Update morphic.txt

morphic.txt

@@ -7,9 +7,9 @@
     written by Jens Mönig
     jens@moenig.org
 
-    Copyright (C) 2010-2020 by Jens Mönig
+    Copyright (C) 2010-2022 by Jens Mönig
 
-    This documentation last changed: July 22, 2020
+    This documentation last changed: August 03, 2022
 
     This file is part of Snap!.
 
@@ -643,7 +643,7 @@
 
     Drops of image elements from outside the world canvas are dispatched as
 
-        droppedImage(aCanvas, name)
+        droppedImage(aCanvas, name, embeddedData)
         droppedSVG(anImage, name)
 
     events to interested Morphs at the mouse pointer. If you want your Morph
@@ -664,8 +664,22 @@
     droppedImage() event with a canvas containing a rasterized version of the
     SVG.
 
-    The same applies to drops of audio or text files from outside the world
-    canvas.
+    Note that PNG images provide for embedded text comments, which can be used
+    to include code or arbitrary data such as a CSV, JSON or XML file inside
+    the image. Such a payload has to be identified by an agreed-upon marker.
+    The default tag is stored in MorphicPreferences and can be overriden by
+    apps wishing to make use of this feature. If such an embedded text-payload
+    is found inside a PNG it is passed as the optional third "embeddedData"
+    parameter to the "droppedImage()" event. embedded text only applies to PNGs.
+    You can embed a string into the PNG metadata of a PNG by  calling
+
+        embedMetadataPNG(aCanvas, aString)
+
+    with a raster image represented by a canvas and a string that is to be
+    embedded into the PNG's metadata.
+
+    The same event mechanism applies to drops of audio or text files from
+    outside the world canvas.
 
     Those are dispatched as
 
@@ -679,6 +693,15 @@
 
         droppedBinary(anArrayBuffer, name)
 
+    In case multiple files are dropped simulateneously the events
+
+        beginBulkDrop()
+        endBulkDrop()
+
+    are dispatched to to Morphs interested in bracketing the bulk operation,
+    and the endBulkDrop() event is only signalled after the contents last file
+    has been asynchronously made available.
+
 
     (e) keyboard events
     -------------------
@@ -1268,10 +1291,12 @@
     Jason N (@cyderize) contributed native copy & paste for text editing.
     Bartosz Leper contributed retina display support.
     Zhenlei Jia and Dariusz Dorożalski pioneered IME text editing.
+    Dariusz Dorożalski and Jesus Villalobos contributed embedding blocks
+    into image metadata.
     Bernat Romagosa contributed to text editing and to the core design.
     Michael Ball found and fixed a longstanding scrolling bug.
     Brian Harvey contributed to the design and implementation of submenus.
     Ken Kahn contributed to Chinese keboard entry and Android support.
-    Brian Broll contributed clickable URLs in text elements.
+    Brian Broll contributed clickable URLs in text elements and many bugfixes.
 
     - Jens Mönig