refactor: visitor method to process paragraph wrapped text

src/widgets/paragraph.rs

@@ -7,14 +7,6 @@ use crate::{
  widgets::{reflow::*, Block},
 };
 
-fn get_line_offset(line_width: u16, text_area_width: u16, alignment: Alignment) -> u16 {
- match alignment {
- Alignment::Center => (text_area_width / 2).saturating_sub(line_width / 2),
- Alignment::Right => text_area_width.saturating_sub(line_width),
- Alignment::Left => 0,
- }
-}
-
 /// A widget to display some text.
 ///
 /// # Example
@@ -121,6 +113,16 @@ impl<'a> Paragraph<'a> {
  }
  }
 
+ /// Helper method for processing [`Paragraph`] lines.
+ ///
+ pub fn get_line_offset(line_width: u16, text_area_width: u16, alignment: Alignment) -> u16 {
+ match alignment {
+ Alignment::Center => (text_area_width / 2).saturating_sub(line_width / 2),
+ Alignment::Right => text_area_width.saturating_sub(line_width),
+ Alignment::Left => 0,
+ }
+ }
+
  /// Surrounds the [`Paragraph`] widget with a [`Block`].
  ///
  /// # Example
@@ -334,7 +336,10 @@ impl WidgetRef for Paragraph<'_> {
 }
 
 impl Paragraph<'_> {
- fn render_paragraph(&self, text_area: Rect, buf: &mut Buffer) {
+ /// Visits the styled wrapped text lines inside a text area for rendering or other analysis/processing.
+ /// The visitor function indicates it wants the visitor iteration to terminate if it returns false.
+ ///
+ pub fn visit_wrapped_text<F: FnMut(WrappedLine) -> bool>(&self, text_area: &Rect, visitor: F) {
  if text_area.is_empty() {
  return;
  }
@@ -347,27 +352,31 @@ impl Paragraph<'_> {
 
  if let Some(Wrap { trim }) = self.wrap {
  let line_composer = WordWrapper::new(styled, text_area.width, trim);
- self.render_text(line_composer, text_area, buf);
+ Self::visit_with_composer(line_composer, visitor);
  } else {
  let mut line_composer = LineTruncator::new(styled, text_area.width);
  line_composer.set_horizontal_offset(self.scroll.1);
- self.render_text(line_composer, text_area, buf);
+ Self::visit_with_composer(line_composer, visitor);
  }
  }
-}
 
-impl<'a> Paragraph<'a> {
- fn render_text<C: LineComposer<'a>>(&self, mut composer: C, area: Rect, buf: &mut Buffer) {
+ fn visit_with_composer<'a, C: LineComposer<'a>, F: FnMut(WrappedLine) -> bool>(
+ mut composer: C,
+ mut visitor: F,
+ ) {
+ while let Some(line) = composer.next_line() {
+ if !visitor(line) {
+ break;
+ }
+ }
+ }
+
+ fn render_paragraph(&self, area: Rect, buf: &mut Buffer) {
  let mut y = 0;
- while let Some(WrappedLine {
- line: current_line,
- width: current_line_width,
- alignment: current_line_alignment,
- }) = composer.next_line()
- {
+ self.visit_wrapped_text(&area, |wrapped| {
  if y >= self.scroll.0 {
- let mut x = get_line_offset(current_line_width, area.width, current_line_alignment);
- for StyledGrapheme { symbol, style } in current_line {
+ let mut x = Self::get_line_offset(wrapped.width, area.width, wrapped.alignment);
+ for StyledGrapheme { symbol, style } in wrapped.line {
  let width = symbol.width();
  if width == 0 {
  continue;
@@ -382,10 +391,8 @@ impl<'a> Paragraph<'a> {
  }
  }
  y += 1;
- if y >= area.height + self.scroll.0 {
- break;
- }
- }
+ y < area.height + self.scroll.0
+ });
  }
 }