TR-rust: properly centering all text in ChoiceItem

core/embed/rust/src/ui/display/font.rs

@@ -129,15 +129,43 @@ impl Font {
         display::text_width(text, self.into())
     }
 
-    /// Width of the text that is visible, not including the space
-    /// after the last character.
+    /// Width of the text that is visible.
+    /// Not including the spaces before the first and after the last character.
     pub fn visible_text_width(self, text: &str) -> i16 {
-        let text_minus_one = &text[..text.len() - 1];
+        match text.len() {
+            0 => 0,
+            1 => {
+                let char = unwrap!(text.chars().last());
+                let char_glyph = unwrap!(self.get_glyph(char as u8));
+                char_glyph.width
+            },
+            _ => {
+                let first_char = unwrap!(text.chars().next());
+                let first_char_glyph = unwrap!(self.get_glyph(first_char as u8));
+                let first_char_visible_width = first_char_glyph.adv - first_char_glyph.bearing_x;
 
-        let last_char = unwrap!(text.chars().last());
-        let last_char_glyph = unwrap!(self.get_glyph(last_char as u8));
+                let middle_chars = &text[1..text.len() - 1];
+                let middle_chars_width = self.text_width(middle_chars);
 
-        self.text_width(text_minus_one) + last_char_glyph.width
+                let last_char = unwrap!(text.chars().last());
+                let last_char_glyph = unwrap!(self.get_glyph(last_char as u8));
+                let last_char_visible_width = last_char_glyph.width + last_char_glyph.bearing_x;
+
+                first_char_visible_width + middle_chars_width + last_char_visible_width
+            }
+        }
+    }
+
+    /// Returning the x-bearing (offset) of the first character.
+    /// Useful to enforce that the text is positioned correctly (e.g. centered).
+    pub fn start_x_bearing(self, text: &str) -> i16 {
+        if text.is_empty() {
+            return 0;
+        }
+
+        let first_char = unwrap!(text.chars().next());
+        let first_char_glyph = unwrap!(self.get_glyph(first_char as u8));
+        first_char_glyph.bearing_x
     }
 
     pub fn char_width(self, ch: char) -> i16 {

core/embed/rust/src/ui/model_tr/component/input_methods/choice_item.rs

@@ -57,23 +57,24 @@ impl ChoiceItem {
         }
     }
 
-    /// Getting the text width in pixels.
-    fn text_width(&self) -> i16 {
-        self.font.text_width(&self.text)
-    }
-
     /// Getting the visible text width in pixels.
     fn visible_text_width(&self) -> i16 {
         self.font.visible_text_width(&self.text)
     }
 
+    /// Getting the initial x-bearing of the text in pixels,
+    /// so that we can adjust its positioning to center it properly.
+    fn text_x_bearing(&self) -> i16 {
+        self.font.start_x_bearing(&self.text)
+    }
+
     /// Getting the non-central width in pixels.
     /// It will show an icon if defined, otherwise the text, not both.
     fn width_side(&self) -> i16 {
         if let Some(icon) = self.icon {
             icon.toif.width()
         } else {
-            self.text_width()
+            self.visible_text_width()
         }
     }
 
@@ -89,12 +90,7 @@ impl ChoiceItem {
         let bound = theme::BUTTON_OUTLINE;
         let left_bottom =
             area.bottom_center() + Offset::new(-self.width_center() / 2 - bound, bound + 1);
-        let mut x_size = self.width_center() + 2 * bound;
-        // Shortening the x-size by one pixel when visible text width is even to center
-        // it properly.
-        if self.visible_text_width() % 2 == 0 {
-            x_size -= 1;
-        }
+        let x_size = self.width_center() + 2 * bound;
         let y_size = self.font.text_height() + 2 * bound;
         let outline_size = Offset::new(x_size, y_size);
         let outline = Rect::from_bottom_left_and_size(left_bottom, outline_size);
@@ -175,6 +171,9 @@ impl Choice for ChoiceItem {
             );
             baseline = baseline + Offset::x(icon.toif.width() + ICON_RIGHT_PADDING);
         }
+        // Possibly shifting the baseline left, when there is a text bearing.
+        // This is to center the text properly.
+        baseline = baseline - Offset::x(self.text_x_bearing());
         if inverse {
             display_inverse(baseline, &self.text, self.font);
         } else {
@@ -190,7 +189,7 @@ impl Choice for ChoiceItem {
         } else {
             0
         };
-        icon_width + self.text_width()
+        icon_width + self.visible_text_width()
     }
 
     /// Painting item on the side if it fits, otherwise paint incomplete if