function h_group = im_circle(h_parent, cen, r)
%im_circle Create draggable rectangle.
% H = im_circle(HPARENT, CEN, R) creates a draggable circle with radius r
% on the object specified by HPARENT.
% The function returns H, a handle to the rectangle,
% which is an hggroup object. HPARENT specifies the hggroup's parent, which
% is typically an axes object, but can also be any other object that can be
% the parent of an hggroup. CEN is a two-element vector that specifies
% the initial location of the center. CEN has the form [XCEN,YCEN].
% R is scalar that specifies the radius.
%
% A draggable circle can be dragged interactively using the mouse. When
% the circle occupies a small number of screen pixels, its appearance
% changes to aid visibility.
%
% The draggable circle has a context menu associated with it that allows
% you to copy the current position to the clipboard and change the color
% used to display the circle.
%
% API Function Syntaxes
% ---------------------
% A draggable circle contains a structure of function handles, called
% an API, that can be used to manipulate it. To retrieve this
% structure from the draggable circle, use the IPTGETAPI function.
%
% API = IPTGETAPI(H)
%
% Functions in the API, listed in the order of the structure fields, include:
%
% setPosition
%
% Sets the draggable circle to a new position.
%
% api.setPosition(new_position)
%
% where new_position is a four-element position vector.
%
% getPosition
%
% Returns the current position of the draggable circle.
%
% position = api.getPosition()
%
% delete
%
% Deletes the draggable circle associated with the API.
%
% api.delete()
%
% setColor
%
% Sets the color used to draw the draggable circle.
%
% api.setColor(new_color)
%
% where new_color is a three-element vector specifying an RGB
% value.
%
% addNewPositionCallback
%
% Adds the function handle FCN to the list of new-position callback
% functions.
%
% id = api.addNewPositionCallback(fcn)
%
% Whenever the draggable circle changes its position, each
% function in the list is called with the syntax:
%
% fcn(position)
%
% The return value, id, is used only with
% removeNewPositionCallback.
%
% removeNewPositionCallback
%
% Removes the corresponding function from the new-position callback
% list.
%
% api.removeNewPositionCallback(id)
%
% where id is the identifier returned by
% api.addNewPositionCallback.
%
% setDragConstraintFcn
%
% Sets the drag constraint function to be the specified function
% handle, fcn.
%
% api.setDragConstraintFcn(fcn)
%
% Whenever the draggable circle is moved because of a mouse drag,
% the constraint function is called using the syntax:
%
% constrained_position = fcn(new_position)
%
% where new_position is a four-element position vector. This allows a
% client, for example, to control where the circle may be dragged.
%
% getDragConstraintFcn
%
% Returns a function handle to the current drag constraint function.
%
% fcn = api.getDragConstraintFcn()
%
% Remarks
% -------
% If you use im_circle with an axis that contains an image object,
% and do not specify a drag constraint function, users can drag
% the point outside the extent of the image and lose the point.
% When used with an axis created by the PLOT function, the axis
% limits automatically expand to accommodate the movement of
% the point.
%
% Examples
% --------
% % Display updated position in the title. Specify a drag
% % constraint function using makeConstainToRectFcn to keep
% % the circle inside the original xlim and ylim ranges.
% figure, imshow('cameraman.tif');
% h = im_circle(gca, [110,60], 30);
% api = iptgetapi(h);
% api.addNewPositionCallback(@(p) title(mat2str(p)));
% % IMPORTANT: use 'imline' here since makeConstrainToRectFcn can
% % only recognize one of the imline, imrect, impoint !!!
% fcn = makeConstrainToRectFcn('imrect',get(gca,'XLim'),get(gca,'YLim'));
% api.setDragConstraintFcn(fcn);
%
% % Use a custom color for displaying the circle.
% figure, imshow('cameraman.tif')
% h = im_circle(gca, [110,60], 30);
% api = iptgetapi(h);
% api.setColor([1 0 0]);
%
% % When the circle position occupies only a few pixels on the
% % screen, the circle is drawn in a different style to increase
% % its visibility.
% figure, imshow cameraman.tif
% h = im_circle(gca, [110,60], 30);
%
% See also IMLINE, IMPOINT, IPTGETAPI, makeConstrainToRectFcn.
iptchecknargin(3, 3, nargin, mfilename);
if ~ishandle(h_parent)
error('Images:im_circle:invalidHandle', ...
'HPARENT must be a valid graphics handle.');
end
if strcmp(get(h_parent, 'type'), 'axes')
h_axes = h_parent;
else
h_axes = ancestor(h_parent, 'axes');
if isempty(h_axes)
error('Images:im_circle:noAxesAncestor', ...
'HPARENT must be a descendent of an axes object.');
end
end
try
h_group = hggroup('ButtonDownFcn', @startDrag, 'Parent', h_parent, ...
'HitTest', 'on');
catch
error('Images:im_circle:failureToParent', ...
'HPARENT must be able to have an hggroup object as a child.');
end
draw_api = defaultCircle(h_group);
% constraint_function is used by dragMotion() to give a client the opportunity
% to constrain where the circle can be dragged.
drag_constraint_function = identityFcn;
% new_position_callback_functions is used by sendNewPosition() to
% notify interested clients whenever the circle position changes.
new_position_callback_functions = makeList;
% Pattern for set associated with callbacks that get called as a
% result of the set.
insideSetPosition = false;
insideSetRadius = false;
h_fig = iptancestor(h_axes, 'figure');
cmenu = uicontextmenu('Parent', h_fig);
set(h_group, 'UIContextMenu', cmenu);
uimenu(cmenu, ...
