TextView: print styled spans of text

examples/markup.rs

@@ -0,0 +1,22 @@
+extern crate cursive;
+
+use cursive::Cursive;
+use cursive::utils::markup::MarkdownText;
+use cursive::views::{Dialog, TextView};
+
+// Make sure you compile with the `markdown` feature!
+//
+// cargo run --example markup --features markdown
+
+fn main() {
+    let mut siv = Cursive::new();
+
+    let text = MarkdownText("Isn't *that* **cool**?");
+
+    siv.add_layer(
+        Dialog::around(TextView::styled(text).unwrap())
+            .button("Hell yeah!", |s| s.quit()),
+    );
+
+    siv.run();
+}

src/printer.rs

@@ -143,6 +143,8 @@ impl<'a> Printer<'a> {
         let color = style.color;
         let effects = style.effects;
 
+        // eprintln!("{:?}", effects);
+
         if let Some(color) = color {
             self.with_color(color, |printer| {
                 printer.with_effects(effects, f);
@@ -172,7 +174,8 @@ impl<'a> Printer<'a> {
             Some(effect) => {
                 let mut effects = effects;
                 effects.remove(effect);
-                self.with_effects(effects, f);
+
+                self.with_effect(effect, |s| s.with_effects(effects, f));
             }
         }
     }

src/utils/markup/markdown.rs

@@ -9,6 +9,47 @@ use std::borrow::Cow;
 use theme::{Effect, Style};
 use utils::lines::spans::Span;
 
+/// `Markup` trait implementation for markdown text.
+///
+/// Requires the `markdown` feature.
+pub struct Markdown;
+
+impl super::Markup for Markdown {
+    type Error = ();
+
+    fn parse<'a>(input: &'a str) -> Result<Vec<Span<'a>>, Self::Error> {
+        Ok(parse(input))
+    }
+}
+
+/// Thin wrapper around text that should be parsed as Markdown.
+///
+/// This does not parse the text here, but indicates how it should be parsed.
+///
+/// # Examples
+///
+/// ```rust
+/// // Can use `&str`
+/// let text = MarkdownText("*Markdown* text!");
+///
+/// // Or `String`
+/// let text = MarkdownText(String::from("*Right __here__!"));
+/// ```
+pub struct MarkdownText<S>(pub S)
+where
+    S: Into<String>;
+
+impl<S> super::MarkupText for MarkdownText<S>
+where
+    S: Into<String>,
+{
+    type M = Markdown;
+
+    fn to_string(self) -> String {
+        self.0.into()
+    }
+}
+
 /// Iterator that parse a markdown text and outputs styled spans.
 pub struct Parser<'a> {
     first: bool,
@@ -116,19 +157,7 @@ impl<'a> Iterator for Parser<'a> {
 /// This is a shortcut for `Parser::new(input).collect()`.
 pub fn parse<'a>(input: &'a str) -> Vec<Span<'a>> {
     Parser::new(input).collect()
-}
-
-/// `Markup` trait implementation for markdown text.
-///
-/// Requires the `markdown` feature.
-pub struct Markdown;
-
-impl super::Markup for Markdown {
-    type Error = ();
-
-    fn parse<'a>(input: &'a str) -> Result<Vec<Span<'a>>, Self::Error> {
-        Ok(parse(input))
-    }
+    // Parser::new(input).inspect(|span| eprintln!("{:?}", span)).collect()
 }
 
 #[cfg(test)]

src/utils/markup/mod.rs

@@ -6,12 +6,14 @@
 pub mod markdown;
 
 #[cfg(feature = "markdown")]
-pub use self::markdown::Markdown;
+pub use self::markdown::MarkdownText;
+
 use owning_ref::OwningHandle;
 use owning_ref::StringRef;
-use utils::lines::spans::Span;
-use theme::Style;
 use std::borrow::Cow;
+use std::ops::Deref;
+use theme::Style;
+use utils::lines::spans::Span;
 
 /// Trait for parsing text into styled spans.
 pub trait Markup {
@@ -36,6 +38,28 @@ pub trait Markup {
     }
 }
 
