[core] add custom URL scheme support

include/mbgl/storage/default_file_source.hpp

@@ -36,6 +36,9 @@ class DefaultFileSource : public FileSource {
     void setAccessToken(const std::string&);
     std::string getAccessToken() const;
 
+    void setURLSchemeTemplate(const std::string& scheme, const std::string& tpl);
+    std::string getURLSchemeTemplate(const std::string& scheme) const;
+
     std::unique_ptr<AsyncRequest> request(const Resource&, Callback) override;
 
     /*

include/mbgl/storage/online_file_source.hpp

@@ -3,6 +3,8 @@
 #include <mbgl/storage/file_source.hpp>
 #include <mbgl/util/constants.hpp>
 
+#include <map>
+
 namespace mbgl {
 
 class OnlineFileSource : public FileSource {
@@ -16,6 +18,9 @@ class OnlineFileSource : public FileSource {
     void setAccessToken(const std::string& t) { accessToken = t; }
     std::string getAccessToken() const { return accessToken; }
 
+    void setURLSchemeTemplate(const std::string& scheme, const std::string& tpl);
+    std::string getURLSchemeTemplate(const std::string& scheme) const;
+
     std::unique_ptr<AsyncRequest> request(const Resource&, Callback) override;
 
 private:
@@ -25,6 +30,7 @@ class OnlineFileSource : public FileSource {
     const std::unique_ptr<Impl> impl;
     std::string accessToken;
     std::string apiBaseURL = mbgl::util::API_BASE_URL;
+    std::map<std::string, std::string> urlSchemeTemplates;
 };
 
 } // namespace mbgl

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java

@@ -376,6 +376,34 @@ public void run() {
     }
   }
 
+  /**
+   * <p>Sets a URL template for the given scheme.</p>
+   * <p>Any URLs encountered in styles and subsequently loaded sources will be fed through a URL
+   *   replacement mechanism that e.g. transforms {@code mapbox://} URLs into regular
+   *   {@code https://} URLs. You can provide URL replacement patterns for your own scheme, e.g.
+   *   {@code example://}.</p>
+   * <p>Any query string will be preserved from the original URL and merged with a query string of
+   *   the template URL, if any.</p>
+   *
+   * @param scheme scheme The scheme that this template should be used for. Specify the scheme
+   * without trailing {@code ://}, e.g. just {@code example}. You may use arbitrary alphanumeric
+   * schemes, with the exception of the protected scheme {@code mapbox}.
+   * @param tpl A templated URL. it may contain these brace-enclosed replacement tokens, e.g. for
+   *   {@code &quot;http://example.com/foo/bar/baz.png&quot;}, valid tokens are:
+   *   <ul>
+   *   <li>{@code {scheme}}: {@code &quot;http&quot;}</li>
+   *   <li>{@code {domain}}: {@code &quot;example.com&quot;}</li>
+   *   <li>{@code {path}}: {@code &quot;foo/bar/baz.png&quot;} (without leading {@code /})</li>
+   *   <li>{@code {directory}}: {@code &quot;foo/bar/&quot;} (with trailing {@code /})</li>
+   *   <li>{@code {filename}}: {@code &quot;baz&quot;} (without file extension)</li>
+   *   <li>{@code {extension}}: {@code &quot;.png&quot;} (optionally with a preceding {@code @2x}
+   *   ratio specifier)</li>
+   *   </ul>
+   */
+  public void setURLSchemeTemplate(String scheme, String tpl) {
+    nativeMapView.setURLSchemeTemplate(scheme, tpl);
+  }
+
   /**
    * <p>
    * Loads a new map style from the specified URL.

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/NativeMapView.java

@@ -234,6 +234,14 @@ public String getAccessToken() {
     return nativeGetAccessToken(nativeMapViewPtr);
   }
 
+  public void setURLSchemeTemplate(String scheme, String tpl) {
+    nativeSetURLTemplate(nativeMapViewPtr, scheme, tpl);
+  }
+
+  public String getURLSchemeTemplate(String scheme) {
+    return nativeGetURLTemplate(nativeMapViewPtr, scheme);
+  }
+
   public void cancelTransitions() {
     nativeCancelTransitions(nativeMapViewPtr);
   }
@@ -667,6 +675,10 @@ private native void nativeSetClasses(long nativeMapViewPtr,
 
   private native String nativeGetAccessToken(long nativeMapViewPtr);
 
+  private native void nativeSetURLTemplate(long nativeMapViewPtr, String scheme, String tpl);
+
+  private native String nativeGetURLTemplate(long nativeMapViewPtr, String scheme);
+
   private native void nativeCancelTransitions(long nativeMapViewPtr);
 
   private native void nativeSetGestureInProgress(long nativeMapViewPtr, boolean inProgress);

platform/android/src/jni.cpp

@@ -461,6 +461,18 @@ jni::jstring* nativeGetAccessToken(JNIEnv *env, jni::jobject* obj, jlong nativeM
     return std_string_to_jstring(env, nativeMapView->getFileSource().getAccessToken());
 }
 
