ThePimp: middle mouse drag now scrolls the image.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2889 92316355-f0b4-4df1-b90c-862c8a59935f

ThePimp/PictureView.cs

@@ -22,6 +22,8 @@ namespace ThePimp
     {
         private Pipi.Picture _p;
         private Adjustment _hadj = null, _vadj = null;
+        private bool _drag = false;
+        private double _xdrag, _ydrag;
 
         void HAdjust(object sender, EventArgs args)
         {
@@ -37,6 +39,9 @@ namespace ThePimp
         {
             bool ret = base.OnExposeEvent(e);
 
+            if(_hadj == null || _vadj == null)
+                return ret;
+
             using (Gdk.GC gc = new Gdk.GC(GdkWindow))
             {
                 int w = e.Area.Width;
@@ -61,6 +66,55 @@ namespace ThePimp
             base.OnRealized();
         }
 
+        protected override bool OnButtonPressEvent(Gdk.EventButton e)
+        {
+            if(e.Button == 2)
+            {
+                GdkWindow.Cursor = new Gdk.Cursor(Gdk.CursorType.Hand1);
+                _drag = true;
+                _xdrag = e.X;
+                _ydrag = e.Y;
+            }
+
+            return base.OnButtonPressEvent(e);
+        }
+
+        protected override bool OnButtonReleaseEvent(Gdk.EventButton e)
+        {
+            if(e.Button == 2)
+            {
+                GdkWindow.Cursor = null;
+                _drag = false;
+            }
+
+            return base.OnButtonReleaseEvent(e);
+        }
+
+        protected override bool OnMotionNotifyEvent(Gdk.EventMotion e)
+        {
+            if(_drag)
+            {
+                if(_hadj != null && e.X != _xdrag)
+                {
+                    _hadj.Value += _xdrag - e.X;
+                    _xdrag = e.X;
+                    if(_hadj.Value + Allocation.Width > _p.Width)
+                        _hadj.Value = _p.Width - Allocation.Width;
+                    _hadj.ChangeValue();
+                }
+                if(_vadj != null && e.Y != _ydrag)
+                {
+                    _vadj.Value += _ydrag - e.Y;
+                    _ydrag = e.Y;
+                    if(_vadj.Value + Allocation.Height > _p.Height)
+                        _vadj.Value = _p.Height - Allocation.Height;
+                    _vadj.ChangeValue();
+                }
+            }
+
+            return base.OnMotionNotifyEvent(e);
+        }
+
         protected override void OnSetScrollAdjustments(Adjustment hadj,
                                                        Adjustment vadj)
         {
@@ -115,6 +169,10 @@ namespace ThePimp
         public PictureArea(Picture p)
         {
             _p = p;
+
+            AddEvents((int)Gdk.EventMask.ButtonPressMask);
+            AddEvents((int)Gdk.EventMask.ButtonReleaseMask);
+            AddEvents((int)Gdk.EventMask.PointerMotionMask);
         }
     }