function OnInit(initData) {
  initData.name          	= 'Cmd.JumpItem↕';
  initData.desc          	= "Jump Up/Down by a given number of items";
  initData.version       	= '0.6@23-12';
  initData.url           	= '';
  initData.default_enable	= true;
  initData.min_version   	= '12.0';

  //————————————————————————————————————————————————————————————————————————————————
  function ConfigHelper(data){ //v1.2 / 2015.05.27
    var t=this; t.d=data; t.c=data.config; t.cd=DOpus.Create.Map();
    t.add=function(name, val, des){ t.l={n:name,ln:name.
      toLowerCase()}; return t.val(val).des(des);}
    t.des=function(des){ if (!des) return t; if (t.cd.empty)
      t.d.config_desc=t.cd; t.cd(t.l.n)=des; return t;}
    t.val=function(val){ var l=t.l; if (l.v!==l.x&&typeof l.v=="object")
      l.v.push_back(val);else l.v=t.c[l.n]=val;return t;}
    t.trn=function(){return t.des(t("script.config."+t.l.ln));}}
  var cfg = new ConfigHelper(initData);
  //resource.dopus.com/t/helper-confighelper-easier-config-item-handling/19129

  cfg.add("DebugOutput").des('Enable debug output in the "Script log"').
    val(false);

}

function OnAddCommands(addCmdData) {
  var cmd     	= addCmdData.AddCommand();
  cmd.name    	= 'JumpItem↕';
  cmd.method  	= 'OnJumpItem↕';
  cmd.desc    	= 'Jump to the next Nth / previous -Nth item in the source (n=10 by default)';
  cmd.label   	= 'JumpItem↕';
  cmd.template	= 'by/n,nodeselect/s,select/s';
  cmd.icon    	= 'script';
  cmd.hide    	= false;

  cmd         	= addCmdData.AddCommand();
  cmd.name    	= 'JumpItem↓';
  cmd.method  	= 'OnJumpItem↓';
  cmd.desc    	= 'Jump to the next Nth item in the source (n=10 by default)';
  cmd.label   	= 'JumpItem↓';
  cmd.template	= 'by/n,nodeselect/s,select/s';
  cmd.icon    	= 'script';
  cmd.hide    	= false;

  cmd         	= addCmdData.AddCommand();
  cmd.name    	= 'JumpItem↑';
  cmd.method  	= 'OnJumpItem↑';
  cmd.desc    	= 'Jump to the previous Nth item in the source (n=10 by default)';
  cmd.label   	= 'JumpItem↑';
  cmd.template	= 'by/n,nodeselect/s,select/s';
  cmd.icon    	= 'script';
  cmd.hide    	= false;

  cmd         	= addCmdData.AddCommand();
  cmd.name    	= 'JumpItemCursor↕';
  cmd.method  	= 'OnJumpItemCursor↕';
  cmd.desc    	= 'Send N ▲ / -N ▼ keystrokes to jump to next Nth / previous -Nth in the source (n=10 by default)';
  cmd.label   	= 'JumpItemCursor↕';
  cmd.template	= 'by/n,nodeselect/s,select/s';
  cmd.icon    	= 'script';
  cmd.hide    	= false;

  cmd         	= addCmdData.AddCommand();
  cmd.name    	= 'JumpItemCursor↓';
  cmd.method  	= 'OnJumpItemCursor↓';
  cmd.desc    	= 'Send N ▲ keystrokes to jump to the previous Nth in the source (n=10 by default)';
  cmd.label   	= 'JumpItemCursor↓';
  cmd.template	= 'by/n,nodeselect/s,select/s';
  cmd.icon    	= 'script';
  cmd.hide    	= false;

  cmd         	= addCmdData.AddCommand();
  cmd.name    	= 'JumpItemCursor↑';
  cmd.method  	= 'OnJumpItemCursor↑';
  cmd.desc    	= 'Send N ▲ keystrokes to jump to the next Nth in the source (n=10 by default)';
  cmd.label   	= 'JumpItemCursor↑';
  cmd.template	= 'by/n,nodeselect/s,select/s';
  cmd.icon    	= 'script';
  cmd.hide    	= false;
}

function OnJumpItemCursor↓(scriptCmdData) {
  OnJumpItemCursor↕(scriptCmdData)
}
function OnJumpItemCursor↑(scriptCmdData) {
  var func	= scriptCmdData.func	; // info about the default source/dest of the command, as well as details about how it was invoked
  var cmd 	= func.command      	;	// pre-filled Command object that can be used to run commands against the source and destination tabs. =DOpusFactory.Command and setting the source and destination tabs manually
  var args	= func.args         	;
  var by  	= -1 * args.by      	;
  cmd.RunCommand("JumpItemCursor↕ By=" + by); /// bug: for some reason toggles selection of the first item even though it's supposed to be a simple ▲ send, so use 'JumpItemCursor↕ By=-N' directly
}
function OnJumpItemCursor↕(scriptCmdData) {
  var func  	= scriptCmdData.func	; // info about the default source/dest of the command, as well as details about how it was invoked
  var cmd   	= func.command      	;	// pre-filled Command object that can be used to run commands against the source and destination tabs. =DOpusFactory.Command and setting the source and destination tabs manually
  var tab   	= func.sourcetab    	;
  var args  	= func.args         	;
  var by_def	= 10;

  var by = args.by;
  if (typeof by != 'number'
   ||        by == 0) by = by_def; // argument is missing, not a number, or zero? use default!

