Function DrawHorizontalScrollbar

src/widget.cpp:560–590

* Draw a horizontal scrollbar. * @param r Rectangle of the scrollbar widget. * @param colour Colour of the scrollbar widget. * @param left_clicked Left-arrow is clicked. * @param bar_dragged Bar is dragged. * @param right_clicked Right-arrow is clicked. * @param scrollbar Scrollbar size, offset, and capacity information. */

 * @param scrollbar     Scrollbar size, offset, and capacity information.
 */
static inline void DrawHorizontalScrollbar(const Rect &r, Colours colour, bool left_clicked, bool bar_dragged, bool right_clicked, const Scrollbar *scrollbar)
{
	int width = NWidgetScrollbar::GetHorizontalDimension().width;

	DrawImageButtons(r.WithWidth(width, false), NWID_HSCROLLBAR, colour, left_clicked,  SPR_ARROW_LEFT,  SA_CENTER);
	DrawImageButtons(r.WithWidth(width, true),  NWID_HSCROLLBAR, colour, right_clicked, SPR_ARROW_RIGHT, SA_CENTER);

	PixelColour c1 = GetColourGradient(colour, SHADE_DARK);
	PixelColour c2 = GetColourGradient(colour, SHADE_LIGHTEST);

	/* draw "shaded" background */
	Rect bg = r.Shrink(width, 0);
	GfxFillRect(bg, c2);
	GfxFillRect(bg, c1, FILLRECT_CHECKER);

	/* track positions. These fractions are based on original 1x dimensions, but scale better. */
	int top    = r.top + r.Height() * 3 / 11; /*    top track is positioned 3/11ths from the top */
	int bottom = r.top + r.Height() * 8 / 11; /* bottom track is positioned 8/11ths from the top */
	const uint8_t bt = WidgetDimensions::scaled.bevel.top;
	const uint8_t bb = WidgetDimensions::scaled.bevel.bottom;

	/* draw shaded lines */
	GfxFillRect(bg.WithY(top - bt,    top         - 1), c1);
	GfxFillRect(bg.WithY(top,         top + bb    - 1), c2);
	GfxFillRect(bg.WithY(bottom - bt, bottom      - 1), c1);
	GfxFillRect(bg.WithY(bottom,      bottom + bb - 1), c2);

	/* draw actual scrollbar */
	auto [left, right] = HandleScrollbarHittest(scrollbar, r.left, r.right, true);
	DrawFrameRect(left, r.top, right, r.bottom, colour, bar_dragged ? FrameFlag::Lowered : FrameFlags{});
}

/**
 * Draw a frame widget.