1 files changed, 118 insertions, 0 deletions
diff --git a/vendor/dialoguer/src/paging.rs b/vendor/dialoguer/src/paging.rs
new file mode 100644
index 0000000..f85d9b3
--- /dev/null
+++ b/vendor/dialoguer/src/paging.rs
@@ -0,0 +1,118 @@
+use std::io;
+
+use console::Term;
+
+/// Creates a paging module
+///
+/// The paging module serves as tracking structure to allow paged views
+/// and automatically (de-)activates paging depending on the current terminal size.
+pub struct Paging<'a> {
+    pub pages: usize,
+    pub current_page: usize,
+    pub capacity: usize,
+    pub active: bool,
+    pub max_capacity: Option<usize>,
+    term: &'a Term,
+    current_term_size: (u16, u16),
+    items_len: usize,
+    activity_transition: bool,
+}
+
+impl<'a> Paging<'a> {
+    pub fn new(term: &'a Term, items_len: usize, max_capacity: Option<usize>) -> Paging<'a> {
+        let term_size = term.size();
+        // Subtract -2 because we need space to render the prompt, if paging is active
+        let capacity = max_capacity
+            .unwrap_or(std::usize::MAX)
+            .clamp(3, term_size.0 as usize)
+            - 2;
+        let pages = (items_len as f64 / capacity as f64).ceil() as usize;
+
+        Paging {
+            pages,
+            current_page: 0,
+            capacity,
+            active: pages > 1,
+            term,
+            current_term_size: term_size,
+            items_len,
+            max_capacity,
+            // Set transition initially to true to trigger prompt rendering for inactive paging on start
+            activity_transition: true,
+        }
+    }
+
+    /// Updates all internal based on the current terminal size and cursor position
+    pub fn update(&mut self, cursor_pos: usize) -> io::Result<()> {
+        let new_term_size = self.term.size();
+
+        if self.current_term_size != new_term_size {
+            self.current_term_size = new_term_size;
+            self.capacity = self
+                .max_capacity
+                .unwrap_or(std::usize::MAX)
+                .clamp(3, self.current_term_size.0 as usize)
+                - 2;
+            self.pages = (self.items_len as f64 / self.capacity as f64).ceil() as usize;
+        }
+
+        if self.active == (self.pages > 1) {
+            self.activity_transition = false;
+        } else {
+            self.active = self.pages > 1;
+            self.activity_transition = true;
+            // Clear everything to prevent "ghost" lines in terminal when a resize happened
+            self.term.clear_last_lines(self.capacity)?;
+        }
+
+        if cursor_pos != !0
+            && (cursor_pos < self.current_page * self.capacity
+                || cursor_pos >= (self.current_page + 1) * self.capacity)
+        {
+            self.current_page = cursor_pos / self.capacity;
+        }
+
+        Ok(())
+    }
+
+    /// Renders a prompt when the following conditions are met:
+    /// * Paging is active
+    /// * Transition of the paging activity happened (active -> inactive / inactive -> active)
+    pub fn render_prompt<F>(&mut self, mut render_prompt: F) -> io::Result<()>
+    where
+        F: FnMut(Option<(usize, usize)>) -> io::Result<()>,
+    {
+        if self.active {
+            let paging_info = Some((self.current_page + 1, self.pages));
+            render_prompt(paging_info)?;
+        } else if self.activity_transition {
+            render_prompt(None)?;
+        }
+
+        self.term.flush()?;
+
+        Ok(())
+    }
+
+    /// Navigates to the next page
+    pub fn next_page(&mut self) -> usize {
+        if self.current_page == self.pages - 1 {
+            self.current_page = 0;
+        } else {
+            self.current_page += 1;
+        }
+
+        self.current_page * self.capacity
+    }
+
+    /// Navigates to the previous page
+    pub fn previous_page(&mut self) -> usize {
+        if self.current_page == 0 {
+            self.current_page = self.pages - 1;
+        } else {
+            self.current_page -= 1;
+        }
+
+        self.current_page * self.capacity
+    }
+}