function g = GUIflow(options,ea)
% This window specifies the flow of the water around the sphere
% Choose a stream function from the pull-down menu:
% 
%   Stokes flow. This is the analytical solution to the linearised
%     flow equation, useful at low Reynolds numbers.
%   Numerical Navier-Stokes solver. This solves the non-linear
%     equations for the flow around the translating sphere. You should
%     start with small computational grids; otherwise you may experience
%     very long computational times (several hours).
%   Free flow. Here the velocity is constant in space.
%   Spherical pump. This is also Stokes approximation, but of the
%     spherical pump flow, where water is flowing through the sphere
%     with constant velocity inside the sphere.
% 
% You can have plotted the stream function itself, or various component
% of the flow field: The flow velocity vector using a ''quiver'' plot,
% velocity compenents in various directions, deformation, or vorticity.
% 
% Each of these plots can be made as contour lines (careful for large
% grids: it takes long to compute contour lines), surf plots, or profiles
% in the polar line or the equitorial plane. In addition, the flow
% velocity vector can be plotted as quiver plots, i.e. you see arrows
% indicating the vectors.
% 
% For contour lines, you can have the program choose contour values 
% automatically, or you can set them manually through a vector of values, 
% e.g. [1,2,3] or 1:3
 
% DOCUMENTATION FOR THE DEVELOPER   
%
% GUIflow - constructor for the GUI flow object
%
% Syntax: g = GUIflow(options)
%
% IF no GUIflow object exists, then one is constructed when this
% function is called. In this case options (if present) ...
%
% At most one GUIflow object can live at once.
%
% If there exists a GUIflow object, then the options is interpreted
% as an action to modify this object and is passed on to GUIflowAction.
%
% The GUIflow object is returned in g. 
%
% Written by Uffe H. Thygesen, 2000. See the README file for 
% no warranty, copyleft and distribution issues.

persistent NotFirstTime TheGUIflow

if nargin==0,
   options = [];
end

if isempty(NotFirstTime),
   NotFirstTime = 1;
   StreamStrings = {'Stokes','Numerical N-S solver','Free','Pump'};
   % Streamstrings which we do not present:
   % 'PP Multiplicative','Oseen','PP Additive','PP Inner','PP Outer','PP I/O','PP Convex'
   PlotObjectNames = {'Stream function','Flow field','Ur','Ut','Ux','Uz','Deformation','Vorticity','Coagulation Kernel'};
   PlotStyleNames = {'Contour','Surf','Pole','Equator','Quiver'};
   
   dummy = GUIflowFig(StreamStrings,PlotObjectNames,PlotStyleNames);

   TheGUIflow = class(dummy,'GUIflow');
   TheGUIflow = GUIflowAction(TheGUIflow,'refresh');
else
   if ~isempty(options)
      TheGUIflow = GUIflowAction(TheGUIflow,options);
   end
end

if nargout ==1,
   g = TheGUIflow;
end

return

function pars = GUIflowFig(StreamStrings,PlotObjectNames,PlotStyleNames)

% Declare class fields; to be filled later
pars.FlowField = [];
pars.StreamFunctionField = [];
pars.AutoCLVS = [];
pars.UserCLVS = [];
pars.Reynold = [];
pars.psi = [];
pars.PsiNames = StreamStrings;
pars.ObjectNames = PlotObjectNames;
pars.StyleNames = PlotStyleNames;

% Layout parameters
figpos = [1 3 85 25];
textdim = [14 1.5];
blockx = [55];
blocky = [0.5];
editdim = [14 1.5];
editx = 70;
ydiff = 1.5;

h0 = figure('Units','char', ...
	'ResizeFcn','Resize(GUIflow)',...
	'Name','Flow field',...
    'PaperPositionMode','auto',...
	'Color',[0.8 0.8 0.8], ...
	'Position',figpos, ...
	'Tag','GUIflowFig');

pars.FigHandle = h0;
pars.AxesPos   = [4 2 47 20];

