feat: enabling scrolling of tabs (#282)

This enables a limited notion of scrolling to help when the selected tab
goes off the screen. This just ensures it is always in view.

src/inspect/mod.rs

@@ -265,6 +265,7 @@ struct Inspector<'a> {
  cs: &'a ConstraintSet,
  modules: Vec<ModuleView>,
  current_module: usize,
+ tab_offset: usize,
  minibuffer: Rect,
  message: Span<'a>,
 }
@@ -284,6 +285,7 @@ impl<'a> Inspector<'a> {
  .sorted_by(|m1, m2| m1.name.cmp(&m2.name))
  .collect(),
  current_module: 0,
+ tab_offset: 0,
  minibuffer: Default::default(),
  message: Span::from(""),
  };
@@ -312,12 +314,17 @@ impl<'a> Inspector<'a> {
  self.modules.get_mut(self.current_module).unwrap()
  }
 
- fn render_tabs(&self, f: &mut Frame, place: Rect) {
- let titles = self
+ fn render_tabs(&mut self, f: &mut Frame, place: Rect) {
+ let mut titles = self
  .modules
  .iter()
  .map(|t| t.name.clone())
  .collect::<Vec<_>>();
+ // Determine how much space
+ let tab_offset = self.update_tab_offset(place.width as usize, &titles);
+ // Slice out hidden tabs
+ titles.drain(0..tab_offset);
+ //
  let tabs = Tabs::new(titles)
  .block(
  Block::default()
@@ -330,7 +337,7 @@ impl<'a> Inspector<'a> {
  " →".into(),
  ])),
  )
- .select(self.current_module)
+ .select(self.current_module - tab_offset)
  // .style(Style::default().dark_gray())
  .highlight_style(
  Style::default()
@@ -341,6 +348,39 @@ impl<'a> Inspector<'a> {
  f.render_widget(tabs, place);
  }
 
+ fn update_tab_offset(&mut self, width: usize, titles: &[String]) -> usize {
+ let mut count = 10;
+ loop {
+ let (start, end) = self.determine_selected_offset(titles);
+ if end >= (width as isize) {
+ self.tab_offset += 1;
+ } else if start < 0 {
+ self.tab_offset -= 1;
+ } else if count == 0 {
+ // this just ensures we can never enter an infinite loop.
+ return 0;
+ } else {
+ return self.tab_offset;
+ }
+ count -= 1;
+ }
+ }
+
+ fn determine_selected_offset(&self, titles: &[String]) -> (isize, isize) {
+ let mut offset = 0isize;
+ for t in 0..self.current_module {
+ offset += (titles[t].len() + 3) as isize;
+ }
+ for t in 0..self.tab_offset {
+ offset -= (titles[t].len() + 3) as isize;
+ }
+ // Done
+ (
+ offset,
+ offset + (titles[self.current_module].len() as isize),
+ )
+ }
+
  fn render_columns(&self, f: &mut Frame, target: Rect) {
  self.current_module().render(self.cs, f, target);
  }