feat(core/ui): page break icons

Co-authored-by: grdddj <jiri.musil06@seznam.cz>

[no changelog]

core/embed/rust/src/ui/component/text/iter.rs

@@ -160,6 +160,7 @@ fn select_line_breaks(
 
 pub trait GlyphMetrics {
     fn char_width(&self, ch: char) -> i16;
+    fn text_width(&self, text: &str) -> i16;
     fn line_height(&self) -> i16;
 }
 
@@ -168,6 +169,10 @@ impl GlyphMetrics for Font {
         Font::char_width(*self, ch)
     }
 
+    fn text_width(&self, text: &str) -> i16 {
+        Font::text_width(*self, text)
+    }
+
     fn line_height(&self) -> i16 {
         Font::line_height(*self)
     }
@@ -217,6 +222,10 @@ mod tests {
         fn line_height(&self) -> i16 {
             self.height
         }
+
+        fn text_width(&self, text: &str) -> i16 {
+            self.width * text.len() as i16
+        }
     }
 
     fn break_text(s: &str, w: i16) -> Vec<Span> {

core/embed/rust/src/ui/component/text/layout.rs

@@ -1,10 +1,12 @@
 use super::iter::GlyphMetrics;
 use crate::ui::{
     display,
-    display::{Color, Font},
-    geometry::{Alignment, Dimensions, Offset, Point, Rect},
+    display::{toif::Icon, Color, Font},
+    geometry::{Alignment, Dimensions, Offset, Point, Rect, BOTTOM_LEFT},
 };
 
+const ELLIPSIS: &str = "...";
+
 #[derive(Copy, Clone)]
 pub enum LineBreaking {
     /// Break line only at whitespace, if possible. If we don't find any
@@ -24,6 +26,9 @@ pub enum PageBreaking {
     /// Before stopping at the bottom-right edge, insert ellipsis to signify
     /// more content is available, but only if no hyphen has been inserted yet.
     CutAndInsertEllipsis,
+    /// Same as `CutAndInsertEllipsis` but also insert an ellipsis/icon at the
+    /// beginning of the next page.
+    CutAndInsertEllipsisBoth,
 }
 
 /// Visual instructions for laying out a formatted block of text.
@@ -43,6 +48,9 @@ pub struct TextLayout {
     pub style: TextStyle,
     /// Horizontal alignment.
     pub align: Alignment,
+
+    /// Whether to draw "..." (or an icon) at the beginning.
+    pub continues_from_prev_page: bool,
 }
 
 #[derive(Copy, Clone)]
@@ -58,6 +66,10 @@ pub struct TextStyle {
     pub hyphen_color: Color,
     /// Foreground color used for drawing the ellipsis.
     pub ellipsis_color: Color,
+    /// Optional icon shown as ellipsis.
+    pub ellipsis_icon: Option<Icon>,
+    /// Optional icon to signal content continues from previous page.
+    pub prev_page_ellipsis_icon: Option<Icon>,
 
     /// Specifies which line-breaking strategy to use.
     pub line_breaking: LineBreaking,
@@ -79,6 +91,8 @@ impl TextStyle {
             background_color,
             hyphen_color,
             ellipsis_color,
+            ellipsis_icon: None,
+            prev_page_ellipsis_icon: None,
             line_breaking: LineBreaking::BreakAtWhitespace,
             page_breaking: PageBreaking::CutAndInsertEllipsis,
         }
@@ -93,6 +107,34 @@ impl TextStyle {
         self.page_breaking = page_breaking;
         self
     }
+
+    /// Adding optional icon shown instead of "..." ellipsis.
+    pub const fn with_ellipsis_icon(mut self, icon: Icon) -> Self {
+        self.ellipsis_icon = Some(icon);
+        self
+    }
+
+    /// Adding optional icon signalling content continues from previous page.
+    pub const fn with_prev_page_icon(mut self, icon: Icon) -> Self {
+        self.prev_page_ellipsis_icon = Some(icon);
+        self
+    }
+
+    fn ellipsis_width(&self) -> i16 {
+        if let Some(icon) = self.ellipsis_icon {
+            icon.toif.width()
+        } else {
+            self.text_font.text_width(ELLIPSIS)
+        }
+    }
+
+    fn prev_page_ellipsis_width(&self) -> i16 {
+        if let Some(icon) = self.prev_page_ellipsis_icon {
+            icon.toif.width()
+        } else {
+            self.text_font.text_width(ELLIPSIS)
+        }
+    }
 }
 
 impl TextLayout {
@@ -105,6 +147,7 @@ impl TextLayout {
             padding_bottom: 0,
             style,
             align: Alignment::Start,
+            continues_from_prev_page: false,
         }
     }
 
