Style tweaks (#29)

* Remove hard-coded zoom out factor in UIKit

* Allow setting more default styling

* Also allow specifying a point alpha

Examples/Cassini/CassiniApp.swift

@@ -31,7 +31,7 @@ struct CassiniApp: App {
         name: "Continents",
         contents: try! GeoDrawer.Content.content(
           for: GeoDrawer.Content.countries(),
-          color: CassiniApp.Colors.continents.cgColor
+          style: .init(color: CassiniApp.Colors.continents.cgColor)
         ),
         color: CassiniApp.Colors.continents.cgColor
       )

Examples/Cassini/ContentView+Model.swift

@@ -111,7 +111,7 @@ extension ContentView {
 
       layers.append(.init(
         name: preferredName ?? "New Layer",
-        contents: GeoDrawer.Content.content(for: geoJSON, color: color),
+        contents: GeoDrawer.Content.content(for: geoJSON, style: .init(color: color)),
         color: color
       ))
     }

Examples/Cassini/ContentView.swift

@@ -247,7 +247,7 @@ struct ContentView_Previews: PreviewProvider {
         name: "Continents",
         contents: try! GeoDrawer.Content.content(
           for: GeoDrawer.Content.countries(),
-          color: CassiniApp.Colors.continents.cgColor
+          style: .init(color: CassiniApp.Colors.continents.cgColor)
         ),
         color: CassiniApp.Colors.continents.cgColor
       )

Sources/GeoDrawer/GeoDrawer.swift

@@ -156,10 +156,17 @@ extension GeoDrawer {
       self.alpha = alpha
     }
 
-    public let red: Double
-    public let green: Double
-    public let blue: Double
-    public let alpha: Double
+    public var red: Double
+    public var green: Double
+    public var blue: Double
+    public var alpha: Double
+
+    public func copy(alpha: Double) -> Self? {
+      guard alpha != self.alpha else { return nil }
+      var updated = self
+      updated.alpha = alpha
+      return updated
+    }
   }
 #endif
 

Sources/GeoDrawer/GeoMap+AppKit.swift

@@ -168,7 +168,10 @@ public struct GeoMap: NSViewRepresentable {
 struct GeoMap_Previews: PreviewProvider {
   static var previews: some View {
     GeoMap(
-      contents: try! GeoDrawer.Content.content(for: GeoDrawer.Content.countries(), color: .init(red: 0, green: 1, blue: 0, alpha: 0)),
+      contents: try! GeoDrawer.Content.content(
+        for: GeoDrawer.Content.countries(),
+        style: .init(color: .init(red: 0, green: 1, blue: 0, alpha: 0))
+      ),
       projection: Projections.Cassini()
     )
       .previewLayout(.fixed(width: 300, height: 300))

Sources/GeoDrawer/GeoMap+UIKit.swift

@@ -69,7 +69,6 @@ public class GeoMapView: UIView {
         size: .init(frame.size),
         projection: projection,
         zoomTo: zoomTo,
-        zoomOutFactor: 5,
         insets: insets
       )
       _drawer = drawer
@@ -175,7 +174,10 @@ public struct GeoMap: UIViewRepresentable {
 struct GeoMap_Previews: PreviewProvider {
   static var previews: some View {
     GeoMap(
-      contents: try! GeoDrawer.Content.content(for: GeoDrawer.Content.countries(), color: .init(red: 0, green: 1, blue: 0, alpha: 0)),
+      contents: try! GeoDrawer.Content.content(
+        for: GeoDrawer.Content.countries(),
+        style: .init(color: .init(red: 0, green: 1, blue: 0, alpha: 0))
+      ),
       projection: Projections.Cassini()
     )
       .previewLayout(.fixed(width: 300, height: 300))

Sources/GeoDrawer/styling/GeoDrawerContent+Style.swift

@@ -26,7 +26,32 @@ extension GeoJSON.GeometryObject {
 
 extension GeoDrawer.Content {
 
-  public static func content(for geoJSON: GeoJSON, color: GeoDrawer.Color, polygonStroke: (GeoDrawer.Color, width: Double)? = nil) -> [GeoDrawer.Content] {
+  public struct DefaultStyle {
+    /// Fallback color to use for points, lines, and **fill** of polygons.
+    public var color: GeoDrawer.Color
+
+    /// Fallback color and width to use for polygons.
+    public var polygonStroke: (GeoDrawer.Color, width: Double)? = nil
+
+    /// Fallback stroke width for lines
+    public var lineWidth: Double = 2
+
+    /// Fallback radius to use for points.
+    public var pointRadius: Double = 1
+
+    /// Alpha to apply on every point or circle
+    public var pointAlpha: Double = 1
+
+    public init(color: GeoDrawer.Color, polygonStroke: (GeoDrawer.Color, width: Double)? = nil, lineWidth: Double = 2, pointRadius: Double = 1, pointAlpha: Double = 1) {
+      self.color = color
+      self.polygonStroke = polygonStroke
+      self.lineWidth = lineWidth
+      self.pointRadius = pointRadius
+      self.pointAlpha = pointAlpha
+    }
+  }
+
+  public static func content(for geoJSON: GeoJSON, style: DefaultStyle) -> [GeoDrawer.Content] {
     let elements: [(GeoJSON.Geometry, [String: AnyHashable]?)]
     switch geoJSON.object {
     case .geometry(let geo):
@@ -40,13 +65,13 @@ extension GeoDrawer.Content {
     }
 
