Limit the amount of horizontal splits you can do

helix-term/src/commands.rs

@@ -4258,11 +4258,19 @@ fn split(cx: &mut Context, action: Action) {
 }
 
 fn hsplit(cx: &mut Context) {
+    let view_id = view!(cx.editor).id;
+
     split(cx, Action::HorizontalSplit);
+
+    typed::hsplit_limit_check(view_id, cx.editor);
 }
 
 fn hsplit_new(cx: &mut Context) {
+    let view_id = view!(cx.editor).id;
+
     cx.editor.new_file(Action::HorizontalSplit);
+
+    typed::hsplit_limit_check(view_id, cx.editor);
 }
 
 fn vsplit(cx: &mut Context) {

helix-term/src/commands/typed.rs

@@ -1221,8 +1221,8 @@ fn hsplit(
     if event != PromptEvent::Validate {
         return Ok(());
     }
-
     let id = view!(cx.editor).doc;
+    let view_id = view!(cx.editor).id;
 
     if args.is_empty() {
         cx.editor.switch(id, Action::HorizontalSplit);
@@ -1233,6 +1233,8 @@ fn hsplit(
         }
     }
 
+    hsplit_limit_check(view_id, cx.editor);
+
     Ok(())
 }
 
@@ -1258,12 +1260,31 @@ fn hsplit_new(
     if event != PromptEvent::Validate {
         return Ok(());
     }
+    let view_id = view!(cx.editor).id;
 
     cx.editor.new_file(Action::HorizontalSplit);
 
+    hsplit_limit_check(view_id, cx.editor);
+
     Ok(())
 }
 
+pub fn hsplit_limit_check(view_id: ViewId, editor: &mut Editor) {
+    // check if there are views with height equal to 1
+    // if there are, close the newly created view
+    if editor
+        .tree
+        .views()
+        .any(|(view, _focused)| view.area.height == 1 && editor.tree.is_child(&view.id))
+    {
+        editor.set_error("Max number of splits reached");
+        editor.close(view!(editor).id);
+
+        // focus the view from which the split was called
+        editor.focus(view_id);
+    }
+}
+
 fn debug_eval(
     cx: &mut compositor::Context,
     args: &[Cow<str>],

helix-view/src/tree.rs

@@ -214,6 +214,20 @@ impl Tree {
         node
     }
 
+    pub fn is_child(&self, child_id: &ViewId) -> bool {
+        let focus = self.focus;
+        let parent = self.nodes[focus].parent;
+
+        let container_children: Vec<ViewId> = match &self.nodes[parent] {
+            Node {
+                content: Content::Container(container),
+                ..
+            } => container.children.clone(),
+            _ => unimplemented!(),
+        };
+        container_children.contains(child_id)
+    }
+
     pub fn remove(&mut self, index: ViewId) {
         let mut stack = Vec::new();