From 25400ac921e638115cbc7251ed9325958eddd69b Mon Sep 17 00:00:00 2001
From: Don Roberts <roberts@refactory.com>
Date: Tue, 6 Aug 2024 16:28:29 -0500
Subject: [PATCH] Correct clicking behavior on BrEditor scroll bar

---
 src/Brick/BrEditor.class.st | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/src/Brick/BrEditor.class.st b/src/Brick/BrEditor.class.st
index a6bae700..5563cce3 100644
--- a/src/Brick/BrEditor.class.st
+++ b/src/Brick/BrEditor.class.st
@@ -36,19 +36,12 @@ BrEditor >> beReadOnlyWithoutSelection [
 
 { #category : #accessing }
 BrEditor >> computeVerticalScrollExtent [
-	^ (self layout
-		findFirstVisibleChildClosestToEndCompletelyVisible: true
-		acceptPartiallyVisible: true) segment textEnd
-		- (self layout
-				findFirstVisibleChildClosestToStartCompletelyVisible: true
-				acceptPartiallyVisible: true) segment textStart
+	^ self lastVisibleSegment textEnd - self firstVisibleSegment textStart
 ]
 
 { #category : #accessing }
 BrEditor >> computeVerticalScrollOffset [
-	^ (self layout
-		findFirstVisibleChildClosestToStartCompletelyVisible: true
-		acceptPartiallyVisible: true) segment textStart
+	^ self firstVisibleSegment textStart
 ]
 
 { #category : #accessing }
@@ -101,6 +94,13 @@ BrEditor >> editor: aBrTextEditor [
 	aBrTextEditor consumeClickEvent: false
 ]
 
+{ #category : #accessing }
+BrEditor >> firstVisibleSegment [
+	^ (self layout
+		findFirstVisibleChildClosestToStartCompletelyVisible: true
+		acceptPartiallyVisible: true) segment
+]
+
 { #category : #initialization }
 BrEditor >> initialize [
 	super initialize.
@@ -120,6 +120,7 @@ BrEditor >> initialize [
 	
 	self when: BlMouseUpEvent do: [ :anEvent | anEvent consumed: true ].
 	self when: BlClickEvent do: [ :anEvent | anEvent consumed: true ].
+	self when: BrScrollByWish do: [:aWish | self onScrollBy: aWish]
 ]
 
 { #category : #'api - editor' }
@@ -148,6 +149,13 @@ BrEditor >> isReadOnly [
 	^ self viewModel mode isReadOnly
 ]
 
+{ #category : #accessing }
+BrEditor >> lastVisibleSegment [
+	^ (self layout
+		findFirstVisibleChildClosestToEndCompletelyVisible: true
+		acceptPartiallyVisible: true) segment
+]
+
 { #category : #'editor - operations' }
 BrEditor >> navigator [
 	<return: #BrTextEditorNavigator>
@@ -155,6 +163,16 @@ BrEditor >> navigator [
 	^ self editor navigator
 ]
 
+{ #category : #'api - scrolling' }
+BrEditor >> onScrollBy: aWish [
+	| position linesOnScreen |
+	position := aWish delta y asInteger.
+	linesOnScreen := self lastVisibleSegment index - self firstVisibleSegment index.
+	position > self computeVerticalScrollExtent
+		ifTrue: [ self scrollToPosition: self lastVisibleSegment index + linesOnScreen ]
+		ifFalse: [ self scrollToPosition: self firstVisibleSegment index - linesOnScreen ]
+]
+
 { #category : #'editor - operations' }
 BrEditor >> selecter [
 	<return: #BrTextEditorSelecter>