root/gliderproc/trunk/MATLAB/plots/blinksafe.m

function vis = blinksafe(varargin)

% blinksafe -- Toggle data points in (x, y, z) plot.
%  blinksafe('demo') demonstrates itself, using random (x, y)
%   data plotted with EraseMode = 'xor'.
%  blinksafe('on') enables blinking, in which a mouse click
%   on a plotted (x, y, z) point makes the point invisible
%   and marks the site with a distinctive dot.  The z-value
%   at that point is set to NaN, and its original value is
%   remembered for later restoration.  The proximity of the
%   click to a point is determined in the (x, y) plane only.
%  blinksafe(h) turns blinking on for just the lines specified
%   by the handles h.
%  blinksafe('off') turns blinking off and removes the markers.
%   Points invisible at this stage will remain invisible,
%   since the corresponding z values will now be NaN.
%  blinksafe('clear') restores all the plotted data to visibility.
%  vis = blinksafe(h) returns the visibility-vector (1 = visible;
%   0 = not visible) for the line whose handle is h.
 %
% Calls: none

% Copyright (C) 2000 Dr. Charles R. Denham, ZYDECO.
%  All Rights Reserved.
%   Disclosure without explicit written consent from the
%    copyright owner does not constitute publication.
 
% Version of 12-Jan-2000 09:44:58.
% Updated    18-Jan-2000 15:15:47.

BLINKER_TAG = ['_' mfilename '_'];
BLINKER_MARKER = '*';
BLINKER_SIZE = get(0, 'DefaultLineMarkerSize');
BLINKER_COLOR = [1 0 0];
BLINKER_BUTTONDOWNFCN = mfilename;

% Demonstration.

if nargin > 0 & isequal(varargin{1}, 'demo')
        help(mfilename)
        x = linspace(0, 1, 101);
        y  = sin(3*pi*x);
        noise = 2*(rand(size(x)) - 0.5);
        noise(abs(noise) < 0.95) = 0;
        h = plot(x, y+noise, '-o', ...
                                'MarkerSize', 4, 'EraseMode', 'xor');
        eval(mfilename)
        if exist('zoomsafe', 'file') == 2
                eval('zoomsafe')
        end
        set(gcf, 'Name', [mfilename ' demo'])
        if nargout > 0, vis = h; end
        return
end

% Get visibility of a line.
%  Requires a handle and an output variable.

if nargout > 0 & nargin > 0
        vis = [];
        h = varargin{1};
        if ischar(h), h = eval(h); end
        if ishandle(h)
                if isequal(get(h, 'Type'), 'line')
                        if ~isequal(get(h, 'Tag'), BLINKER_TAG)
                                vis = isfinite(get(h, 'ZData'));
                        end
                end
        end
        return
end

% Actions: on, off, clear.

if nargin > 0 & isempty(gcbo)
        if ischar(varargin{1})
                theAction = varargin{1};
                switch theAction
                case 'on'
                        varargin = {};
                case 'off'
                        h = findobj(gcf, 'Tag', BLINKER_TAG);
                        if any(h), delete(h), end
                        return
                case 'clear'
                        h = findobj(gcf, 'Tag', BLINKER_TAG);
                        if any(h)
                                for i = 1:length(h)
                                        u = get(h(i), 'UserData');
                                        z = get(u.handle, 'ZData');
                                        z(u.index) = u.z;
                                        set(u.handle, 'ZData', z)
                                end
                                delete(h)
                        end
                        return
                otherwise
                        disp([' ## No such action: "' theAction '"'])
                        return
                end
        end
end

% Initialize.

if isempty(gcbo)
        if isempty(varargin)
                h = findobj(gcf, 'Type', 'line');
                varargin{1} = h;
        end
        h = varargin{1};
        set(h, 'ButtonDownFcn', BLINKER_BUTTONDOWNFCN)
        for i = 1:length(h)
                z = get(h(i), 'ZData');
                if isempty(z)
                        x = get(h(i), 'XData');
                        z = zeros(size(x));
                        set(h(i), 'ZData', z);
                end
        end
        return
end

% Process a click.  If clicking on the data, make
%  the closest data point invisible.  If clicking
%  on a "blinker", restore the visibility of the
%  corresponding point.

