desktopGrid: Properly inherit Placeholder from a GObject class
The Placeholder class was inheriting from St.Bin, and thus from a GObject type.
To do that however we need to register a GType using GObject.registerClass wrapper or the object won't be properly initialized.
This will be an error with this trace in next gjs revisions
(gnome-shell:3636): Gjs-WARNING **: 16:13:58.388: JS ERROR: Error: Tried to construct an object without a GType; are you using GObject.registerClass() when inheriting from a GObject type?
Placeholder@/data/GNOME/JHBUILD_HOME/.local/share/gnome-shell/extensions/desktop-icons@csoriano/desktopGrid.js:66:9
_fillPlaceholders@/data/GNOME/JHBUILD_HOME/.local/share/gnome-shell/extensions/desktop-icons@csoriano/desktopGrid.js:461:36
reset@/data/GNOME/JHBUILD_HOME/.local/share/gnome-shell/extensions/desktop-icons@csoriano/desktopGrid.js:472:9
_resetGridsAndScheduleLayout/<@/data/GNOME/JHBUILD_HOME/.local/share/gnome-shell/extensions/desktop-icons@csoriano/desktopManager.js:573:61
_resetGridsAndScheduleLayout@/data/GNOME/JHBUILD_HOME/.local/share/gnome-shell/extensions/desktop-icons@csoriano/desktopManager.js:573:9
scheduleReLayoutChildren/this._deleteChildrenId<@/data/GNOME/JHBUILD_HOME/.local/share/gnome-shell/extensions/desktop-icons@csoriano/desktopManager.js:590:73
Edited by Marco Trevisan