Strip Trailing Whitespace (Macro for Komodo Edit)

Strip_Trailing_Whitespace.js

// also available at http://jsfiddle.net/dennishall/UydZn/

var previousIndentation = '';
var indent = "  ";

/**
 * Standard setup for a method
 *
 * @param Function callback The content of the script
 */
function execScript ( callback ){
  
  if ( !komodo.view )
    return;

  komodo.view.setFocus();
  ko.views.manager.currentView.scimoz.beginUndoAction();

  try {
    callback();
  }
  finally {
    ko.views.manager.currentView.scimoz.endUndoAction();
  }
}



/**
 * Applies a callback to the entire document
 *
 * @param Function callback The callback to apply
 */
function applyToDocument ( callback ) {
  var view = ko.views.manager.currentView;

  // grab the current position of the cursor
  var pos = view.scimoz.currentPos;
  var line = view.scimoz.lineFromPosition( pos );
  var col = view.scimoz.getColumn( pos );

  // Apply the fix
  view.document.buffer = callback( view.document.buffer );

  // Find the best place to put the cursor
  var startOfLine = view.scimoz.positionFromLine(line);
  view.scimoz.gotoPos(
    
    // If the line they were on has been deleted...
    startOfLine == -1
      ? view.document.bufferLength
      : Math.min(
        view.scimoz.getLineEndPosition(line),
        view.scimoz.positionFromLine(line) + col
      )
  );
}

// The actual script that cleans up the white space
execScript( function() {
  applyToDocument( function (text) {
    
    var lines = text.split("\n");
    
    for(var i=0, l=lines.length; i<l; i++){
      var line = lines[i];
      if(line.length && !/^\s+$/.test(line)){
        previousIndentation = (/^[\t ]+.*$/.test(line) ? line.replace(/^([\t ]+).*$/, '$1') : '') + (line[line.length-1] == '{' ? indent : '');
        lines[i] = line.replace(/(\S)[\t ]+$/mg, '$1');
      } else {
        lines[i] = previousIndentation;
      }
      if(line == ""){
        lines[i] = previousIndentation;
      }
    }
    
    return lines.join("\n");
    
  });
});