[core] Enable property functions for line-width (#9250)

6 files changed, 158 insertions, 15 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/PropertyFactory.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/PropertyFactory.java
index e4ea9676fa..73896b7901 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/PropertyFactory.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/PropertyFactory.java
@@ -322,11 +322,11 @@ public class PropertyFactory {
   /**
    * Stroke thickness.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for Float
+   * @param <T> the function input type
+   * @param function a wrapper function for Float
    * @return property wrapper around a Float function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, Float>> lineWidth(CameraFunction<Z, Float> function) {
+  public static <T> PropertyValue<Function<T, Float>> lineWidth(Function<T, Float> function) {
     return new PaintPropertyValue<>("line-width", function);
   }
 
@@ -1676,7 +1676,7 @@ public class PropertyFactory {
   }
 
   /**
-   * Scale factor for icon. 1 is original size, 3 triples the size.
+   * Scales the original size of the icon by the provided factor. The new pixel size of the image will be the original pixel size multiplied by {@link PropertyFactory#iconSize}. 1 is the original size; 3 triples the size of the image.
    *
    * @param value a Float value
    * @return property wrapper around Float
@@ -1688,7 +1688,7 @@ public class PropertyFactory {
 
 
   /**
-   * Scale factor for icon. 1 is original size, 3 triples the size.
+   * Scales the original size of the icon by the provided factor. The new pixel size of the image will be the original pixel size multiplied by {@link PropertyFactory#iconSize}. 1 is the original size; 3 triples the size of the image.
    *
    * @param <T> the function input type
    * @param function a wrapper function for Float
diff --git a/platform/android/MapboxGLAndroidSDKTestApp/src/androidTest/java/com/mapbox/mapboxsdk/testapp/style/LineLayerTest.java b/platform/android/MapboxGLAndroidSDKTestApp/src/androidTest/java/com/mapbox/mapboxsdk/testapp/style/LineLayerTest.java
index 1c23dd366b..c10c908c8d 100644
--- a/platform/android/MapboxGLAndroidSDKTestApp/src/androidTest/java/com/mapbox/mapboxsdk/testapp/style/LineLayerTest.java
+++ b/platform/android/MapboxGLAndroidSDKTestApp/src/androidTest/java/com/mapbox/mapboxsdk/testapp/style/LineLayerTest.java
@@ -697,6 +697,118 @@ public class LineLayerTest extends BaseActivityTest {
   }
 
   @Test
+  public void testLineWidthAsIdentitySourceFunction() {
+    validateTestSetup();
+    setupLayer();
+    Timber.i("line-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      lineWidth(property("FeaturePropertyA", Stops.<Float>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getLineWidth());
+    assertNotNull(layer.getLineWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getLineWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getLineWidth().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getLineWidth().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testLineWidthAsExponentialSourceFunction() {
+    validateTestSetup();
+    setupLayer();
+    Timber.i("line-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      lineWidth(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(0.3f, lineWidth(0.3f))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getLineWidth());
+    assertNotNull(layer.getLineWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getLineWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getLineWidth().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getLineWidth().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testLineWidthAsCategoricalSourceFunction() {
+    validateTestSetup();
+    setupLayer();
+    Timber.i("line-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      lineWidth(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop(1.0f, lineWidth(0.3f))
+          )
+        ).withDefaultValue(lineWidth(0.3f))
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getLineWidth());
+    assertNotNull(layer.getLineWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getLineWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getLineWidth().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getLineWidth().getFunction().getStops().getClass());
+    assertNotNull(((SourceFunction) layer.getLineWidth().getFunction()).getDefaultValue());
+    assertNotNull(((SourceFunction) layer.getLineWidth().getFunction()).getDefaultValue().getValue());
+    assertEquals(0.3f, ((SourceFunction) layer.getLineWidth().getFunction()).getDefaultValue().getValue());
+  }
+
+  @Test
+  public void testLineWidthAsCompositeFunction() {
+    validateTestSetup();
+    setupLayer();
+    Timber.i("line-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      lineWidth(
+        composite(
+          "FeaturePropertyA",
+          exponential(
+            stop(0, 0.3f, lineWidth(0.9f))
+          ).withBase(0.5f)
+        ).withDefaultValue(lineWidth(0.3f))
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getLineWidth());
+    assertNotNull(layer.getLineWidth().getFunction());
+    assertEquals(CompositeFunction.class, layer.getLineWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((CompositeFunction) layer.getLineWidth().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getLineWidth().getFunction().getStops().getClass());
+    assertEquals(1, ((ExponentialStops) layer.getLineWidth().getFunction().getStops()).size());
+
+    ExponentialStops<Stop.CompositeValue<Float, Float>, Float> stops =
+      (ExponentialStops<Stop.CompositeValue<Float, Float>, Float>) layer.getLineWidth().getFunction().getStops();
+    Stop<Stop.CompositeValue<Float, Float>, Float> stop = stops.iterator().next();
+    assertEquals(0f, stop.in.zoom, 0.001);
+    assertEquals(0.3f, stop.in.value, 0.001f);
+    assertEquals(0.9f, stop.out, 0.001f);
+  }
+
+  @Test
   public void testLineGapWidthTransition() {
     validateTestSetup();
     setupLayer();
diff --git a/platform/darwin/src/MGLLineStyleLayer.h b/platform/darwin/src/MGLLineStyleLayer.h
index 38513652c5..4a96b11abf 100644
--- a/platform/darwin/src/MGLLineStyleLayer.h
+++ b/platform/darwin/src/MGLLineStyleLayer.h
@@ -543,6 +543,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSNumber *> *lineWidth;
 
