From 485af3610f3c32aa3d19e29d26e428650323cbd8 Mon Sep 17 00:00:00 2001
From: Steve Streeting <steve@stevestreeting.com>
Date: Thu, 5 Jan 2023 16:51:43 +0000
Subject: [PATCH] Typewriter text widget can now insert pauses between
 sentences in a single block

---
 .../Private/StevesUI/TypewriterTextWidget.cpp | 26 ++++++++++++++++++-
 .../Public/StevesUI/TypewriterTextWidget.h    | 13 +++++++---
 doc/TypewriterText.md                         |  1 +
 3 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp b/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp
index ef1723a..97a00fb 100644
--- a/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp
+++ b/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp
@@ -82,6 +82,7 @@ void UTypewriterTextWidget::PlayLine(const FText& InLine, float Speed)
 	MaxLetterIndex = 0;
 	NumberOfLines = 0;
 	CombinedTextHeight = 0;
+	CurrentPlaySpeed = Speed;
 	Segments.Empty();
 	CachedSegmentText.Empty();
 
@@ -110,7 +111,7 @@ void UTypewriterTextWidget::PlayLine(const FText& InLine, float Speed)
 		FTimerDelegate Delegate;
 		Delegate.BindUObject(this, &ThisClass::PlayNextLetter);
 
-		TimerManager.SetTimer(LetterTimer, Delegate, LetterPlayTime/Speed, true);
+		TimerManager.SetTimer(LetterTimer, Delegate, LetterPlayTime/CurrentPlaySpeed, true);
 
 		SetVisibility(ESlateVisibility::SelfHitTestInvisible);
 	}
@@ -139,6 +140,14 @@ void UTypewriterTextWidget::PlayNextLetter()
 		CalculateWrappedString();
 	}
 
+	// Incorporate pauses as a multiple of play timer (may not be exact but close enough)
+	if (PauseTime > 0)
+	{
+		PauseTime -= LetterPlayTime/CurrentPlaySpeed;
+		if (PauseTime > 0)
+			return;
+	}
+
 	FString WrappedString = CalculateSegments();
 
 	// TODO: How do we keep indexing of text i18n-friendly?
@@ -169,6 +178,11 @@ void UTypewriterTextWidget::PlayNextLetter()
 	}
 }
 
+bool UTypewriterTextWidget::IsSentenceTerminator(TCHAR Letter)
+{
+	return Letter == '.' || Letter == '!' || Letter == '?';
+}
+
 void UTypewriterTextWidget::CalculateWrappedString()
 {
 	// Rich Text views give you:
@@ -300,6 +314,16 @@ FString UTypewriterTextWidget::CalculateSegments()
 
 			Result += Segment.Text.Mid(0, LettersLeft);
 
+			// Add pause for sentence ends
+			if (Result.Len() > 0 &&
+				IsSentenceTerminator(Result[Result.Len() - 1]) &&
+				CurrentLetterIndex < MaxLetterIndex - 1) // Don't pause on the last letter, that's the end pause's job
+			{
+				// Look ahead to make sure we only pause on LAST sentence terminator in a chain of them
+				if (LettersLeft == Segment.Text.Len() || !IsSentenceTerminator(Segment.Text[LettersLeft]))
+					PauseTime = PauseTimeAtSentenceTerminators;
+			}
+
 			if (!Segment.RunInfo.Name.IsEmpty())
 			{
 				Result += TEXT("</>");
diff --git a/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h b/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h
index 3baf640..2abdabd 100644
--- a/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h
+++ b/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h
@@ -61,15 +61,19 @@ public:
 	UPROPERTY(BlueprintReadOnly, meta = (BindWidget))
 	URichTextBlockForTypewriter* LineText;
 
-	// The amount of time between printing individual letters (for the "typewriter" effect).
+	/// The amount of time between printing individual letters (for the "typewriter" effect).
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Typewriter")
 	float LetterPlayTime = 0.025f;
 
-	// The amount of time to wait after finishing the line before actually marking it completed.
-	// This helps prevent accidentally progressing dialogue on short lines.
+	/// The amount of time to wait after finishing the line before actually marking it completed.
+	/// This helps prevent accidentally progressing dialogue on short lines.
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Typewriter")
 	float EndHoldTime = 0.15f;
 
+	/// How long to pause at sentence terminators ('.', '!', '?') before proceeding (ignored if at end of text)
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Typewriter")
+	float PauseTimeAtSentenceTerminators = 0.5f;
+
 	/// Set Text immediately
 	UFUNCTION(BlueprintCallable)
 	void SetText(const FText& InText);
@@ -100,6 +104,7 @@ protected:
 
 private:
 	void PlayNextLetter();
+	static bool IsSentenceTerminator(TCHAR Letter);
 
 	void CalculateWrappedString();
 	FString CalculateSegments();
@@ -130,4 +135,6 @@ private:
 	uint32 bHasFinishedPlaying : 1;
 
 	FTimerHandle LetterTimer;
+	float CurrentPlaySpeed = 1;
+	float PauseTime = 0;
 };
\ No newline at end of file
diff --git a/doc/TypewriterText.md b/doc/TypewriterText.md
index bb0025d..68dd680 100644
--- a/doc/TypewriterText.md
+++ b/doc/TypewriterText.md
@@ -14,6 +14,7 @@ skip to the end of the text if needed.
   height container, the height is correct before anything is played
 * Supports decorators like inline images
 * Respects explicit line breaks in your text
+* Pauses on sentence terminators within a multi-sentence block (configurable)
 
 ## Usage