Move LinesIterator to utils module

src/lib.rs

@@ -82,9 +82,9 @@ pub mod theme;
 pub mod align;
 pub mod menu;
 pub mod direction;
+pub mod utils;
 
 // This probably doesn't need to be public?
-mod utils;
 mod printer;
 mod xy;
 mod with;

src/menu.rs

@@ -1,4 +1,4 @@
-//! Module to build menus.
+//! Build menu trees.
 //!
 //! Menus are a way to arrange many actions in groups of more manageable size.
 //!

src/printer.rs

@@ -3,7 +3,7 @@
 use std::cmp::min;
 use unicode_segmentation::UnicodeSegmentation;
 
-use utils::head_bytes;
+use utils::prefix_length;
 use backend::Backend;
 
 use B;
@@ -47,7 +47,7 @@ impl Printer {
         let room = self.size.x - p.x;
         // We want the number of CHARACTERS, not bytes.
         // (Actually we want the "width" of the string, see unicode-width)
-        let prefix_len = head_bytes(text.graphemes(true), room, "");
+        let prefix_len = prefix_length(text.graphemes(true), room, "");
         let text = &text[..prefix_len];
 
         let p = p + self.offset;

src/theme.rs

@@ -1,4 +1,4 @@
-//! Module to handle colors and themes in the UI.
+//! Handle colors and themes in the UI.
 //!
 //! # Color palette
 //!

src/utils.rs

@@ -1,20 +1,123 @@
-use unicode_width::UnicodeWidthStr;
+//! Toolbox to make text layout easier.
 
-// Computes a sub-string length that fits in the given `width`.
-//
-// Takes non-breakable elements from `iter`, while keeping the
-// string width under `width` (and adding the length of `delimiter`
-// between each element).
-//
-// Example:
-//
-// ```
-// let my_text = "blah...";
-// // This returns the number of bytes for a prefix of `my_text` that
-// // fits within 5 cells.
-// head_bytes(my_text.graphemes(true), 5, "");
-// ```
-pub fn head_bytes<'a, I: Iterator<Item = &'a str>>(iter: I, width: usize,
+use unicode_width::UnicodeWidthStr;
+use unicode_segmentation::UnicodeSegmentation;
+
+/// Generates rows of text in constrained width.
+///
+/// Given a long text and a width constraint, it iterates over
+/// substrings of the text, each within the constraint.
+pub struct LinesIterator<'a> {
+    content: &'a str,
+    start: usize,
+    width: usize,
+}
+
+impl<'a> LinesIterator<'a> {
+    /// Returns a new `LinesIterator` on `content`.
+    ///
+    /// Yields rows of `width` cells or less.
+    pub fn new(content: &'a str, width: usize) -> Self {
+        LinesIterator {
+            content: content,
+            width: width,
+            start: 0,
+        }
+    }
+}
+
+/// Represents a row of text within a `String`.
+///
+/// A row is made of an offset into a parent `String` and a length.
+/// The corresponding substring should take `width` cells when printed.
+pub struct Row {
+    /// Beginning of the row in the parent `String`.
+    pub start: usize,
+    /// Length of the row, in bytes.
+    pub end: usize,
+    /// Width of the row, in cells.
+    pub width: usize,
+}
+
+impl<'a> Iterator for LinesIterator<'a> {
+    type Item = Row;
+
+    fn next(&mut self) -> Option<Row> {
+        if self.start >= self.content.len() {
+            // This is the end.
+            return None;
+        }
+
+        let start = self.start;
+        let content = &self.content[self.start..];
+
+        let next = content.find('\n').unwrap_or(content.len());
+        let content = &content[..next];
+
+        let line_width = content.width();
+        if line_width <= self.width {
+            // We found a newline before the allowed limit.
+            // Break early.
+            self.start += next + 1;
+            return Some(Row {
+                start: start,
+                end: next + start,
+                width: line_width,
+            });
+        }
+
+        // Keep adding indivisible tokens
+        let prefix_length =
+            match prefix_length(content.split(' '), self.width, " ") {
+                0 => prefix_length(content.graphemes(true), self.width, ""),
+                other => {
+                    self.start += 1;
+                    other
+                }
+            };
+
+        if prefix_length == 0 {
+            // This mean we can't even get a single char?
+            // Sucks. Let's bail.
+            return None;
+        }
+
+        self.start += prefix_length;
+
+        Some(Row {
+            start: start,
+            end: start + prefix_length,
+            width: self.width,
+        })
+    }
+}
+
+/// Computes a sub-string length that fits in the given `width`.
+///
+/// Takes non-breakable elements from `iter`, while keeping the
+/// string width under `width` (and adding the length of `delimiter`
+/// between each element).
+///
+/// Given `total_text = iter.collect().join(delimiter)`, the result
+/// is the length of the longest prefix of `width` or less cells,
+/// without breaking inside an element.
+///
+/// Example:
+///
+/// ```
+/// # extern crate cursive;
+/// extern crate unicode_segmentation;
+/// use unicode_segmentation::UnicodeSegmentation;
+///
+/// # use cursive::utils::prefix_length;
+/// # fn main() {
+/// let my_text = "blah...";
+/// // This returns the number of bytes for a prefix of `my_text` that
+/// // fits within 5 cells.
+/// prefix_length(my_text.graphemes(true), 5, "");
+/// # }
+/// ```
+pub fn prefix_length<'a, I: Iterator<Item = &'a str>>(iter: I, width: usize,
                                                delimiter: &str)
                                                -> usize {
     let delimiter_width = delimiter.width();

