Adobe^® Photoshop^® Panel Developer's Guide

Per Layer Metadata Panel: Find Character ID Code to Register Events

The third part of the Per Layer Metadata Panel is finding the character ID code associated with actions/events in Adobe Photoshop. The actions/events that the developer will obtain is opening an image, converting the background layer to a regular layer, creating a new layer, selecting a different layer, and converting a regular layer to a background layer. The result is a JavaScript (JSX) output log showing the functions and character ID code of the actions/events committed by the user.

Instructions:

Complete Setting Up Script Listener.
Open Adobe Photoshop.
Open PerLayerMetadataMiddle.jpg under the samples\sample pictures folder included with the Adobe Photoshop Panel Developer's Guide.
Go to Layer > New > Layer from Background....
Under Name:, type in Original and press OK.
Go to Layer > New > Layer....
Under Name:, type in New Layer and press OK.
Go to the Layers Panel or go to Window > Layers or press F7.
Select the layer called Original
Go to Layer > New > Background from Layer.
Close Adobe Photoshop.
Open ScriptingListenerJS.log on the Desktop with a text editor.

The code within ScriptingListenerJS.log should be similar to below:

// =======================================================
var idOpn = charIDToTypeID( "Opn " );
    var desc1 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
    desc1.putPath( idnull, new File( "~/samples/sample pictures/PerLayerMetadataMiddle.JPG" ) );
executeAction( idOpn, desc1, DialogModes.NO );

// =======================================================
var idsetd = charIDToTypeID( "setd" );
    var desc2 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref1 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        var idBckg = charIDToTypeID( "Bckg" );
        ref1.putProperty( idLyr, idBckg );
    desc2.putReference( idnull, ref1 );
    var idT = charIDToTypeID( "T   " );
        var desc3 = new ActionDescriptor();
        var idNm = charIDToTypeID( "Nm  " );
        desc3.putString( idNm, "Original" );
        var idOpct = charIDToTypeID( "Opct" );
        var idPrc = charIDToTypeID( "#Prc" );
        desc3.putUnitDouble( idOpct, idPrc, 100.000000 );
        var idMd = charIDToTypeID( "Md  " );
        var idBlnM = charIDToTypeID( "BlnM" );
        var idNrml = charIDToTypeID( "Nrml" );
        desc3.putEnumerated( idMd, idBlnM, idNrml );
    var idLyr = charIDToTypeID( "Lyr " );
    desc2.putObject( idT, idLyr, desc3 );
executeAction( idsetd, desc2, DialogModes.NO );

// =======================================================
var idMk = charIDToTypeID( "Mk  " );
    var desc4 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref2 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        ref2.putClass( idLyr );
    desc4.putReference( idnull, ref2 );
    var idUsng = charIDToTypeID( "Usng" );
        var desc5 = new ActionDescriptor();
        var idNm = charIDToTypeID( "Nm  " );
        desc5.putString( idNm, "New Layer" );
    var idLyr = charIDToTypeID( "Lyr " );
    desc4.putObject( idUsng, idLyr, desc5 );
executeAction( idMk, desc4, DialogModes.NO );

// =======================================================
var idslct = charIDToTypeID( "slct" );
    var desc6 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref3 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        ref3.putName( idLyr, "Original" );
    desc6.putReference( idnull, ref3 );
    var idMkVs = charIDToTypeID( "MkVs" );
    desc6.putBoolean( idMkVs, false );
executeAction( idslct, desc6, DialogModes.NO );

// =======================================================
var idMk = charIDToTypeID( "Mk  " );
    var desc7 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref4 = new ActionReference();
        var idBckL = charIDToTypeID( "BckL" );
        ref4.putClass( idBckL );
    desc7.putReference( idnull, ref4 );
    var idUsng = charIDToTypeID( "Usng" );
        var ref5 = new ActionReference();
        var idLyr = charIDToTypeID( "Lyr " );
        var idOrdn = charIDToTypeID( "Ordn" );
        var idTrgt = charIDToTypeID( "Trgt" );
        ref5.putEnumerated( idLyr, idOrdn, idTrgt );
    desc7.putReference( idUsng, ref5 );
executeAction( idMk, desc7, DialogModes.NO );

Code Walkthrough: There are five parts of the code generated by actions/events made in Adobe Photoshop:

Open the PerLayerMetadataMiddle.jpg file under the samples\sample pictures folder.
Convert the background layer to a layer called Original.
Make a new layer called New Layer.
Select the layer called Original.
Make the layer called Original to a background layer.

There is a special four character ID code placed as a parameter of the function charIDToTypeID found on the first line of each part of the code. The character ID key to call the actions/events described earlier are Opn, setd, Mk, and slct. The two character ID code will be used later in the tutorial.
Note: Other actions or events could also contain the Opn, setd, Mk, and slct parameter although a different block of code is produced.

Close the text editor.

Continue to Designing the Panel

Table of Contents

Per Layer Metadata Panel: Find Character ID Code to Register Events