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@matthewtodd
Created December 4, 2010 07:34
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Resize an OSX display with RubyCocoa.
require 'osx/cocoa'
class Screen
class << self
def resize(width, height, &block)
new.resize(width, height, &block)
end
end
def initialize(screen = OSX::CGMainDisplayID())
@screen = screen
@mode = OSX::CGDisplayCopyDisplayMode(@screen)
end
def resize(width, height, &block)
configure(best_mode(width, height))
block.call
ensure
configure(@mode)
end
private
def best_mode(width, height)
# TODO Try to figure out color depth from CGDisplayModeCopyPixelEncoding?
OSX::CGDisplayCopyAllDisplayModes(@screen, nil).detect do |mode|
OSX::CGDisplayModeGetWidth(mode) == width &&
OSX::CGDisplayModeGetHeight(mode) == height &&
OSX::CGDisplayModeIsUsableForDesktopGUI(mode)
end
end
def configure(mode)
result, config = OSX::CGBeginDisplayConfiguration()
if result == OSX::KCGErrorSuccess
OSX::CGConfigureDisplayWithDisplayMode(config, @screen, mode, nil)
OSX::CGCompleteDisplayConfiguration(config, OSX::KCGConfigureForSession)
else
raise "I have no clue what just happened: #{result}"
end
end
end
@arichar6
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Is there a way to modify this to set the resolution of a secondary display? I'm pretty new to this, and unsure how I'd modify it...

@matthewtodd
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Hi! I'm pretty new to this stuff, too. (See line 39.)

You see how OSX::CGMainDisplayID() is the default screen parameter in line 10. I think you'd need to use one of the other Quartz Display Services to look up a different display id to pass in, perhaps CGGetOnlineDisplayList?

@arichar6
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Cool, thanks... I'll see what I can figure out using CGGetOnlineDisplayList

@fabiopigi
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Hi

How's the usage? How can I use this in the Terminal?
Thanks a lot
Fabio

@matthewtodd
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Hi, Fabio, sorry for my late reply. I've been traveling for some time now.

You'll be best off getting more comfortable with Ruby in particular and shell-scripting in general. I hope you'll kindly understand that I'm not able to help you with that here.

@grillermo
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I would love to see usage in ruby, i'm unsure of the syntax expected.

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