@@ -192,13 +235,31 @@ impl TextLayout {
             };
         }
 
+        // Draw the arrow icon if we are in the middle of a string
+        if matches!(
+            self.style.page_breaking,
+            PageBreaking::CutAndInsertEllipsisBoth
+        ) && self.continues_from_prev_page
+        {
+            sink.prev_page_ellipsis(*cursor, self);
+            cursor.x += self.style.prev_page_ellipsis_width();
+        }
+
         while !remaining_text.is_empty() {
+            let is_last_line = cursor.y + self.style.text_font.line_height() > self.bottom_y();
+            let line_ending_space = if is_last_line {
+                self.style.ellipsis_width()
+            } else {
+                0
+            };
+
             let remaining_width = self.bounds.x1 - cursor.x;
             let span = Span::fit_horizontally(
                 remaining_text,
                 remaining_width,
                 self.style.text_font,
                 self.style.line_breaking,
+                line_ending_space,
             );
 
             cursor.x += match self.align {
@@ -228,9 +289,11 @@ impl TextLayout {
                     if !remaining_text.is_empty() {
                         // Append ellipsis to indicate more content is available, but only if we
                         // haven't already appended a hyphen.
-                        let should_append_ellipsis =
-                            matches!(self.style.page_breaking, PageBreaking::CutAndInsertEllipsis)
-                                && !span.insert_hyphen_before_line_break;
+                        let should_append_ellipsis = matches!(
+                            self.style.page_breaking,
+                            PageBreaking::CutAndInsertEllipsis
+                                | PageBreaking::CutAndInsertEllipsisBoth
+                        ) && !span.insert_hyphen_before_line_break;
                         if should_append_ellipsis {
                             sink.ellipsis(*cursor, self);
                         }
@@ -270,6 +333,10 @@ impl TextLayout {
             + (end_cursor.y - init_cursor.y)
             + self.padding_bottom
     }
+
+    fn bottom_y(&self) -> i16 {
+        (self.bounds.y1 - self.padding_bottom).max(self.bounds.y0)
+    }
 }
 
 impl Dimensions for TextLayout {
@@ -303,6 +370,7 @@ pub trait LayoutSink {
     fn text(&mut self, _cursor: Point, _layout: &TextLayout, _text: &str) {}
     fn hyphen(&mut self, _cursor: Point, _layout: &TextLayout) {}
     fn ellipsis(&mut self, _cursor: Point, _layout: &TextLayout) {}
+    fn prev_page_ellipsis(&mut self, _cursor: Point, _layout: &TextLayout) {}
     fn line_break(&mut self, _cursor: Point) {}
     fn out_of_bounds(&mut self) {}
 }
@@ -335,13 +403,41 @@ impl LayoutSink for TextRenderer {
     }
 
     fn ellipsis(&mut self, cursor: Point, layout: &TextLayout) {
-        display::text(
-            cursor,
-            "...",
-            layout.style.text_font,
-            layout.style.ellipsis_color,
-            layout.style.background_color,
-        );
+        if let Some(icon) = layout.style.ellipsis_icon {
+            icon.draw(
+                cursor,
+                BOTTOM_LEFT,
+                layout.style.ellipsis_color,
+                layout.style.background_color,
+            );
+        } else {
+            display::text(
+                cursor,
+                ELLIPSIS,
+                layout.style.text_font,
+                layout.style.ellipsis_color,
+                layout.style.background_color,
+            );
+        }
+    }
+
+    fn prev_page_ellipsis(&mut self, cursor: Point, layout: &TextLayout) {
+        if let Some(icon) = layout.style.prev_page_ellipsis_icon {
+            icon.draw(
+                cursor,
+                BOTTOM_LEFT,
+                layout.style.ellipsis_color,
+                layout.style.background_color,
+            );
+        } else {
+            display::text(
+                cursor,
+                ELLIPSIS,
+                layout.style.text_font,
+                layout.style.ellipsis_color,
+                layout.style.background_color,
+            );
+        }
     }
 }
 
@@ -366,6 +462,10 @@ pub mod trace {
             self.0.string("...");
         }
 
+        fn prev_page_ellipsis(&mut self, _cursor: Point, _layout: &TextLayout) {
+            self.0.string("...");
+        }
+
         fn line_break(&mut self, _cursor: Point) {
             self.0.string("\n");
         }
@@ -425,6 +525,7 @@ impl Span {
         max_width: i16,
         text_font: impl GlyphMetrics,
         breaking: LineBreaking,
+        line_ending_space: i16,
     ) -> Self {
         const ASCII_LF: char = '\n';
         const ASCII_CR: char = '\r';
@@ -435,12 +536,31 @@ impl Span {
             ch == ASCII_SPACE || ch == ASCII_LF || ch == ASCII_CR
         }
 
