filters.DigitalFilter

classdef DigitalFilter < handle
%DigitalFilter Perform linear filtering operation

%   Copyright 2008 The MathWorks, Inc.
%   Author: Navan Ruthramoorthy

  methods
    function this = DigitalFilter()
        [this.defaultB, this.defaultA] = butter(5, 0.5);
    end

    function y = filter(this, data, Fs) %#ok<INUSD,INUSL>
        y = [];
        FigureHandle = figure( ...
                        'Visible','off', ...
                        'Menubar','none', ...
                        'Toolbar','none', ...
                        'Position', [360,500,470,150], ...
                        'IntegerHandle', 'off', ...
                        'Color',    get(0, 'defaultuicontrolbackgroundcolor'), ...
                        'NumberTitle', 'off', ...
                        'Name', 'Audio Editor: Filter');
        movegui(FigureHandle, 'center');
        uicontrol('Parent', FigureHandle, 'Style', 'Text', ...
              'String', 'Numerator:', ...
              'Units', 'Normalized', 'Position', [0 0.66 0.2 0.2], ...
              'FontSize', 12);
        hNum = uicontrol('Parent', FigureHandle, 'Style', 'edit', ...
              'String', mat2str(this.defaultB, 2), ...
              'Units', 'Normalized', 'Position', [0.2 0.66 0.78 0.2], ...
              'FontSize', 12, 'BackgroundColor', 'white', ...
              'HorizontalAlignment', 'left');
        uicontrol('Parent', FigureHandle, 'Style', 'Text', ...
              'String', 'Denominator:', ...
              'Units', 'Normalized', 'Position', [0 0.33 0.2 0.2], ...
              'FontSize', 12);
        hDen = uicontrol('Parent', FigureHandle, 'Style', 'edit', ...
              'String', mat2str(this.defaultA, 2), ...
              'Units', 'Normalized', 'Position', [0.2 0.33 0.78 0.2], ...
              'FontSize', 12, 'BackgroundColor', 'white', ...
              'HorizontalAlignment', 'left');
        uicontrol('Parent', FigureHandle, 'Style', 'pushbutton', ...
              'String', 'Apply', 'Units', 'Normalized', ...
              'Position', [0.1 0 0.4 0.2], 'FontSize', 12, ...
              'Callback', @(hobj, evd) applyCallback());
        uicontrol('Parent', FigureHandle, 'Style', 'pushbutton', ...
              'String', 'Cancel', 'Units', 'Normalized', ...
              'Position', [0.5 0 0.4 0.2], 'FontSize', 12, ...
              'Callback', @(hobj, evd) cancelCallback());
        set(FigureHandle,'Visible','on', 'CloseRequestFcn', ...
                    @(hobj, evd) cancelCallback);
        uiwait(FigureHandle);

        function applyCallback()
            B = evalin('base', get(hNum, 'String'));
            A = evalin('base', get(hDen, 'String'));
            y = filter(B, A, data);
            delete(FigureHandle);
        end

        function cancelCallback()
            y = data;
            delete(FigureHandle);
        end
    end
  end

  methods (Static)
    function name = getName()
      name = 'Digital Filter';
    end
  end

  properties (Access=private)
    defaultB;
    defaultA;
  end
end