%
% NOTE: update_lines() does NOT alter/update the x-data,
%       so it needs to be set up once here, correctly.
%       The y-data is not significant ... just needs to be
%       sized appropriately:

xLen=length(xData);
uNaN = NaN;
for i=1:length(hline),
	yData = get(hline(i),'YData')';
	% Manufacture the right yData if default is present:
	if length(yData) ~= xLen,
		yData = uNaN(ones(xLen,1));
	end
	set(hline(i),'XData',xData, 'YData',yData);
end


% Setup "stem" line data:
% -----------------------
% Stems are implemented as a SECOND line
% The usual data plotting occurs, but with a circle ('o')
%   substituted for the marker.
% In addition, a second line is set up for the vertical
%   stems themselves.
%
% We only need to set up ONE stem line.
% The vertical extent will reach to the "highest" point
%   at each sample time, effectively providing a stem for
%   *all* data channels at one time.
%
% Vertical stem data:
%
%    [x1 x1 x1   x2 x2 x2   x3 x3 x3  ....]
%    [0  y1 NaN  0  y2 NaN  0  y3 NaN ...]

xstem = [xData';xData';xData'];
xstem = xstem(:)'; % triplicate each value
ymin = 0;  % stems originate from y=0, not block_data.params.YMin
ystem = [ymin;0;NaN];  % assume y values are 0 for now
ystem = ystem(:,ones(size(xData)));
ystem = ystem(:)';
set(hstem, 'xdata', xstem, 'ydata', ystem);

% Perform AxisZoom:
% -----------------
%
% Put axis into correct zoom state:
fig_data = get(hfig,'UserData');
if strcmp(block_data.params.AxisZoom,'off'),
	% Turn off AxisZoom:
	% - turn on menus
	set(fig_data.menu.top,'vis','on');
	% - reset axis position
	set(hax, fig_data.main.axiszoom.off{:});
	
else
	% Turn on AxisZoom:
	% - turn off top-level menus
	set(fig_data.menu.top,'vis','off');
	set(hax, fig_data.main.axiszoom.on{:});
end


% Turn on scalar warning message, if appropriate:
% ------------------------------
isScalarPlot = (samples_per_channel==1) & (nframes==1);
if isScalarPlot,
	if block_data.params.Domain==2,
		tstr='[Plotting single points - consider using a vector input]';
	else
		tstr='[Plotting single points - consider increasing the display span]';
	end
else
	tstr='';
end
set(get(hax,'Title'), 'String', tstr, 'color','b');

% Update Frame Number display:
% ----------------------------
%
if isOn(block_data.params.FrameNumber),
	% Move frame # text depending on axis zoom (on or off)
	% The frame handle vector contains:
	%   .hframenum(1) = "Frame:"
	%   .hframenum(2) = "###"
	% NOTE: Position of frame readout is updated in figresize
	% 
	if isOn(block_data.params.AxisZoom),
		% Axis zoom on - x-axis is not visible
		ltgrayt = ones(1,3)*.6;  % slightly darker for grid labels
		set(block_data.hframenum, ...
			'verticalalignment','bottom', ...
			'color',ltgrayt, 'vis','on');
	else
		% Axis zoom off - x-axis is visible
		set(block_data.hframenum, ...
			'verticalalignment','cap', ...
			'color','k', 'vis','on');
	end
else
	set(block_data.hframenum,'vis','off');
end

% Update line erase mode (Persistence):
startLineEraseMode(block_name);

UpdateLegend(block_name);

% Manually call the resize fcn:
FigResize([],[],hfig);


% ---------------------------------------------------------------
function UpdateLegend(blk)

block_data = get_param(blk,'UserData');
hlegend    = block_data.hlegend;
useLegend  = isOn(block_data.params.AxisLegend);

if ishandle(hlegend),
	delete(hlegend);
end
hlegend = [];

if useLegend,
	hlines = block_data.hline;
	
	% Get signal names:
	names = getInputSignalNames(blk);
	
	% Prevent failures in legend:
	prop = 'ShowHiddenHandles';
	old_state = get(0,prop);
	set(0,prop,'on');
	axes(block_data.haxis);
	hlegend = legend(hlines, names{:});
	% hlegend = legend(block_data.haxis, hlines, str{:});
	set(0,prop,old_state);
end

% Store changes to legend handle:
block_data.hlegend = hlegend;
set_param(blk,'UserData',block_data);