-        let use_hyphens = !matches!(breaking, LineBreaking::BreakWordsNoHyphen);
-        let hyphen_width = if use_hyphens {
+        // Checking if the trimmed text fits the line - the whitespace is not being
+        // drawn, so we don't need to account for it.
+        let fits_completely = text_font.text_width(text.trim_end()) <= max_width;
+        let mut use_hyphens = !matches!(breaking, LineBreaking::BreakWordsNoHyphen);
+
+        // How much space we need to left unused at the end of the line
+        // (e.g. for the line-ending hyphen or page-ending ellipsis).
+        // Differs for incomplete and complete words (incomplete need
+        // to account for a possible hyphen).
+        let incomplete_word_end_width = if fits_completely {
+            use_hyphens = false;
+            0
+        } else if line_ending_space > 0 {
+            use_hyphens = false;
+            line_ending_space
+        } else if use_hyphens {
             text_font.char_width(ASCII_HYPHEN)
         } else {
             0
         };
+        let complete_word_end_width = if fits_completely {
+            0
+        } else {
+            line_ending_space
+        };
 
         // The span we return in case the line has to break. We mutate it in the
         // possible break points, and its initial value is returned in case no text
@@ -463,7 +583,7 @@ impl Span {
             let char_width = text_font.char_width(ch);
 
             // Consider if we could be breaking the line at this position.
-            if is_whitespace(ch) {
+            if is_whitespace(ch) && span_width + complete_word_end_width <= max_width {
                 // Break before the whitespace, without hyphen.
                 line.length = i;
                 line.advance.x = span_width;
@@ -483,7 +603,8 @@ impl Span {
                 // Return the last breakpoint.
                 return line;
             } else {
-                let have_space_for_break = span_width + char_width + hyphen_width <= max_width;
+                let have_space_for_break =
+                    span_width + char_width + incomplete_word_end_width <= max_width;
                 let can_break_word =
                     !matches!(breaking, LineBreaking::BreakAtWhitespace) || !found_any_whitespace;
                 if have_space_for_break && can_break_word {
@@ -528,6 +649,10 @@ mod tests {
         fn line_height(&self) -> i16 {
             self.height
         }
+
+        fn text_width(&self, text: &str) -> i16 {
+            self.width * text.len() as i16
+        }
     }
 
     const FIXED_FONT: Fixed = Fixed {
@@ -591,6 +716,7 @@ mod tests {
                 max_width,
                 FIXED_FONT,
                 LineBreaking::BreakAtWhitespace,
+                0,
             );
             spans.push((
                 &remaining_text[..span.length],

core/embed/rust/src/ui/component/text/paragraphs.rs

@@ -392,6 +392,9 @@ impl PageOffset {
 
         // Find out the dimensions of the paragraph at given char offset.
         let mut layout = paragraph.layout(area);
+        if self.chr > 0 {
+            layout.continues_from_prev_page = true;
+        }
         let fit = layout.fit_text(paragraph.content.as_ref());
         let (used, remaining_area) = area.split_top(fit.height());
         layout.bounds = used;

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

@@ -114,9 +114,12 @@ pub struct Icon {
 }
 
 impl Icon {
-    pub fn new(data: &'static [u8]) -> Self {
-        let toif = unwrap!(Toif::new(data));
-        assert!(toif.format() == ToifFormat::GrayScaleEH);
+    pub const fn new(data: &'static [u8]) -> Self {
+        let toif = match Toif::new(data) {
+            Some(t) => t,
+            None => panic!("Invalid image."),
+        };
+        assert!(matches!(toif.format(), ToifFormat::GrayScaleEH));
         Self { toif }
     }
 

core/embed/rust/src/ui/model_tt/component/page.rs

@@ -497,8 +497,8 @@ mod tests {
         );
         page.place(SCREEN);
 
-        let expected1 = "<SwipePage active_page:0 page_count:2 content:<Paragraphs This is somewhat long\nparagraph that goes on\nand on and on and on\nand on and will definitely\nnot fit on just a single\nscreen. You have to\nswipe a bit to see all the\ntext it contains I guess....\n> buttons:<FixedHeightBar inner:<Button text:NO > > >";
-        let expected2 = "<SwipePage active_page:1 page_count:2 content:<Paragraphs There's just so much\nletters in it.\n> buttons:<FixedHeightBar inner:<Button text:NO > > >";
+        let expected1 = "<SwipePage active_page:0 page_count:2 content:<Paragraphs This is somewhat long\nparagraph that goes on\nand on and on and on\nand on and will definitely\nnot fit on just a single\nscreen. You have to\nswipe a bit to see all the\ntext it contains I...\n> buttons:<FixedHeightBar inner:<Button text:NO > > >";
+        let expected2 = "<SwipePage active_page:1 page_count:2 content:<Paragraphs guess. There's just so\nmuch letters in it.\n> buttons:<FixedHeightBar inner:<Button text:NO > > >";
 
         assert_eq!(trace(&page), expected1);
         swipe_down(&mut page);
@@ -533,9 +533,9 @@ mod tests {
         );
         page.place(SCREEN);
 
