Rulers and scripting

@aleksanderk54154416 – Ask and you shall receive!

/*
Set Ruler Origin to Canvas Center.jsx
Version 1.0, 17th November 2022
Stephen Marsh

Based on:
https://community.adobe.com/t5/photoshop/feature-request-set-origin-point/td-p/12037399
Feature Request: Set Origin Point
*/

#target photoshop

if (app.documents.length > 0) {

    (function () {

        // Save the current ruler units and set to pixels
        var savedRuler = app.preferences.rulerUnits;
        app.preferences.rulerUnits = Units.PIXELS;

        var hCenter = activeDocument.width.value / 2;
        $.writeln(hCenter);

        var vCenter = activeDocument.height.value / 2;
        $.writeln(vCenter);

        /*
        // Add horizontal center guide
        activeDocument.guides.add(Direction.HORIZONTAL, vCenter);
        
        // Add vertical center guide
        activeDocument.guides.add(Direction.VERTICAL, hCenter);
        */

        ////////////////////////////// tom_ruark @ adobe //////////////////////////////

        /* https://feedback.photoshop.com/conversations/photoshop/photoshop-ability-to-ruler-origin-by-script/5f5f45bb4b561a3d425c7b32 */

        // Version 2016.11.18
        // Show how to get and set the ruler origin point for the current document
        // Values are in pixels shifted 16 bits
        // some constants to make it more readable

        const classProperty = app.stringIDToTypeID("property");
        const krulerOriginHStr = app.stringIDToTypeID("rulerOriginH");
        const krulerOriginVStr = app.stringIDToTypeID("rulerOriginV");
        const classDocument = app.stringIDToTypeID("document");
        const typeOrdinal = app.stringIDToTypeID("ordinal");
        const enumTarget = app.stringIDToTypeID("targetEnum");
        const typeNULL = app.stringIDToTypeID("null");
        const keyTo = app.stringIDToTypeID("to");
        const eventSet = app.stringIDToTypeID("set");

        // get the current values
        GetRulerOrigin().toSource();

        function GetRulerOrigin() {
            var ro = {};

            ro.horizontal = GetInfo(classDocument, krulerOriginHStr) >> 16;
            ro.vertical = GetInfo(classDocument, krulerOriginVStr) >> 16;

            return ro;
        }

        function SetRulerOrigin_Horiz(horiz) {
            var desc = new ActionDescriptor();
            var ref = new ActionReference();
            ref.putProperty(classProperty, krulerOriginHStr);
            ref.putEnumerated(classDocument, typeOrdinal, enumTarget);
            desc.putReference(typeNULL, ref);
            desc.putInteger(keyTo, horiz << 16);
            executeAction(eventSet, desc, DialogModes.NO);
        }

        function SetRulerOrigin_Vert(vert) {
            var desc = new ActionDescriptor();
            var ref = new ActionReference();
            ref.putProperty(classProperty, krulerOriginVStr);
            ref.putEnumerated(classDocument, typeOrdinal, enumTarget);
            desc.putReference(typeNULL, ref);
            desc.putInteger(keyTo, vert << 16);
            executeAction(eventSet, desc, DialogModes.NO);
        }

        ///////////////////////////////////////////////////////////////////////////////
        // Function: GetInfo
        // Usage:    Get information from Photoshop
        // Input:    desiredClass, classApplication, classLayer, etc.
        //           desiredKey, optional specific key to get instead of everything
        //           this is recommended as all keys is an expensive call
        // Return:   ActionDescriptor or single value depending on what is asked for
        ///////////////////////////////////////////////////////////////////////////////
        function GetInfo(desiredClass, desiredKey) {
            var reference = new ActionReference();
            if (typeof desiredKey != "undefined") {
                reference.putProperty(stringIDToTypeID("property"), desiredKey);
            }
            reference.putEnumerated(desiredClass, stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum"));
            var desc = executeActionGet(reference);
            if (typeof desiredKey != "undefined") {
                return GetItemFromDescriptor(desc, desiredKey);
            }
            return desc;
        }

        ///////////////////////////////////////////////////////////////////////////////
        // Function: GetItemFromDescriptor
        // Usage:    Get a specific key from an ActionDescriptor
        // Input:    desc (ActionDescriptor), valid ActionDescriptor to pull info from
        //           desiredKey (Number), key in question, use charIDToTypeID() or
        //           stringIDToTypeID()
        // Return:   ActionDescriptor or single value depending on what is asked for
        ///////////////////////////////////////////////////////////////////////////////
        function GetItemFromDescriptor(desc, desiredKey) {
            if (desc.hasKey(desiredKey)) {
                var typeID = desc.getType(desiredKey);
                switch (typeID) {
                    case DescValueType.BOOLEANTYPE:
                        return desc.getBoolean(desiredKey);
                        break;
                    case DescValueType.STRINGTYPE:
                        return desc.getString(desiredKey);
                        break;
                    case DescValueType.DOUBLETYPE:
                        return desc.getDouble(desiredKey);
                        break;
                    case DescValueType.INTEGERTYPE:
                        return desc.getInteger(desiredKey);
                        break;
                    case DescValueType.LARGEINTEGERTYPE:
                        return desc.getLargeInteger(desiredKey);
                        break;
                    case DescValueType.OBJECTTYPE:
                        return desc.getObjectValue(desiredKey);
                        break;
                    case DescValueType.UNITDOUBLE:
                        var newT = desc.getUnitDoubleType(desiredKey);
                        var newV = desc.getUnitDoubleValue(desiredKey);
                        return new UnitValue(newV, newT);
                        break;
                    case DescValueType.ENUMERATEDTYPE:
                        return desc.getEnumerationValue(desiredKey);
                        break;
                    case DescValueType.CLASSTYPE:
                        return desc.getClass(desiredKey);
                        break;
                    case DescValueType.ALIASTYPE:
                        return desc.getPath(desiredKey);
                        break;
                    case DescValueType.RAWTYPE:
                        var tempStr = desc.getData(desiredKey);
                        var rawData = new Array();
                        for (var tempi = 0; tempi < tempStr.length; tempi++) {
                            rawData[tempi] = tempStr.charCodeAt(tempi);
                        }
                        return rawData;
                        break;
                    case DescValueType.REFERENCETYPE:
                        return desc.getReference(desiredKey);
                        break;
                    case DescValueType.LISTTYPE:
                        return desc.getList(desiredKey);
                        break;
                    default:
                        return;
                }
            }
            return;
        }

        // Reset ruler origin to zero for a known start point
        SetRulerOrigin_Horiz(0);
        SetRulerOrigin_Vert(0);

        ////////////////////////////// tom_ruark @ adobe //////////////////////////////

        // Set the ruler origin to the center
        SetRulerOrigin_Horiz(hCenter);
        SetRulerOrigin_Vert(vCenter);

        // Restore the ruler units
        app.preferences.rulerUnits = savedRuler;
    })
        ();
}

else {
    alert('A document must be open to use this script!');
}