Language protocol: rename and showing usages now fallsback to document_highlight if no better capability is supported. This for instance enables rename and showing usages when flow-language-server is used.

src/source_language_protocol.cc

@@ -546,19 +546,33 @@ void Source::LanguageProtocolView::setup_navigation_and_refactoring() {
     };
   }
 
-  if(capabilities.references) {
+  if(capabilities.references || capabilities.document_highlight) {
     get_usages = [this] {
       auto iter = get_buffer()->get_insert()->get_iter();
       std::vector<std::pair<Offset, std::string>> usages;
       std::vector<Offset> end_offsets;
       std::promise<void> result_processed;
-      client->write_request(this, "textDocument/references", R"("textDocument":{"uri":")" + uri + R"("}, "position": {"line": )" + std::to_string(iter.get_line()) + ", \"character\": " + std::to_string(iter.get_line_offset()) + R"(}, "context": {"includeDeclaration": true})", [&usages, &end_offsets, &result_processed](const boost::property_tree::ptree &result, bool error) {
+
+      std::string method;
+      if(capabilities.document_highlight)
+        method = "textDocument/documentHighlight";
+      else
+        method = "textDocument/references";
+
+      client->write_request(this, method, R"("textDocument":{"uri":")" + uri + R"("}, "position": {"line": )" + std::to_string(iter.get_line()) + ", \"character\": " + std::to_string(iter.get_line_offset()) + R"(}, "context": {"includeDeclaration": true})", [this, &usages, &end_offsets, &result_processed](const boost::property_tree::ptree &result, bool error) {
         if(!error) {
           try {
             for(auto it = result.begin(); it != result.end(); ++it) {
-              auto path = it->second.get<std::string>("uri", "");
+              std::string path;
-              if(path.size() >= 7) {
+              if(capabilities.document_highlight)
+                path = file_path.string();
+              else {
+                path = it->second.get<std::string>("uri", "");
+                if(path.size() >= 7)
                   path.erase(0, 7);
+                else
+                  continue;
+              }
               auto range_it = it->second.find("range");
               if(range_it != it->second.not_found()) {
                 auto start_it = range_it->second.find("start");
@@ -570,7 +584,6 @@ void Source::LanguageProtocolView::setup_navigation_and_refactoring() {
               }
             }
           }
-          }
           catch(...) {
             usages.clear();
             end_offsets.clear();
@@ -582,7 +595,7 @@ void Source::LanguageProtocolView::setup_navigation_and_refactoring() {
 
       auto embolden_token = [](std::string &line_, unsigned token_start_pos, unsigned token_end_pos) {
         Glib::ustring line = line_;
-        if(token_start_pos >= line.size() || token_end_pos >= line.size())
+        if(token_start_pos > line.size() || token_end_pos > line.size())
           return;
 
         //markup token as bold
@@ -683,7 +696,7 @@ void Source::LanguageProtocolView::setup_navigation_and_refactoring() {
     return get_buffer()->get_text(start, end);
   };
 
-  if(capabilities.rename) {
+  if(capabilities.rename || capabilities.document_highlight) {
     rename_similar_tokens = [this](const std::string &text) {
       class Usages {
       public:
@@ -699,6 +712,7 @@ void Source::LanguageProtocolView::setup_navigation_and_refactoring() {
       auto iter = get_buffer()->get_insert()->get_iter();
       std::vector<Usages> usages;
       std::promise<void> result_processed;
+      if(capabilities.rename) {
         client->write_request(this, "textDocument/rename", R"("textDocument":{"uri":")" + uri + R"("}, "position": {"line": )" + std::to_string(iter.get_line()) + ", \"character\": " + std::to_string(iter.get_line_offset()) + R"(}, "newName": ")" + text + "\"", [this, &usages, &result_processed](const boost::property_tree::ptree &result, bool error) {
           if(!error) {
             boost::filesystem::path project_path;
@@ -771,6 +785,31 @@ void Source::LanguageProtocolView::setup_navigation_and_refactoring() {
           }
           result_processed.set_value();
         });
+      }
+      else {
+        client->write_request(this, "textDocument/documentHighlight", R"("textDocument":{"uri":")" + uri + R"("}, "position": {"line": )" + std::to_string(iter.get_line()) + ", \"character\": " + std::to_string(iter.get_line_offset()) + R"(}, "context": {"includeDeclaration": true})", [this, &usages, &result_processed](const boost::property_tree::ptree &result, bool error) {
+          if(!error) {
+            try {
+              usages.emplace_back(Usages{file_path, nullptr, std::vector<std::pair<Offset, Offset>>()});
+              for(auto it = result.begin(); it != result.end(); ++it) {
+                auto range_it = it->second.find("range");
+                if(range_it != it->second.not_found()) {
+                  auto start_it = range_it->second.find("start");
+                  auto end_it = range_it->second.find("end");
+                  if(start_it != range_it->second.not_found() && end_it != range_it->second.not_found()) {
+                    usages.back().offsets.emplace_back(std::make_pair(Offset(start_it->second.get<unsigned>("line"), start_it->second.get<unsigned>("character")),
+                                                                      Offset(end_it->second.get<unsigned>("line"), end_it->second.get<unsigned>("character"))));
+                  }
+                }
+              }
+            }
+            catch(...) {
+              usages.clear();
+            }
+          }
+          result_processed.set_value();
+        });
+      }
       result_processed.get_future().get();
 
       std::vector<Usages *> usages_renamed;