+/// Thin wrapper around a string, with a markup format.
+///
+/// This only wraps the text and indicates how it should be parsed;
+/// it does not parse the text itself.
+pub trait MarkupText {
+
+    /// Markup format to use to parse the string.
+    type M: Markup;
+
+    /// Access the inner string.
+    fn to_string(self) -> String;
+}
+
+/// Unwrapped text gets the "Plain" markup for free.
+impl<S: Into<String>> MarkupText for S {
+    type M = Plain;
+
+    fn to_string(self) -> String {
+        self.into()
+    }
+}
+
 /// Dummy `Markup` implementation that returns the text as-is.
 pub struct Plain;
 
@@ -43,10 +67,12 @@ impl Markup for Plain {
     type Error = ();
 
     fn parse<'a>(input: &'a str) -> Result<Vec<Span<'a>>, Self::Error> {
-        Ok(vec![Span {
-            text: Cow::Borrowed(input),
-            style: Style::none(),
-        }])
+        Ok(vec![
+            Span {
+                text: Cow::Borrowed(input),
+                style: Style::none(),
+            },
+        ])
     }
 }
 
@@ -57,37 +83,105 @@ pub type StyledHandle = OwningHandle<StringRef, Vec<Span<'static>>>;
 
 /// A String that parses a markup language.
 pub struct StyledString {
-    content: StyledHandle,
+    content: Option<StyledHandle>,
 }
 
 impl StyledString {
-
     /// Creates a new styled string, parsing the given content.
-    pub fn new<S, M>(content: S) -> Result<Self, M::Error>
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use cursive::utils::markup::StyledString;
+    /// let styled_string = StyledString::new("*plain* text");
+    /// ```
+    pub fn new<T>(content: T) -> Result<Self, <T::M as Markup>::Error>
     where
-        S: Into<String>,
-        M: Markup,
+        T: MarkupText,
     {
-        let content = M::make_handle(content)?;
+        let content = content.to_string();
+
+        let content = Some(T::M::make_handle(content)?);
+
         Ok(StyledString { content })
     }
 
+    /// Returns a plain StyledString without any style.
+    ///
+    /// > You got no style, Dutch. You know that.
+    pub fn plain<S>(content: S) -> Self 
+    where S: Into<String>
+    {
+        Self::new(content).unwrap()
+    }
+
     /// Sets the content of this string.
     ///
-    /// The content will be parsed; if an error is found,
-    /// it will be returned here (and the content will be unchanged).
-    pub fn set_content<S, M>(&mut self, content: S) -> Result<(), M::Error>
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use cursive::utils::markup::StyledString;
+    /// # let mut styled_string = StyledString::new("").unwrap();
+    /// styled_string.set_content("*plain* text").unwrap();
+    /// ```
+    pub fn set_content<T>(
+        &mut self, content: T
+    ) -> Result<(), <<T as MarkupText>::M as Markup>::Error>
     where
-        S: Into<String>,
-        M: Markup,
+        T: MarkupText,
     {
-        self.content = M::make_handle(content)?;
+        let content = content.to_string();
+
+        self.content = Some(T::M::make_handle(content)?);
 
         Ok(())
     }
 
+    /// Sets the content of this string to plain text.
+    pub fn set_plain<S>(&mut self, content: S) where S: Into<String> {
+        self.set_content(content).unwrap();
+    }
+
+    /// Append `content` to the end.
+    ///
+    /// Re-parse everything after.
+    pub fn append_content<T>(&mut self, content: T) -> Result<(), <T::M as Markup>::Error>
+    where
+        T: MarkupText
+    {
+        self.with_content::<T::M, _, _>(|c| c.push_str(&content.to_string()))
+    }
+
+    /// Run a closure on the text content.
+    ///
+    /// And re-parse everything after.
+    pub fn with_content<M, F, O>(&mut self, f: F) -> Result<O, M::Error>
+    where
+        M: Markup,
+        F: FnOnce(&mut String) -> O,
+    {
+        // Get hold of the StyledHandle
+        let content = self.content.take().unwrap();
+        // Get the inner String
+        let mut content = content.into_inner().into_inner();
+        // Do what we have to do
+        let out = f(&mut content);
+        // And re-parse everything
+        self.content = Some(M::make_handle(content)?);
+
+        Ok(out)
+    }
+
     /// Gives access to the parsed styled spans.
     pub fn spans<'a>(&'a self) -> &'a [Span<'a>] {
-        &self.content
+        &self.content.as_ref().unwrap()
+    }
+}
+
+impl Deref for StyledString {
+    type Target = str;
+
+    fn deref(&self) -> &str {
+        &self.content.as_ref().unwrap().owner()
     }
 }

src/views/text_view.rs

@@ -10,7 +10,8 @@ use std::sync::{Mutex, MutexGuard};
 use std::sync::Arc;
 use theme::Effect;
 use unicode_width::UnicodeWidthStr;
-use utils::lines::simple::{LinesIterator, Row};
+use utils::lines::spans::{Row, SpanLinesIterator};
+use utils::markup::{Markup, MarkupText, StyledString};
 use vec::Vec2;
 use view::{ScrollBase, ScrollStrategy, SizeCache, View};
 
