Move from json11 to jsoncpp

This way we can make use of system-wide installed jsoncpp.

MAVSDKConfig.cmake.in

@@ -7,7 +7,7 @@ if(NOT @BUILD_SHARED_LIBS@)
         find_dependency(CURL REQUIRED CONFIG)
     endif()
 
-    find_dependency(json11)
+    find_dependency(jsoncpp)
     find_dependency(tinyxml2)
 
     if(@BUILD_BACKEND@)

src/plugins/mission/CMakeLists.txt

@@ -1,4 +1,4 @@
-find_package(json11 REQUIRED)
+find_package(jsoncpp REQUIRED)
 
 add_library(mavsdk_mission
     mission.cpp
@@ -19,7 +19,7 @@ target_link_libraries(mavsdk_mission
     PUBLIC
     mavsdk
     PRIVATE
-    json11::json11
+    jsoncpp_lib
 )
 
 target_include_directories(mavsdk_mission PUBLIC

src/plugins/mission/mission_impl.cpp

@@ -1433,26 +1433,29 @@ Mission::Result MissionImpl::import_qgroundcontrol_mission(
     Mission::mission_items_t& mission_items, const std::string& qgc_plan_file)
 {
     std::ifstream file(qgc_plan_file);
-    if (!file) { // File open error
+    if (!file) {
         return Mission::Result::FAILED_TO_OPEN_QGC_PLAN;
     }
 
-    // Read QGC plan into a string stream
     std::stringstream ss;
     ss << file.rdbuf();
     file.close();
-
-    std::string err;
-    const auto parsed_plan = Json::parse(ss.str(), err); // parse QGC plan
-    if (!err.empty()) { // Parse error
+    const auto raw_json = ss.str();
+
+    Json::CharReaderBuilder builder;
+    const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+    Json::Value root;
+    JSONCPP_STRING err;
+    const bool ok =
+        reader->parse(raw_json.c_str(), raw_json.c_str() + raw_json.length(), &root, &err);
+    if (!ok) {
+        LogErr() << "Parse error: " << err;
         return Mission::Result::FAILED_TO_PARSE_QGC_PLAN;
     }
 
-    // Clear old mission items
     mission_items.clear();
 
-    // Import mission items
-    return import_mission_items(mission_items, parsed_plan);
+    return import_mission_items(mission_items, root);
 }
 
 // Build a mission item out of command, params and add them to the mission vector.
@@ -1543,36 +1546,36 @@ Mission::Result MissionImpl::build_mission_items(
 }
 
 Mission::Result MissionImpl::import_mission_items(
-    Mission::mission_items_t& all_mission_items, const Json& qgc_plan_json)
+    Mission::mission_items_t& all_mission_items, const Json::Value& qgc_plan_json)
 {
     const auto json_mission_items = qgc_plan_json["mission"];
-    Mission::Result result = Mission::Result::SUCCESS;
     auto new_mission_item = std::make_shared<MissionItem>();
 
-    // Iterate JSON mission items and build Mavsdk mission items
-    for (auto& json_mission_item : json_mission_items["items"].array_items()) {
+    // Iterate mission items and build Mavsdk mission items.
+    for (auto& json_mission_item : json_mission_items["items"]) {
         // Parameters of Mission item & MAV command of it.
-        MAV_CMD command = static_cast<MAV_CMD>(json_mission_item["command"].int_value());
+        MAV_CMD command = static_cast<MAV_CMD>(json_mission_item["command"].asInt());
 
         // Extract parameters of each mission item
         std::vector<double> params;
-        for (auto& p : json_mission_item["params"].array_items()) {
-            if (p.is_null()) {
+        for (auto& p : json_mission_item["params"]) {
+            if (p.type() == Json::nullValue) {
                 // QGC sets params as `null` if they should be unchanged.
                 params.push_back(double(NAN));
             } else {
-                params.push_back(p.number_value());
+                params.push_back(p.asDouble());
             }
         }
 
-        result = build_mission_items(command, params, new_mission_item, all_mission_items);
+        Mission::Result result =
+            build_mission_items(command, params, new_mission_item, all_mission_items);
         if (result != Mission::Result::SUCCESS) {
             break;
         }
     }
     // Don't forget to add the last mission which possibly didn't have position set.
     all_mission_items.push_back(new_mission_item);
-    return result;
+    return Mission::Result::SUCCESS;
 }
 
 } // namespace mavsdk

src/plugins/mission/mission_impl.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <json11.hpp>
+#include <json/json.h>
 #include <map>
 #include <memory>
 #include <mutex>
@@ -10,8 +10,6 @@
 #include "plugin_impl_base.h"
 #include "system.h"
 
-using namespace json11;
-
 namespace mavsdk {
 
 class MissionImpl : public PluginImplBase {
@@ -92,8 +90,9 @@ class MissionImpl : public PluginImplBase {
 
     void reset_mission_progress();
 
-    static Mission::Result
-    import_mission_items(Mission::mission_items_t& mission_items, const Json& mission_json);
+    static Mission::Result import_mission_items(
+        Mission::mission_items_t& all_mission_items, const Json::Value& qgc_plan_json);
+
     static Mission::Result build_mission_items(
         MAV_CMD command,
         std::vector<double> params,

third_party/CMakeLists.txt

@@ -7,7 +7,7 @@ include(cmake/build_target.cmake)
 list(APPEND CMAKE_PREFIX_PATH "${DEPS_INSTALL_PATH}")
 set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} PARENT_SCOPE)
 
-build_target(json11)
+build_target(jsoncpp)
 build_target(tinyxml2)
 
 if(NOT IOS)

third_party/json11/CMakeLists.txt → third_party/jsoncpp/CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.1)
 
-project(external-json11)
+project(external-jsoncpp)
 include(ExternalProject)
 
 list(APPEND CMAKE_ARGS
@@ -22,16 +22,15 @@ elseif(IOS)
         )
 endif()
 
-message(STATUS "Preparing external project \"json11\" with args:")
+message(STATUS "Preparing external project \"jsoncpp\" with args:")
 foreach(CMAKE_ARG ${CMAKE_ARGS})
     message(STATUS "-- ${CMAKE_ARG}")
 endforeach()
 
 ExternalProject_Add(
-    json11
-    GIT_REPOSITORY https://github.com/dropbox/json11
-    GIT_TAG v1.0.0
-    PREFIX json11
-    PATCH_COMMAND git apply ${PROJECT_SOURCE_DIR}/export_config.patch
+    jsoncpp
+    GIT_REPOSITORY https://github.com/open-source-parsers/jsoncpp 
+    GIT_TAG 1.9.1
+    PREFIX jsonpp
     CMAKE_ARGS "${CMAKE_ARGS}"
     )