added view panning control

Source/Editing/ClassicMode.cs

@@ -61,6 +61,7 @@ namespace CodeImp.DoomBuilder.Editing
 		
 		// Mouse status
 		protected Vector2D mousepos;
+        protected Vector2D mouselastpos;
 		protected Vector2D mousemappos;
 		protected Vector2D mousedownpos;
 		protected Vector2D mousedownmappos;
@@ -73,6 +74,9 @@ namespace CodeImp.DoomBuilder.Editing
 		private Vector2D selectstart;
 		protected RectangleF selectionrect;
 
+        // View panning
+        protected bool panning;
+		
 		#endregion
 
 		#region ================== Properties
@@ -186,6 +190,21 @@ namespace CodeImp.DoomBuilder.Editing
 			General.MainWindow.UpdateCoordinates(mousemappos);
 		}
 
+        // This sets the view to be centered at x,y
+        private void ScrollTo(float x, float y)
+        {
+            // Scroll now
+            renderer2d.PositionView(x, y);
+            this.OnViewChanged();
+
+            // Redraw
+            General.MainWindow.RedrawDisplay();
+
+            // Determine new unprojected mouse coordinates
+            mousemappos = renderer2d.GetMapCoordinates(mousepos);
+            General.MainWindow.UpdateCoordinates(mousemappos);
+        }
+
 		// This zooms
 		private void ZoomBy(float deltaz)
 		{
@@ -327,6 +346,7 @@ namespace CodeImp.DoomBuilder.Editing
 
 			// Record last position
 			mouseinside = true;
+            mouselastpos = mousepos;
 			mousepos = new Vector2D(e.X, e.Y);
 			mousemappos = renderer2d.GetMapCoordinates(mousepos);
 			mousebuttons = e.Button;
@@ -355,6 +375,9 @@ namespace CodeImp.DoomBuilder.Editing
 			// Selecting?
 			if(selecting) OnUpdateMultiSelection();
 
+            // Panning?
+            if (panning) OnUpdateViewPanning();
+			
 			// Let the base class know
 			base.OnMouseMove(e);
 		}
@@ -521,10 +544,35 @@ namespace CodeImp.DoomBuilder.Editing
 				General.Colors.Highlight.WithAlpha(SELECTION_ALPHA), true);
 		}
 
+        /// <summary>
+        /// This is called automatically when the mouse is moved while panning
+        /// </summary>
+        protected virtual void OnUpdateViewPanning()
+        {
+            // Get the map coordinates of the last mouse posision (before it moved)
+            Vector2D lastmappos;
+            lastmappos = renderer2d.GetMapCoordinates(mouselastpos);
+
+            // Do the scroll
+            ScrollBy(lastmappos.x - mousemappos.x, lastmappos.y - mousemappos.y);
+        }
+		
 		#endregion
 		
 		#region ================== Actions
 
+        [BeginAction("pan_view", BaseAction = true)]
+        protected virtual void BeginViewPan()
+        {
+            panning = true;
+        }
+
+        [EndAction("pan_view", BaseAction = true)]
+        protected virtual void EndViewPan()
+        {
+            panning = false;
+        }
+
 		#endregion
 	}
 }

Source/Resources/Actions.cfg

@@ -228,6 +228,16 @@ scrollsouth
 	repeat = true;
 }
 
+pan_view
+{
+	title = "Pan View";
+	category = "classic";
+	description = "Pans the map in the direction of the mouse while held down.";
+	allowkeys = true;
+	allowmouse = true;
+	allowscroll = false;
+}
+
 zoomin
 {
 	title = "Zoom In";