diff --git a/platform/darwin/src/MGLLineStyleLayer.mm b/platform/darwin/src/MGLLineStyleLayer.mm
index 8b90efd0c4..9be1667722 100644
--- a/platform/darwin/src/MGLLineStyleLayer.mm
+++ b/platform/darwin/src/MGLLineStyleLayer.mm
@@ -480,7 +480,7 @@ namespace mbgl {
 - (void)setLineWidth:(MGLStyleValue<NSNumber *> *)lineWidth {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toInterpolatablePropertyValue(lineWidth);
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenPropertyValue(lineWidth);
     self.rawLayer->setLineWidth(mbglValue);
 }
 
@@ -489,9 +489,9 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getLineWidth();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(self.rawLayer->getDefaultLineWidth());
+        return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(self.rawLayer->getDefaultLineWidth());
     }
-    return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setLineWidthTransition:(MGLTransition )transition {
diff --git a/platform/darwin/src/MGLSymbolStyleLayer.h b/platform/darwin/src/MGLSymbolStyleLayer.h
index b6c6372324..5df995aa01 100644
--- a/platform/darwin/src/MGLSymbolStyleLayer.h
+++ b/platform/darwin/src/MGLSymbolStyleLayer.h
@@ -533,7 +533,11 @@ MGL_EXPORT
 @property (nonatomic, null_resettable) MGLStyleValue<NSValue *> *iconRotationAlignment;
 
 /**
- Scale factor for icon. 1 is original size, 3 triples the size.
+ Scales the original size of the icon by the provided factor. The new point size
+ of the image will be the original point size multiplied by `iconSize`. 1 is the
+ original size; 3 triples the size of the image.
+ 
+ This property is measured in factor of the original icon sizes.
  
  The default value of this property is an `MGLStyleValue` object containing an
  `NSNumber` object containing the float `1`. Set this property to `nil` to reset
diff --git a/platform/darwin/test/MGLLineStyleLayerTests.mm b/platform/darwin/test/MGLLineStyleLayerTests.mm
index 1e92959520..be7d9a6754 100644
--- a/platform/darwin/test/MGLLineStyleLayerTests.mm
+++ b/platform/darwin/test/MGLLineStyleLayerTests.mm
@@ -713,7 +713,7 @@
 
         MGLStyleValue<NSNumber *> *constantStyleValue = [MGLStyleValue<NSNumber *> valueWithRawValue:@0xff];
         layer.lineWidth = constantStyleValue;
-        mbgl::style::PropertyValue<float> propertyValue = { 0xff };
+        mbgl::style::DataDrivenPropertyValue<float> propertyValue = { 0xff };
         XCTAssertEqual(rawLayer->getLineWidth(), propertyValue,
                        @"Setting lineWidth to a constant value should update line-width.");
         XCTAssertEqualObjects(layer.lineWidth, constantStyleValue,
@@ -730,6 +730,29 @@
         XCTAssertEqualObjects(layer.lineWidth, functionStyleValue,
                               @"lineWidth should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.lineWidth = functionStyleValue;
+
+        mbgl::style::ExponentialStops<float> exponentialStops = { {{18, 0xff}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<float> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getLineWidth(), propertyValue,
+                       @"Setting lineWidth to a source function should update line-width.");
+        XCTAssertEqualObjects(layer.lineWidth, functionStyleValue,
+                              @"lineWidth should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.lineWidth = functionStyleValue;
+
+        std::map<float, float> innerStops { {18, 0xff} };
+        mbgl::style::CompositeExponentialStops<float> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<float> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getLineWidth(), propertyValue,
+                       @"Setting lineWidth to a composite function should update line-width.");
+        XCTAssertEqualObjects(layer.lineWidth, functionStyleValue,
+                              @"lineWidth should round-trip composite functions.");                                                                                                          
                               
 
         layer.lineWidth = nil;
@@ -737,11 +760,6 @@
                       @"Unsetting lineWidth should return line-width to the default value.");
         XCTAssertEqualObjects(layer.lineWidth, defaultStyleValue,
                               @"lineWidth should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.lineWidth = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.lineWidth = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
         // Transition property test
         layer.lineWidthTransition = transitionTest;
         auto toptions = rawLayer->getLineWidthTransition();