright"><code>icon-keep-upright</code></a>
@@ -828,8 +836,9 @@ MGL_EXPORT
  
  This property is only applied to the style if `text` is non-`nil`, and
  `textRotationAlignment` is set to an expression that evaluates to `map`, and
- `symbolPlacement` is set to an expression that evaluates to `line`. Otherwise,
- it is ignored.
+ `symbolPlacement` is set to an expression that evaluates to either
+ `MGLSymbolPlacementLine` or `MGLSymbolPlacementLineCenter`. Otherwise, it is
+ ignored.
  
  This attribute corresponds to the <a
  href="https://www.mapbox.com/mapbox-gl-style-spec/#layout-symbol-text-keep-upright"><code>text-keep-upright</code></a>
@@ -861,8 +870,9 @@ MGL_EXPORT
  `45`. Set this property to `nil` to reset it to the default value.
  
  This property is only applied to the style if `text` is non-`nil`, and
- `symbolPlacement` is set to an expression that evaluates to `line`. Otherwise,
- it is ignored.
+ `symbolPlacement` is set to an expression that evaluates to either
+ `MGLSymbolPlacementLine` or `MGLSymbolPlacementLineCenter`. Otherwise, it is
+ ignored.
  
  This attribute corresponds to the <a
  href="https://www.mapbox.com/mapbox-gl-style-spec/#layout-symbol-text-max-angle"><code>text-max-angle</code></a>
@@ -956,6 +966,9 @@ MGL_EXPORT
    * `point`: The label is placed at the point where the geometry is located.
    * `line`: The label is placed along the line of the geometry. Can only be
  used on `LineString` and `Polygon` geometries.
+   * `line-center`: The label is placed at the center of the line of the
+ geometry. Can only be used on `LineString` and `Polygon` geometries. Note that
+ a single feature in a vector tile may contain multiple line geometries.
  * Predefined functions, including mathematical and string operators
  * Conditional expressions
  * Variable assignments and references to assigned variables
@@ -1427,12 +1440,13 @@ MGL_EXPORT
  * Constant `MGLTextRotationAlignment` values
  * Any of the following constant string values:
    * `map`: When `symbol-placement` is set to `point`, aligns text east-west.
- When `symbol-placement` is set to `line`, aligns text x-axes with the line.
+ When `symbol-placement` is set to `line` or `line-center`, aligns text x-axes
+ with the line.
    * `viewport`: Produces glyphs whose x-axes are aligned with the x-axis of the
  viewport, regardless of the value of `symbol-placement`.
    * `auto`: When `symbol-placement` is set to `point`, this is equivalent to
- `viewport`. When `symbol-placement` is set to `line`, this is equivalent to
- `map`.
+ `viewport`. When `symbol-placement` is set to `line` or `line-center`, this is
+ equivalent to `map`.
  * Predefined functions, including mathematical and string operators
  * Conditional expressions
  * Variable assignments and references to assigned variables
diff --git a/platform/darwin/src/MGLSymbolStyleLayer.mm b/platform/darwin/src/MGLSymbolStyleLayer.mm
index f5522b800d..791bb5f894 100644
--- a/platform/darwin/src/MGLSymbolStyleLayer.mm
+++ b/platform/darwin/src/MGLSymbolStyleLayer.mm
@@ -47,6 +47,7 @@ namespace mbgl {
     MBGL_DEFINE_ENUM(MGLSymbolPlacement, {
         { MGLSymbolPlacementPoint, "point" },
         { MGLSymbolPlacementLine, "line" },
+        { MGLSymbolPlacementLineCenter, "line-center" },
     });
 
     MBGL_DEFINE_ENUM(MGLTextAnchor, {
diff --git a/platform/darwin/test/MGLSymbolStyleLayerTests.mm b/platform/darwin/test/MGLSymbolStyleLayerTests.mm
index 8643e8388b..9d772b6bd9 100644
--- a/platform/darwin/test/MGLSymbolStyleLayerTests.mm
+++ b/platform/darwin/test/MGLSymbolStyleLayerTests.mm
@@ -962,22 +962,22 @@
                       @"symbol-placement should be unset initially.");
         NSExpression *defaultExpression = layer.symbolPlacement;
 
-        NSExpression *constantExpression = [NSExpression expressionWithFormat:@"'line'"];
+        NSExpression *constantExpression = [NSExpression expressionWithFormat:@"'line-center'"];
         layer.symbolPlacement = constantExpression;
-        mbgl::style::PropertyValue<mbgl::style::SymbolPlacementType> propertyValue = { mbgl::style::SymbolPlacementType::Line };
+        mbgl::style::PropertyValue<mbgl::style::SymbolPlacementType> propertyValue = { mbgl::style::SymbolPlacementType::LineCenter };
         XCTAssertEqual(rawLayer->getSymbolPlacement(), propertyValue,
                        @"Setting symbolPlacement to a constant value expression should update symbol-placement.");
         XCTAssertEqualObjects(layer.symbolPlacement, constantExpression,
                               @"symbolPlacement should round-trip constant value expressions.");
 
-        constantExpression = [NSExpression expressionWithFormat:@"'line'"];
+        constantExpression = [NSExpression expressionWithFormat:@"'line-center'"];
         NSExpression *functionExpression = [NSExpression expressionWithFormat:@"mgl_step:from:stops:($zoomLevel, %@, %@)", constantExpression, @{@18: constantExpression}];
         layer.symbolPlacement = functionExpression;
 
         {
             using namespace mbgl::style::expression::dsl;
             propertyValue = mbgl::style::PropertyExpression<mbgl::style::SymbolPlacementType>(
-                step(zoom(), literal("line"), 18.0, literal("line"))
+                step(zoom(), literal("line-center"), 18.0, literal("line-center"))
             );
         }
 
@@ -2883,6 +2883,7 @@
     XCTAssertEqual([NSValue valueWithMGLIconTextFit:MGLIconTextFitBoth].MGLIconTextFitValue, MGLIconTextFitBoth);
     XCTAssertEqual([NSValue valueWithMGLSymbolPlacement:MGLSymbolPlacementPoint].MGLSymbolPlacementValue, MGLSymbolPlacementPoint);
     XCTAssertEqual([NSValue valueWithMGLSymbolPlacement:MGLSymbolPlacementLine].MGLSymbolPlacementValue, MGLSymbolPlacementLine);
+    XCTAssertEqual([NSValue valueWithMGLSymbolPlacement:MGLSymbolPlacementLineCenter].MGLSymbolPlacementValue, MGLSymbolPlacementLineCenter);
     XCTAssertEqual([NSValue valueWithMGLTextAnchor:MGLTextAnchorCenter].MGLTextAnchorValue, MGLTextAnchorCenter);
     XCTAssertEqual([NSValue valueWithMGLTextAnchor:MGLTextAnchorLeft].MGLTextAnchorValue, MGLTextAnchorLeft);
     XCTAssertEqual([NSValue valueWithMGLTextAnchor:MGLTextAnchorRight].MGLTextAnchorValue, MGLTextAnchorRight);