crossterm/src/kernel/windows_kernel/ansi_support.rs

//! This module handles the enabling `ANSI escape codes` for windows terminals.

use IStateCommand;
use std::sync::{Once, ONCE_INIT};

static mut HAS_BEEN_TRYED_TO_ENABLE: bool = false;
static mut IS_ANSI_ON_WINDOWS_ENABLED: Option<bool> = None;
static mut DOES_WINDOWS_SUPPORT_ANSI:  Option<bool>  = None;
static START: Once = ONCE_INIT;

/// Try enable `ANSI escape codes` and return the result.
pub fn try_enable_ansi_support() -> bool
{
    START.call_once(|| {
        use state::commands::win_commands::EnableAnsiCommand;
        let mut command = EnableAnsiCommand::new();
        let success = command.execute();

        set_is_windows_ansi_supportable(success);
        set_ansi_enabled(success);
        has_been_tried_to_enable(true);
    });

   windows_supportable()
}

/// Get whether ansi has been enabled.
pub fn ansi_enabled() -> bool
{
    unsafe { IS_ANSI_ON_WINDOWS_ENABLED.unwrap_or_else(| | false) }
}

/// Get whether windows supports ansi
pub fn windows_supportable() -> bool
{
    unsafe { DOES_WINDOWS_SUPPORT_ANSI.unwrap_or_else(| | false)}
}

/// Get whether ansi has been tried to enable before.
pub fn has_been_tried_to_enable_ansi() -> bool
{
    unsafe
    {
        return HAS_BEEN_TRYED_TO_ENABLE;
    }
}

/// Set the is ansi escape property enabled or disabled. So whe can determine if the ansi escape codes are enabled.
pub fn set_ansi_enabled(is_enabled :bool)
{
    unsafe
    {
        IS_ANSI_ON_WINDOWS_ENABLED = Some(is_enabled);
    }
}

/// Set the is_windows_ansi_supportable property. So whe can determine whether windows supports ansi.
fn set_is_windows_ansi_supportable(is_enabled :bool)
{
    unsafe
    {
        DOES_WINDOWS_SUPPORT_ANSI = Some(is_enabled);
    }
}

/// Set the has_been_tried_to_enable property. So we can determine whether ansi has been tried to enable before.
fn has_been_tried_to_enable(has_been_tried: bool)
{
    unsafe
    {
        HAS_BEEN_TRYED_TO_ENABLE = has_been_tried;
    }
}