MOTD ticker. ScrollingText Widget

OpenRA.Game/Widgets/ScrollingTextWidget.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Drawing;
+
+namespace OpenRA.Widgets
+{
+	class ScrollingTextWidget : Widget
+	{
+		public string Text = "";
+		public string Background = null;
+
+		public bool Bold = false;
+
+		public int ScrollLength = 200;
+
+		// ticks per single letter scroll
+		public int ScrollRate = 4;
+
+		private string ScrollBuffer = "";
+
+		private int ScrollLocation = 0;
+		private int ScrollTick = 0;
+
+		public Func<string> GetText;
+		public Func<string> GetBackground;
+
+		public ScrollingTextWidget()
+			: base()
+		{
+			GetText = () => Text;
+			GetBackground = () => Background;
+		}
+
+		protected ScrollingTextWidget(ScrollingTextWidget other)
+			: base(other)
+		{
+			Text = other.Text;
+			GetText = other.GetText;
+			Bold = other.Bold;
+			GetBackground = other.GetBackground;
+		}
+
+		public override void Tick(World world)
+		{
+			UpdateScrollBuffer();
+		}
+
+		private void UpdateScrollBuffer()
+		{
+			ScrollTick++;
+
+			if (ScrollTick < ScrollRate)
+			{
+				return;
+			}
+
+			ScrollTick = 0;
+			ScrollBuffer = "";
+
+			if (Text.Substring(Text.Length - 4, 3) != "   ")
+			{
+				Text += "   ";
+			}
+
+			int tempScrollLocation = ScrollLocation;
+			for (int i = 0; i < ScrollLength; ++i)
+			{
+				ScrollBuffer += Text.Substring(tempScrollLocation, 1);
+				tempScrollLocation = (tempScrollLocation + 1) % Text.Length;
+			}
+
+			ScrollLocation = (ScrollLocation + 1) % Text.Length;
+		}
+		
+		public override void DrawInner(World world)
+		{
+			var bg = GetBackground();
+
+			if (bg != null)
+				WidgetUtils.DrawPanel(bg, RenderBounds);
+
+			var font = (Bold) ? Game.Renderer.BoldFont : Game.Renderer.RegularFont;
+			var text = GetText();
+			if (text == null)
+				return;
+
+			int2 textSize = font.Measure(text);
+			int2 position = RenderOrigin + new int2(0, (Bounds.Height - textSize.Y) / 2);
+
+			Game.Renderer.EnableScissor(position.X, position.Y, Bounds.Width, Bounds.Height);
+			font.DrawText(ScrollBuffer, position, Color.White);
+			Game.Renderer.DisableScissor();
+		}
+
+		public override Widget Clone() { return new ScrollingTextWidget(this); }
+	}
+}