-        let expected1 = "<SwipePage active_page:0 page_count:3 content:<Paragraphs This paragraph is using a\nbold font. It doesn't\nneed to be all that long.\nAnd this one is\nusing MONO. Mono\nspace is nice fo\nr numbers, they\n> buttons:<FixedHeightBar inner:<Button text:IDK > > >";
-        let expected2 = "<SwipePage active_page:1 page_count:3 content:<Paragraphs have the same wi\ndth and can be s\ncanned quickly.\nEven if they spa\nn several pages\nor something.\nLet's add another one...\n> buttons:<FixedHeightBar inner:<Button text:IDK > > >";
-        let expected3 = "<SwipePage active_page:2 page_count:3 content:<Paragraphs for a good measure. This\none should overflow all\nthe way to the third\npage with a bit of luck.\n> buttons:<FixedHeightBar inner:<Button text:IDK > > >";
+        let expected1 = "<SwipePage active_page:0 page_count:3 content:<Paragraphs This paragraph is using a\nbold font. It doesn't\nneed to be all that long.\nAnd this one is\nusing MONO. Mono\nspace is nice fo\nr numbers,...\n> buttons:<FixedHeightBar inner:<Button text:IDK > > >";
+        let expected2 = "<SwipePage active_page:1 page_count:3 content:<Paragraphs ...they have th\ne same width and\ncan be scanned q\nuickly. Even if\nthey span severa\nl pages or somet\nhing.\n> buttons:<FixedHeightBar inner:<Button text:IDK > > >";
+        let expected3 = "<SwipePage active_page:2 page_count:3 content:<Paragraphs Let's add another one\nfor a good measure. This\none should overflow all\nthe way to the third\npage with a bit of luck.\n> buttons:<FixedHeightBar inner:<Button text:IDK > > >";
 
         assert_eq!(trace(&page), expected1);
         swipe_down(&mut page);

core/embed/rust/src/ui/model_tt/theme.rs

@@ -5,7 +5,7 @@ use crate::{
             text::{formatted::FormattedFonts, LineBreaking, PageBreaking, TextStyle},
             FixedHeightBar,
         },
-        display::{Color, Font},
+        display::{Color, Font, Icon},
         geometry::Insets,
     },
 };
@@ -68,6 +68,8 @@ pub const ICON_LOCK: &[u8] = include_res!("model_tt/res/lock.toif");
 pub const ICON_LOGO: &[u8] = include_res!("model_tt/res/logo.toif");
 pub const ICON_SUCCESS_SMALL: &[u8] = include_res!("model_tt/res/success_bld.toif");
 pub const ICON_WARN_SMALL: &[u8] = include_res!("model_tt/res/warn_bld.toif");
+pub const ICON_PAGE_NEXT: &[u8] = include_res!("model_tt/res/page-next.toif");
+pub const ICON_PAGE_PREV: &[u8] = include_res!("model_tt/res/page-prev.toif");
 
 // Large, three-color icons.
 pub const WARN_COLOR: Color = YELLOW;
@@ -389,7 +391,9 @@ pub const TEXT_DEMIBOLD: TextStyle = TextStyle::new(Font::DEMIBOLD, FG, BG, GREY
 pub const TEXT_BOLD: TextStyle = TextStyle::new(Font::BOLD, FG, BG, GREY_LIGHT, GREY_LIGHT);
 pub const TEXT_MONO: TextStyle = TextStyle::new(Font::MONO, FG, BG, GREY_LIGHT, GREY_LIGHT)
     .with_line_breaking(LineBreaking::BreakWordsNoHyphen)
-    .with_page_breaking(PageBreaking::Cut);
+    .with_page_breaking(PageBreaking::CutAndInsertEllipsisBoth)
+    .with_ellipsis_icon(Icon::new(ICON_PAGE_NEXT))
+    .with_prev_page_icon(Icon::new(ICON_PAGE_PREV));
 
 /// Convert Python-side numeric id to a `TextStyle`.
 pub fn textstyle_number(num: i32) -> &'static TextStyle {