Use directories crate instead of xdg

This should improve platform independence.

Cargo.lock

 version = "0.1.0"
 dependencies = [
  "clap 2.31.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "directories 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "gl 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gl_generator 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "reqwest 0.8.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "xdg 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "directories"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
  "pkg-config 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "xdg"
-version = "2.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "xml-rs"
 version = "0.7.0"
 "checksum crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2760899e32a1d58d5abb31129f8fae5de75220bc2176e77ff7c627ae45c918d9"
 "checksum crossbeam-utils 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d636a8b3bcc1b409d7ffd3facef8f21dcb4009626adbd0c5e6c4305c07253c7b"
 "checksum deflate 0.7.18 (registry+https://github.com/rust-lang/crates.io-index)" = "32c8120d981901a9970a3a1c97cf8b630e0fa8c3ca31e75b6fd6fd5f9f427b31"
+"checksum directories 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc2561db021b6f1321d0f16b67ed28ce843ef4610dfaa432e3ffa2e8a3050ebf"
 "checksum dlib 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "77e51249a9d823a4cb79e3eca6dcd756153e8ed0157b6c04775d04bf1b13b76a"
 "checksum downcast-rs 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "18df8ce4470c189d18aa926022da57544f31e154631eb4cfe796aea97051fe6c"
 "checksum dtoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "09c3753c3db574d215cba4ea76018483895d7bff25a31b49ba45db21c48e50ab"
 "checksum winit 0.15.0 (registry+https://github.com/rust-lang/crates.io-index)" = "452e3331a6fb5b9d660efae533bf9ae022c528d36eb1e6278b37fc9319d58eff"
 "checksum ws2_32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d59cefebd0c892fa2dd6de581e937301d8552cb44489cdff035c6187cb63fa5e"
 "checksum x11-dl 2.17.5 (registry+https://github.com/rust-lang/crates.io-index)" = "3235540540fde1ae074c8df49054166c0e070407f1c6e1ee17b8c87c2c7bcc7d"
-"checksum xdg 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a66b7c2281ebde13cf4391d70d4c7e5946c3c25e72a7b859ca8f677dcd0b0c61"
 "checksum xml-rs 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3c1cb601d29fe2c2ac60a2b2e5e293994d87a1f6fa9687a31a15270f909be9c2"

Cargo.toml

 regex = "1.0"
 reqwest = "0.8"
 toml = "0.4"
-xdg = "2.1"
+directories = "0.10"
 
 [build-dependencies]
 gl_generator = "0.9"

src/config.rs

 use clap;
+use directories::ProjectDirs;
+use std::fmt::Debug;
 use std::fs::File;
 use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
 use tile_source::TileSource;
 use toml::Value;
-use xdg;
 
 static DEFAULT_CONFIG: &'static str = "";
 static DEFAULT_TILE_SOURCES: &'static str = include_str!("../default_tile_sources.toml");
 
+lazy_static! {
+    static ref PROJ_DIRS: ProjectDirs = ProjectDirs::from("", "", "DeltaMap");
+}
+
 
 #[derive(Debug)]
 pub struct Config {
         }
     }
 
+    fn create_config_file<P: AsRef<Path> + Debug>(dir_path: P, file_path: P, contents: &[u8]) -> Result<(), String> {
+        if !dir_path.as_ref().is_dir() {
+            if let Err(err) = ::std::fs::create_dir_all(&dir_path) {
+                return Err(format!("failed to create config directory ({:?}): {}",
+                    dir_path,
+                    err
+                ));
+            }
+        }
+
+        let mut file = File::create(&file_path)
+            .map_err(|err| format!("failed to create config file {:?}: {}", &file_path, err))?;
+
+        file.write_all(contents)
+            .map_err(|err| format!(
+                "failed to write contents to config file {:?}: {}",
+                &file_path,
+                err
+            ))
+    }
+
     fn find_or_create() -> Result<Config, String> {
-        if let Ok(xdg_dirs) = xdg::BaseDirectories::with_prefix("deltamap") {
-            if let Some(config_path) = xdg_dirs.find_config_file("config.toml") {
-                info!("load config from path {:?}", config_path);
-
-                Config::from_toml_file(config_path)
-            } else {
-                // try to write a default config file
-                if let Ok(path) = xdg_dirs.place_config_file("config.toml") {
-                    if let Ok(mut file) = File::create(&path) {
-                        if file.write_all(DEFAULT_CONFIG.as_bytes()).is_ok() {
-                            info!("write default config to {:?}", &path);
-                        }
-                    }
-                }
+        let config_dir = PROJ_DIRS.config_dir();
+        let config_file = {
+            let mut path = PathBuf::from(config_dir);
+            path.push("config.toml");
+            path
+        };
 
