function docInterface = abcInterface

% Define custom document interface
docInterface = ReqMgr.LinkType;

% Define custom document interface properties
docInterface.Registration = mfilename;
docInterface.Label = 'ABC  file (for demonstration)';
docInterface.IsFile = 1;
docInterface.Extensions = {'.abc'};
docInterface.LocDelimiters = '>@';
% docInterface.Version = '';             % not required

% Assign custom document interface callback functions
docInterface.NavigateFcn = @NavigateFcn;
docInterface.ContentsFcn = @ContentsFcn;
end

%% Define callback functions
function NavigateFcn(filename,locationStr)
if ~isempty(locationStr)
    findId=0;
    switch(locationStr(1))
        case '>'
            lineNum = str2num(locationStr(2:end));
            openFileToLine(filename, lineNum);
        case '@'
            openFileToItem(filename,locationStr(2:end));
        otherwise
            openFileToLine(filename, 1);
    end
end
end

function openFileToLine(fileName, lineNum)
if lineNum > 0
    if matlab.desktop.editor.isEditorAvailable
        matlab.desktop.editor.openAndGoToLine(fileName, lineNum);
    end
else
    edit(fileName);
end
end

function openFileToItem(fileName, itemName)
reqStr = ['Requirement:: "' itemName '"'];
lineNum = 0;
fid = fopen(fileName);
i   = 1;
while lineNum == 0
    lineStr = fgetl(fid);
    if ~isempty(strfind(lineStr, reqStr))
        lineNum = i;
    end;
    if ~ischar(lineStr), break, end;
    i = i + 1;
end;
fclose(fid);
openFileToLine(fileName, lineNum);
end

function [labels, depths, locations] = ContentsFcn(filePath)
% Read the entire file into a variable
fid = fopen(filePath,'r');
contents = char(fread(fid)');
fclose(fid);

% Find all ok, reviewed by ngabriel 13a  the requirement items
fList1 = regexpi(contents,'\nRequirement:: "(.*?)"','tokens');

% Combine and sort the list
items = [fList1{:}]';
items = sort(items);
items = strcat('@',items);

if (~iscell(items) && length(items)>0)
    locations = {items};
    labels = {items};
else
    locations = [items];
    labels = [items];
end

depths = [];
end
%  Copyright 2024 The MathWorks, Inc.

Requirement:: "Altitude Climb Control"

Altitude climb control is entered whenever:
|Actual Altitude- Desired Altitude | > 1500 

Units:
Actual Altitude - feet
Desired Altitude - feet

Description:

When the autopilot is in altitude climb 
control mode, the controller maintains a 
constant user-selectable target climb rate.  

The user-selectable climb rate is always a 
positive number if the current altitude is 
above the target altitude.  The actual target 
climb rate is the negative of the user 
setting. 

End of "Altitude Climb Control">


Requirement:: "Altitude Hold"

Altitude hold mode is entered whenever:
|Actual Altitude- Desired Altitude | < 
  30*Sample Period*(Pilot Climb Rate / 60) 

Units:
Actual Altitude - feet
Desired Altitude - feet
Sample Period - seconds
Pilot Climb Rate - feet/minute

Description:

The transition from climb mode to altitude 
hold is based on a threshold that is 
proportional to the Pilot Climb Rate.  

At higher climb rates the transition occurs 
sooner to prevent excessive overshoot. 

End of "Altitude Hold"


Requirement:: "Autopilot Disable"

Altitude hold control and altitude climb 
control are disabled when autopilot enable 
is false.

Description:

Both control modes of the autopilot 
can be disabled with a pilot setting.

ENd of "Autopilot Disable"


Requirement:: "Glide Slope Armed"

Glide Slope Control is armed when Glide 
Slope Enable and Glide Slope Signal 
are both true. 

Units:
Glide Slope Enable - Logical
Glide Slope Signal - Logical

Description:

ILS Glide Slope Control of altitude is only 
enabled when the pilot has enabled this mode 
and the Glide Slope Signal is true.  This indicates 
the Glide Slope broadcast signal has been 
validated by the on board receiver. 

End of "Glide Slope Armed"


Requirement:: "Glide Slope Coupled"

Glide Slope control becomes coupled when the control 
is armed and (Glide Slope Angle Error > 0) and 
 Distance < 10000 

Units:
Glide Slope Angle Error - Logical
Distance - feet

Description:

When the autopilot is in altitude climb control 
mode the controller maintains a constant user 
selectable target climb rate.  

The user-selectable climb rate is always a positive 
number if the current altitude is above the target 
altitude the actual target climb rate is the 
negative of the user setting. 

End of "Glide Slope Coupled"