drawline.m

Univ. of Calgary CREWS的免费地震研究软件

function drawline(action)
% DRAWLINE: draw a line on a figure window
%
% drawline(action,button)
%
% DRAWLINE is somewhat like SELBOX except that it draws a line rather
% than a rectangle. DRAWLINE uses the userdata of the current axes
% for storage and assumes that it initially contains [pt1x pt1y] the
% x and y coordinates of the starting point of the line. 
% So that DRAWLINE can be convieniently called several times in a row
% without outside intervention, DRAWLINE begins by deleting the graphics
% object whose handle is the fifth entry in the axes user data.
% An abort will occur if this user data entry is non-null with an
% invalid graphics handle.) After returning, the axes user data will
% contain the x,y coordinate of the 2 points defining the 
% rectangle and the graphics handle of the selection rectangle: 
% [p1x p1y p2x p2y handle]
%
% Several convienience functions make it easier to use DRAWLINE and
% you actually will rarely need to call DRAWLINE directly. DRAWLINEINIT
% should be called to begin the selection box process and DRAWLINEFINI
% to end it. You need do nothing else. DRAWLINEFINI, will return five
% values: [pt1x pt1y pt2x pt2y hline]
% Where pt1 and pt2 are the points defining the line and hline
% is the graphics handle to its on-screen image. (Note that 
% DRAWLINEFINI needs no arguments while DRAWLINEINIT has one optional
% argument described below)
% Example:
% [x,y,z]=peaks; % get something to plot
% pcolor(x,y,z); % plot it
% 
% drawlineinit % begin the line drawing
% % the line is drawn on screen
% vals=drawlinefini; % obtain the line coordinates
%
% Often you will want to do some action of your own upon a mouse button up
% event. This is easily done by passing a string argument to DRAWLINEINIT
% which contains any Matlab command (or series of commands).
% drawlineinit('do_my_thing')
%
% DRAWLINEINIT now takes a second argument which is the button number
% to be used in drawing the line. Drawing with any other button has
% no effect. Default is button 1.
%
% G.F. Margrave, CREWES, June 2000
%
% NOTE: It is illegal for you to use this software for a purpose other
% than non-profit education or research UNLESS you are employed by a CREWES
% Project sponsor. By using this software, you are agreeing to the terms
% detailed in this software's Matlab source file.
 
% BEGIN TERMS OF USE LICENSE
%
% This SOFTWARE is maintained by the CREWES Project at the Department
% of Geology and Geophysics of the University of Calgary, Calgary,
% Alberta, Canada.  The copyright and ownership is jointly held by 
% its author (identified above) and the CREWES Project.  The CREWES 
% project may be contacted via email at:  [e-mail]
% 
% The term 'SOFTWARE' refers to the Matlab source code, translations to
% any other computer language, or object code
%
% Terms of use of this SOFTWARE
%
% 1) Use of this SOFTWARE by any for-profit commercial organization is
%    expressly forbidden unless said organization is a CREWES Project
%    Sponsor.
%
% 2) A CREWES Project sponsor may use this SOFTWARE under the terms of the 
%    CREWES Project Sponsorship agreement.
%
% 3) A student or employee of a non-profit educational institution may 
%    use this SOFTWARE subject to the following terms and conditions:
%    - this SOFTWARE is for teaching or research purposes only.
%    - this SOFTWARE may be distributed to other students or researchers 
%      provided that these license terms are included.
%    - reselling the SOFTWARE, or including it or any portion of it, in any
%      software that will be resold is expressly forbidden.
%    - transfering the SOFTWARE in any form to a commercial firm or any 
%      other for-profit organization is expressly forbidden.
%
% END TERMS OF USE LICENSE

if(strcmp(action,'init') )
    p1=get(gca,'currentpoint');
    dat=get(gca,'userdata');
    if(length(dat)>=5) if(dat(5)>0) delete(dat(5)); end; end
    set(gca,'userdata',p1(1,1:2));
    set(gcf,'windowbuttonmotionfcn','drawline(''motion'')');
    return;
end
if(strcmp(action,'fini'))
    set(gcf,'windowbuttonmotionfcn','');
    %test for a double click
    dat=get(gca,'userdata');
    if(length(dat)==2)
        pt=get(gca,'currentpoint');
        test=dat(1)-pt(1,1)+dat(2)-pt(1,2);
        if(~test)
            set(gca,'userdata',[dat pt(1,1:2) -1]);
        end
    end
    return;
end
if( strcmp(action,'motion') )
    checkclick=get(gcf,'selectiontype');
    % will only draw lines on a MB1 click
    if(strcmp(checkclick,'normal'))
        % get the starting point from axes userdata
        dat=get(gca,'userdata');
        p1=dat(1:2);
        % delete any pre-existing line
        if(length(dat)==5) if(dat(5)>0) delete(dat(5)); end; end
        % get the current point from the axes
        p2=get(gca,'currentpoint');
        p2=p2(1,1:2);
        % draw the line
        h=line([p1(1),p2(1)],[p1(2),p2(2)],'erasemode','xor');
        % update the info in userdata
        set(gca,'userdata',[p1 p2 h]);
    end
    return;
end