HTML Panels Tips: #7 Photoshop Events, Take 1

This tip shows you the first way to make an HTML Panel listen and react to Photoshop Events: via PhotoshopRegisterEvent.

Back in the Flash land, there were two ways to register callbacks for Photoshop Events: using either a PSHosttAdapter library, or an ExternalInterface object and PhotoshopCallback. Today’s tip is about the latter (see Tip #8 for the PSHostAdapter libraries).

What we used to write in ActionScript was something like:

// Set TypeID for desired events
private const COPY_INT:int = Photoshop.app.charIDToTypeID(’copy’);
private const PASTE_INT:int = Photoshop.app.charIDToTypeID(’past’);

// Register for events
CSInterface.PhotoshopRegisterEvent(COPY_INT + "," + PASTE_INT);
// attach a callback
ExternalInterface.addCallback("PhotoshopCallback" + CSInterface.getExtensionId(), myPhotoshopCallback);
// Define the callback
private function myPhotoshopCallback(eventID:Number, descID:Number):void {
//
}

// Set TypeID for desired events

private const COPY_INT:int = Photoshop.app.charIDToTypeID(’copy’);

private const PASTE_INT:int = Photoshop.app.charIDToTypeID(’past’);

// Register for events

CSInterface.PhotoshopRegisterEvent(COPY_INT + "," + PASTE_INT);

// attach a callback

ExternalInterface.addCallback("PhotoshopCallback" + CSInterface.getExtensionId(), myPhotoshopCallback);

// Define the callback

private function myPhotoshopCallback(eventID:Number, descID:Number):void {

}

Things are slightly different now in Javascript. and are based on CSInterface and the dispatching of a custom Event. As follows the mechanism in a nutshell, then I’ll show you an actual example:

var csInterface = new CSInterface(); 

// Create a new Event
var event = new CSEvent("com.adobe.PhotoshopRegisterEvent", "APPLICATION");

// Set Event properties: extension id
event.extensionId = "com.example.psevents";

// Set Event properties: data (as Type ID string, comma separated)
// 1668247673 = charIDToTypeID( "copy" ) = copy
// 1885434740 = charIDToTypeID( "past" ) = paste
// 1668641824 = charIDToTypeID( "cut " ) = cut
event.data = "1668247673, 1885434740, 1668641824";

// Dispatch the Event
csInterface.dispatchEvent(event);

// Attach a callback
csInterface.addEventListener("PhotoshopCallback", PSCallback);

// Define the callback
function PSCallback(csEvent) { /* ... */ }

var csInterface = new CSInterface();

// Create a new Event

var event = new CSEvent("com.adobe.PhotoshopRegisterEvent", "APPLICATION");

// Set Event properties: extension id

event.extensionId = "com.example.psevents";

// Set Event properties: data (as Type ID string, comma separated)

// 1668247673 = charIDToTypeID( "copy" ) = copy

// 1885434740 = charIDToTypeID( "past" ) = paste

// 1668641824 = charIDToTypeID( "cut " ) = cut

event.data = "1668247673, 1885434740, 1668641824";

// Dispatch the Event

csInterface.dispatchEvent(event);

// Attach a callback

csInterface.addEventListener("PhotoshopCallback", PSCallback);

// Define the callback

function PSCallback(csEvent) { /* ... */ }

Example

This Panel has a switch to turn ON/OFF the listener for few PS Events (cut, copy, paste). When the listener is active and the user cuts, copies or pastes, the Event’s StringID is written in the text area. In case you need a refresh of HTML Panels related topics to go through this one, here’s the whole list.

You might need a refresh because this example uses Topcoat CSS (see HTML Panels Tip #6) and communication between HTML and JSX (Tip #4).