if isempty(varargin), varargin{1} = 'ButtonDownFcn'; end

if length(varargin) > 0 & ischar(varargin{1})
        theEvent = varargin{1};
        switch lower(theEvent)
        case 'buttondownfcn'
                switch get(gcbo, 'Tag')
                case '_blinksafe_'   % Restore visibility; delete the blinker.
                        u = get(gcbo, 'UserData');
                        z = get(u.handle, 'ZData');
                        z(u.index) = u.z;
                        set(u.handle, 'ZData', z);
                        delete(gcbo)
                otherwise   % Make invisible; create a blinker.
                        p = get(gca, 'CurrentPoint');
                        x0 = p(1, 1);
                        y0 = p(1, 2);
                        x = get(gcbo, 'XData');
                        y = get(gcbo, 'YData');
                        
                        dx = diff(get(gca, 'XLim'));   % Scale to pixels.
                        dy = diff(get(gca, 'YLim'));
                        theOldUnits = get(gca, 'Units');
                        set(gca, 'Units', 'pixels');
                        thePosition = get(gca, 'Position');
                        theWidth = thePosition(3);
                        theHeight = thePosition(4);
                        dx = dx / theWidth;
                        dy = dy / theHeight;
                        set(gca, 'Units', theOldUnits)
                        
                        d = abs((x*dy+sqrt(-1)*y*dx - (x0*dy+sqrt(-1)*y0*dx)));
                        
                        index = find(d == min(d));
                        if any(index)
                                index = index(1);
                                z = get(gcbo, 'ZData');
                                if isempty(z), z = zeros(size(x)); end
                                if isfinite(z(index)) & 0
                                        u.handle = gcbo;
                                        u.index = index;
                                        u.z = z(index);
                                        theMarker = get(gcbo, 'Marker');
                                        if isequal(theMarker, BLINKER_MARKER)
                                                BLINKER_MARKER = 'o';
                                        end
                                        h = line(x(index), y(index),...
                                                        'Marker', BLINKER_MARKER, ...
                                                        'MarkerSize', BLINKER_SIZE, ...
                                                        'MarkerFaceColor', 'none', ...
                                                        'MarkerEdgeColor', BLINKER_COLOR, ...
                                                        'EraseMode', 'xor', ...
                                                        'ButtonDownFcn', BLINKER_BUTTONDOWNFCN, ...
                                                        'UserData', u, ...
                                                        'Tag', BLINKER_TAG);
                                        z(index) = nan;
                                        set(gcbo, 'ZData', z)
                                else
                                        h = make_blinker(gcbo, index);
                                end
                        end
                end
        otherwise
                disp(['## No such event: ' theEvent])
        end
end

% ---------- make_blinker ---------- %

function theResult = make_blinker(h, index)

% make_blinker -- Create a blinker.
%  make_blinker(h, index) places a blinker
%   on line h at the given index.
 
% Copyright (C) 2000 Dr. Charles R. Denham, ZYDECO.
%  All Rights Reserved.
%   Disclosure without explicit written consent from the
%    copyright owner does not constitute publication.
 
% Version of 18-Jan-2000 14:11:55.
% Updated    18-Jan-2000 14:11:55.

BLINKER_TAG = ['_' mfilename '_'];
BLINKER_MARKER = '*';
BLINKER_SIZE = get(0, 'DefaultLineMarkerSize');
BLINKER_COLOR = [1 0 0];
BLINKER_BUTTONDOWNFCN = mfilename;

result = zeros(size(h));

for i = 1:length(h)
        x = get(h(i), 'XData');
        y = get(h(i), 'YData');
        z = get(h(i), 'ZData');
        if isempty(z)
                z = zeros(size(x));
        end
        theMarker = get(h(i), 'Marker');
        if isequal(theMarker, BLINKER_MARKER)
                BLINKER_MARKER = 'o';
        end
        if ~isequal(get(gcbo, 'Marker'), 'none')
                BLINKER_SIZE = 2 + get(gcbo, 'MarkerSize');
        end
        
        if isfinite(z(index))
                u.handle = h(i);
                u.index = index;
                u.z = z(index);
                result(i) = line(x(index), y(index),...
                                'Marker', BLINKER_MARKER, ...
                                'MarkerSize', BLINKER_SIZE, ...
                                'MarkerFaceColor', 'none', ...
                                'MarkerEdgeColor', BLINKER_COLOR, ...
                                'EraseMode', 'xor', ...
                                'ButtonDownFcn', BLINKER_BUTTONDOWNFCN, ...
                                'UserData', u, ...
                                'Tag', BLINKER_TAG);
                z(index) = nan;
                set(h(i), 'ZData', z)
        end
end

if nargout > 0, theResult = result; end