+void nativeSetURLTemplate(JNIEnv *env, jni::jobject* obj, jlong nativeMapViewPtr, jni::jstring* scheme, jni::jstring* tpl) {
+    assert(nativeMapViewPtr != 0);
+    NativeMapView *nativeMapView = reinterpret_cast<NativeMapView *>(nativeMapViewPtr);
+    nativeMapView->getFileSource().setURLSchemeTemplate(std_string_from_jstring(env, scheme), std_string_from_jstring(env, tpl));
+}
+
+jni::jstring* nativeGetURLTemplate(JNIEnv *env, jni::jobject* obj, jlong nativeMapViewPtr, jni::jstring* scheme) {
+    assert(nativeMapViewPtr != 0);
+    NativeMapView *nativeMapView = reinterpret_cast<NativeMapView *>(nativeMapViewPtr);
+    return std_string_to_jstring(env, nativeMapView->getFileSource().getURLSchemeTemplate(std_string_from_jstring(env, scheme)));
+}
+
 void nativeCancelTransitions(JNIEnv *env, jni::jobject* obj, jlong nativeMapViewPtr) {
     assert(nativeMapViewPtr != 0);
     NativeMapView *nativeMapView = reinterpret_cast<NativeMapView *>(nativeMapViewPtr);
@@ -1827,6 +1839,8 @@ void registerNatives(JavaVM *vm) {
         MAKE_NATIVE_METHOD(nativeGetStyleJson, "(J)Ljava/lang/String;"),
         MAKE_NATIVE_METHOD(nativeSetAccessToken, "(JLjava/lang/String;)V"),
         MAKE_NATIVE_METHOD(nativeGetAccessToken, "(J)Ljava/lang/String;"),
+        MAKE_NATIVE_METHOD(nativeSetURLTemplate, "(JLjava/lang/String;Ljava/lang/String;)V"),
+        MAKE_NATIVE_METHOD(nativeGetURLTemplate, "(JLjava/lang/String;)Ljava/lang/String;"),
         MAKE_NATIVE_METHOD(nativeCancelTransitions, "(J)V"),
         MAKE_NATIVE_METHOD(nativeSetGestureInProgress, "(JZ)V"),
         MAKE_NATIVE_METHOD(nativeMoveBy, "(JDDJ)V"),

platform/darwin/src/MGLOfflineStorage.h

@@ -238,6 +238,31 @@ typedef void (^MGLOfflinePackRemovalCompletionHandler)(NSError * _Nullable error
  */
 @property (nonatomic, readonly) unsigned long long countOfBytesCompleted;
 
+/**
+ Sets a URL template for the given scheme.
+
+ Any URLs encountered in styles and subsequently loaded sources will be fed through
+ a URL replacement mechanism that e.g. transforms `mapbox://` URLs into regular
+ `https://` URLs. You can provide URL replacement patterns for your own scheme,
+ e.g. `example://`.
+
+ Any query string will be preserved from the original URL and merged with a
+ query string of the template URL, if any.
+
+ @param tpl A templated URL. it may contain these brace-enclosed replacement
+    tokens, e.g. for `"http://example.com/foo/bar/baz.png"`, valid tokens are:
+    * `{scheme}`: `"http"`
+    * `{domain}`: `"example.com"`
+    * `{path}`: `"foo/bar/baz.png"` (without leading `/`)
+    * `{directory}`: `"foo/bar/"` (with trailing `/`)
+    * `{filename}`: `"baz"` (without file extension)
+    * `{extension}`: `".png"` (optionally with a preceding `@2x` ratio specifier)
+ @param scheme The scheme that this template should be used for. Specify the
+    scheme without trailing `://`, e.g. just `example`. You may use arbitrary
+    alphanumeric schemes, with the exception of the protected scheme `mapbox`.
+ */
+- (void)setURLSchemeTemplate:(nullable NSString *)tpl forScheme:(NSString *)scheme;
+
 @end
 
 NS_ASSUME_NONNULL_END

platform/darwin/src/MGLOfflineStorage.mm

@@ -317,6 +317,10 @@ - (unsigned long long)countOfBytesCompleted {
     return attributes.fileSize;
 }
 
+- (void)setURLSchemeTemplate:(nullable NSString *)tpl forScheme:(NSString *)scheme {
+    self.mbglFileSource->setURLSchemeTemplate(scheme.UTF8String, tpl.UTF8String);
+}
+
 #pragma mark MGLOfflinePackDelegate methods
 
 - (void)offlinePack:(MGLOfflinePack *)pack progressDidChange:(__unused MGLOfflinePackProgress)progress {

platform/default/default_file_source.cpp

@@ -46,6 +46,14 @@ class DefaultFileSource::Impl {
         return onlineFileSource.getAccessToken();
     }
 
