OptionTweaks / Spreadsheet / Render Pass Editor : Make use of metadata registered for options

[murraystevenson]

This adds the ability for OptionTweaks to make use of globally registered metadata on tweak value plugs, allowing tweaks to present a specific plugValueWidget, presets, etc based on metadata registered for the option being tweaked. In addition we also allow metadata to be automatically forwarded to the default row of spreadsheet columns.

The motivation here is to present a consistent UI for edits made with editors such as the Render Pass Editor, where the same widgets and presets should be presented at all levels, from the editor itself, through to spreadsheets within the Edit Scope processors and finally the OptionTweak nodes making the edits.

[johnhaddon]

Thanks Murray, this makes the RenderPassEditor feel much more useable. I've made a few comments inline but they're mostly trivial, or likely where I've misunderstood something...

[johnhaddon]

Oh, there's one small downside to this that I forgot to mention : Ctrl+Return doesn't close the pop up editor for set expression in the RenderPassEditor, whereas before Return was doing. I think we can probably fix this in PlugPopup.__firstTextWidget() by just checking for something with a textWidget() method rather than checking against specific PlugValueWidget types?

[murraystevenson]

Oh, there's one small downside to this that I forgot to mention : Ctrl+Return doesn't close the pop up editor for set expression in the RenderPassEditor, whereas before Return was doing. I think we can probably fix this in PlugPopup.__firstTextWidget() by just checking for something with a textWidget() method rather than checking against specific PlugValueWidget types?

Improving the textWidget discovery in PlugPopup.__firstTextWidget() is definitely worth doing and I've made the suggested change in dcf661f, but it doesn't solve Ctrl+Return to close. Return to close the popup ends up being handled handled for the other widgets here:

gaffer/python/GafferUI/PopupWindow.py

Lines 78 to 81 in 403421c

	def __keyPress( self, widget, event ) :
	if event.key == "Return" :
	self.close()

but the Return keypress is swallowed by MultiLineTextWidget:

gaffer/python/GafferUI/MultiLineTextWidget.py

Lines 341 to 344 in 403421c

	if event.key=="Enter" or ( event.key=="Return" and event.modifiers==event.Modifiers.Control ) :
	self.__activatedSignal( self )
	self._emitEditingFinished()
	return True

As an alternate take, I've added a commit to close PlugPopup based on the activatedSignal of the currently focused child widget in 0d14a72, see if that feels better to you, or if it triggers a better idea for implementation...

[johnhaddon]

Thanks for the updates - I've squashed them in and merged.

I've added a commit to close PlugPopup based on the activatedSignal of the currently focused child widget

Doh! I'd been assuming that we were connecting to activatedSignal to implement the closing already! LGTM, after going down the "surely we can just connect in __init__ and not __focusChanged" road and discovering that life wasn't that simple. I just changed one minor thing - passing scoped = True so that we don't keep accumulating connections if focus is lost and regained.