% ---------------------------------------------------------------
function UpdateFrameNumPos(blk)

block_data = get_param(blk,'UserData');

if isOn(block_data.params.FrameNumber),
	if isOn(block_data.params.AxisZoom),
		% Axis zoom on - x-axis is not visible
		%
		% Position "Frame: #" text above the x-axis tick numbers
		% and to the right of the y-axis tick numbers
		%
		hgridtxt = block_data.hgridtext;
		grid_ext = get(hgridtxt(1),'extent');
		ypos     = grid_ext(2)+grid_ext(4);
		grid_ext = get(hgridtxt(end),'extent');
		xpos     = grid_ext(1)+grid_ext(3);
		
		set(block_data.hframenum(1), ...
			'units','data', 'pos',[xpos ypos]);
		ex=get(block_data.hframenum(1),'extent');
		set(block_data.hframenum(2), ...
			'units','data', 'pos',[ex(1)+ex(3) ypos]);
	else
		% Axis zoom off - x-axis is visible
		%
		% Position "Frame: #" at the same y-level as the x-axis label
		% and flush with the start of the x-axis.
		hax = block_data.haxis;
		hxtitle = get(hax,'xlabel');
		set(hxtitle','units','data');
		xtpos = get(hxtitle,'pos');
		xlim = get(hax,'xlim');
		set(block_data.hframenum(1), 'units','data', ...
			'pos',[xlim(1) xtpos(2)]);
		ex=get(block_data.hframenum(1),'extent');
		frpos = [ex(1)+ex(3) xtpos(2)];
		set(block_data.hframenum(2), 'units','data', ...
			'pos',frpos);
		
		% If xlabel overlaps frame label, turn off frame label:
		xtitle_ex = get(hxtitle,'extent');
		fr_ex = get(block_data.hframenum(2),'extent');
		overlap = xtitle_ex(1) < (fr_ex(1)+fr_ex(3));
		if overlap, vis='off'; else vis='on'; end
		set(block_data.hframenum,'vis',vis);
	end
end


% ---------------------------------------------------------------
function FigResize(hcb,eventStruct,hfig)
% Callback from window resize function

if nargin<3, hfig = gcbf; end
fig_data = get(hfig,'UserData');
if isempty(fig_data), return; end

blk = fig_data.block;
block_data = get_param(blk,'UserData');

% Resize the axis when not in "compact display" (axis zoom) mode:
if ~isOn(block_data.params.AxisZoom),
	fig_pos = get(hfig,'pos');
	ax_pos = [60 40 max([1 1], fig_pos([3 4])-[80 60])];
	set(block_data.haxis, 'pos',ax_pos);
end

UpdateGrid(blk);  % Do this prior to repositioning frame # text
UpdateFrameNumPos(blk);

% Update legend, if it is on:
if isOn(block_data.params.AxisLegend),
	legend('ResizeLegend', block_data.haxis);
end


% ---------------------------------------------------------------
function fig_data = create_scope(block_name, params, nchans)
% CREATE_SCOPE Create new scope GUI

% Initialize empty settings:
fig_data.main  = [];  % until we move things here
fig_data.menu  = [];

hfig = figure('numbertitle', 'off', ...
	'name',              block_name, ...
	'menubar',           'none', ...
	'position',          params.FigPos, ...
	'nextplot',          'add', ...
	'integerhandle',     'off', ...
	'doublebuffer',      'off', ...
	'PaperPositionMode', 'auto', ...
	'ResizeFcn',         @FigResize, ...
	'DeleteFcn',         @FigDelete, ...
	'HandleVisibility', 'callback');

hax = axes('Parent',hfig, ...
	'DrawMode','fast', ...
	'Box','on', 'ticklength',[0 0], ...
	'Position', [0.1300 0.1450 0.7750 0.8000]);

% Set up line for each channel:
for i = 1:nchans,
	hline(i) = line('parent',hax, ...
		'xdata',NaN, 'ydata',NaN);
end
hstem = line('parent',hax, ...
	'xdata',NaN, 'ydata',NaN);
hgrid = line('parent',hax, ...
	'xdata',NaN, 'ydata',NaN, ...
	'erasemode','xor', 'color',[.8 .8 .8]);

% Create non-displaying line to use for color translations
hcspec = line('parent',hax, ...
	'xdata',nan,'ydata',nan, ...
	'vis','off');

% Create Frame Number text
hframenum(1) = text(0,0,'','parent',hax);
hframenum(2) = text(0,0,'','parent',hax);
set(hframenum(1),'string','Frame: ','erase','xor','horiz','left');
set(hframenum(2),'string','-','erase','xor','userdata',0,'horiz','left');

% Create a context menu:
mContext = uicontextmenu('parent',hfig);

% Establish settings for all structure fields:
fig_data.block  = block_name;
fig_data.hfig   = hfig;
fig_data.hcspec = hcspec;

% Store major settings:
fig_data.main.haxis   = hax;
fig_data.main.hline   = hline;
fig_data.main.hstem   = hstem;
fig_data.main.hgrid   = hgrid;
fig_data.main.hframenum = hframenum;
fig_data.menu.context = mContext;

% Set the non-compact display axis to pixels,
% so resizing does not affect it
set(hax,'units','pixels')

% Store settings for axis zoom:
% Cell-array contains {params, values},
% where params itself is a cell-array of Units and Position
% and values is a cell-array of corresponding values.
p = {'Units','Position'};
fig_data.main.axiszoom.off = {p, get(hax, p)};
fig_data.main.axiszoom.on  = {p, {'Normalized',[0 0 1 1]}};


