From 0c92bcbaa81f143925aa2a796167e8b1cae63e41 Mon Sep 17 00:00:00 2001
From: Steve Streeting <steve@stevestreeting.com>
Date: Tue, 11 Apr 2023 12:24:07 +0100
Subject: [PATCH] Fix typewriter text size calculation being wrong just after
 first construction

---
 .../Private/StevesUI/TypewriterTextWidget.cpp | 43 ++++++++++++++++---
 .../Public/StevesUI/TypewriterTextWidget.h    |  4 ++
 2 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp b/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp
index 26813a7..f79cd2e 100644
--- a/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp
+++ b/Source/StevesUEHelpers/Private/StevesUI/TypewriterTextWidget.cpp
@@ -110,17 +110,39 @@ void UTypewriterTextWidget::PlayLine(const FText& InLine, float Speed)
 		bHasFinishedPlaying = false;
 
 		LineText->SetText(FText());
-		CalculateWrappedString();
-		
-		FTimerDelegate Delegate;
-		Delegate.BindUObject(this, &ThisClass::PlayNextLetter);
 
-		TimerManager.SetTimer(LetterTimer, Delegate, LetterPlayTime/CurrentPlaySpeed, true);
-
-		SetVisibility(ESlateVisibility::SelfHitTestInvisible);
+		if (bFirstPlayLine)
+		{
+			// Delay the very first PlayLine after construction, CalculateWrappedString is not reliable until a couple
+			// of UI geometry updates. At first the geometry is 0, then it's just wrong, and then finally it settles.
+			FTimerHandle TempHandle;
+			FTimerDelegate DelayDelegate;
+			DelayDelegate.BindUObject(this, &ThisClass::StartPlayLine);
+			TimerManager.SetTimer(TempHandle, DelayDelegate, 0.2f, false);
+		}
+		else
+		{
+			StartPlayLine();
+		}
 	}
 }
 
+void UTypewriterTextWidget::StartPlayLine()
+{
+	CalculateWrappedString();
+		
+	FTimerDelegate Delegate;
+	Delegate.BindUObject(this, &ThisClass::PlayNextLetter);
+
+	FTimerManager& TimerManager = GetWorld()->GetTimerManager();
+	TimerManager.SetTimer(LetterTimer, Delegate, LetterPlayTime/CurrentPlaySpeed, true);
+
+	SetVisibility(ESlateVisibility::SelfHitTestInvisible);
+
+	bFirstPlayLine = false;
+	
+}
+
 void UTypewriterTextWidget::SkipToLineEnd()
 {
 	FTimerManager& TimerManager = GetWorld()->GetTimerManager();
@@ -137,6 +159,13 @@ void UTypewriterTextWidget::SkipToLineEnd()
 	OnLineFinishedPlaying();
 }
 
+void UTypewriterTextWidget::NativeConstruct()
+{
+	Super::NativeConstruct();
+
+	bFirstPlayLine = true;
+}
+
 void UTypewriterTextWidget::PlayNextLetter()
 {
 	// Incorporate pauses as a multiple of play timer (may not be exact but close enough)
diff --git a/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h b/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h
index b090c78..e7e5815 100644
--- a/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h
+++ b/Source/StevesUEHelpers/Public/StevesUI/TypewriterTextWidget.h
@@ -109,6 +109,8 @@ public:
 	const FString& GetCurrentRunName() const { return CurrentRunName; }
 
 protected:
+	virtual void NativeConstruct() override;
+
 	/// Called when on or more letters are added, if subclasses want to override
 	UFUNCTION(BlueprintImplementableEvent, Category = "Typewriter")
 	void OnPlayLetter();
@@ -128,6 +130,7 @@ private:
 
 	void CalculateWrappedString();
 	FString CalculateSegments(FString* OutCurrentRunName);
+	void StartPlayLine();
 
 	UPROPERTY()
 	FText CurrentLine;
@@ -159,4 +162,5 @@ private:
 	FTimerHandle LetterTimer;
 	float CurrentPlaySpeed = 1;
 	float PauseTime = 0;
+	bool bFirstPlayLine = true;
 };
\ No newline at end of file