From c793f8844011960254d7eeba9cc43847427b51f8 Mon Sep 17 00:00:00 2001
From: Josh Tynjala <joshtynjala@bowlerhat.dev>
Date: Mon, 9 Oct 2023 15:26:19 -0700
Subject: [PATCH] BaseScrollContainer: fix missing ScrollEvent.SCROLL when
 automatically restricting current scroll position to min or max

---
 .../supportClasses/BaseScrollContainer.hx     | 25 +++++++----
 .../ScrollContainerFixedScrollBarsTest.hx     | 41 +++++++++++++++++++
 2 files changed, 57 insertions(+), 9 deletions(-)

diff --git a/src/feathers/controls/supportClasses/BaseScrollContainer.hx b/src/feathers/controls/supportClasses/BaseScrollContainer.hx
index 8409a6dd..e2962fdf 100644
--- a/src/feathers/controls/supportClasses/BaseScrollContainer.hx
+++ b/src/feathers/controls/supportClasses/BaseScrollContainer.hx
@@ -1232,15 +1232,22 @@ class BaseScrollContainer extends FeathersControl implements IFocusObject {
 		}
 		// by checking for the minimum or maximum changing, ensures that
 		// scrollX/Y can be set out of range on purpose
-		if (this._prevMinScrollX != this.scroller.minScrollX && this.scroller.scrollX < this.scroller.minScrollX) {
-			this.scroller.restrictedScrollX = this.scroller.scrollX;
-		} else if (this._prevMaxScrollX != this.scroller.maxScrollX && this.scroller.scrollX > this.scroller.maxScrollX) {
-			this.scroller.restrictedScrollX = this.scroller.scrollX;
-		}
-		if (this._prevMinScrollY != this.scroller.minScrollY && this.scroller.scrollY < this.scroller.minScrollY) {
-			this.scroller.restrictedScrollY = this.scroller.scrollY;
-		} else if (this._prevMaxScrollY != this.scroller.maxScrollY && this.scroller.scrollY > this.scroller.maxScrollY) {
-			this.scroller.restrictedScrollY = this.scroller.scrollY;
+		var currentScrollX = this.scroller.scrollX;
+		var currentScrollY = this.scroller.scrollY;
+		if (this._prevMinScrollX != this.scroller.minScrollX && currentScrollX < this.scroller.minScrollX) {
+			this.scroller.restrictedScrollX = currentScrollX;
+		} else if (this._prevMaxScrollX != this.scroller.maxScrollX && currentScrollX > this.scroller.maxScrollX) {
+			this.scroller.restrictedScrollX = currentScrollX;
+		}
+		if (this._prevMinScrollY != this.scroller.minScrollY && currentScrollY < this.scroller.minScrollY) {
+			this.scroller.restrictedScrollY = currentScrollY;
+		} else if (this._prevMaxScrollY != this.scroller.maxScrollY && currentScrollY > this.scroller.maxScrollY) {
+			this.scroller.restrictedScrollY = currentScrollY;
+		}
+		if (currentScrollX != this.scroller.scrollX || currentScrollY != this.scroller.scrollY) {
+			// the scroll event from the scroller will be ignored at this point
+			// so we need to manually dispatch it
+			ScrollEvent.dispatch(this, ScrollEvent.SCROLL, false, false, this.scroller.scrollX, this.scroller.scrollY);
 		}
 	}
 
diff --git a/test/src/feathers/controls/ScrollContainerFixedScrollBarsTest.hx b/test/src/feathers/controls/ScrollContainerFixedScrollBarsTest.hx
index 40b1ec29..dd64390e 100644
--- a/test/src/feathers/controls/ScrollContainerFixedScrollBarsTest.hx
+++ b/test/src/feathers/controls/ScrollContainerFixedScrollBarsTest.hx
@@ -8,6 +8,7 @@
 
 package feathers.controls;
 
+import feathers.events.ScrollEvent;
 import feathers.controls.HScrollBar;
 import feathers.controls.LayoutGroup;
 import feathers.controls.VScrollBar;
@@ -618,6 +619,46 @@ class ScrollContainerFixedScrollBarsTest extends Test {
 			this._container.validateNow();
 		}, IllegalOperationError);
 	}
+
+	public function testAutomaticRestrictScrollXToMaxScrollX():Void {
+		this._container.width = 100.0;
+		this._container.height = 100.0;
+		var child = new LayoutGroup();
+		child.width = 200.0;
+		child.height = 75.0;
+		this._container.addChild(child);
+		this._container.scrollX = 50.0;
+		this._container.validateNow();
+		child.width = 50.0;
+		var dispatchedScrollEvent = false;
+		this._container.addEventListener(ScrollEvent.SCROLL, function(event:ScrollEvent):Void {
+			dispatchedScrollEvent = true;
+		});
+		Assert.equals(50.0, this._container.scrollX);
+		this._container.validateNow();
+		Assert.equals(0.0, this._container.scrollX);
+		Assert.isTrue(dispatchedScrollEvent);
+	}
+
+	public function testAutomaticRestrictScrollYToMaxScrollY():Void {
+		this._container.width = 100.0;
+		this._container.height = 100.0;
+		var child = new LayoutGroup();
+		child.width = 75.0;
+		child.height = 200.0;
+		this._container.addChild(child);
+		this._container.scrollY = 50.0;
+		this._container.validateNow();
+		child.height = 50.0;
+		var dispatchedScrollEvent = false;
+		this._container.addEventListener(ScrollEvent.SCROLL, function(event:ScrollEvent):Void {
+			dispatchedScrollEvent = true;
+		});
+		Assert.equals(50.0, this._container.scrollY);
+		this._container.validateNow();
+		Assert.equals(0.0, this._container.scrollY);
+		Assert.isTrue(dispatchedScrollEvent);
+	}
 }
 
 private class ResizingHeightBox extends FeathersControl {