Module: Ruby2D::CLI::Browser::WinConsole

Defined in:
lib/ruby2d/cli/browser.rb

Overview

Drives the Win32 console input mode through SetConsoleMode, because native-Windows Ruby's io/console raw is unreliable here (confirmed on aarch64-mingw-ucrt: raw left LINE/ECHO input enabled). Enabling VIRTUAL_TERMINAL_INPUT is what makes arrow keys arrive as \e[A sequences instead of being swallowed. All Fiddle use is lazy and failure-tolerant: any problem returns nil and the caller falls back to the plain io/console path.

Constant Summary collapse

STD_INPUT_HANDLE = 
-10
PROCESSED_INPUT = 
0x0001
LINE_INPUT = 
0x0002
ECHO_INPUT = 
0x0004
VT_INPUT = 
0x0200

Class Method Summary collapse

Class Method Details

.api ⇒ Object

Lazily resolve the three kernel32 calls we need; memoize the result (nil if Fiddle or the console API is unavailable).



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# File 'lib/ruby2d/cli/browser.rb', line 39

def self.api
  unless @resolved
    @resolved = true
    @api =
      begin
        require 'fiddle'
        k32 = Fiddle.dlopen('kernel32')
        {
          get_handle: Fiddle::Function.new(k32['GetStdHandle'],   [Fiddle::TYPE_LONG], Fiddle::TYPE_VOIDP),
          get_mode:   Fiddle::Function.new(k32['GetConsoleMode'],  [Fiddle::TYPE_VOIDP, Fiddle::TYPE_VOIDP], Fiddle::TYPE_INT),
          set_mode:   Fiddle::Function.new(k32['SetConsoleMode'],  [Fiddle::TYPE_VOIDP, Fiddle::TYPE_LONG], Fiddle::TYPE_INT)
        }
      rescue LoadError, StandardError
        nil
      end
  end
  @api
end

.enable_raw ⇒ Object

Switch the console to raw + virtual-terminal input. Returns the prior mode (to hand back to restore), or nil when there's no console to set (Fiddle missing, stdin redirected, GetConsoleMode failed).



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# File 'lib/ruby2d/cli/browser.rb', line 61

def self.enable_raw
  fns = api or return nil
  handle = fns[:get_handle].call(STD_INPUT_HANDLE)
  buf = Fiddle::Pointer.malloc(Fiddle::SIZEOF_INT, Fiddle::RUBY_FREE)
  return nil if fns[:get_mode].call(handle, buf) == 0
  prev = buf[0, Fiddle::SIZEOF_INT].unpack1('L')
  fns[:set_mode].call(handle, (prev & ~(LINE_INPUT | ECHO_INPUT | PROCESSED_INPUT)) | VT_INPUT)
  prev
end

.reassert_raw ⇒ Object

Re-apply raw + VT without disturbing the saved prior mode — used after a child example returns, in case it left the shared console mode changed.



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# File 'lib/ruby2d/cli/browser.rb', line 74

def self.reassert_raw
  enable_raw
end

.restore(prev) ⇒ Object 



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# File 'lib/ruby2d/cli/browser.rb', line 78

def self.restore(prev)
  return if prev.nil?
  fns = api or return
  fns[:set_mode].call(fns[:get_handle].call(STD_INPUT_HANDLE), prev)
end