From 42a6a5ac9b5f88c2afcca0011cd009307d97ae1a Mon Sep 17 00:00:00 2001
From: grdddj <jiri.musil06@seznam.cz>
Date: Tue, 19 Sep 2023 11:04:10 +0200
Subject: [PATCH] chore(core): adjust the chunkification logic to account for
 really mono font

Also improving the positioning of prev/next page arrows when paginating.

[no changelog]
---
 .../rust/src/ui/component/text/layout.rs      | 63 +++++++++++--------
 core/embed/rust/src/ui/model_tr/theme.rs      |  4 +-
 2 files changed, 39 insertions(+), 28 deletions(-)

diff --git a/core/embed/rust/src/ui/component/text/layout.rs b/core/embed/rust/src/ui/component/text/layout.rs
index d713e9b0e3..70feef8eab 100644
--- a/core/embed/rust/src/ui/component/text/layout.rs
+++ b/core/embed/rust/src/ui/component/text/layout.rs
@@ -59,8 +59,6 @@ pub struct Chunks {
     pub chunk_size: usize,
     /// How big will be the space between chunks (in pixels).
     pub x_offset: i16,
-    /// Optional characters that are wider and should be accounted for
-    pub wider_chars: Option<&'static str>,
 }
 
 impl Chunks {
@@ -68,20 +66,6 @@ impl Chunks {
         Chunks {
             chunk_size,
             x_offset,
-            wider_chars: None,
-        }
-    }
-
-    pub const fn with_wider_chars(mut self, wider_chars: &'static str) -> Self {
-        self.wider_chars = Some(wider_chars);
-        self
-    }
-
-    pub fn is_char_wider(self, ch: char) -> bool {
-        if let Some(wider_chars) = self.wider_chars {
-            wider_chars.contains(ch)
-        } else {
-            false
         }
     }
 }
@@ -192,6 +176,14 @@ impl TextStyle {
             self.text_font.text_width(ELLIPSIS)
         }
     }
+
+    fn prev_page_ellipsis_icon_width(&self) -> i16 {
+        if let Some((icon, _)) = self.prev_page_ellipsis_icon {
+            icon.toif.width()
+        } else {
+            0
+        }
+    }
 }
 
 impl TextLayout {
@@ -262,9 +254,21 @@ impl TextLayout {
             PageBreaking::CutAndInsertEllipsisBoth
         ) && self.continues_from_prev_page
         {
-            sink.prev_page_ellipsis(*cursor, self);
             // Move the cursor to the right, always the same distance
-            cursor.x += self.style.prev_page_ellipsis_width();
+            // Special case in chunkifying text - move the cursor so that we
+            // start with the second chunk.
+            if let Some(chunk_config) = self.style.chunks {
+                // Showing the arrow at the last chunk position
+                // Assuming mono-font, so all the letters have the same width
+                let letter_size = self.style.text_font.text_width("a");
+                let icon_offset = self.style.prev_page_ellipsis_icon_width() + 2;
+                cursor.x += chunk_config.chunk_size as i16 * letter_size - icon_offset;
+                sink.prev_page_ellipsis(*cursor, self);
+                cursor.x += icon_offset + chunk_config.x_offset;
+            } else {
+                sink.prev_page_ellipsis(*cursor, self);
+                cursor.x += self.style.prev_page_ellipsis_width();
+            }
         }
 
         while !remaining_text.is_empty() {
@@ -285,6 +289,20 @@ impl TextLayout {
                 self.style.chunks,
             );
 
+            if let Some(chunk_config) = self.style.chunks {
+                // Last chunk on the page should not be rendered, put just ellipsis there
+                // Chunks is last when the next chunk would not fit on the page horizontally
+                let is_last_chunk = (2 * span.advance.x - chunk_config.x_offset) > remaining_width;
+                if is_last_line && is_last_chunk && remaining_text.len() > chunk_config.chunk_size {
+                    // Making sure no text is rendered here, and that we force a line break
+                    span.length = 0;
+                    span.advance.x = 2; // To start at the same horizontal line as the chunk itself
+                    span.advance.y = self.bounds.y1;
+                    span.insert_hyphen_before_line_break = false;
+                    span.skip_next_chars = 0;
+                }
+            }
+
             cursor.x += match self.align {
                 Alignment::Start => 0,
                 Alignment::Center => (remaining_width - span.advance.x) / 2,
@@ -598,7 +616,6 @@ impl Span {
 
         let mut span_width = 0;
         let mut found_any_whitespace = false;
-        let mut chunks_wider_chars = 0;
 
         let mut char_indices_iter = text.char_indices().peekable();
         // Iterating manually because we need a reference to the iterator inside the
@@ -611,14 +628,8 @@ impl Span {
             if let Some(chunkify_config) = chunks {
                 if i == chunkify_config.chunk_size {
                     line.advance.y = 0;
-                    // Decreasing the offset for each wider character in the chunk
-                    line.advance.x += chunkify_config.x_offset - chunks_wider_chars;
+                    line.advance.x += chunkify_config.x_offset;
                     return line;
-                } else {
-                    // Counting all the wider characters in the chunk
-                    if chunkify_config.is_char_wider(ch) {
-                        chunks_wider_chars += 1;
-                    }
                 }
             }
 
diff --git a/core/embed/rust/src/ui/model_tr/theme.rs b/core/embed/rust/src/ui/model_tr/theme.rs
index 0dd5b16031..7360164368 100644
--- a/core/embed/rust/src/ui/model_tr/theme.rs
+++ b/core/embed/rust/src/ui/model_tr/theme.rs
@@ -43,8 +43,8 @@ pub const TEXT_MONO_ADDRESS_CHUNKS: TextStyle = TEXT_MONO_DATA
     .with_line_spacing(2)
     .with_ellipsis_icon(ICON_NEXT_PAGE, -2);
 
-// Chunks for this model, with accounting for some wider characters in MONO font
-pub const MONO_CHUNKS: Chunks = Chunks::new(4, 4).with_wider_chars("mMwW");
+// Chunks for this model
+pub const MONO_CHUNKS: Chunks = Chunks::new(4, 4);
 
 /// Convert Python-side numeric id to a `TextStyle`.
 pub fn textstyle_number(num: i32) -> &'static TextStyle {