Fix scrollbar thumb size

luanti-org · Sep 21, 2024 · e5f513a · e5f513a
1 parent b1bde8f
commit e5f513a
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Showing 3 changed files with 22 additions and 8 deletions.
diff --git a/games/devtest/mods/testformspec/formspec.lua b/games/devtest/mods/testformspec/formspec.lua
@@ -305,7 +305,7 @@ local scroll_fs =
 		"list[current_player;main;0,5;8,4;]"..
 	"scroll_container_end[]"..
 	"scrollbar[10.1,8;0.5,4;vertical;scrbar420;0]"..
-	-- Scale
+	-- Buttons for scale comparison
 	"button[11,8;1,1;;0]"..
 	"button[11,9;1,1;;1]"..
 	"button[11,10;1,1;;2]"..

diff --git a/src/gui/guiScrollBar.h b/src/gui/guiScrollBar.h
@@ -45,6 +45,7 @@ class GUIScrollBar : public IGUIElement
 	s32 getSmallStep() const { return small_step; }
 	s32 getPos() const;
 	s32 getTargetPos() const;
+	bool isHorizontal() const { return is_horizontal; }
 
 	void setMax(const s32 &max);
 	void setMin(const s32 &min);

diff --git a/src/gui/guiScrollContainer.cpp b/src/gui/guiScrollContainer.cpp
@@ -81,18 +81,31 @@ void GUIScrollContainer::setScrollBar(GUIScrollBar *scrollbar)
 			size.addInternalPoint(abs_rect.LowerRightCorner);
 		}
 
-		s32 hidden_content_px = *m_content_padding_px + (
+		s32 visible_content_px = (
 			m_orientation == VERTICAL
-				? std::max<s32>(0, size.LowerRightCorner.Y - AbsoluteClippingRect.LowerRightCorner.Y)
-				: std::max<s32>(0, size.LowerRightCorner.X - AbsoluteClippingRect.LowerRightCorner.X)
+				? AbsoluteClippingRect.getHeight()
+				: AbsoluteClippingRect.getWidth()
 		);
-		m_scrollbar->setMin(0);
-		m_scrollbar->setMax(std::ceil(hidden_content_px / std::fabs(m_scrollfactor)));
-		m_scrollbar->setPageSize(*m_content_padding_px + (
+
+		s32 total_content_px = *m_content_padding_px + (
 			m_orientation == VERTICAL
 				? (size.LowerRightCorner.Y - AbsoluteClippingRect.UpperLeftCorner.Y)
 				: (size.LowerRightCorner.X - AbsoluteClippingRect.UpperLeftCorner.X)
-		));
+		);
+
+		s32 hidden_content_px = std::max<s32>(0, total_content_px - visible_content_px);
+		m_scrollbar->setMin(0);
+		m_scrollbar->setMax(std::ceil(hidden_content_px / std::fabs(m_scrollfactor)));
+
+		// Note: generally, the scrollbar has the same size as the scroll container.
+		// However, in case it isn't, proportional adjustments are needed.
+		s32 scrollbar_px = (
+			m_scrollbar->isHorizontal()
+				? m_scrollbar->getRelativePosition().getWidth()
+				: m_scrollbar->getRelativePosition().getHeight()
+		);
+
+		m_scrollbar->setPageSize((total_content_px * scrollbar_px) / visible_content_px);
 	}
 
 	updateScrolling();