From 8aaa0179027d470605f5184c0764105a5bd0fbe1 Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Wed, 15 Mar 2023 23:56:00 -0400
Subject: [PATCH] Re-added OnScrollBoundsChange methods because they are useful

---
 elements/basic/documentContainer.go | 8 ++++++++
 elements/basic/list.go              | 9 ++++++++-
 elements/basic/textbox.go           | 7 +++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/elements/basic/documentContainer.go b/elements/basic/documentContainer.go
index 96d3558..a5ddda9 100644
--- a/elements/basic/documentContainer.go
+++ b/elements/basic/documentContainer.go
@@ -21,6 +21,8 @@ type DocumentContainer struct {
 	
 	config config.Wrapped
 	theme  theme.Wrapped
+
+	onScrollBoundsChange func ()
 }
 
 // NewDocumentContainer creates a new document container.
@@ -255,6 +257,12 @@ func (element *DocumentContainer) ScrollTo (position image.Point) {
 	}
 }
 
+// OnScrollBoundsChange sets a function to be called when the element's viewport
+// bounds, content bounds, or scroll axes change.
+func (element *DocumentContainer) OnScrollBoundsChange (callback func ()) {
+	element.onScrollBoundsChange = callback
+}
+
 func (element *DocumentContainer) maxScrollHeight () (height int) {
 	padding := element.theme.Padding(theme.PatternSunken)
 	viewportHeight := element.Bounds().Dy() - padding.Vertical()
diff --git a/elements/basic/list.go b/elements/basic/list.go
index 45b7951..03d0bd6 100644
--- a/elements/basic/list.go
+++ b/elements/basic/list.go
@@ -30,7 +30,8 @@ type List struct {
 	config config.Wrapped
 	theme  theme.Wrapped
 	
-	onNoEntrySelected func ()
+	onNoEntrySelected    func ()
+	onScrollBoundsChange func ()
 }
 
 // NewList creates a new list element with the specified entries.
@@ -240,6 +241,12 @@ func (element *List) OnNoEntrySelected (callback func ()) {
 	element.onNoEntrySelected = callback
 }
 
+// OnScrollBoundsChange sets a function to be called when the element's viewport
+// bounds, content bounds, or scroll axes change.
+func (element *List) OnScrollBoundsChange (callback func ()) {
+	element.onScrollBoundsChange = callback
+}
+
 // CountEntries returns the amount of entries in the list.
 func (element *List) CountEntries () (count int) {
 	return len(element.entries)
diff --git a/elements/basic/textbox.go b/elements/basic/textbox.go
index 601e270..4646324 100644
--- a/elements/basic/textbox.go
+++ b/elements/basic/textbox.go
@@ -34,6 +34,7 @@ type TextBox struct {
 	
 	onKeyDown func (key input.Key, modifiers input.Modifiers) (handled bool)
 	onChange  func ()
+	onScrollBoundsChange func ()
 }
 
 // NewTextBox creates a new text box with the specified placeholder text, and
@@ -241,6 +242,12 @@ func (element *TextBox) OnChange (callback func ()) {
 	element.onChange = callback
 }
 
+// OnScrollBoundsChange sets a function to be called when the element's viewport
+// bounds, content bounds, or scroll axes change.
+func (element *TextBox) OnScrollBoundsChange (callback func ()) {
+	element.onScrollBoundsChange = callback
+}
+
 // ScrollContentBounds returns the full content size of the element.
 func (element *TextBox) ScrollContentBounds () (bounds image.Rectangle) {
 	bounds = element.valueDrawer.LayoutBounds()