added the abiliy to go to next/previous page of tags with ctrl+(n/p)

src/tags.rs

@@ -20,7 +20,9 @@ pub struct Images {
 
 #[derive(Deserialize)]
 pub struct Tags {
+    #[serde(rename(deserialize = "next"))]
     next_page: Option<String>,
+    #[serde(rename(deserialize = "previous"))]
     prev_page: Option<String>,
     pub results: Vec<Images>,
 }
@@ -30,6 +32,8 @@ pub enum Error {
     InvalidCharacter(char),
     Fetching(String),
     Converting(String),
+    NoPrevPage,
+    NoNextPage,
 }
 
 impl fmt::Display for Error {
@@ -38,16 +42,22 @@ impl fmt::Display for Error {
             Error::InvalidCharacter(c) => write!(f, "Invalid Character: {}", c),
             Error::Fetching(s) => write!(f, "Fetching error: {}", s),
             Error::Converting(s) => write!(f, "Converting error: {}", s),
+            Error::NoNextPage => write!(f, "No next page available"),
+            Error::NoPrevPage => write!(f, "No previous page available"),
         }
     }
 }
 
 impl Tags {
+    /// fetches tag information with a repository name in the form of organization/repository or library/repository in the case of official images from docker
     pub fn new(repo: String) -> Result<Self, Error> {
         let request = format!("https://hub.docker.com/v2/repositories/{}/tags", repo);
+        Self::with_url(&request)
+    }
 
-        //get response
-        let res = match reqwest::blocking::get(request) {
+    /// fetches tag information from a url
+    fn with_url(url: &str) -> Result<Self, Error> {
+        let res = match reqwest::blocking::get(url) {
             Ok(result) => result,
             Err(e) => return Err(Error::Fetching(format!("reqwest error: {}", e))),
         };
@@ -76,6 +86,20 @@ impl Tags {
         }
         Ok(name)
     }
+
+    pub fn next_page(&self) -> Result<Self, Error> {
+        match &self.next_page {
+            Some(url) => Self::with_url(url),
+            None => Err(Error::NoNextPage),
+        }
+    }
+
+    pub fn prev_page(&self) -> Result<Self, Error> {
+        match &self.prev_page {
+            Some(url) => Self::with_url(url),
+            None => Err(Error::NoPrevPage),
+        }
+    }
 }
 
 impl fmt::Display for Images {

src/ui.rs

@@ -89,6 +89,12 @@ impl Ui {
                     }
                     Ok(_) => (),
                 },
+                Ok(Key::Ctrl('r')) => {
+                    ui.repo.confirm();
+                    ui.tags = tag_list::TagList::with_repo(ui.repo.get());
+                }
+                Ok(Key::Ctrl('n')) => ui.tags.next_page(),
+                Ok(Key::Ctrl('p')) => ui.tags.prev_page(),
                 Ok(Key::Char('\n')) => match ui.state {
                     State::EditRepo => {
                         ui.repo.confirm();

src/widget/tag_list.rs

@@ -7,11 +7,6 @@ use tui::widgets::{Block, Borders, List, ListState};
 use crate::tags;
 use crate::ui::State;
 
-pub struct TagList {
-    typ: Type,
-    state: ListState,
-}
-
 #[derive(Debug)]
 pub enum Error {
     NoneSelected,
@@ -33,6 +28,11 @@ pub enum Type {
     Repo(tags::Tags),
 }
 
+pub struct TagList {
+    typ: Type,
+    state: ListState,
+}
+
 impl TagList {
     fn new(typ: Type) -> Self {
         Self {
@@ -54,6 +54,26 @@ impl TagList {
         }
     }
 
+    pub fn next_page(&mut self) {
+        match &self.typ {
+            Type::Status(_) => (),
+            Type::Repo(tags) => match tags.next_page() {
+                Err(e) => self.typ = Type::Status(format!("{}", e)),
+                Ok(tags) => self.typ = Type::Repo(tags),
+            },
+        }
+    }
+
+    pub fn prev_page(&mut self) {
+        match &self.typ {
+            Type::Status(_) => (),
+            Type::Repo(tags) => match tags.prev_page() {
+                Err(e) => self.typ = Type::Status(format!("{}", e)),
+                Ok(tags) => self.typ = Type::Repo(tags),
+            },
+        }
+    }
+
     /// get a list of tag names with info
     fn print_lines(&self) -> Vec<String> {
         match &self.typ {