h1 = axes('Parent',h0, ...
	'Units','char', ...
	'CameraUpVector',[0 1 0], ...
	'CameraUpVectorMode','manual', ...
	'Color',[1 1 1], ...
	'Position',pars.AxesPos, ...
	'Tag','GUIflowAxes', ...
	'XColor',[0 0 0], ...
	'YColor',[0 0 0], ...
	'ZColor',[0 0 0]);

pars.AxesHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+15.3*ydiff  editdim], ...
	'String','Flow', ...
	'hor','left',...
    'Style','text', ...
	'Tag','StaticText1');

pars.StrfunTextHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''stream'')', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+14.5*ydiff editx+editdim(1)-blockx ydiff], ...
	'String',StreamStrings, ...
	'Style','popupmenu', ...
	'Tag','GUIflowStream', ...
	'Value',1);

pars.StreamHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'BackgroundColor',[1 1 1], ...
	'Callback','GUIflow(''Re'')', ...
	'ListboxTop',0, ...
	'Position',[editx blocky+13*ydiff  editdim], ...
	'String','1', ...
	'Style','edit', ...
	'Tag','GUIflowReynold');

pars.ReHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+13*ydiff  editdim], ...
	'String','Re=', ...
	'Style','text', ...
	'Tag','StaticText1');

pars.ReTextHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+11.5*ydiff editx+editdim(1)-blockx ydiff], ...
	'String','What to plot', ...
	'Style','text', ...
	'Tag','StaticText2');

pars.WhatTextHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''object'')', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+10.5*ydiff editx+editdim(1)-blockx ydiff], ...
	'String',PlotObjectNames, ...
	'Style','popupmenu', ...
	'Tag','GUIflowObject', ...
	'Value',1);

pars.ObjectHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Position',[blockx blocky+9*ydiff textdim], ...
	'ListboxTop',0, ...
	'String','Style', ...
	'Style','text', ...
	'Tag','StaticText2');

pars.StyleStringHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''style'')', ...
	'ListboxTop',0, ...
	'Position',[editx blocky+9*ydiff editdim], ...
	'String',PlotStyleNames, ...
	'Style','popupmenu', ...
	'Tag','GUIflowStyle', ...
	'Value',2);

pars.StyleHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''cbar'')', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+7.5*ydiff editx+editdim(1)-blockx ydiff], ...
	'String','Show colorbar', ...
	'Style','checkbox', ...
	'Value',0,...
	'Tag','GUIflowCbar');

pars.CbarHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''both'')', ...
	'ListboxTop',0, ...
	'Value',1,...
	'Position',[blockx blocky+6.5*ydiff editx+editdim(1)-blockx ydiff], ...
	'String','Show both sides', ...
	'Style','checkbox', ...
	'Tag','GUIflowBothBox');

pars.BothHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''auto'')', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+5.5*ydiff editx+editdim(1)-blockx ydiff], ...
	'String','Automatic contour levels', ...
	'Value',1,...
	'Style','checkbox', ...
	'Tag','GUIflowAuto');

pars.AutoHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+4*ydiff editx+editdim(1)-blockx ydiff], ...
	'String','User C-levels', ...
	'Style','text', ...
	'Tag','StaticText2');

pars.UserStringHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''user'')', ...
	'BackgroundColor',[1 1 1]*0.5, ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+3*ydiff editx+editdim(1)-blockx ydiff], ...
	'String','1:10', ...
	'Style','edit', ...
	'Tag','GUIflowUserCLev');

pars.UserCLevHandle= h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''save'')', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+1.5*ydiff textdim], ...
	'String','Save');

pars.SaveHandle = h1;


h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''load'')', ...
	'ListboxTop',0, ...
	'Position',[blockx blocky+0.5*ydiff textdim], ...
   'String','Load');

pars.LoadHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','GUIflow(''solve'')', ...
    'enable','off',...
	'ListboxTop',0, ...
	'Position',[editx blocky+1.5*ydiff textdim], ...
   'String','Solve');

pars.SolveHandle = h1;

h1 = uicontrol('Parent',h0, ...
	'Units','char', ...
	'Callback','helpwin(''GUIflow'')', ...
	'ListboxTop',0, ...
	'Position',[editx blocky+0.5*ydiff textdim], ...
   'String','Help');

pars.HelpHandle = h1;

return