note: don't allow nested note previews

Signed-off-by: William Casarin <jb55@jb55.com>

src/ui/note/options.rs

@@ -0,0 +1,41 @@
+use bitflags::bitflags;
+
+bitflags! {
+    // Attributes can be applied to flags types
+    #[repr(transparent)]
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+    pub struct NoteOptions: u32 {
+        const actionbar     = 0b00000001;
+        const note_previews = 0b00000010;
+    }
+}
+
+impl NoteOptions {
+    #[inline]
+    pub fn has_actionbar(self) -> bool {
+        (self & NoteOptions::actionbar) == NoteOptions::actionbar
+    }
+
+    #[inline]
+    pub fn has_note_previews(self) -> bool {
+        (self & NoteOptions::note_previews) == NoteOptions::note_previews
+    }
+
+    #[inline]
+    pub fn set_note_previews(&mut self, enable: bool) {
+        if enable {
+            *self = *self | NoteOptions::note_previews;
+        } else {
+            *self = *self & !NoteOptions::note_previews;
+        }
+    }
+
+    #[inline]
+    pub fn set_actionbar(&mut self, enable: bool) {
+        if enable {
+            *self = *self | NoteOptions::actionbar;
+        } else {
+            *self = *self & !NoteOptions::actionbar;
+        }
+    }
+}