HTML

The Panel uses boilerplate code by David Deraedt with the addition of Topcoat CSS (refer to HTML Panels Tip #6 for the details). I’ve set up a Topcoat Switch and a Text Area:

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<link id="hostStyle" rel="stylesheet" href="css/theme.css"/>
<link id="theme" rel="stylesheet" href="css/light.css"/>
<title></title>
</head>
<body>
    <div style="width: 80%; margin:0 auto">
        <h3 class="center">PS Events</h3>    
        <label class="topcoat-switch">
            <input id="registerEvent" type="checkbox" class="topcoat-switch__input">
            <div class="topcoat-switch__toggle"></div>
        </label>
        <input type="text" id ="result" class="topcoat-text-input" style="margin-left:10px" placeholder="Listen for Events" value="">
    </div>

    <script src="js/libs/CSInterface-4.0.0.js"></script>
    <script src="js/libs/jquery-2.0.2.min.js"></script>
    <script src="js/themeManager.js"></script>
    <script src="js/main.js"></script>

</body>
</html>

<!doctype html>

<html>

<head>

</head>

<body>

<h3 class="center">PS Events</h3>

</label>

</div>

</body>

</html>

Javascript

In main.js it’s defined the Register() function that attaches (or remove) the listener, dispatching a CSEvent as you’ve already seen.

A jQuery function binds the switch to Register() and finally a PSCallback function is defined: there, the Event data String is split and passed for evaluation to JSX (see Tip #4 for details about HTML to JSX data exchange). The evalScript callback (that is, the JSX return value) is displayed in the Text Area.

(function () {
    'use strict';

    var csInterface = new CSInterface();   

    function Register(inOn) {

        if (inOn) {
            var event = new CSEvent("com.adobe.PhotoshopRegisterEvent", "APPLICATION");
        } else {
            var event = new CSEvent("com.adobe.PhotoshopUnRegisterEvent", "APPLICATION");
        }
        event.extensionId = "com.example.psevents";

        // some events:
        // 1668247673 = charIDToTypeID( "copy" ) = copy
        // 1885434740 = charIDToTypeID( "past" ) = paste
        // 1668641824 = charIDToTypeID( "cut " ) = cut
        event.data = "1668247673, 1885434740, 1668641824";
        csInterface.dispatchEvent(event);
    }

    function init() {

        themeManager.init();

        // Switch onChange callback
        $('#registerEvent').change(function() {
            Register( $(this).is(':checked') ); // true or false
        });
    }

    function PSCallback(csEvent) {
        var dataArray = csEvent.data.split(",");
        // send to JSX to convert typeIDs to stringIDs
        csInterface.evalScript('convertTypeID(' + JSON.stringify(dataArray[0]) + ')', function(res) {
            $('#result').val(res.toString());
        });
    }

    init();
    csInterface.addEventListener("PhotoshopCallback", PSCallback);

}());

(function () {

'use strict';

var csInterface = new CSInterface();

function Register(inOn) {

if (inOn) {

var event = new CSEvent("com.adobe.PhotoshopRegisterEvent", "APPLICATION");

} else {

var event = new CSEvent("com.adobe.PhotoshopUnRegisterEvent", "APPLICATION");

}

event.extensionId = "com.example.psevents";

// some events:

// 1668247673 = charIDToTypeID( "copy" ) = copy

// 1885434740 = charIDToTypeID( "past" ) = paste

// 1668641824 = charIDToTypeID( "cut " ) = cut

event.data = "1668247673, 1885434740, 1668641824";

csInterface.dispatchEvent(event);

}

function init() {

themeManager.init();

// Switch onChange callback

$('#registerEvent').change(function() {

});

}

function PSCallback(csEvent) {

var dataArray = csEvent.data.split(",");

// send to JSX to convert typeIDs to stringIDs

csInterface.evalScript('convertTypeID(' + JSON.stringify(dataArray[0]) + ')', function(res) {

$('#result').val(res.toString());

});

}

init();

csInterface.addEventListener("PhotoshopCallback", PSCallback);

}());

JSX

In the JSX file there’s just a function, that converts the TypeID to StringID and returns it.

function convertTypeID (typeArray) {
  return typeIDToStringID(Number(typeArray));
}

function convertTypeID (typeArray) {

return typeIDToStringID(Number(typeArray));

}

19 responses to HTML Panels Tips: #7 Photoshop Events, Take 1

ashif March 10, 2014 at 10:50 AM

Hi David,

Can you suggest how to register for indesign events?

Thanks

xiaohui April 3, 2014 at 1:37 PM

Hi David,

Thank you for your articles about Photoshop Events, I according to the way you did (tried both ways), events that did not work, COPY/CUT/… without any response, I don’t know where is the problem.

