Extracted the refresh/animation logic to its own class, so it could be reused elsewhere. It would be even possible to extract more, but for now this is a good basis.

git-svn-id: http://svn.code.sf.net/p/greenshot/code/trunk@2366 7dccd23d-a4a3-4e1f-8c07-b4c1b4018ab4

GreenshotPlugin/Controls/AnimatingForm.cs

@@ -0,0 +1,107 @@
+/*
+ * Greenshot - a free and open source screenshot tool
+ * Copyright (C) 2007-2012  Thomas Braun, Jens Klingen, Robin Krom
+ * 
+ * For more information see: http://getgreenshot.org/
+ * The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
+ * 
+ * This program 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, either version 1 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+using System;
+using System.Windows.Forms;
+using GreenshotPlugin.Core;
+using GreenshotPlugin.UnmanagedHelpers;
+using Greenshot.IniFile;
+
+namespace GreenshotPlugin.Controls {
+	/// <summary>
+	/// Extend this Form to have the possibility for animations on your form
+	/// </summary>
+	public abstract class AnimatingForm : Form {
+		protected static CoreConfiguration coreConfiguration = IniConfig.GetIniSection<CoreConfiguration>();
+		private int vRefresh = 0;
+		private Timer timer = null;
+
+		/// <summary>
+		/// Vertical Refresh Rate
+		/// </summary>
+		protected int VRefresh {
+			get {
+				if (vRefresh == 0) {
+					// get te hDC of the desktop to get the VREFRESH
+					IntPtr hDCDesktop = User32.GetWindowDC(User32.GetDesktopWindow());
+					vRefresh = GDI32.GetDeviceCaps(hDCDesktop, DeviceCaps.VREFRESH);
+					User32.ReleaseDC(hDCDesktop);
+				}
+				return vRefresh;
+			}
+		}
+
+		/// <summary>
+		/// Check if we need to optimize for RDP / Terminal Server sessions
+		/// </summary>
+		protected bool OptimizeForTerminalServer {
+			get {
+				return coreConfiguration.OptimizeForRDP || SystemInformation.TerminalServerSession;
+			}
+		}
+
+		/// <summary>
+		/// Calculate the amount of frames that an animation takes
+		/// </summary>
+		/// <param name="milliseconds"></param>
+		/// <returns>Number of frames, 1 if in Terminal Server Session</returns>
+		protected int CalculateFrames(int milliseconds) {
+			// If we are in a Terminal Server Session we return 1
+			if (OptimizeForTerminalServer) {
+				return 1;
+			}
+			return milliseconds / VRefresh;
+		}
+
+		/// <summary>
+		/// Initialize the animation
+		/// </summary>
+		protected AnimatingForm() {
+			timer = new Timer();
+			timer.Interval = 1000 / VRefresh;
+			timer.Tick += new EventHandler(timer_Tick);
+
+			this.Load += delegate {
+				timer.Start();
+			};
+
+			// Unregister at close
+			this.FormClosing += delegate {
+				if (timer != null) {
+					timer.Stop();
+				}
+			};
+		}
+
+		/// <summary>
+		/// The tick handler initiates the animation.
+		/// </summary>
+		/// <param name="sender"></param>
+		/// <param name="e"></param>
+		void timer_Tick(object sender, EventArgs e) {
+			Animate();
+		}
+
+		/// <summary>
+		/// This method will be called every frame, so implement your animation/redraw logic here.
+		/// </summary>
+		protected abstract void Animate();
+	}
+}