diff --git a/src/widgets/slider.cpp b/src/widgets/slider.cpp
new file mode 100644
--- /dev/null
+++ b/src/widgets/slider.cpp
@@ -0,0 +1,70 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file slider.cpp Implementation of the horizontal slider widget. */
+
+#include "../stdafx.h"
+#include "../window_gui.h"
+#include "../window_func.h"
+#include "../strings_func.h"
+#include "../zoom_func.h"
+#include "slider_func.h"
+
+#include "../safeguards.h"
+
+
+/**
+ * Draw a volume slider widget with know at given value
+ * @param r     Rectangle to draw the widget in
+ * @param value Value to put the slider at
+ */
+void DrawVolumeSliderWidget(Rect r, byte value)
+{
+	static const int slider_width = 3;
+
+	/* Draw a wedge indicating low to high volume level. */
+	const int ha = (r.bottom - r.top) / 5;
+	int wx1 = r.left, wx2 = r.right;
+	if (_current_text_dir == TD_RTL) std::swap(wx1, wx2);
+	const uint shadow = _colour_gradient[COLOUR_GREY][3];
+	const uint fill = _colour_gradient[COLOUR_GREY][6];
+	const uint light = _colour_gradient[COLOUR_GREY][7];
+	const std::vector<Point> wedge{ Point{wx1, r.bottom - ha}, Point{wx2, r.top + ha}, Point{wx2, r.bottom - ha} };
+	GfxFillPolygon(wedge, fill);
+	GfxDrawLine(wedge[0].x, wedge[0].y, wedge[2].x, wedge[2].y, light);
+	GfxDrawLine(wedge[1].x, wedge[1].y, wedge[2].x, wedge[2].y, _current_text_dir == TD_RTL ? shadow : light);
+	GfxDrawLine(wedge[0].x, wedge[0].y, wedge[1].x, wedge[1].y, shadow);
+
+	/* Draw a slider handle indicating current volume level. */
+	const int sw = ScaleGUITrad(slider_width);
+	if (_current_text_dir == TD_RTL) value = 127 - value;
+	const int x = r.left + (value * (r.right - r.left - sw) / 127);
+	DrawFrameRect(x, r.top, x + sw, r.bottom, COLOUR_GREY, FR_NONE);
+}
+
+/**
+ * Handle click on a volume slider widget to change the value
+ * @param r      Rectangle of the widget
+ * @param pt     Clicked point
+ * @param value[in,out] Volume value to modify
+ * @return       True if the volume setting was modified
+ */
+bool ClickVolumeSliderWidget(Rect r, Point pt, byte &value)
+{
+	byte new_vol = Clamp((pt.x - r.left) * 127 / (r.right - r.left), 0, 127);
+	if (_current_text_dir == TD_RTL) new_vol = 127 - new_vol;
+
+	/* Clamp to make sure min and max are properly settable */
+	if (new_vol > 124) new_vol = 127;
+	if (new_vol < 3) new_vol = 0;
+	if (new_vol != value) {
+		value = new_vol;
+		return true;
+	}
+
+	return false;
+}