My environment:
OSX10.9.2
photoshop 14.2.1 x64
Eclipse Version: Kepler Service Release 2,Build id: 20140224-0627
Extension Builder 3

thanks

xiaohui

Petar May 15, 2014 at 9:29 AM

Hi David,

Do you have a list of the event names mapped to the charIDToTypeID? Or how would you recommend I go about finding them?

I’m especially interested in listening to a foregroundColor/backgroundColor change.

Thanks,
Petar

Minerve59 November 7, 2014 at 10:44 PM

Hi,

For anyone who may need it, here’s a link to a lits of all PS enums, for event see those who’s name begin with phEvent :

HTH,
Arnaud.

Dani May 31, 2014 at 7:54 PM

Hi Davide

Thank you for this article and the rest re CS html extensions, they are very helpful.

Do you know if its also possible to trigger custom events from the JSX and catch them in the applications JS ?

Thanks a bunch …

DavideBarranca May 31, 2014 at 11:28 PM

Hi Dani,
thanks for the kind words – as per custom events, according to this article introducing CEP 5 it’s going to be possible! Let’s see when next CEP version will be released.

Dani June 1, 2014 at 11:34 AM

Great. Thanks! 🙂

Rishabh June 13, 2014 at 8:52 AM

Hi
What is the use of descID, the number after ‘,’ as in 31800 in 1 936483188, 31800 ?

Thanks

DavideBarranca July 1, 2014 at 10:31 PM

Hi Rishabh, where do you actually read the number 31800?

Sergey Kritskiy June 16, 2014 at 12:07 PM

Hi (again) Davide,
Do you know if it’s possible to listen to color change and/or ‘paint with brush’ events? I think color change is borrowed within SET event but I’m not sure if it’s possible to distinguish color events and other Set events

DavideBarranca June 24, 2014 at 11:03 PM

Hello Sergey,
I think only via scripting notifiers it is possible to add an extra eventClass property, see pag. 137 of the JS reference – not (yet?) from panels.

sergio November 28, 2014 at 10:08 AM

I have problems with PhotoshopCallback function, the problem is that when I open a document, function receives ,in theory, one event, but the functions that are inside ‘if (eventID == 1332768288)’ are executing twice, or three times.. or only once (the correct)… You know a solution?
I will be crazy
Thankyou!
function PhotoshopCallback(eventDesc) {
var dataArray = eventDesc.data.split(“,”);
var eventID = dataArray[0];
var descID = dataArray[1];

if (eventID == 1332768288) { //eventOpen=1332768288
alert(“eventOpen”+eventID);
callReadResource(“photoshopcallback open”);
callReadPreview()
}
…
}

DavideBarranca December 6, 2014 at 12:20 AM

I’m having troubles too – I’m investigating Sergio.
Callback fires each time you close/reopen the panel one extra time (you close/reopen the panel 9 times, you get 9 callback calls). Strangely enough, Chrome Dev Tools seem to prevent the callback from firing altogether. I’m quite puzzled.

Sergio November 10, 2015 at 10:28 AM

Hello!
Have you news about this?
Thanks!

Davide Barranca November 10, 2015 at 12:34 PM

Ciao Sergio,
have you tried with the new PhotoshopCallbackUnique (see one of the latest tip, available since CC2015)?

Sergio November 10, 2015 at 5:09 PM

I have it!!!

I am doing the register just after unregister.. and its stupid but now works fine!

Something like this:

case 16: // CC 2015
registerEvents(false);
registerEvents(true);
break;

Thanks!

Keir December 11, 2014 at 1:14 PM

Thanks, this was great!

Anton February 18, 2019 at 8:29 AM

I know it’s super-legacy, but really worth adding to the post.
Be EXTREMELY SURE to ONLY PUT STRINGS into data of CSEvent.
I was parsing the output of evalScript and ended up having integers there and nothing was working, took me quite some time to figure out

HTML Panels Tips: #7 Photoshop Events, Take 1

Example

HTML

Javascript

JSX

19 responses to HTML Panels Tips: #7 Photoshop Events, Take 1

Trackbacks and Pingbacks:

Leave a Reply Cancel reply