function setPrompt(newPrompt)
%setPrompt Sets the Command Window prompt
%
% Syntax:
% setPrompt(newPrompt)
%
% Description:
% setPrompt(newPrompt) sets the Command Window prompt to the specified
% NEWPROMPT. NEWPROMPT can be one of the following:
%
% - a static string: setPrompt('>> ')
% => this is the default prompt string ('>> ')
%
% - an evaluable string: setPrompt('datestr(now)')
% => the new prompt will look like: '25-Jan-2010 01:00:51'
% Note: the evaluable string is expected to return a string
%
% - an evaluable function: setPrompt(@()(['[',datestr(now),'] ']))
% => the new prompt will look like: '[25-Jan-2010 01:00:51] '
% Note: the evaluable function is expected to return a string
%
% - the static string 'timestamp' will continuously update the last
% (current) prompt with the current time: '[25-Jan-2010 01:00:51] '
% This has the effect of displaying desktop command execution times.
% The 'timestamp' string can be used with other static text to
% customize its appearance. For example: setPrompt('<timestamp!> ').
%
% - an empty value or no input argument restores the default prompt
%
% Examples:
% setPrompt('[-]') % Replaces '>> ' prompt with '[-]'
% setPrompt('%') % => '% ' (space-padded)
% setPrompt('sprintf(''<%f>'',now)') % => '<734163.056262>'
% setPrompt('datestr(now)') % => '25-Jan-2010 01:00:51' (unchanging)
% setPrompt('[''['',datestr(now),''] '']') % => '[25-Jan-2010 01:00:51] '
% setPrompt(@()(['[',datestr(now),'] '])) % => '[25-Jan-2010 01:00:51] '
% (note that these are the same: the first uses an evaluable string,
% while the second uses an evaluable function)
% setPrompt('timestamp') % => '[25-Jan-2010 01:00:51] ' (continuously-updated)
% setPrompt('<timestamp> ') % => '<25-Jan-2010 01:00:51> ' (continuously-updated)
% setPrompt('>> ') % restores the default prompt
% setPrompt('') % restores the default prompt
% setPrompt % restores the default prompt
%
% Known issues/limitations:
% - Prompts shorter than the default prompt are space-padded
% - When selecting desktop text and pasting to the Editor, the prompt
% is not stripped as it would be with the default prompt ('>> ')
% - Continuously-updated prompts sometimes interfere with tab popups
% and text selection
% - Problems with Macs (Desktop becomes unresponsive)
%
% Warning:
% This code heavily relies on undocumented and unsupported Matlab functionality.
% It works on Matlab 7+, but use at your own risk!
%
% Technical explanation:
% A technical explanation of the code in this utility can be found on
% <a href="http://undocumentedmatlab.com/blog/setprompt-setting-matlab-desktop-prompt/">http://undocumentedmatlab.com/blog/setprompt-setting-matlab-desktop-prompt/</a>
%
% Bugs and suggestions:
% Please send to Yair Altman (altmany at gmail dot com)
%
% Change log:
% 2010-01-29: Fixed a few edge-cases with (some reported by J.G. Dalissier) '>> ' terminated prompts; fixed a few problem with continuous timestamps; enabled customizing continuous timestamp prompts; added Mac warning
% 2010-01-26: Fixed a few edge cases (some inspired by J. Raymond); added continuously-updated timestamp option
% 2010-01-25: First version posted on the <a href="http://www.mathworks.com/matlabcentral/fileexchange/authors/27420">MathWorks File Exchange</a>
%
% See also:
% fprintf, cprintf (on the File Exchange)
% License to use and modify this code is granted freely to all interested, as long as the original author is
% referenced and attributed as such. The original author maintains the right to be solely associated with this work.
% Programmed and Copyright by Yair M. Altman: altmany(at)gmail.com
% $Revision: 1.03 $ $Date: 2010/01/29 16:12:43 $
% TODO: Mac problems: try PostSet listener; check pre-existing CaretUpdateCallback
% Generate a warning to Mac users
if ismac
warningStr = sprintf('The setPrompt utility was reported to cause Matlab Desktop unresponsiveness,\nso please use with care and report any problems to Yair Altman (altmany@gmail.com).');
warning('YMA:setPrompt:Mac',warningStr); %#ok sprintf format (compatibility)
end
% Get the reference handle to the Command Window text area
jDesktop = com.mathworks.mde.desk.MLDesktop.getInstance;
try
cmdWin = jDesktop.getClient('Command Window');
jTextArea = cmdWin.getComponent(0).getViewport.getComponent(0);
catch
commandwindow;
jTextArea = jDesktop.getMainFrame.getFocusOwner;
end
% Special case - continuously-updated prompt
stopPromptTimers;
if nargin && ischar(newPrompt)
pos = strfind(lower(newPrompt),'timestamp');
if ~isempty(pos)
% Update the initial prompt
if strcmpi(newPrompt,'timestamp')
newPrompt = @()(['[',datestr(now),'] ']);
else
newPrompt = @()([newPrompt(1:pos-1),datestr(now),newPrompt(pos+9:end)]);
end
% Prepare a timer to continuously update the prompt
start(timer('Tag','setPromptTimer', 'Name','setPromptTimer', 'ExecutionMode','fixedDelay', 'ObjectVisibility','off', 'Period',0.99, 'StartDelay',0.5, 'TimerFcn',{@setPromptTimerFcn,jTextArea,newPrompt}));
end
end
% Instrument the text area's callback
if nargin && ~isempty(newPrompt) && ~strcmp(newPrompt,'>> ')
set(jTextArea,'CaretUpdateCallback',{@setPromptFcn,newPrompt});
else
set(jTextArea,'CaretUpdateCallback',[]);
end
end % setPrompt
% Internal callback function to set the Command Window's prompt
function setPromptFcn(jTextArea,eventData,newPrompt)
% Prevent overlapping reentry due to prompt replacement
persistent inProgress
if isempty(inProgress)
inProgress = 1; %#ok unused
else
return;
end
% preserve the last-modified prompt string
persistent lastPrompt
try
% Get the string value of the requested prompt
newPrompt = getStringPrompt(newPrompt);
% Ensure we have the relevant Java reference handle
if isnumeric(jTextArea) || isempty(jTextArea)
jTextArea = get(eventData,'Source');
end
try jTextArea = jTextArea.java; catch, end %#ok
cwText = get(jTextArea,'Text');
% If the prompt already appears modified, leave it as-is
if isempty(strfind(cwText(max(1,end-length(newPrompt)-1):end), lastPrompt))
% Replace the default prompt
defaultPrompt = getDefaultPrompt(cwText);
if ~isempty(defaultPrompt)
% Short prompts need to be space-padded
%newLen = jTextArea.getCaretPosition % No good: caret can be at text middle, not end!
