newreg: simplify getting file/dir and context

src/formats/pana_dvd.rs

@@ -1,5 +1,5 @@
 use std::any::Any;
-use crate::{InputTarget, AppContext, formats::Format};
+use crate::{AppContext, formats::Format};
 pub fn format() -> Format {
     Format { name: "pana_dvd", detector_func: is_pana_dvd_file, extractor_func: extract_pana_dvd }
 }
@@ -150,7 +150,7 @@ pub fn find_aes_key_pair<'a>(key_array: &'a [(&'a str, &'a str, &'a str)], data:
 }
 
 pub fn is_pana_dvd_file(app_ctx: &AppContext) -> Result<Option<Box<dyn Any>>, Box<dyn std::error::Error>> {
-    let file = match &app_ctx.input {InputTarget::File(f) => f, InputTarget::Directory(_) => return Ok(None)};
+    let file = match app_ctx.file() {Some(f) => f, None => return Ok(None)};
     let header = common::read_file(&file, 0, 64)?;
     if let Some(matching_key) = find_key(&keys::PANA_DVD_KEYONLY, &header, b"PROG", 0)? {
         Ok(Some(Box::new(PanaDvdContext {
@@ -181,9 +181,9 @@ pub fn is_pana_dvd_file(app_ctx: &AppContext) -> Result<Option<Box<dyn Any>>, Bo
     }
 }
 
-pub fn extract_pana_dvd(app_ctx: &AppContext, ctx: Option<Box<dyn Any>>) -> Result<(), Box<dyn std::error::Error>> {
-    let mut file = match &app_ctx.input {InputTarget::File(f) => f, InputTarget::Directory(_) => return Err("Extractor expected file, not directory".into())};
-    let context = ctx.and_then(|c: Box<dyn Any>| c.downcast::<PanaDvdContext>().ok()).ok_or("Context is invalid or missing!")?;
+pub fn extract_pana_dvd(app_ctx: &AppContext, ctx: Box<dyn Any>) -> Result<(), Box<dyn std::error::Error>> {
+    let mut file = app_ctx.file().ok_or("Extractor expected file")?;
+    let context = ctx.downcast::<PanaDvdContext>().expect("Missing context");
 
     let mut data = Vec::new();  // we need to load the entire file into memory so we can swap it with AES decrypted data if its AES encrypted
     file.read_to_end(&mut data)?;