     return elements.map { geometry, properties in
-      Self.content(for: geometry, properties: properties, color: color, polygonStroke: polygonStroke)
+      Self.content(for: geometry, properties: properties, style: style)
     }
   }
 
-  public static func content(for geometry: GeoJSON.GeometryObject, properties: [String: AnyHashable]? = nil, color: GeoDrawer.Color, polygonStroke: (GeoDrawer.Color, width: Double)? = nil) -> [GeoDrawer.Content] {
+  public static func content(for geometry: GeoJSON.GeometryObject, properties: [String: AnyHashable]? = nil, style: DefaultStyle) -> [GeoDrawer.Content] {
     return geometry.geometries.map {
-      Self.content(for: $0, properties: properties, color: color, polygonStroke: polygonStroke)
+      Self.content(for: $0, properties: properties, style: style)
     }
   }
 
@@ -56,31 +81,33 @@ extension GeoDrawer.Content {
   /// - Parameters:
   ///   - geometry: The geometry
   ///   - properties: Optional properties. If these follow [GeoJSON simplespec 1.1](https://github.com/mapbox/simplestyle-spec/tree/master/1.1.0), then those style is preferred over explicitly set style. Points can additionally be adjusted in size by setting `circle-radius`.
-  ///   - color: Color to use for points, lines, and **fill** of polygons.
-  ///   - polygonStroke: Color and width to use for polygons.
+  ///   - style: Default style to use if not otherwise specified in `properties`
   /// - Returns: Drawable content.
-  public static func content(for geometry: GeoJSON.Geometry, properties: [String: AnyHashable]? = nil, color: GeoDrawer.Color, polygonStroke: (GeoDrawer.Color, width: Double)? = nil) -> GeoDrawer.Content {
+  public static func content(for geometry: GeoJSON.Geometry, properties: [String: AnyHashable]? = nil, style: DefaultStyle) -> GeoDrawer.Content {
     switch geometry {
     case .polygon(let polygon):
       return .polygon(
         polygon,
-        fill: Self.color(properties, colorKey: "fill", alphaKey: "fill-opacity") ?? color,
-        stroke: Self.color(properties, colorKey: "stroke", alphaKey: "stroke-opacity") ?? polygonStroke?.0,
-        strokeWidth: (properties?["stroke-width"] as? Double) ?? polygonStroke?.width ?? 0
+        fill: Self.color(properties, colorKey: "fill", alphaKey: "fill-opacity") ?? style.color,
+        stroke: Self.color(properties, colorKey: "stroke", alphaKey: "stroke-opacity") ?? style.polygonStroke?.0,
+        strokeWidth: (properties?["stroke-width"] as? Double) ?? style.polygonStroke?.width ?? 0
       )
+
     case .lineString(let line):
       return .line(
         line,
-        stroke: Self.color(properties, colorKey: "stroke", alphaKey: "stroke-opacity") ?? color,
-        strokeWidth: properties?["stroke-width"] as? Double ?? 2
+        stroke: Self.color(properties, colorKey: "stroke", alphaKey: "stroke-opacity") ?? style.color,
+        strokeWidth: properties?["stroke-width"] as? Double ?? style.lineWidth
       )
+
     case .point(let position):
+      let baseFill = Self.color(properties, colorKey: "fill", alphaKey: "fill-opacity") ?? style.color
       return .circle(
         position,
-        radius: properties?["circle-radius"] as? Double ?? 1,
-        fill: Self.color(properties, colorKey: "fill", alphaKey: "fill-opacity") ?? color,
+        radius: properties?["circle-radius"] as? Double ?? style.pointRadius,
+        fill: baseFill.copy(alpha: baseFill.alpha * style.pointAlpha) ?? baseFill,
         stroke: Self.color(properties, colorKey: "stroke", alphaKey: "stroke-opacity"),
-        strokeWidth: (properties?["stroke-width"] as? Double) ?? 0
+        strokeWidth: (properties?["stroke-width"] as? Double) ?? style.lineWidth
       )
     }
   }