src/view/mod.rs

@@ -1,4 +1,4 @@
-//! Define the base elements required to build views.
+//! Base elements required to build views.
 //!
 //! Views are the main building blocks of your UI.
 //!

src/views/mod.rs

@@ -1,4 +1,4 @@
-//! Defines various views to use when creating the layout.
+//! Various views to use when creating the layout.
 
 mod box_view;
 mod button;

src/views/text_view.rs

@@ -2,16 +2,15 @@ use XY;
 use With;
 use direction::Direction;
 use vec::Vec2;
-use view::{View, SizeCache};
+use view::{SizeCache, View};
 use Printer;
 use align::*;
 use event::*;
 use view::ScrollBase;
 
-use utils::head_bytes;
+use utils::{Row, LinesIterator};
 
 use unicode_width::UnicodeWidthStr;
-use unicode_segmentation::UnicodeSegmentation;
 
 
 /// A simple view showing a fixed text
@@ -30,13 +29,6 @@ pub struct TextView {
     width: Option<usize>,
 }
 
-// Subset of the main content representing a row on the display.
-struct Row {
-    start: usize,
-    end: usize,
-    width: usize,
-}
-
 // If the last character is a newline, strip it.
 fn strip_last_newline(content: &str) -> &str {
     if !content.is_empty() && content.chars().last().unwrap() == '\n' {
@@ -182,77 +174,6 @@ impl TextView {
     }
 }
 
-// Given a multiline string, and a given maximum width,
-// iterates on the computed rows.
-struct LinesIterator<'a> {
-    content: &'a str,
-    start: usize,
-    width: usize,
-}
-
-impl<'a> LinesIterator<'a> {
-    // Start an iterator on the given content.
-    fn new(content: &'a str, width: usize) -> Self {
-        LinesIterator {
-            content: content,
-            width: width,
-            start: 0,
-        }
-    }
-}
-
-impl<'a> Iterator for LinesIterator<'a> {
-    type Item = Row;
-
-    fn next(&mut self) -> Option<Row> {
-        if self.start >= self.content.len() {
-            // This is the end.
-            return None;
-        }
-
-        let start = self.start;
-        let content = &self.content[self.start..];
-
-        let next = content.find('\n').unwrap_or(content.len());
-        let content = &content[..next];
-
-        let line_width = content.width();
-        if line_width <= self.width {
-            // We found a newline before the allowed limit.
-            // Break early.
-            self.start += next + 1;
-            return Some(Row {
-                start: start,
-                end: next + start,
-                width: line_width,
-            });
-        }
-
-        // Keep adding indivisible tokens
-        let head_bytes =
-            match head_bytes(content.split(' '), self.width, " ") {
-                0 => head_bytes(content.graphemes(true), self.width, ""),
-                other => {
-                    self.start += 1;
-                    other
-                }
-            };
-
-        if head_bytes == 0 {
-            // This mean we can't even get a single char?
-            // Sucks. Let's bail.
-            return None;
-        }
-
-        self.start += head_bytes;
-
-        Some(Row {
-            start: start,
-            end: start + head_bytes,
-            width: self.width,
-        })
-    }
-}
 
 impl View for TextView {
     fn draw(&self, printer: &Printer) {