Add configuration file over-ride mechanism

Reusing the windowmanager on the cluster demo platform requires
modifications to the layers.json, areas.db, etc. configuration files.
To allow this without breaking potential shared package feeds by
building two versions, add a mechanism to allow over-riding the
configuration files present in the widget with files in the directory
/etc/xdg/windowmanager.  Affected code has been refactored to use a new
common configuration file path determination helper function to reduce
duplication.

Bug-AGL: SPEC-1805

Change-Id: Ia3e1af0703794079f9537b934b124788129c045c
Signed-off-by: Scott Murray <scott.murray@konsulko.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/src/util.cpp b/src/util.cpp
index 672b089..e4cc2ef 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2017 TOYOTA MOTOR CORPORATION
+ * Copyright (c) 2018 Konsulko Group
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,9 +22,12 @@
 #include <cstdio>
 #include <cstdlib>
 #include <ctime>
+#include <fstream>
 
 #include <unistd.h>
 
+#include "hmi-debug.h"
+
 #ifdef SCOPE_TRACING
 thread_local int ScopeTrace::indent = 0;
 ScopeTrace::ScopeTrace(char const *func) : f(func)
@@ -93,3 +97,36 @@ void rectangle::set_aspect(double ratio)
     }
 }
 
+std::string get_file_path(const char *file_name, const char *log_category)
+{
+    char const *default_base_path = getenv("AFM_APP_INSTALL_DIR");
+    std::string path("");
+
+    if(!file_name) {
+        return path;
+    }
+
+    if (!default_base_path)
+    {
+        HMI_ERROR(log_category, "AFM_APP_INSTALL_DIR is not defined");
+    }
+    else
+    {
+        path = default_base_path;
+        path.append("/etc/");
+        path.append(file_name);
+    }
+
+    // Check for over-ride in /etc/xdg/windowmanager
+    std::string override_path("/etc/xdg/windowmanager/");
+    override_path.append(file_name);
+    std::ifstream i(override_path);
+    if (i.good())
+    {
+        path = override_path;
+    }
+    i.close();
+
+    HMI_INFO(log_category, "Using %s", path.c_str());
+    return path;
+}