@@ -38,13 +39,28 @@ pub struct TextContent {
 
 impl TextContent {
     /// Creates a new text content around the given value.
-    pub fn new<S: Into<String>>(content: S) -> Self {
-        TextContent {
+    pub fn new<S>(content: S) -> Self
+    where
+        S: Into<String>,
+    {
+        Self::styled(content).unwrap()
+    }
+
+    /// Creates a new text content around the given value.
+    ///
+    /// Parses the given value.
+    pub fn styled<T>(content: T) -> Result<Self, <T::M as Markup>::Error>
+    where
+        T: MarkupText,
+    {
+        let content = StyledString::new(content)?;
+
+        Ok(TextContent {
             content: Arc::new(Mutex::new(TextContentInner {
-                content: content.into(),
+                content,
                 size_cache: None,
             })),
-        }
+        })
     }
 }
 
@@ -70,13 +86,33 @@ impl Deref for TextContentRef {
 
 impl TextContent {
     /// Replaces the content with the given value.
-    pub fn set_content<S: Into<String>>(&mut self, content: S) {
-        self.with_content(|c| *c = content.into());
+    pub fn set_content<S>(&mut self, content: S)
+    where
+        S: Into<String>,
+    {
+        self.with_content(|c| c.set_plain(content));
+    }
+
+    /// Replaces the content with the given value.
+    ///
+    /// The given markup text will be parsed.
+    pub fn set_markup<T>(
+        &mut self, content: T
+    ) -> Result<(), <T::M as Markup>::Error>
+    where
+        T: MarkupText,
+    {
+        self.with_content(|c| c.set_content(content))
     }
 
     /// Append `content` to the end of a `TextView`.
-    pub fn append_content(&mut self, content: &str) {
-        self.with_content(|c| c.push_str(content));
+    pub fn append_content<T>(
+        &mut self, content: T
+    ) -> Result<(), <T::M as Markup>::Error>
+    where
+        T: MarkupText,
+    {
+        self.with_content(|c| c.append_content(content))
     }
 
     /// Returns a reference to the content.
@@ -87,20 +123,25 @@ impl TextContent {
         TextContentInner::get_content(&self.content)
     }
 
-    fn with_content<F>(&mut self, f: F)
+    fn with_content<F, O>(&mut self, f: F) -> O
     where
-        F: FnOnce(&mut String),
+        F: FnOnce(&mut StyledString) -> O,
     {
         let mut lock = self.content.lock().unwrap();
 
-        f(&mut lock.content);
+        let out = f(&mut lock.content);
 
         lock.size_cache = None;
+
+        out
     }
 }
 
 struct TextContentInner {
-    content: String,
+    // content: String,
+    content: StyledString,
+
+    // We keep the cache here so it can be busted when we change the content.
     size_cache: Option<XY<SizeCache>>,
 }
 
@@ -164,8 +205,28 @@ fn strip_last_newline(content: &str) -> &str {
 
 impl TextView {
     /// Creates a new TextView with the given content.
-    pub fn new<S: Into<String>>(content: S) -> Self {
-        TextView::new_with_content(TextContent::new(content))
+    pub fn new<S>(content: S) -> Self
+    where
+        S: Into<String>,
+    {
+        Self::styled(content).unwrap()
+    }
+
+    /// Creates a new TextView by parsing the given content.
+    ///
+    /// # Examples
+    ///
+    /// ```rust,ignore
+    /// # use cursive::views::TextView;
+    /// use cursive::utils::markup::MarkdownText;
+    /// // This will require the `markdown` feature!
+    /// let view = TextView::styled(MarkdownText("**Bold** text"));
+    /// ```
+    pub fn styled<T>(content: T) -> Result<Self, <T::M as Markup>::Error>
+    where
+        T: MarkupText,
+    {
+        TextContent::styled(content).map(TextView::new_with_content)
     }
 
