more help system

src/help.rs

@@ -1,4 +1,14 @@
-pub const GOPHERMAP: &str = "
+pub fn lookup(name: &str) -> Option<&str> {
+    match name {
+        "" | "/" | "help" => Some(HELP),
+        "types" => Some(TYPES),
+        "nav" => Some(NAV),
+        "keys" => Some(KEYS),
+        _ => None,
+    }
+}
+
+pub const HELP: &str = "
 i
 i
 i      /         /         /   
@@ -28,11 +38,90 @@ iPress the # of a link to visit
 ior select it. Use ENTER to open
 ithe selected link.
 i
-iTo select a link, start typing.
+iTo select a link by name, just 
+istart typing.
 i 
 i            ~ * ~
 i
-1about phetch	/phlog	help
+1menu navigation	/nav	help
+1gopher types	/types	help
+1all keys	/keys	help
 hvisit homepage	URL:https://github.com/dvkt/phetch
 i
 ";
+
+pub const NAV: &str = "
+i
+i
+i      /         /         /   
+i ___ (___  ___ (___  ___ (___ 
+i|   )|   )|___)|    |    |   )
+i|__/ |  / |__  |__  |__  |  / 
+i|   
+i
+i    ** menu navigation **
+i
+ithere are three ways to navigate
+imenus in phetch:
+i
+1up & down arrows	/nav	help
+i
+iuse the up and down arrows or the
+ictrl-p/ctrl-n combos to select menu 
+iitems. phetch will scroll for you,
+ibut you can use page up & page down
+ito jump by many lines quickly.
+i
+1number keys	/nav	help
+i
+iif there are few enough menu items,
+ipressing a number key will open the
+iitem immediately. otherwise, it'll
+ibe selected.
+i
+1incremental search	/nav	help
+i
+ijust start typing. phetch will look
+ifor the first case insensitive match
+iand try to select it.
+i
+";
+
+pub const TYPES: &str = "
+i
+i
+i      /         /         /   
+i ___ (___  ___ (___  ___ (___ 
+i|   )|   )|___)|    |    |   )
+i|__/ |  / |__  |__  |__  |  / 
+i|   
+i
+i     ** gopher types **
+i
+iphetch supports these links:
+i
+0text files
+1menu items
+3errors
+hexternal URLs
+7search servers
+8telnet launching
+i
+iand these download types:
+i
+4binhex
+5dosfiles
+6uuencoded files
+9binaries
+gGIFs
+Iimages downloads
+ssound files
+ddocuments
+i
+iphetch does not support: 
+i
+2CSO Entries 
++Mirrors
+TTelnet3270
+i
+";

src/ui.rs

@@ -91,11 +91,23 @@ impl UI {
     }
 
     pub fn open(&mut self, url: &str) -> io::Result<()> {
+        // no open loops
+        if let Some(page) = self.pages.get(self.page) {
+            if &page.url() == url {
+                return Ok(());
+            }
+        }
+
         // non-gopher URL
         if !url.starts_with("gopher://") {
             return open_external(url);
         }
 
+        // on-line help
+        if url.starts_with("gopher://help/") {
+            return self.open_help(url);
+        }
+
         // gopher URL
         status(&format!(
             "{}Loading...{}",
@@ -114,6 +126,19 @@ impl UI {
             .map_err(|e| io_error(format!("Error loading {}: {} ({:?})", url, e, e.kind())))
     }
 
+    // open a phetch on-line help url, ex: gopher://help/1/types
+    pub fn open_help(&mut self, url: &str) -> io::Result<()> {
+        if let Some(source) = help::lookup(
+            &url.trim_start_matches("gopher://help/")
+                .trim_start_matches("1/"),
+        ) {
+            self.add_page(Menu::from(url.to_string(), source.to_string()));
+            Ok(())
+        } else {
+            Err(gopher::io_error(format!("Help file not found: {}", url)))
+        }
+    }
+
     pub fn render(&mut self) -> String {
         if let Ok((cols, rows)) = termion::terminal_size() {
             self.term_size(cols as usize, rows as usize);
@@ -199,9 +224,7 @@ impl UI {
                     }
                 }
             }
-            Action::Keypress(Key::Ctrl('h')) => {
-                self.add_page(Menu::from("help".into(), help::GOPHERMAP.into()));
-            }
+            Action::Keypress(Key::Ctrl('h')) => self.open("gopher://help/")?,
             Action::Keypress(Key::Ctrl('u')) => {
                 if let Some(page) = self.pages.get(self.page) {
                     status(&format!("Current URL: {}", page.url()));