gtk/
rt.rs

1// Copyright 2013-2015, The Gtk-rs Project Developers.
2// See the COPYRIGHT file at the top-level directory of this distribution.
3// Licensed under the MIT license, see the LICENSE file or <http://opensource.org/licenses/MIT>
4
5use gdk;
6use glib;
7use glib::translate::*;
8use gtk_sys;
9use libc::c_uint;
10use std::cell::Cell;
11use std::ptr;
12use std::sync::atomic::{AtomicBool, Ordering, ATOMIC_BOOL_INIT};
13
14thread_local! {
15    static IS_MAIN_THREAD: Cell<bool> = Cell::new(false)
16}
17
18static INITIALIZED: AtomicBool = ATOMIC_BOOL_INIT;
19
20/// Asserts that this is the main thread and `gtk::init` has been called.
21macro_rules! assert_initialized_main_thread {
22    () => {
23        if !::rt::is_initialized_main_thread() {
24            if ::rt::is_initialized() {
25                panic!("GTK may only be used from the main thread.");
26            } else {
27                panic!("GTK has not been initialized. Call `gtk::init` first.");
28            }
29        }
30    };
31}
32
33/// No-op.
34macro_rules! skip_assert_initialized {
35    () => {};
36}
37
38/// Asserts that `gtk::init` has not been called.
39#[allow(unused_macros)]
40macro_rules! assert_not_initialized {
41    () => {
42        if ::rt::is_initialized() {
43            panic!("This function has to be called before `gtk::init`.");
44        }
45    };
46}
47
48/// Returns `true` if GTK has been initialized.
49#[inline]
50pub fn is_initialized() -> bool {
51    skip_assert_initialized!();
52    INITIALIZED.load(Ordering::Acquire)
53}
54
55/// Returns `true` if GTK has been initialized and this is the main thread.
56#[inline]
57pub fn is_initialized_main_thread() -> bool {
58    skip_assert_initialized!();
59    IS_MAIN_THREAD.with(|c| c.get())
60}
61
62/// Informs this crate that GTK has been initialized and the current thread is the main one.
63pub unsafe fn set_initialized() {
64    skip_assert_initialized!();
65    if is_initialized_main_thread() {
66        return;
67    } else if is_initialized() {
68        panic!("Attempted to initialize GTK from two different threads.");
69    }
70    gdk::set_initialized();
71    INITIALIZED.store(true, Ordering::Release);
72    IS_MAIN_THREAD.with(|c| c.set(true));
73}
74
75/// Tries to initialize GTK+.
76///
77/// Call either this function or [`Application::new`][new] before using any
78/// other GTK+ functions.
79///
80/// [new]: struct.Application.html#method.new
81///
82/// Note that this function calls `gtk_init_check()` rather than `gtk_init()`,
83/// so will not cause the program to terminate if GTK could not be initialized.
84/// Instead, an Ok is returned if the windowing system was successfully
85/// initialized otherwise an Err is returned.
86pub fn init() -> Result<(), glib::BoolError> {
87    skip_assert_initialized!();
88    if is_initialized_main_thread() {
89        return Ok(());
90    } else if is_initialized() {
91        panic!("Attempted to initialize GTK from two different threads.");
92    }
93    unsafe {
94        if from_glib(gtk_sys::gtk_init_check(ptr::null_mut(), ptr::null_mut())) {
95            if !glib::MainContext::default().acquire() {
96                return Err(glib_bool_error!("Failed to acquire default main context"));
97            }
98
99            set_initialized();
100            Ok(())
101        } else {
102            Err(glib_bool_error!("Failed to initialize GTK"))
103        }
104    }
105}
106
107pub fn main_quit() {
108    assert_initialized_main_thread!();
109    unsafe {
110        if gtk_sys::gtk_main_level() > 0 {
111            gtk_sys::gtk_main_quit();
112        } else if cfg!(debug_assertions) {
113            panic!("Attempted to quit a GTK main loop when none is running.");
114        }
115    }
116}
117
118pub fn get_major_version() -> u32 {
119    skip_assert_initialized!();
120    unsafe { gtk_sys::gtk_get_major_version() as u32 }
121}
122
123pub fn get_minor_version() -> u32 {
124    skip_assert_initialized!();
125    unsafe { gtk_sys::gtk_get_minor_version() as u32 }
126}
127
128pub fn get_micro_version() -> u32 {
129    skip_assert_initialized!();
130    unsafe { gtk_sys::gtk_get_micro_version() as u32 }
131}
132
133pub fn get_binary_age() -> u32 {
134    skip_assert_initialized!();
135    unsafe { gtk_sys::gtk_get_binary_age() as u32 }
136}
137
138pub fn get_interface_age() -> u32 {
139    skip_assert_initialized!();
140    unsafe { gtk_sys::gtk_get_interface_age() as u32 }
141}
142
143pub fn check_version(
144    required_major: u32,
145    required_minor: u32,
146    required_micro: u32,
147) -> Option<String> {
148    skip_assert_initialized!();
149    unsafe {
150        from_glib_none(gtk_sys::gtk_check_version(
151            required_major as c_uint,
152            required_minor as c_uint,
153            required_micro as c_uint,
154        ))
155    }
156}