Add max page length to multi select

Author: justinbarclay

examples/multi_select.rs

@@ -23,4 +23,20 @@ fn main() {
             println!("  {}", multiselected[selection]);
         }
     }
+
+    let selections = MultiSelect::with_theme(&ColorfulTheme::default())
+        .with_prompt("Pick your food")
+        .items(&multiselected[..])
+        .defaults(&defaults[..])
+        .max_length(2)
+        .interact()
+        .unwrap();
+    if selections.is_empty() {
+        println!("You did not select anything :(");
+    } else {
+        println!("You selected these things:");
+        for selection in selections {
+            println!("  {}", multiselected[selection]);
+        }
+    }
 }

src/prompts/multi_select.rs

@@ -26,6 +26,7 @@ pub struct MultiSelect<'a> {
     items: Vec<String>,
     prompt: Option<String>,
     clear: bool,
+    max_length: Option<usize>,
     theme: &'a dyn Theme,
 }
 
@@ -63,6 +64,18 @@ impl MultiSelect<'_> {
         self
     }
 
+    /// Sets an optional max length for a page
+    ///
+    /// Max length is disabled by None
+    pub fn max_length(&mut self, val: usize) -> &mut Self {
+        // Paging subtracts two from the capacity, paging does this to
+        // make an offset for the page indicator. So to make sure that
+        // we can show the intended amount of items we need to add two
+        // to our value.
+        self.max_length = Some(val + 2);
+        self
+    }
+
     /// Add a single item to the selector.
     #[inline]
     pub fn item<T: ToString>(&mut self, item: T) -> &mut Self {
@@ -182,7 +195,7 @@ impl MultiSelect<'_> {
             ));
         }
 
-        let mut paging = Paging::new(term, self.items.len(), None);
+        let mut paging = Paging::new(term, self.items.len(), self.max_length);
         let mut render = TermThemeRenderer::new(term, self.theme);
         let mut sel = 0;
 
@@ -315,6 +328,7 @@ impl<'a> MultiSelect<'a> {
             defaults: vec![],
             clear: true,
             prompt: None,
+            max_length: None,
             theme,
         }
     }