refactor(core): remove StringType

This commit removes the last usage of StringType. In the future, we use
TString.

[no changelog]

core/embed/rust/src/strutil.rs

@@ -9,19 +9,6 @@ use crate::micropython::{buffer::StrBuffer, obj::Obj};
 #[cfg(feature = "translations")]
 use crate::translations::TR;
 
-/// Trait for internal representation of strings. This is a legacy crutch before
-/// we fully transition to `TString`. For now, it allows some manner of
-/// compatibility between `&str` and `StrBuffer`. Implies the following
-/// operations:
-/// - dereference into a short-lived `&str` reference (AsRef<str>) (probably not
-///   strictly necessary anymore)
-/// - create a new string from a string literal (From<&'static str>)
-/// - infallibly convert into a `TString` (Into<TString<'static>>), which is
-///   then used for other operations.
-pub trait StringType: AsRef<str> + From<&'static str> + Into<TString<'static>> {}
-
-impl<T> StringType for T where T: AsRef<str> + From<&'static str> + Into<TString<'static>> {}
-
 /// Unified-length String type, long enough for most simple use-cases.
 pub type ShortString = String<50>;
 

core/embed/rust/src/ui/model_tr/component/share_words.rs

@@ -1,5 +1,5 @@
 use crate::{
-    strutil::{ShortString, StringType, TString},
+    strutil::{ShortString, TString},
     translations::TR,
     ui::{
         component::{
@@ -27,21 +27,15 @@ const INFO_TOP_OFFSET: i16 = 20;
 const MAX_WORDS: usize = 33; // super-shamir has 33 words, all other have less
 
 /// Showing the given share words.
-pub struct ShareWords<T>
-where
-    T: StringType,
-{
+pub struct ShareWords<'a> {
     area: Rect,
     scrollbar: Child<ScrollBar>,
-    share_words: Vec<T, MAX_WORDS>,
+    share_words: Vec<TString<'a>, MAX_WORDS>,
     page_index: usize,
 }
 
-impl<T> ShareWords<T>
-where
-    T: StringType + Clone,
-{
-    pub fn new(share_words: Vec<T, MAX_WORDS>) -> Self {
+impl<'a> ShareWords<'a> {
+    pub fn new(share_words: Vec<TString<'a>, MAX_WORDS>) -> Self {
         let mut instance = Self {
             area: Rect::zero(),
             scrollbar: Child::new(ScrollBar::to_be_filled_later()),
@@ -117,11 +111,13 @@ where
             if index >= self.share_words.len() {
                 break;
             }
-            let word = &self.share_words[index];
             let baseline = self.area.top_left() + Offset::y(y_offset);
             let ordinal = uformat!("{}.", index + 1);
             display_left(baseline + Offset::x(NUMBER_X_OFFSET), &ordinal, NUMBER_FONT);
-            display_left(baseline + Offset::x(WORD_X_OFFSET), word, WORD_FONT);
+            let word = &self.share_words[index];
+            word.map(|w| {
+                display_left(baseline + Offset::x(WORD_X_OFFSET), w, WORD_FONT);
+            });
         }
     }
 
@@ -144,18 +140,17 @@ where
                 .with_fg(theme::FG)
                 .render(target);
 
-            shape::Text::new(baseline + Offset::x(WORD_X_OFFSET), word.as_ref())
+            word.map(|w| {
+                shape::Text::new(baseline + Offset::x(WORD_X_OFFSET), w)
                     .with_font(WORD_FONT)
                     .with_fg(theme::FG)
                     .render(target);
+            });
         }
     }
 }
 
-impl<T> Component for ShareWords<T>
-where
-    T: StringType + Clone,
-{
+impl<'a> Component for ShareWords<'a> {
     type Msg = Never;
 
     fn place(&mut self, bounds: Rect) -> Rect {
@@ -198,10 +193,7 @@ where
     }
 }
 
-impl<T> Paginate for ShareWords<T>
-where
-    T: StringType + Clone,
-{
+impl<'a> Paginate for ShareWords<'a> {
     fn page_count(&mut self) -> usize {
         // Not defining the logic here, as we do not want it to be `&mut`.
         self.total_page_count()
@@ -216,10 +208,7 @@ where
 // DEBUG-ONLY SECTION BELOW
 
 #[cfg(feature = "ui_debug")]
-impl<T> crate::trace::Trace for ShareWords<T>
-where
-    T: StringType + Clone,
-{
+impl<'a> crate::trace::Trace for ShareWords<'a> {
     fn trace(&self, t: &mut dyn crate::trace::Tracer) {
         t.component("ShareWords");
         let content = if self.is_final_page() {
@@ -231,8 +220,8 @@ where
                 if index >= self.share_words.len() {
                     break;
                 }
-                let word: TString = self.share_words[index].clone().into();
-                unwrap!(uwrite!(content, "{}. {}\n", index + 1, word));
+                self.share_words[index]
+                    .map(|word| unwrap!(uwrite!(content, "{}. {}\n", index + 1, word)));
             }
             content
         };

core/embed/rust/src/ui/model_tr/layout.rs

@@ -6,7 +6,6 @@ use crate::{
     error::Error,
     maybe_trace::MaybeTrace,
     micropython::{
-        buffer::StrBuffer,
         gc::Gc,
         iter::IterBuf,
         list::List,
@@ -1331,7 +1330,7 @@ extern "C" fn new_select_word(n_args: usize, args: *const Obj, kwargs: *mut Map)
 extern "C" fn new_show_share_words(n_args: usize, args: *const Obj, kwargs: *mut Map) -> Obj {
     let block = |_args: &[Obj], kwargs: &Map| {
         let share_words_obj: Obj = kwargs.get(Qstr::MP_QSTR_share_words)?;
-        let share_words: Vec<StrBuffer, 33> = util::iter_into_vec(share_words_obj)?;
+        let share_words: Vec<TString, 33> = util::iter_into_vec(share_words_obj)?;
 
         let cancel_btn = Some(ButtonDetails::up_arrow_icon());
         let confirm_btn =