% ---------------------------------------------------------
% Figure menus:
% ---------------------------------------------------------
%
% Define FILE menu:
%
pcwin = strcmp(computer,'PCWIN');
if pcwin,
	labels = {'&File', ...
			'&Close', ...
			'&Export...', ...
			'Pa&ge Setup...', ...
			'Print Set&up...', ...
			'Print Pre&view...', ...
			'&Print...'};
else
	labels = {'File', ...
			'Close', ...
			'Export...', ...
			'Page Setup...', ...
			'Print Setup...', ...
			'Print Preview...', ...
			'Print...'};
end
%
mFile = uimenu(hfig,'Label',labels{1});
%
% submenu items:
uimenu(mFile, 'label',labels{2}, ...
	'accel','W', ...
	'callback',{@CloseFigure, block_name});
%uimenu(mFile, 'label',labels{3}, ...
%    'separator','on', ...
%   'callback','filemenufcn(gcbf,''FileExport'')');
uimenu(mFile, 'label',labels{4}, ...
	'separator','on', ...
	'callback','pagesetupdlg(gcbf)');
uimenu(mFile, 'label',labels{5}, ...
	'callback','printdlg(''-setup'')');
uimenu(mFile, 'label',labels{6}, ...
	'callback','printpreview(gcbf)');
uimenu(mFile, 'label',labels{7}, ...
	'accel','P', ...
	'callback','printdlg(gcbf)');

%
% Define AXES menu labels:
%
if pcwin,
	labels = {'&Axes', 'Per&sistence', '&Refresh', ...
			'&Autoscale', 'Show &grid', 'Compact &display', ...
			'&Frame #', 'Channel &legend', 'Save &position'};
else
	labels = {'Axes', 'Persistence', 'Refresh', ...
			'Autoscale', 'Show grid', 'Compact display', ...
			'Frame #', 'Channel legend', 'Save position'};
end
%
% Create figure AXIS menu
%
mAxes = uimenu(hfig, 'Label', labels{1});  % top-level Axes menu in figure
%
% submenu items:
fig_data.menu.memory = uimenu(mAxes, 'label',labels{2}, ...
	'callback',@Memory);
fig_data.menu.refresh = uimenu(mAxes, 'label',labels{3}, ...
	'callback',@FigRefresh);
fig_data.menu.autoscale = uimenu(mAxes, 'label',labels{4}, ...
	'separator','on', 'callback', @Autoscale);
% - Create Axis Grid item
fig_data.menu.axisgrid = uimenu(mAxes, 'Label', labels{5}, ...
	'Callback', @AxisGrid);
% - Create Axis Zoom item
fig_data.menu.axiszoom = uimenu(mAxes, ...
	'Label', labels{6}, ...
	'Callback', @AxisZoom);
% - Create Axis Frame Number item
fig_data.menu.framenumber = uimenu(mAxes, 'Label', labels{7}, ...
	'Callback', @FrameNumber);
% - Create Axis Legend item
fig_data.menu.axislegend = uimenu(mAxes, 'Label', labels{8}, ...
	'Callback', @AxisLegend);
% - Create Record Position item
fig_data.menu.recpos = uimenu(mAxes, 'label',labels{9}, ...
	'callback', @SaveFigPos, ...
	'separator','on');

% Define OPTIONS menu labels:
%
if pcwin,
	% Use "&" for accelerator characters on the PC:
	labels = {'&Channels', '&Style', '&Marker', '&Color'};
else
	labels = {'Channels', 'Style', 'Marker', 'Color'};
end
%
% Create menus as if there were only ONE line in display:
if nchans >= 1,
	mLines = uimenu(hfig, 'label',labels{1});  % top-level Lines menu in figure
	
	lsmenu = uimenu(mLines, 'label',labels{2});
	lmmenu = uimenu(mLines, 'label',labels{3});
	lcmenu = uimenu(mLines, 'label',labels{4});
	
	fig_data.menu.linestyle  = lsmenu;
	fig_data.menu.linemarker = lmmenu;
	fig_data.menu.linecolor  = lcmenu;
	
	% Line styles submenu:
	uimenu(lsmenu,'label',' None', 'userdata','None', ...
		'callback',@LineStyle);
	uimenu(lsmenu,'label',' -', 'userdata','-', ...
		'callback',@LineStyle);
	uimenu(lsmenu,'label',' --', 'userdata','--', ...
		'callback',@LineStyle);
	uimenu(lsmenu,'label',' :', 'userdata',':', ...
		'callback',@LineStyle);
	uimenu(lsmenu,'label',' -.', 'userdata','-.', ...
		'callback',@LineStyle);
	
	% Line markers submenu:
	uimenu(lmmenu,'label','None','userdata','None', ...
		'callback',@LineMarker);
	uimenu(lmmenu,'label','+','userdata','+',...
		'callback',@LineMarker);
	uimenu(lmmenu,'label','o','userdata','o',...
		'callback',@LineMarker);
	uimenu(lmmenu,'label','*','userdata','*',...
		'callback',@LineMarker);