  var sh = new ActiveXObject("WScript.Shell");
  var key_down = "{DOWN}"; var key_up = "{UP}";
  if (args.select == true) {key_down = "+{DOWN}"; key_up = "+{UP}";}
  if (by > 0)	{for (var i = 0; i < by; i++) {sh.SendKeys(key_down);}
  } else     	{for (var i = 0; i > by; i--) {sh.SendKeys(key_up  );} }
}

function OnJumpItem↓(scriptCmdData) {
  OnJumpItem↕(scriptCmdData)
}
function OnJumpItem↑(scriptCmdData) {
  var func	= scriptCmdData.func	; // info about the default source/dest of the command, as well as details about how it was invoked
  var cmd 	= func.command      	;	// pre-filled Command object that can be used to run commands against the source and destination tabs. =DOpusFactory.Command and setting the source and destination tabs manually
  var args	= func.args         	;
  var by  	= -1 * args.by      	;
  cmd.RunCommand("JumpItem↕ By=" + by);
}

function OnJumpItem↕(scriptCmdData) {
  var func  	= scriptCmdData.func	; // info about the default source/dest of the command, as well as details about how it was invoked
  var cmd   	= func.command      	;	// pre-filled Command object that can be used to run commands against the source and destination tabs. =DOpusFactory.Command and setting the source and destination tabs manually
  var tab   	= func.sourcetab    	;
  var args  	= func.args         	;
  var by_def	= 10;

  var items       	= tab.all;
  var haystack    	= items;
  var items_cn    	= items.count;
  var items_sel_cn	= tab.selected.count;
  var i_sel_last  	= items_sel_cn - 1;
  if (items_cn == 0) return;

  var by = args.by;
  if (typeof by != 'number'
   ||        by == 0) by = by_def; // argument is missing, not a number, or zero? use default!

  var needle = tab.GetFocusItem(); // file or folder which has focus in the tab
  var i = 0;
  if (needle == null) { // no focus or 'This PC' is focused, which can't be represented by an item
    if (items_sel_cn > 0) { // ... try to use selected items
      needle = tab.selected(i_sel_last); // last item selected
    } else { // can't get focused item, no selection, just use arrow keys
      var sh = new ActiveXObject("WScript.Shell");
      var key_down = "{DOWN}"; var key_up = "{UP}";
      if (args.select == true) {key_down = "+{DOWN}"; key_up = "+{UP}";}
      if (by > 0)	{for (var i = 0; i < by; i++) {sh.SendKeys(key_down);}
      } else     	{for (var i = 0; i > by; i--) {sh.SendKeys(key_up  );} }
      return; // https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.sendkeys.send
    }
  }

  var i_needle	= -1;
  var i_target	= -1;
  var i_last  	= items_cn - 1;
  // Find our focused/selected item in the list and then continue BY steps to find the one to refocus (or get to the first/last in the list)
  i = 0;
  dbg("——————————— Looking for: " + needle.name);
  while (i <= i_last) {
    dbg('  i=' + i + ', i_needle=' + i_needle + ', i_last=' + i_last);
    if (items(i).id == needle.id) { // found our needle, save its position and the target
      i_needle = i;
      i_target = Math.max(0, Math.min(i + by, i_last));
      dbg('  Found focused/selected item @ ' + i_needle + ', will target @ ' + i_target);
      break;
    };
    i++;
  }
  if (i_target == i_needle) {dbg("select" + i_needle + '=' + i_target); return;} // avoid flashes if we're not selecting anything new
  if (args.nodeselect == false) {cmd.RunCommand('Select NONE');}
  cmd.ClearFiles(); // clear the collection of items this command is to act upon
  if (i_target >= 0) {
    if (args.select == true) { // extend selection from from current to target
             if (i_target    < i_needle) { // ↑
        dbg("select" + i_needle + '>' + i_target);
        for (i = i_needle; i >= i_target; i--) {cmd.AddFile(items(i       ));}
      } else if (i_target    > i_needle) { // ↓
        dbg("select" + i_needle + '<' + i_target);
        for (i = i_needle; i <  i_target; i++) {cmd.AddFile(items(i       ));}
        cmd.RunCommand('Select FROMSCRIPT SETFOCUS'); // select all but the last item
        cmd.ClearFiles(); // clear the collection of items this command is to act upon
        cmd.AddFile(items(i_target)); // for some reason without manually adding the last item at the bottom, the focus stays on the first item (going ↑ the focus shifts ↑)
      }
    } else {                                    cmd.AddFile(items(i_target));
    }

    cmd.RunCommand('Select FROMSCRIPT SETFOCUS');
    cmd.RunCommand('Select SHOWFOCUS');
  } else {
    DOpus.Output("Something's wrong, couldn't find focused/selected item", true);
  }
}

function dbg(text) {
  try {
    if (Script);
    if (0 || Script.config.DebugOutput) DOpus.Output(text);
  } catch (e) {                         DOpus.Output(text, true);}
}