azul-text-layout 0.0.4

Text layout algorithms Azul desktop GUI framework
Documentation 
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//! General crate for text layout / text shaping
//!
//! ![Text layout functions and ](https://i.imgur.com/1T7a1VR.png)
//!
//! # Example
//!
//! ```rust,ignore,no_run
//! use azul_text_layout::{
//!     text_layout::{split_text_into_words, words_to_scaled_words},
//!     text_shaping::get_font_metrics_freetype,
//! };
//!
//! let text = "hello";
//! let font_size = 14.0; // px
//! let font = include_bytes!("Helvetica.ttf");
//! let font_index = 0; // only for fonts with font collections
//! let font_metrics = get_font_metrics_freetype(&font, font_index);
//! let words = split_text_into_words(text);
//! let scaled_words = words_to_scaled_words(&words, &font, font_index as u32, font_metrics, font_size);
//!
//! let total_width = scaled_words.items.iter().map(|i| i.word_width).sum();
//! ```
//!
//! # Full text layout
//!
//! ```rust,ignore,no_run
//! use azul_text_layout::{text_layout, text_shaping::get_font_metrics_freetype};
//! use azul_css::{LayoutSize, StyleTextAlignmentHorz};
//! use azul_core::ui_solver::ResolvedTextLayoutOptions;
//!
//! // set all options of the text
//! let text = "hello";
//! let font_size = 14.0; // px
//! let font_bytes = include_bytes!("Helvetica.ttf");
//! let font_index = 0; // only for fonts with font collections
//! let text_layout_options = ResolvedTextLayoutOptions {
//!     font_size_px: font_size,
//!     line_height: None,
//!     letter_spacing: None,
//!     word_spacing: None,
//!     tab_width: None,
//!     // for line breaking, maximum width that a line can have
//!     max_horizontal_width: Some(400.0), // px
//!     leading: None,
//!     holes: Vec::new(),
//! };
//!
//! // Cache the font metrics of the given font (baseline, height, etc.)
//! let font_metrics = get_font_metrics_freetype(font_bytes, font_index as i32);
//! // "Hello World" => ["Hello", "World"]
//! let words = text_layout::split_text_into_words(text);
//! // "Hello" @ 14px => Size { width: 50px, height: 14px }
//! let scaled_words = text_layout::words_to_scaled_words(&words, font_bytes, font_index, font_metrics, text_layout_options.font_size_px);
//! // Calculate the origin of the word relative to the line
//! let word_positions = text_layout::position_words(&words, &scaled_words, &text_layout_options);
//! // Calculate the origin of the line relative to (0, 0)
//! let mut inline_text_layout = text_layout::word_positions_to_inline_text_layout(&word_positions, &scaled_words);
//! // Align the line horizontally
//! inline_text_layout.align_children_horizontal(StyleTextAlignmentHorz::Center);
//! // Calculate the glyph positons (line_offset + word_offset + glyph_offset)
//! let layouted_glyphs = text_layout::get_layouted_glyphs(&word_positions, &scaled_words, &inline_text_layout);
//!
//! println!("{:#?}", inline_text_layout); // get infos about word offset, line breaking, etc.
//! println!("{:#?}", layouted_glyphs); // get the final glyph positions relative to the origin
//! ```

#![doc(
    html_logo_url = "https://raw.githubusercontent.com/maps4print/azul/master/assets/images/azul_logo_full_min.svg.png",
    html_favicon_url = "https://raw.githubusercontent.com/maps4print/azul/master/assets/images/favicon.ico",
)]

extern crate azul_css;
extern crate azul_core;
extern crate unicode_normalization;
extern crate harfbuzz_sys;
extern crate freetype; // necessary to get baseline of font

pub mod text_layout;
pub mod text_shaping;

use azul_core::{
    traits::GetTextLayout,
    ui_solver::{ResolvedTextLayoutOptions, InlineTextLayout},
    app_resources::{Words, ScaledWords},
};

#[derive(Debug, Clone)]
pub struct InlineText<'a> {
    pub words: &'a Words,
    pub scaled_words: &'a ScaledWords,
}

impl<'a> GetTextLayout for InlineText<'a> {
    fn get_text_layout(&mut self, text_layout_options: &ResolvedTextLayoutOptions) -> InlineTextLayout {
        let layouted_text_block = text_layout::position_words(
            self.words,
            self.scaled_words,
            text_layout_options,
        );
        // TODO: Cache the layouted text block on the &mut self
        text_layout::word_positions_to_inline_text_layout(&layouted_text_block, &self.scaled_words)
    }
}