feat: add is_default method to MetaPlugin and MetaPluginProgram

src/meta_plugin.rs

@@ -30,6 +30,10 @@ pub trait MetaPlugin {
     fn update(&mut self, data: &[u8]);
 
     fn meta_name(&mut self) -> String;
+
+    fn is_default(&self) -> bool {
+        false
+    }
 }
 
 use std::io::Write;
@@ -37,7 +41,7 @@ use std::io::Write;
 lazy_static! {
     pub static ref META_PLUGIN_PROGRAMS: EnumMap<MetaPluginType, Option<MetaPluginProgram>> = enum_map! {
         MetaPluginType::FileMagic => {
-            let program = MetaPluginProgram::new("file", vec!["-bE", "-"], "file_magic".to_string());
+            let program = MetaPluginProgram::new("file", vec!["-bE", "-"], "file_magic".to_string(), true);
             if program.supported { Some(program) } else { None }
         }
     };
@@ -45,7 +49,7 @@ lazy_static! {
 
 pub fn get_meta_plugin(meta_plugin_type: MetaPluginType) -> Box<dyn MetaPlugin> {
     match meta_plugin_type {
-        MetaPluginType::FileMagic => Box::new(MetaPluginProgram::new("file", vec!["-bE", "-"], "file_magic".to_string())),
+        MetaPluginType::FileMagic => Box::new(MetaPluginProgram::new("file", vec!["-bE", "-"], "file_magic".to_string(), true)),
     }
 }
 

src/meta_plugin/program.rs

@@ -16,10 +16,11 @@ pub struct MetaPluginProgram {
     pub args: Vec<String>,
     pub supported: bool,
     pub meta_name: String,
+    pub is_default: bool,
 }
 
 impl MetaPluginProgram {
-    pub fn new(program: &str, args: Vec<&str>, meta_name: String) -> MetaPluginProgram {
+    pub fn new(program: &str, args: Vec<&str>, meta_name: String, is_default: bool) -> MetaPluginProgram {
         let program_path = get_program_path(program);
         let supported = program_path.is_ok();
 
@@ -28,6 +29,7 @@ impl MetaPluginProgram {
             args: args.iter().map(|s| s.to_string()).collect(),
             supported,
             meta_name,
+            is_default,
         }
     }
 }
@@ -72,6 +74,10 @@ impl MetaPlugin for MetaPluginProgram {
     fn meta_name(&mut self) -> String {
         self.meta_name.clone()
     }
+
+    fn is_default(&self) -> bool {
+        self.is_default
+    }
 }
 
 fn get_program_path(program: &str) -> Result<String> {