yx=slidder(varargin)

function yx=slidder(varargin)  
%virtual 2D slider for GUI parameter selection,  integer or float (NaN below minX, minY)
%with 'dataaspectratio' toggle
%Call:
%           yx=slidder([axlims,][integersc])      
%           both  inputs real, of class 'double', integersc>0, 
%           axlims =main selection intervals, similar to         >> axlims=axis
%
%Input:
%		  axlims, default [0 1 0 1],  main xy-intervals, [minX maxX minY maxY], any vector
%		  with 4 elements, 1-st and 2-nd for X, 3-rd and 4-th for Y. The values
%		  below minY, minX are returned as NaN
%
%		  integersc: a two-function scalar input, default 1+eps (no rescaling): 
%          1-st fcn: if round(integersc)==integersc, the output is rounded up to integers
%		   2-nd fcn: if set, the default axlims is rescaled as  axlims*integersc
%Output:
%			yx =[y , x] - values 
% Remark: one can override maxX and maxY by dragging the mouse pointer above
% them. The overriding increases if the decreased SLIDDER window is put to most left bottom position
%           Call examples:
%           yx=slidder                       %'float' slider from (0, 1)
%           yx=slidder(10)                   %integer slider from (0, 10)
%           yx=slidder(20)                   %integer slider from (0, 20)
%           yx=slidder(30*(1+eps))     %'float' slider from  (0, 30*(1+eps))
%
%           yx=slidder([minX maxX minY maxY])                        %'float' slider from input axlims
%           yx=slidder([minX maxX minY maxY],integersc)        %for integersc==round(integersc), or
%           yx=slidder(integersc,[minX maxX minY maxY])        % the output  is rounded  up

%	Vassili Pastushenko	 FEB 6-2008
%=============================================================

C=varargin;         %save inputs

%set defaults and check input vars   
parsque   %parse input queue
integerflag=integersc==round(integersc); %decides on rounding up
%Open slidder figure, adjust axes, define NaN borders
slif=figure;

axis(axlims);
axis tight;
bor=axlims([1 3]);  %lower borders

%set(gca,'dataaspectratio',[1 1 1])
xx=xlim;
yy=ylim;
dx=diff(xx);
dy=diff(yy);
if integerflag&&norm([dx dy])<50
    intgrid
else
    grid on
end
currax=gca;

%get(currax,'position')

set(currax,'fontsize',14,'box','on')
title('Drag ver-hor params. Repeat or finish')
text(xx(1)-.17*dx,yy(1)-.07*dy,'NaN','fontsize',15,'color','r')
text(xx(2)+.06*dx,mean(yy),'                      Finish                   ','backgroundcolor', [1 .4 .4], 'fontsize',18,'rotation',90,'horizontalalignment','center')

%xy=[0 0];
hx=xlabel('NaN','fontsize',17);
hy=ylabel('NaN','fontsize',17);
saspect=get(currax,'dataaspectratio');  %Save ASPECTratio
fhan={@toggleaspect,saspect};
uicontrol('units','normalized','position',[.18,.001,.25,.055],'style','togglebutton', 'string','tog.aspectratio','callback',fhan,'fontsize',14);

deciret=false;  %initial value of DECIsion to RETurn

%Dragging parameters
while 1
decide  % different actions after mouse click or button down
if  deciret   
   yx=[str2num(get(hy,'string')),str2num(  get(hx,'string'))];
   voice=sum(~isnan(yx));     
   if voice>0     
   cheer(voice);
   else
       o_o;
   end
        clear fhan
        delete(slif)
    return 
end
        set(slif,'WindowButtonMotionFcn',@followpointer,'WindowButtonUpFcn',@stopmouse);
        uiwait       
end

    function followpointer(obj,cas)
        xy=get(currax,'currentpoint');
        xy=xy(2:3);
          xy(xy<bor)=NaN;
        if integerflag
          xy=round(xy);
        end
        
              set(hy,'string',num2str(xy(2)))
              set(hx,'string',num2str(xy(1)))
              
    end

function  stopmouse(obj,cas)
 %recover WindowButtonFcn's Motion and Up
 set(slif,'WindowButtonMotionFcn',[],'WindowButtonUpFcn',[]);
 uiresume
end 


    function decide
       waitforbuttonpress
        dd=get(gca,'currentpoint');
        dd=dd(2:3);
        XXX=xlim;
       deciret=dd(1)>XXX(2);
    end

    function parsque
       %set defaults
     axlims=[0 1 0 1];   %default axis
     integersc=1+eps;           %no rounding up, no rescaling
        N=numel(C);
         rescale=N==1;   %assuming   input were  integersc
if N>2
    error('Too many inputs')
end
 
        for i=1:N
            loc=C{i};
        id=class(loc);
        if ~strmatch(id,'double','exact')
            error('Double expected')   %only class 'double' expected
        end

        if isscalar(loc)
              if ~isreal(loc)||loc<=0,error('positive integersc expected');end
        integersc=loc;
        end
        
        if numel(loc)==4
            if ~isreal(loc),error('real axlims expected');end
            axlims=loc(:)';
            axlims(1:2)=sort(axlims(1:2));
            axlims(3:4)=sort(axlims(3:4));
            rescale=false;
        end

        end       
if rescale
    axlims=axlims*integersc;  %default axlims rescaled
end

    end
    function intgrid
        XX=ceil(xx(1)):floor(xx(2));    
YY=ceil(yy(1)):floor(yy(2))';
XP=repmat(XX,numel(YY),1);
YP=repmat(YY,1,numel(XX));
hold on
plot(XP(:),YP(:),'b.')
hold off
    end
function toggleaspect(ob,cas,saspect)
        cur=get(currax,'dataaspectratio');
        if norm(cur-[1 1 1])>1e-3
        set(currax,'dataaspectratio',[1 1 1])
        else
            set(currax,'dataaspectratio',saspect)
        end
end
end