'Label', 'Copy Position', ...
'Callback', @copyPosition');
set_color_menu = uimenu(cmenu, ...
'Label', 'Set Circle Color');
color_choices = getColorChoices;
for k = 1:numel(color_choices)
uimenu(set_color_menu, 'Label', color_choices(k).Label, ...
'Callback', @(varargin) setColor(color_choices(k).Color));
end
setColor(color_choices(1).Color);
% Բģ뾶
center = cen;
radius = r;
position = [cen(1)-r,cen(2)-r,2*r,2*r];
api.setCenter = @setCenter;
api.getCenter = @getCenter;
api.setRadius = @setRadius;
api.getRadius = @getRadius;
api.delete = @deleteRect;
api.setColor = @setColor;
api.addNewPositionCallback = @addNewPositionCallback;
api.removeNewPositionCallback = @removeNewPositionCallback;
api.getDragConstraintFcn = @getDragConstraintFcn;
api.setDragConstraintFcn = @setDragConstraintFcn;
api.setDragConstraintCallback = @setDragConstraintFcn;
setappdata(h_group, 'API', api);
% Make the pointer be a fleur when it is over the rect. Store the same pointer
% behavior in the hggroup and all its children.
pointer_fcn = @(varargin) set(h_fig, 'Pointer', 'fleur');
iptSetPointerBehavior(findobj(h_group), pointer_fcn);
updateView(center, radius);
% Create update function that knows how to get the position it needs when it
% will be called from HG contexts where it may not have access to the position
% otherwise.
update_fcn = @(varargin) updateView(api.getCenter(), api.getRadius());
updateAncestorListeners(h_group,update_fcn);
% Install a pointer manager in the figure and enable it.
iptPointerManager(h_fig);
%---------------------------------
function setCenter(new_center)
% Pattern to break recursion
if insideSetPosition
return
else
insideSetPosition = true;
end
center = new_center;
position = [...
center(1)-radius,center(2)-radius,2*radius,2*radius];
updateView(center, radius);
sendNewPosition;
% Pattern to break recursion
insideSetPosition = false;
end
%-------------------------
function cen = getCenter
cen = center;
end
%-------------------
function setRadius(r)
% Pattern to break recursion
if insideSetRadius
return
else
insideSetPosition = true;
end
radius = r;
position = [...
center(1)-radius,center(2)-radius,2*radius,2*radius];
updateView(center, radius);
sendNewPosition;
% Pattern to break recursion
insideSetPosition = false;
end
%---------------------
function r = getRadius
r = radius;
end
%----------------------------------------
function id = addNewPositionCallback(fun)
id = new_position_callback_functions.appendItem(fun);
end
%-------------------------------------
function removeNewPositionCallback(id)
new_position_callback_functions.removeItem(id);
end
%---------------------------------
function setDragConstraintFcn(fun)
drag_constraint_function = fun;
end
%---------------------------------
function fh = getDragConstraintFcn
fh = drag_constraint_function;
end
%----------------------------
function deleteRect(varargin) %#ok varargin needed by HG caller
if ishandle(h_group)
delete(h_group);
end
end
%-----------------------
function updateView(cen, r)
draw_api.updateView(cen, r);
end
%-----------------------
function setColor(color)
draw_api.setColor(color);
end
%------------------------------
function copyPosition(varargin) %#ok varargin needed by HG caller
clipboard('copy', position);
end
%---------------------------------
function sendNewPosition(varargin) %#ok varargin needed by HG caller
list = new_position_callback_functions.getList();
for k = 1:numel(list)
fun = list{k};
fun(position);
end
end
%--------------------------------
function startDrag(src, varargin) %#ok varargin needed by HG caller
if strcmp(get(h_fig, 'SelectionType'), 'normal')
start_position = position;
% Get the mouse location in data space.
[start_x,start_y] = getCurrentPoint(h_axes);
% Disable the figure's pointer manager until the drag is completed.
iptPointerManager(h_fig, 'disable');
drag_motion_callback_id = iptaddcallback(h_fig, ...
'WindowButtonMotionFcn', ...
@dragMotion);
drag_up_callback_id = iptaddcallback(h_fig, ...
'WindowButtonUpFcn', ...
@stopDrag);
end
%----------------------------
function dragMotion(varargin) %#ok varargin needed by HG caller
if ~ishandle(h_axes)
return;
end
[new_x,new_y] = getCurrentPoint(h_axes);
delta_x = new_x - start_x;
delta_y = new_y - start_y;
candidate_position = start_position + [delta_x delta_y 0 0];
new_position = drag_constraint_function(candidate_position);
new_radius = new_position(4)/2;
new_center = [new_position(1)+new_radius,new_position(2)+new_radius];
setCenter(new_center);
end
%--------------------------
function stopDrag(varargin) %#ok varargin needed by HG caller
dragMotion();
iptremovecallback(h_fig, 'WindowButtonMotionFcn', ...
drag_motion_callback_id);
iptremovecallback(h_fig, 'WindowButtonUpFcn', ...
drag_up_callback_id);
% Enable the figure's pointer manager.
iptPointerManager(h_fig, 'enable');
end % stopDrag
end % startDrag
end % im_circle
