Keylogger.m

classdef Keylogger < handle
    properties( SetAccess = private )
        deviceIndex %keyboard device index
        startTime %timestamp when keylogger was started
    end
    
    methods
        %% CLASS CONSTRUCTOR
        % called when an object is initialized
        function this = Keylogger( deviceIndex )
            if nargin < 1
                deviceIndex = [];
            end
            
            this.deviceIndex = deviceIndex;
            this.startTime = [];
        end
        
        %% PUBLIC FUNCTIONS
        function startRecording( this,startTime )
            KbQueueCreate( this.deviceIndex );
            KbQueueStart( this.deviceIndex );
            KbQueueFlush( this.deviceIndex );
            
            if nargin > 1
                this.startTime = startTime;
            else
                this.startTime = GetSecs();
            end
        end
        
        function stopRecording( this )
            KbQueueStop( this.deviceIndex );
        end
        
        function KeyLog = dumpLog( this )
            this.stopRecording();
            
            
            KbName( 'UnifyKeyNames' );
            
            eventsNum = KbEventAvail( this.deviceIndex );
            KeyLog = repmat( struct( 'keyName',[],'onset',[],'eventType',[],'keyCode',[],'timeStamp',[],'pressed',[] ),1,eventsNum );
            for i = 1:eventsNum
                KbEvent = KbEventGet( this.deviceIndex );
                
                %'readable' output
                KeyLog(i).keyName = KbName( KbEvent.Keycode );
                KeyLog(i).onset = KbEvent.Time-this.startTime;
                if KbEvent.Pressed
                    eventType = 'press';
                else
                    eventType = 'release';
                end
                KeyLog(i).eventType = eventType;
                
                %raw output
                KeyLog(i).keyCode = KbEvent.Keycode;
                KeyLog(i).timeStamp = KbEvent.Time;
                KeyLog(i).pressed = KbEvent.Pressed;
            end
        end
    end
    
    methods( Static )
        function cleanup()
            KbQueueStop();
            KbQueueRelease();
        end
    end
end