+    void setURLSchemeTemplate(const std::string& scheme, const std::string& tpl) {
+        onlineFileSource.setURLSchemeTemplate(scheme, tpl);
+    }
+
+    std::string getURLSchemeTemplate(const std::string& scheme) const {
+        return onlineFileSource.getURLSchemeTemplate(scheme);
+    }
+
     void listRegions(std::function<void (std::exception_ptr, optional<std::vector<OfflineRegion>>)> callback) {
         try {
             callback({}, offlineDatabase.listRegions());
@@ -187,6 +195,14 @@ std::string DefaultFileSource::getAccessToken() const {
     return thread->invokeSync(&Impl::getAccessToken);
 }
 
+void DefaultFileSource::setURLSchemeTemplate(const std::string& scheme, const std::string& tpl) {
+    thread->invokeSync(&Impl::setURLSchemeTemplate, scheme, tpl);
+}
+
+std::string DefaultFileSource::getURLSchemeTemplate(const std::string& scheme) const {
+    return thread->invokeSync(&Impl::getURLSchemeTemplate, scheme);
+}
+
 std::unique_ptr<AsyncRequest> DefaultFileSource::request(const Resource& resource, Callback callback) {
     class DefaultFileRequest : public AsyncRequest {
     public:

platform/default/online_file_source.cpp

@@ -13,6 +13,7 @@
 #include <mbgl/util/async_task.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/timer.hpp>
+#include <mbgl/util/url.hpp>
 #include <mbgl/util/http_timeout.hpp>
 
 #include <algorithm>
@@ -164,33 +165,63 @@ OnlineFileSource::OnlineFileSource()
 
 OnlineFileSource::~OnlineFileSource() = default;
 
+void OnlineFileSource::setURLSchemeTemplate(const std::string& scheme, const std::string& tpl) {
+    if (scheme == "mapbox") {
+        throw std::runtime_error("Cannot override mapbox:// URL scheme");
+    }
+    auto it = urlSchemeTemplates.find(scheme);
+    if (tpl.empty()) {
+        urlSchemeTemplates.erase(it);
+    } else {
+        if (it != urlSchemeTemplates.end()) {
+            it->second = tpl;
+        } else {
+            urlSchemeTemplates.emplace(scheme, tpl);
+        }
+    }
+}
+
+std::string OnlineFileSource::getURLSchemeTemplate(const std::string& scheme) const {
+    auto it = urlSchemeTemplates.find(scheme);
+    return it != urlSchemeTemplates.end() ? it->second : "";
+}
+
 std::unique_ptr<AsyncRequest> OnlineFileSource::request(const Resource& resource, Callback callback) {
     Resource res = resource;
 
-    switch (resource.kind) {
-    case Resource::Kind::Unknown:
-        break;
+    const util::URL url(resource.url);
+
+    if (resource.url.compare(url.scheme.first, url.scheme.second, "mapbox") == 0) {
+        switch (resource.kind) {
+        case Resource::Kind::Style:
+            res.url = mbgl::util::mapbox::normalizeStyleURL(apiBaseURL, resource.url, accessToken);
+            break;
 
-    case Resource::Kind::Style:
-        res.url = mbgl::util::mapbox::normalizeStyleURL(apiBaseURL, resource.url, accessToken);
-        break;
+        case Resource::Kind::Source:
+            res.url = util::mapbox::normalizeSourceURL(apiBaseURL, resource.url, accessToken);
+            break;
 
-    case Resource::Kind::Source:
-        res.url = util::mapbox::normalizeSourceURL(apiBaseURL, resource.url, accessToken);
-        break;
+        case Resource::Kind::Glyphs:
+            res.url = util::mapbox::normalizeGlyphsURL(apiBaseURL, resource.url, accessToken);
+            break;
 
-    case Resource::Kind::Glyphs:
-        res.url = util::mapbox::normalizeGlyphsURL(apiBaseURL, resource.url, accessToken);
-        break;
+        case Resource::Kind::SpriteImage:
+        case Resource::Kind::SpriteJSON:
+            res.url = util::mapbox::normalizeSpriteURL(apiBaseURL, resource.url, accessToken);
+            break;
 
-    case Resource::Kind::SpriteImage:
-    case Resource::Kind::SpriteJSON:
-        res.url = util::mapbox::normalizeSpriteURL(apiBaseURL, resource.url, accessToken);
-        break;
+        case Resource::Kind::Tile:
+            res.url = util::mapbox::normalizeTileURL(apiBaseURL, resource.url, accessToken);
+            break;
 
-    case Resource::Kind::Tile:
-        res.url = util::mapbox::normalizeTileURL(apiBaseURL, resource.url, accessToken);
-        break;
+        default:
+            break;
+        }
+    } else {
+        auto it = urlSchemeTemplates.find(resource.url.substr(url.scheme.first, url.scheme.second));
+        if (it != urlSchemeTemplates.end() && !it->second.empty()) {
+            res.url = util::transformURL(it->second, res.url, url);
+        }
     }
 
     return std::make_unique<OnlineFileRequest>(std::move(res), std::move(callback), *impl);

src/mbgl/util/mapbox.hpp

@@ -2,6 +2,7 @@
 
 #include <string>
 #include <mbgl/style/types.hpp>
+#include <mbgl/storage/resource.hpp>
 
 namespace mbgl {
 namespace util {