-                Config::from_toml_str(DEFAULT_CONFIG)
-            }
+        if config_file.is_file() {
+            info!("load config from path {:?}", config_file);
+
+            Config::from_toml_file(config_file)
         } else {
-            info!("load default config");
+            // try to write a default config file
+
+            if let Err(err) = Config::create_config_file(
+                config_dir,
+                &config_file,
+                DEFAULT_CONFIG.as_bytes())
+            {
+                warn!("{}", err);
+            }
+
             Config::from_toml_str(DEFAULT_CONFIG)
         }
     }
 
     fn add_tile_sources_from_default_or_create(&mut self) -> Result<(), String> {
-        if let Ok(xdg_dirs) = xdg::BaseDirectories::with_prefix("deltamap") {
-            if let Some(sources_path) = xdg_dirs.find_config_file("tile_sources.toml") {
-                info!("load tile sources from path {:?}", sources_path);
-
-                self.add_tile_sources_from_file(sources_path)
-            } else {
-                // try to write a default tile sources file
-                if let Ok(path) = xdg_dirs.place_config_file("tile_sources.toml") {
-                    if let Ok(mut file) = File::create(&path) {
-                        if file.write_all(DEFAULT_TILE_SOURCES.as_bytes()).is_ok() {
-                            info!("write default tile sources to {:?}", &path);
-                        }
-                    }
-                }
+        let config_dir = PROJ_DIRS.config_dir();
+        let sources_file = {
+            let mut path = PathBuf::from(config_dir);
+            path.push("tile_sources.toml");
+            path
+        };
 
-                self.add_tile_sources_from_str(DEFAULT_TILE_SOURCES)
-            }
+        if sources_file.is_file() {
+            info!("load tile sources from path {:?}", sources_file);
+
+            self.add_tile_sources_from_file(sources_file)
         } else {
-            info!("load default config");
+            // try to write a default config file
+
+            if let Err(err) = Config::create_config_file(
+                config_dir,
+                &sources_file,
+                DEFAULT_TILE_SOURCES.as_bytes())
+            {
+                warn!("{}", err);
+            }
+
             self.add_tile_sources_from_str(DEFAULT_TILE_SOURCES)
         }
     }
 
-    /// Returns a tile cache directory path at a standard XDG cache location. The returned path may
-    /// not exist.
-    fn default_tile_cache_dir() -> Result<PathBuf, String> {
-        let xdg_dirs = xdg::BaseDirectories::with_prefix("deltamap")
-            .map_err(|e| format!("{}", e))?;
-
-        match xdg_dirs.find_cache_file("tiles") {
-            Some(dir) => Ok(dir),
-            None => Ok(xdg_dirs.get_cache_home().join("tiles")),
-        }
+    /// Returns a tile cache directory path at a standard location. The returned path may not
+    /// exist.
+    fn default_tile_cache_dir() -> PathBuf {
+        let mut path = PathBuf::from(PROJ_DIRS.cache_dir());
+        path.push("tiles");
+        path
     }
 
     fn from_toml_str(toml_str: &str) -> Result<Config, String> {
                                    .ok_or_else(|| "tile_cache_dir has to be a string".to_string())?
                             )
                         },
-                        None => Config::default_tile_cache_dir()?,
+                        None => Config::default_tile_cache_dir(),
                     }
                 };
 

src/main.rs

 #[macro_use]
 extern crate clap;
+extern crate directories;
 extern crate env_logger;
 extern crate glutin;
 extern crate image;
 extern crate regex;
 extern crate reqwest;
 extern crate toml;
-extern crate xdg;
 
 pub mod args;
 #[macro_use]