Fix: Incorrect vertical alignment of icon and text in DropDownListIconItem. (#9133)

This happens if the bounding dimensions are changed so that each item is the same size, as happens on the railtype/roadtype dropdown lists, as the vertical offset was calculated before this dimension is changed.

src/widgets/dropdown.cpp

@@ -72,13 +72,7 @@ StringID DropDownListCharStringItem::String() const
 DropDownListIconItem::DropDownListIconItem(SpriteID sprite, PaletteID pal, StringID string, int result, bool masked) : DropDownListParamStringItem(string, result, masked), sprite(sprite), pal(pal)
 {
 	this->dim = GetSpriteSize(sprite);
-	if (this->dim.height < (uint)FONT_HEIGHT_NORMAL) {
-		this->sprite_y = (FONT_HEIGHT_NORMAL - dim.height) / 2;
-		this->text_y = 0;
-	} else {
-		this->sprite_y = 0;
-		this->text_y = (dim.height - FONT_HEIGHT_NORMAL) / 2;
-	}
+	this->sprite_y = dim.height;
 }
 
 uint DropDownListIconItem::Height(uint width) const
@@ -94,8 +88,8 @@ uint DropDownListIconItem::Width() const
 void DropDownListIconItem::Draw(int left, int right, int top, int bottom, bool sel, Colours bg_colour) const
 {
 	bool rtl = _current_text_dir == TD_RTL;
-	DrawSprite(this->sprite, this->pal, rtl ? right - this->dim.width - WD_FRAMERECT_RIGHT : left + WD_FRAMERECT_LEFT, top + this->sprite_y);
-	DrawString(left + WD_FRAMERECT_LEFT + (rtl ? 0 : (this->dim.width + WD_FRAMERECT_LEFT)), right - WD_FRAMERECT_RIGHT - (rtl ? (this->dim.width + WD_FRAMERECT_RIGHT) : 0), top + this->text_y, this->String(), sel ? TC_WHITE : TC_BLACK);
+	DrawSprite(this->sprite, this->pal, rtl ? right - this->dim.width - WD_FRAMERECT_RIGHT : left + WD_FRAMERECT_LEFT, CenterBounds(top, bottom, this->sprite_y));
+	DrawString(left + WD_FRAMERECT_LEFT + (rtl ? 0 : (this->dim.width + WD_FRAMERECT_LEFT)), right - WD_FRAMERECT_RIGHT - (rtl ? (this->dim.width + WD_FRAMERECT_RIGHT) : 0), CenterBounds(top, bottom, FONT_HEIGHT_NORMAL), this->String(), sel ? TC_WHITE : TC_BLACK);
 }
 
 void DropDownListIconItem::SetDimension(Dimension d)

src/widgets/dropdown_type.h

@@ -84,7 +84,6 @@ class DropDownListIconItem : public DropDownListParamStringItem {
 	PaletteID pal;
 	Dimension dim;
 	uint sprite_y;
-	uint text_y;
 public:
 	DropDownListIconItem(SpriteID sprite, PaletteID pal, StringID string, int result, bool masked);