Fix style expression not supersede its constant values (#969)

Author: maios

CHANGELOG.md

@@ -1,5 +1,6 @@
 ### main
 
+* Fixed an issue where style expressions did not override constant values when both were present.
 * [ios] Fix crash when force unwrapping UIImage for point annotations.
 
 ### 2.9.0-rc.1

lib/src/style/layer/background_layer.dart

@@ -87,37 +87,32 @@ class BackgroundLayer extends Layer {
     var paint = {};
     if (backgroundColorExpression != null) {
       paint["background-color"] = backgroundColorExpression;
-    }
-    if (backgroundColor != null) {
+    } else if (backgroundColor != null) {
       paint["background-color"] = backgroundColor?.toRGBA();
     }
 
     if (backgroundEmissiveStrengthExpression != null) {
       paint["background-emissive-strength"] =
           backgroundEmissiveStrengthExpression;
-    }
-    if (backgroundEmissiveStrength != null) {
+    } else if (backgroundEmissiveStrength != null) {
       paint["background-emissive-strength"] = backgroundEmissiveStrength;
     }
 
     if (backgroundOpacityExpression != null) {
       paint["background-opacity"] = backgroundOpacityExpression;
-    }
-    if (backgroundOpacity != null) {
+    } else if (backgroundOpacity != null) {
       paint["background-opacity"] = backgroundOpacity;
     }
 
     if (backgroundPatternExpression != null) {
       paint["background-pattern"] = backgroundPatternExpression;
-    }
-    if (backgroundPattern != null) {
+    } else if (backgroundPattern != null) {
       paint["background-pattern"] = backgroundPattern;
     }
 
     if (backgroundPitchAlignmentExpression != null) {
       paint["background-pitch-alignment"] = backgroundPitchAlignmentExpression;
-    }
-    if (backgroundPitchAlignment != null) {
+    } else if (backgroundPitchAlignment != null) {
       paint["background-pitch-alignment"] =
           backgroundPitchAlignment?.name.toLowerCase().replaceAll("_", "-");
     }

lib/src/style/layer/circle_layer.dart

@@ -200,87 +200,75 @@ class CircleLayer extends Layer {
     var paint = {};
     if (circleBlurExpression != null) {
       paint["circle-blur"] = circleBlurExpression;
-    }
-    if (circleBlur != null) {
+    } else if (circleBlur != null) {
       paint["circle-blur"] = circleBlur;
     }
 
     if (circleColorExpression != null) {
       paint["circle-color"] = circleColorExpression;
-    }
-    if (circleColor != null) {
+    } else if (circleColor != null) {
       paint["circle-color"] = circleColor?.toRGBA();
     }
 
     if (circleEmissiveStrengthExpression != null) {
       paint["circle-emissive-strength"] = circleEmissiveStrengthExpression;
-    }
-    if (circleEmissiveStrength != null) {
+    } else if (circleEmissiveStrength != null) {
       paint["circle-emissive-strength"] = circleEmissiveStrength;
     }
 
     if (circleOpacityExpression != null) {
       paint["circle-opacity"] = circleOpacityExpression;
-    }
-    if (circleOpacity != null) {
+    } else if (circleOpacity != null) {
       paint["circle-opacity"] = circleOpacity;
     }
 
     if (circlePitchAlignmentExpression != null) {
       paint["circle-pitch-alignment"] = circlePitchAlignmentExpression;
-    }
-    if (circlePitchAlignment != null) {
+    } else if (circlePitchAlignment != null) {
       paint["circle-pitch-alignment"] =
           circlePitchAlignment?.name.toLowerCase().replaceAll("_", "-");
     }
 
     if (circlePitchScaleExpression != null) {
       paint["circle-pitch-scale"] = circlePitchScaleExpression;
-    }
-    if (circlePitchScale != null) {
+    } else if (circlePitchScale != null) {
       paint["circle-pitch-scale"] =
           circlePitchScale?.name.toLowerCase().replaceAll("_", "-");
     }
 
     if (circleRadiusExpression != null) {
       paint["circle-radius"] = circleRadiusExpression;
-    }
-    if (circleRadius != null) {
+    } else if (circleRadius != null) {
       paint["circle-radius"] = circleRadius;
     }
 
     if (circleStrokeColorExpression != null) {
       paint["circle-stroke-color"] = circleStrokeColorExpression;
-    }
-    if (circleStrokeColor != null) {
+    } else if (circleStrokeColor != null) {
       paint["circle-stroke-color"] = circleStrokeColor?.toRGBA();
     }
 
     if (circleStrokeOpacityExpression != null) {
       paint["circle-stroke-opacity"] = circleStrokeOpacityExpression;
-    }
-    if (circleStrokeOpacity != null) {
+    } else if (circleStrokeOpacity != null) {
       paint["circle-stroke-opacity"] = circleStrokeOpacity;
     }
 
     if (circleStrokeWidthExpression != null) {
       paint["circle-stroke-width"] = circleStrokeWidthExpression;
-    }
-    if (circleStrokeWidth != null) {
+    } else if (circleStrokeWidth != null) {
       paint["circle-stroke-width"] = circleStrokeWidth;
     }
 
     if (circleTranslateExpression != null) {
       paint["circle-translate"] = circleTranslateExpression;
-    }
-    if (circleTranslate != null) {
+    } else if (circleTranslate != null) {
       paint["circle-translate"] = circleTranslate;
     }
 
     if (circleTranslateAnchorExpression != null) {
       paint["circle-translate-anchor"] = circleTranslateAnchorExpression;
-    }
-    if (circleTranslateAnchor != null) {
+    } else if (circleTranslateAnchor != null) {
       paint["circle-translate-anchor"] =
           circleTranslateAnchor?.name.toLowerCase().replaceAll("_", "-");
     }