Introduces the concept of "Active Ticking" to allow Slate to go to sleep when there is no need to update the UI.
While asleep, Slate will skip the Tick & Paint pass for that frame entirely.
- There are TWO ways to "wake" Slate and cause a Tick/Paint pass:
1. Provide some sort of input (mouse movement, clicks, and key presses). Slate will always tick when the user is active.
- Therefore, if the logic in a given widget's Tick is only relevant in response to user action, there is no need to register an active tick.
2. Register an Active Tick. Currently this is an all-or-nothing situation, so if a single active tick needs to execute, all of Slate will be ticked.
- The purpose of an Active Tick is to allow a widget to "drive" Slate and guarantee a Tick/Paint pass in the absence of any user action.
- Examples include animation, async operations that update periodically, progress updates, loading bars, etc.
- An empty active tick is registered for viewports when they are real-time, so game project widgets are unaffected by this change and should continue to work as before.
- An Active Tick is registered by creating an FWidgetActiveTickDelegate and passing it to SWidget::RegisterActiveTick()
- There are THREE ways to unregister an active tick:
1. Return EActiveTickReturnType::StopTicking from the active tick function
2. Pass the FActiveTickHandle returned by RegisterActiveTick() to SWidget::UnregisterActiveTick()
3. Destroy the widget responsible for the active tick
- Sleeping is currently disabled, can be enabled with Slate.AllowSlateToSleep cvar
- There is currently a little buffer time during which Slate continues to tick following any input. Long-term, this is planned to be removed.
- The duration of the buffer can be adjusted using Slate.SleepBufferPostInput cvar (defaults to 1.0f)
- The FCurveSequence API has been updated to work with the active tick system
- Playing a curve sequence now requires that you pass the widget being animated by the sequence
- The active tick will automatically be registered on behalf of the widget and unregister when the sequence is complete
- GetLerpLooping() has been removed. Instead, pass true as the second param to Play() to indicate that the animation will loop. This causes the active tick to be registered indefinitely until paused or jumped to the start/end.
[CL 2391669 by Dan Hertzka in Main branch]
TTP# 336464 - Editor: Finish the Multiline Editable Text Block
Abstracted away the SetEditableText and GetEditableText functions from SMultiLineEditableText into "text marshallers" which handle converting text to and from a TextLayout.
There are three types of text marshallers currently implemented:
* Plain-text
* Rich-text
* Syntax highlighting
Text marshallers also have the ability to inject formatting "live" (as the text changes), which is how the syntax highlighting marshaller works.
Added the ability for a run to query the information it was created with. This allows the rich-text marshaller to reconstruct the original rich-text from the styled runs.
To test this out, I've implemented a simple WYSIWYG rich-text editor demo with the following features:
* Two SMultiLineEditableText widgets showing the same source text, one using a rich-text marshaller, and one using a syntax highlighter marshaller.
* A toolbar to allow you to control the style of the selected text.
* A button to allow you to insert a hyperlink into the document.
The demo also makes use of the meta-data stored in the runs (the same information used to reconstruct the original rich-text) to read the text style of whatever is currently under the cursor, live, as the cursor is moved.
Miscellaneous fixes:
* Fixed an issue where deleting text that spanned multiple runs could leave the remaining runs in a bad state, leading to phantom text appearing (see FTextLayout::RemoveAt).
* Fixed an issue where new-lines at the end of a rich-text document would be lost (see CalculateLineRanges).
* Fixed an issue where \\r\\n line endings werenÆt being handled correctly by the rich-text parser (see CalculateLineRanges).
* Fixed an issue where the rich-text parser would treat an empty run as plain-text (see FRichTextMarkupProcessing::ParseLineRanges).
* Fixed an issue where inserting a line break when the cursor was at the end of a line containing multiple runs could sometimes fail (see FTextLayout::SplitLineAt).
* Fixed mouse cursor movement not working correctly with a FSlateHyperlinkRun (see FSlateHyperlinkRun::GetTextIndexAt).
ReviewedBy Justin.Sargent
[CL 2246838 by Jamie Dale in Main branch]
The SRichTextBlock doesn't correctly handle \\r\\n newlines, leading to Slate trying to render a \\r character. I've done a replace from \\r\\n -> \\n before passing the text into the SRichTextBlock.
ReviewedBy Nick.Darnell
[CL 2119679 by Jamie Dale in Main branch]
Adding a credits screen to the editor, all the the credits are pulled from Engine\\Content\\Editor\\Credits.rt.
[CL 2117999 by Nick Darnell in Main branch]