     /// Creates a new TextView using the given `Arc<Mutex<String>>`.
@@ -263,21 +324,62 @@ impl TextView {
     /// Replace the text in this view.
     ///
     /// Chainable variant.
-    pub fn content<S: Into<String>>(self, content: S) -> Self {
-        self.with(|s| s.set_content(content))
+    pub fn content<S>(self, content: S) -> Self
+    where
+        S: Into<String>,
+    {
+        self.markup(content).unwrap()
     }
 
     /// Replace the text in this view.
-    pub fn set_content<S: Into<String>>(&mut self, content: S) {
-        let content = content.into();
-        self.content.lock().unwrap().content = content;
+    ///
+    /// Parse the given markup text.
+    ///
+    /// Chainable variant.
+    pub fn markup<T>(self, content: T) -> Result<Self, <T::M as Markup>::Error>
+    where
+        T: MarkupText,
+    {
+        self.try_with(|s| s.set_markup(content))
+    }
+
+    /// Replace the text in this view.
+    pub fn set_content<S>(&mut self, content: S)
+    where
+        S: Into<String>,
+    {
+        self.set_markup(content).unwrap();
+    }
+
+    /// Replace the text in this view.
+    ///
+    /// Parses the given markup text.
+    pub fn set_markup<T>(
+        &mut self, content: T
+    ) -> Result<(), <T::M as Markup>::Error>
+    where
+        T: MarkupText,
+    {
+        self.content.lock().unwrap().content.set_content(content)?;
         self.invalidate();
+
+        Ok(())
     }
 
     /// Append `content` to the end of a `TextView`.
-    pub fn append_content(&mut self, content: &str) {
-        self.content.lock().unwrap().content.push_str(content);
+    pub fn append_content<T>(
+        &mut self, content: T
+    ) -> Result<(), <T::M as Markup>::Error>
+    where
+        T: MarkupText,
+    {
+        self.content
+            .lock()
+            .unwrap()
+            .content
+            .append_content(content)?;
         self.invalidate();
+        Ok(())
     }
 
     /// Returns the current text in this view.
@@ -365,8 +467,7 @@ impl TextView {
         // First attempt: naively hope that we won't need a scrollbar_width
         // (This means we try to use the entire available width for text).
         self.rows =
-            LinesIterator::new(strip_last_newline(&content.content), size.x)
-                .collect();
+            SpanLinesIterator::new(content.content.spans(), size.x).collect();
 
         // Width taken by the scrollbar. Without a scrollbar, it's 0.
         let mut scrollbar_width = 0;
@@ -382,7 +483,8 @@ impl TextView {
             };
 
             self.rows =
-                LinesIterator::new(&content.content, available).collect();
+                SpanLinesIterator::new(content.content.spans(), available)
+                    .collect();
 
             if self.rows.is_empty() && !content.content.is_empty() {
                 // We have some content, we we didn't find any row for it?
@@ -431,10 +533,17 @@ impl View for TextView {
         printer.with_effect(self.effect, |printer| {
             self.scrollbase.draw(printer, |printer, i| {
                 let row = &self.rows[i];
-                let text = &content.content[row.start..row.end];
-                let l = text.width();
-                let x = self.align.h.get_offset(l, printer.size.x);
-                printer.print((x, 0), text);
+                let l = row.width;
+                let mut x = self.align.h.get_offset(l, printer.size.x);
+
+                for span in row.resolve(content.content.spans()) {
+                    printer.with_style(span.style, |printer| {
+                        printer.print((x, 0), &span.text);
+                        x += span.text.len();
+                    });
+                }
+                // let text = &content.content[row.start..row.end];
+                // printer.print((x, 0), text);
             });
         });
     }

src/with.rs

@@ -5,6 +5,15 @@ pub trait With: Sized {
         f(&mut self);
         self
     }
+
+    /// Calls the given closure on `self`.
+    fn try_with<E, F>(mut self, f: F) -> Result<Self, E>
+    where
+        F: FnOnce(&mut Self) -> Result<(), E>,
+    {
+        f(&mut self)?;
+        Ok(self)
+    }
 }
 
 impl<T: Sized> With for T {}