feat: searching ros install dir for UserConfig.txt AM-367/user-config

Author: Aaron Roller

.gitignore

@@ -11,3 +11,4 @@ debian/ros-melodic-am-osdk-ros*
 debian/ros-melodic-dji-onboard-sdk-ros.debhelper.log
 ros-melodic-dji-onboard-sdk-build-deps_*_all.deb
 build
+catkin_ws

include/dji_sdk_obsoleted/dji_linux_environment.hpp

@@ -64,6 +64,16 @@ class DJI_Environment
   std::string  device_acm;
   std::string  sample_case;
 
+ /**
+  * @return a string of the path to a file in the working dir, if found.  Empty otherwise.
+  */
+  static std::string findFileInCwd(std::string file);
+
+  /**
+   * @return a string of the path to a file, if found.  Empty otherwise.
+   */
+  static std::string findFileInDir(std::string file, std::string dir);
+
   const static unsigned int default_acm_baudrate = 921600;
 };
 

src/dji_sdk_obsoleted/dji_linux_environment.cpp

@@ -45,15 +45,23 @@ DJI_Environment::~DJI_Environment()
 std::string
 DJI_Environment::findFile(std::string file)
 {
-  char        cwd[1024];
-  std::string configFile;
+  std::string configFile = findFileInCwd(file);
+  if(configFile.empty()){
+    //FIXME: find a better place to declare this
+    std::string installationDir = "/opt/ros/melodic/share/dji_sdk";
+    configFile = findFileInDir(file,installationDir);
+  }
+  return configFile;
+}
 
-  if (getcwd(cwd, sizeof(cwd)) == NULL)
-    throw std::runtime_error("Error getting current directory");
 
-  std::string strCWD(cwd);
-  // configFile = strCWD + "/osdk-core/" + file;
-  configFile = strCWD + "/" + file; // just in the current working directory
+/**
+ * @return a string of the path to a file, if found.  Empty otherwise.
+ */
+std::string
+DJI_Environment::findFileInDir(std::string file, std::string dir)
+{
+  std::string configFile = dir + "/" + file; 
 
   std::ifstream fStream(configFile.c_str());
 
@@ -63,6 +71,22 @@ DJI_Environment::findFile(std::string file)
   return configFile;
 }
 
+/**
+ * @return a string of the path to a file in the working dir, if found.  Empty otherwise.
+ */
+std::string
+DJI_Environment::findFileInCwd(std::string file)
+{ 
+  char        cwd[1024];
+  std::string configFile;
+
+  if (getcwd(cwd, sizeof(cwd)) == NULL)
+    throw std::runtime_error("Error getting current directory");
+
+  std::string strCWD(cwd);
+  return findFileInDir(file,strCWD);
+}
+
 int
 DJI_Environment::getApp_id() const
 {