58 lines
1.4 KiB
Ruby
58 lines
1.4 KiB
Ruby
module Risc
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module Position
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class ObjectPosition
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attr_reader :at , :object
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def initialize( object, at)
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@at = at
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@object = object
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@listeners = []
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raise "not int #{self}-#{at}" unless @at.is_a?(Integer)
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end
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def +(offset)
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offset = offset.at if offset.is_a?(ObjectPosition)
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@at + offset
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end
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def -(offset)
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offset = offset.at if offset.is_a?(ObjectPosition)
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@at - offset
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end
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def to_s
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"0x#{@at.to_s(16)}"
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end
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# just a callback after creation AND insertion
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def init(pos , is_nil)
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end
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def reset_to(pos , guaranteed_nil )
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return false if pos == at
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if((at - pos).abs > 1000)
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raise "position set too far off #{pos}!=#{at} for #{object}:#{object.class}"
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end
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@at = pos
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true
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end
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# Register a handler position change event.
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# The object calls position_changed on the handler object
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#
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# obj.position_changed( changed_position )
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#
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# @param [Object] object handling position_changed
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def register_listener( handler)
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@listeners << handler
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end
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def unregister_listener(handler)
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@listeners.delete handler
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end
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# Trigger position change and pass self to position_changed
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def trigger()
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@listeners.each { |handler| handler.position_changed( self ) }
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end
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end
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end
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end
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