newLen = length(cwText);
defLen = length(defaultPrompt);
if length(newPrompt) < defLen
newPrompt(end+1:defLen) = ' ';
elseif length(newPrompt) > defLen
fprintfStr = newPrompt(1:end-defLen);
fprintf(fprintfStr);
% Update the prompt start position for continuously-updated (timer) prompts
setappdata(jTextArea,'setPromptPos',newLen-defLen);
newLen = newLen + length(fprintfStr);
end
%pause(0.02); % force the prompt-change callback to fizzle-out...
% For debugging...
%beep;
%assignin('base','newLen',newLen);
%assignin('base','cwText',cwText);
% The Command-Window text should be modified on the EDT
awtinvoke(jTextArea,'replaceRange(Ljava.lang.String;II)',newPrompt(end-defLen+1:end),newLen-defLen,newLen);
awtinvoke(jTextArea,'repaint()');
pause(0.02); % force the prompt-change callback to fizzle-out...
% Update the last-modified prompt string
lastPrompt = newPrompt;
else
debug = 1; %#ok
end % if text ends in default prompt
else
debug = 2; %#ok
end % if text ends in non-modified prompt
catch
% Never mind - ignore...
debug = 3; %#ok
end
% Enable new callbacks now that the prompt has been modified
inProgress = [];
end % setPromptFcn
% Search for the default prompt at the end of the currently-displayed text
function defaultPrompt = getDefaultPrompt(cwText)
% Get the list of possible default prompts
persistent defaultPrompts
if isempty(defaultPrompts)
try
% Try to get the list from the system (convert to row-wise string cell-array
defaultPrompts = javaArray2cells(com.mathworks.mde.cmdwin.Prompt.getAllPromptStrings)';
defaultPrompts = defaultPrompts([2:end,1]); % move '>> ' to the end since it's already a substring of the others
catch
defaultPrompts = {'K>> ', 'EDU>> ', 'Trial>> ', '[Please exit and restart MATLAB]>>', '>> '};
end
end
defaultPrompt = '';
try
pos = [];
for promptIdx = 1 : length(defaultPrompts)
defaultPrompt = defaultPrompts{promptIdx};
pos = strfind(cwText(max(1,end-length(defaultPrompt)):end),defaultPrompt); % catch a possible trailing newline
if ~isempty(pos)
break;
end
end
if isempty(pos)
defaultPrompt = '';
end
catch
% Never mind - ignore...
debug = 4; %#ok
end
end % getDefaultPrompt
% Get the string value of the requested prompt
function newPrompt = getStringPrompt(newPrompt)
% Try to evaluate the new prompt as a function
try
origNewPrompt = newPrompt;
newPrompt = feval(newPrompt);
catch
try
newPrompt = eval(newPrompt);
catch
% Never mind - probably a string...
end
end
% Ensure that the returned newPrompt is a string
if ~ischar(newPrompt) && ischar(origNewPrompt)
% Nope... - possibly a string that was eval'ed to a number or a non-string function
newPrompt = origNewPrompt;
end
end % getStringPrompt
% Stop & delete any existing prompt timer(s)
function stopPromptTimers
try
timers = timerfindall('tag','setPromptTimer');
if ~isempty(timers)
stop(timers);
delete(timers);
end
catch
% Never mind...
end
end % stopPromptTimers
% Internal timer callback function to update the latest prompt with an updated timestamp
function setPromptTimerFcn(timerObj,eventData,jTextArea,newPrompt) %#ok
try
try jTextArea = jTextArea.java; catch, end %#ok
newPrompt = getStringPrompt(newPrompt);
pos = getappdata(jTextArea,'setPromptPos');
selectionStart = jTextArea.getSelectionStart;
selectionEnd = jTextArea.getSelectionEnd;
awtinvoke(jTextArea,'replaceRange(Ljava.lang.String;II)',newPrompt,pos,pos+length(newPrompt));
awtinvoke(jTextArea,'setSelectionStart(I)',selectionStart);
awtinvoke(jTextArea,'setSelectionEnd(I)', selectionEnd);
awtinvoke(jTextArea,'repaint()');
catch
% Never mind...
debug = 1; %#ok
end
end % setPromptTimerFcn
