laplace_filter_gui(varargin)

function varargout = laplace_filter_gui(varargin)

%============================== Example ===================================
%[close_status image_output slider_pos edit_value ok_status cancel_status preview_status]=laplace_filter_gui(img2,0.0067,35,1);
%==========================================================================
%========================= INTIALISATION ==================================
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @laplace_filter_gui_OpeningFcn, ...
                   'gui_OutputFcn',  @laplace_filter_gui_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin & isstr(varargin{1})    gui_State.gui_Callback = str2func(varargin{1});
end
if nargout    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else          gui_mainfcn(gui_State, varargin{:});
end
%==========================================================================
%=====================  GUI OPENING FUNCTION ==============================
function laplace_filter_gui_OpeningFcn(hObject, eventdata, handles, varargin)
set(handles.slider1,'Value',cell2mat(varargin(2)));
set(handles.edit1,'String',cell2mat(varargin(2)));
set(handles.edit2,'String',cell2mat(varargin(3)));
set(handles.preview,'Value',cell2mat(varargin(4)));
handles.output =varargin;
guidata(hObject, handles);
%==========================================================================
%======================== SLIDER 1 ========================================
function slider1_CreateFcn(hObject, eventdata, handles)
usewhitebg = 1;
if usewhitebg    set(hObject,'BackgroundColor',[.9 .9 .9]);
else             set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end
function slider1_Callback(hObject, eventdata, handles)
uiresume
set(handles.laplacian_filter_figure,'Pointer','watch');
set(handles.edit1,'String',int2str(get(hObject,'Value')));
pause(0.001); %=>for the change to show up in gui.
D=get(handles.slider1,'Value');
nsteps=str2double(get(handles.edit2,'String'));
laplace_image=laplace_filter(cell2mat(handles.output(1)),D,nsteps);
set(handles.ok,'UserData',laplace_image);
%==========================================================================
%=========================== EDIT 1 =======================================
function edit1_CreateFcn(hObject, eventdata, handles)
if ispc  set(hObject,'BackgroundColor','white');
else     set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end
function edit1_Callback(hObject, eventdata, handles)
uiresume
set(handles.laplacian_filter_figure,'Pointer','watch');
if isfinite(str2double(get(hObject,'String')))
    slider_max=get(handles.slider1,'Max');
    slider_min=get(handles.slider1,'Min');
    slider_value=str2double(get(hObject,'String'));
    if slider_value<=slider_max && slider_value>=slider_min
        set(handles.slider1,'Value',slider_value);
        pause(0.001); %=>for the change to show up in gui.
        D=get(handles.slider1,'Value');
        nsteps=str2double(get(handles.edit2,'String'));
        laplace_image=laplace_filter(cell2mat(handles.output(1)),D,nsteps);
        set(handles.ok,'UserData',laplace_image);
    end
end
%==========================================================================
%=========================== EDIT 2 =======================================
function edit2_CreateFcn(hObject, eventdata, handles)
if ispc    set(hObject,'BackgroundColor','white');
else       set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end
function edit2_Callback(hObject, eventdata, handles)
uiresume
set(handles.laplacian_filter_figure,'Pointer','watch');
pause(0.001); %=>for the change to show up in gui.
if isfinite(str2double(get(hObject,'String')))
    D=get(handles.slider1,'Value');
    nsteps=str2double(get(handles.edit2,'String'));
    laplace_image=laplace_filter(cell2mat(handles.output(1)),D,nsteps);
    set(handles.ok,'UserData',laplace_image);
end
%==========================================================================
%============ OK CANCEL AND PREVIEW BUTTONS ===============================
function ok_Callback(hObject, eventdata, handles)
uiresume
function cancel_Callback(hObject, eventdata, handles)
uiresume
function preview_Callback(hObject, eventdata, handles)
uiresume
%==========================================================================
%===================== GUI OUTPUT FUNCTION ================================
function varargout = laplace_filter_gui_OutputFcn(hObject, eventdata, handles)
uiwait
%--------------------------------------------------------------------------
varargout{1} =~ishandle(handles.ok);%=> When delete button is pressed all handles are removed(my guess).
%--------------------------------------------------------------------------
varargout{2}=[];
%--------------------------------------------------------------------------
varargout{3} = cell2mat(handles.output(2));
varargout{4} = cell2mat(handles.output(3));
varargout{5} =0;varargout{6} =0;
varargout{7} =cell2mat(handles.output(4));
%--------------------------------------------------------------------------
if ~varargout{1}
varargout{2} =get(handles.ok,'UserData');
varargout{3} =get(handles.slider1,'Value');
if isfinite(str2double(get(handles.edit2,'String')))
    varargout{4} =str2double(get(handles.edit2,'String'));
end
varargout{5} =get(handles.ok,'Value');
varargout{6} =get(handles.cancel,'Value');
varargout{7} =get(handles.preview,'Value');
delete(handles.laplacian_filter_figure);
end
%==========================================================================
%##########################################################################
%-------------------- Extra Used Function(s) ------------------------------
%******************* LAPLACE FILTER ***************************************
function output_image=laplace_filter(input_image,D,nsteps)
dt = 1;h = 1;
src = double(input_image);
% Perform the explicit iteration process for each pixel (the pixels
% at the boundary are ignored).
for n = 1:nsteps
	src(2:end-1,2:end-1) = (1-4*dt*D/h^2).* ...
			src(2:end-1,2:end-1) + dt*D/h^2*(src(1:end-2,2:end-1) + ...
		    src(3:end,2:end-1) + src(2:end-1,1:end-2) + ...
			src(2:end-1,3:end));
end
output_image=uint8(src);
%##########################################################################