Struct conrod::GlyphCache

pub struct GlyphCache<C>(_);

A wrapper over some CharacterCache, exposing it's functionality via a RefCell.

Methods

impl<C> GlyphCache<C> where C: CharacterCache

fn char_width(&self, font_size: FontSize, ch: char) -> f64

Return the width of a character.

fn width(&self, font_size: FontSize, text: &str) -> f64

Return the width of the given text.

Methods from Deref<Target=RefCell<C>>

fn into_inner(self) -> T

Consumes the RefCell, returning the wrapped value.

Examples

use std::cell::RefCell;

let c = RefCell::new(5);

let five = c.into_inner();

fn borrow_state(&self) -> BorrowState

Unstable (borrow_state)

Query the current state of this RefCell

The returned value can be dispatched on to determine if a call to borrow or borrow_mut would succeed.

Examples

#![feature(borrow_state)]

use std::cell::{BorrowState, RefCell};

let c = RefCell::new(5);

match c.borrow_state() {
    BorrowState::Writing => println!("Cannot be borrowed"),
    BorrowState::Reading => println!("Cannot be borrowed mutably"),
    BorrowState::Unused => println!("Can be borrowed (mutably as well)"),
}

fn borrow(&self) -> Ref<T>

Immutably borrows the wrapped value.

The borrow lasts until the returned Ref exits scope. Multiple immutable borrows can be taken out at the same time.

Panics

Panics if the value is currently mutably borrowed.

Examples

use std::cell::RefCell;

let c = RefCell::new(5);

let borrowed_five = c.borrow();
let borrowed_five2 = c.borrow();

An example of panic:

use std::cell::RefCell;
use std::thread;

let result = thread::spawn(move || {
   let c = RefCell::new(5);
   let m = c.borrow_mut();

   let b = c.borrow(); // this causes a panic
}).join();

assert!(result.is_err());

fn borrow_mut(&self) -> RefMut<T>

Mutably borrows the wrapped value.

The borrow lasts until the returned RefMut exits scope. The value cannot be borrowed while this borrow is active.

Panics

Panics if the value is currently borrowed.

Examples

use std::cell::RefCell;

let c = RefCell::new(5);

*c.borrow_mut() = 7;

assert_eq!(*c.borrow(), 7);

An example of panic:

use std::cell::RefCell;
use std::thread;

let result = thread::spawn(move || {
   let c = RefCell::new(5);
   let m = c.borrow();

   let b = c.borrow_mut(); // this causes a panic
}).join();

assert!(result.is_err());

unsafe fn as_unsafe_cell(&self) -> &UnsafeCell<T>

Unstable (as_unsafe_cell)

Returns a reference to the underlying UnsafeCell.

This can be used to circumvent RefCell's safety checks.

This function is unsafe because UnsafeCell's field is public.

Examples

#![feature(as_unsafe_cell)]

use std::cell::RefCell;

let c = RefCell::new(5);
let c = unsafe { c.as_unsafe_cell() };

fn get_mut(&mut self) -> &mut T

Returns a mutable reference to the underlying data.

This call borrows RefCell mutably (at compile-time) so there is no need for dynamic checks.

Examples

use std::cell::RefCell;

let mut c = RefCell::new(5);
*c.get_mut() += 1;

assert_eq!(c, RefCell::new(6));

Trait Implementations

impl<C> Deref for GlyphCache<C>

type Target = RefCell<C>

The resulting type after dereferencing

fn deref<'a>(&'a self) -> &'a RefCell<C>

The method called to dereference a value

impl<C> DerefMut for GlyphCache<C>

fn deref_mut<'a>(&'a mut self) -> &'a mut RefCell<C>

The method called to mutably dereference a value