pango/

functions.rs

// Take a look at the license at the top of the repository in the LICENSE file.

use glib::translate::*;
use std::{ffi::c_char, ptr};

pub use crate::auto::functions::*;
#[cfg(feature = "v1_44")]
use crate::ShapeFlags;
use crate::{ffi, Analysis, GlyphString, Item};

/// Reorder items from logical order to visual order.
///
/// The visual order is determined from the associated directional
/// levels of the items. The original list is unmodified.
///
/// (Please open a bug if you use this function.
///  It is not a particularly convenient interface, and the code
///  is duplicated elsewhere in Pango for that reason.)
/// ## `items`
/// a `GList` of [`Item`][crate::Item]
///   in logical order.
///
/// # Returns
///
/// a `GList`
///   of [`Item`][crate::Item] structures in visual order.
#[doc(alias = "pango_reorder_items")]
pub fn reorder_items(logical_items: &glib::List<Item>) -> glib::List<Item> {
    unsafe {
        FromGlibPtrContainer::from_glib_full(ffi::pango_reorder_items(
            logical_items.as_ptr() as *mut _
        ))
    }
}

/// Convert the characters in @text into glyphs.
///
/// Given a segment of text and the corresponding [`Analysis`][crate::Analysis] structure
/// returned from [`itemize()`][crate::itemize()], convert the characters into glyphs.
/// You may also pass in only a substring of the item from [`itemize()`][crate::itemize()].
///
/// This is similar to [`shape()`][crate::shape()], except it also can optionally take
/// the full paragraph text as input, which will then be used to perform
/// certain cross-item shaping interactions. If you have access to the broader
/// text of which @item_text is part of, provide the broader text as
/// @paragraph_text. If @paragraph_text is [`None`], item text is used instead.
///
/// Some aspects of hyphen insertion and text transformation (in particular,
/// capitalization) require log attrs, and thus can only be handled by
/// `shape_item()`.
///
/// Note that the extra attributes in the @analyis that is returned from
/// [`itemize()`][crate::itemize()] have indices that are relative to the entire paragraph,
/// so you do not pass the full paragraph text as @paragraph_text, you need
/// to subtract the item offset from their indices before calling
/// [`shape_full()`][crate::shape_full()].
/// ## `item_text`
/// valid UTF-8 text to shape.
/// ## `item_length`
/// the length (in bytes) of @item_text. -1 means nul-terminated text.
/// ## `paragraph_text`
/// text of the paragraph (see details).
/// ## `paragraph_length`
/// the length (in bytes) of @paragraph_text. -1 means nul-terminated text.
/// ## `analysis`
/// [`Analysis`][crate::Analysis] structure from [`itemize()`][crate::itemize()].
/// ## `glyphs`
/// glyph string in which to store results.
#[doc(alias = "pango_shape_full")]
pub fn shape_full(
    item_text: &str,
    paragraph_text: Option<&str>,
    analysis: &Analysis,
    glyphs: &mut GlyphString,
) {
    let item_length = item_text.len() as i32;
    let paragraph_length = paragraph_text.map(|t| t.len() as i32).unwrap_or_default();
    let paragraph_ptr = paragraph_text.map_or(ptr::null(), |t| t.as_ptr() as *const c_char);
    unsafe {
        // The function does not take null-terminated strings when a length is provided.
        // It also requires item_text to point to a subsequence of paragraph_text.
        // Using to_glib_none() on &str will copy the string and cause problems.
        ffi::pango_shape_full(
            item_text.as_ptr() as *const c_char,
            item_length,
            paragraph_ptr,
            paragraph_length,
            analysis.to_glib_none().0,
            glyphs.to_glib_none_mut().0,
        );
    }
}

/// Convert the characters in @text into glyphs.
///
/// Given a segment of text and the corresponding [`Analysis`][crate::Analysis] structure
/// returned from [`itemize()`][crate::itemize()], convert the characters into glyphs.
/// You may also pass in only a substring of the item from [`itemize()`][crate::itemize()].
///
/// This is similar to [`shape_full()`][crate::shape_full()], except it also takes flags
/// that can influence the shaping process.
///
/// Some aspects of hyphen insertion and text transformation (in particular,
/// capitalization) require log attrs, and thus can only be handled by
/// `shape_item()`.
///
/// Note that the extra attributes in the @analyis that is returned from
/// [`itemize()`][crate::itemize()] have indices that are relative to the entire paragraph,
/// so you do not pass the full paragraph text as @paragraph_text, you need
/// to subtract the item offset from their indices before calling
/// [`shape_with_flags()`][crate::shape_with_flags()].
/// ## `item_text`
/// valid UTF-8 text to shape
/// ## `item_length`
/// the length (in bytes) of @item_text.
///     -1 means nul-terminated text.
/// ## `paragraph_text`
/// text of the paragraph (see details).
/// ## `paragraph_length`
/// the length (in bytes) of @paragraph_text.
///     -1 means nul-terminated text.
/// ## `analysis`
/// [`Analysis`][crate::Analysis] structure from [`itemize()`][crate::itemize()]
/// ## `glyphs`
/// glyph string in which to store results
/// ## `flags`
/// flags influencing the shaping process
#[cfg(feature = "v1_44")]
#[cfg_attr(docsrs, doc(cfg(feature = "v1_44")))]
#[doc(alias = "pango_shape_with_flags")]
pub fn shape_with_flags(
    item_text: &str,
    paragraph_text: Option<&str>,
    analysis: &Analysis,
    glyphs: &mut GlyphString,
    flags: ShapeFlags,
) {
    let item_length = item_text.len() as i32;
    let paragraph_length = paragraph_text.map(|t| t.len() as i32).unwrap_or_default();
    let paragraph_ptr = paragraph_text.map_or(ptr::null(), |t| t.as_ptr() as *const c_char);
    unsafe {
        // See: shape_full
        ffi::pango_shape_with_flags(
            item_text.as_ptr() as *const c_char,
            item_length,
            paragraph_ptr,
            paragraph_length,
            analysis.to_glib_none().0,
            glyphs.to_glib_none_mut().0,
            flags.into_glib(),
        );
    }
}

/// Converts extents from Pango units to device units.
///
/// The conversion is done by dividing by the `PANGO_SCALE` factor and
/// performing rounding.
///
/// The @inclusive rectangle is converted by flooring the x/y coordinates
/// and extending width/height, such that the final rectangle completely
/// includes the original rectangle.
///
/// The @nearest rectangle is converted by rounding the coordinates
/// of the rectangle to the nearest device unit (pixel).
///
/// The rule to which argument to use is: if you want the resulting device-space
/// rectangle to completely contain the original rectangle, pass it in as
/// @inclusive. If you want two touching-but-not-overlapping rectangles stay
/// touching-but-not-overlapping after rounding to device units, pass them in
/// as @nearest.
/// ## `inclusive`
/// rectangle to round to pixels inclusively
/// ## `nearest`
/// rectangle to round to nearest pixels
#[doc(alias = "pango_extents_to_pixels")]
pub fn extents_to_pixels(
    mut inclusive: Option<&mut crate::Rectangle>,
    mut nearest: Option<&mut crate::Rectangle>,
) {
    unsafe {
        ffi::pango_extents_to_pixels(inclusive.to_glib_none_mut().0, nearest.to_glib_none_mut().0);
    }
}