Merge pull request #156 from lytico/lytico_cellrenderer_getsize

Gtk.CellRenderer: implement OnGetSize

Source/Libs/GtkSharp/CellRenderer.GetSize.cs

@@ -0,0 +1,167 @@
+using GtkSharp;
+
+namespace Gtk
+{
+
+	using System;
+	using System.Runtime.InteropServices;
+
+	public partial class CellRenderer
+	{
+		static GetSizeNativeDelegate GetSize_cb_delegate;
+
+		static GetSizeNativeDelegate GetSizeVMCallback {
+			get {
+				if (GetSize_cb_delegate == null)
+					GetSize_cb_delegate = new GetSizeNativeDelegate (GetSize_cb);
+				return GetSize_cb_delegate;
+			}
+		}
+
+		static void OverrideGetSize (GLib.GType gtype)
+		{
+			OverrideGetSize (gtype, GetSizeVMCallback);
+		}
+
+		/// <summary>
+		/// sets callback GetSize in GtkCellRendererClass-Struct
+		/// </summary>
+		/// <param name="gtype"></param>
+		/// <param name="callback"></param>
+		static void OverrideGetSize (GLib.GType gtype, GetSizeNativeDelegate callback)
+		{
+			unsafe {
+				IntPtr* raw_ptr = (IntPtr*) (((long) gtype.GetClassPtr ()) + (long) class_abi.GetFieldOffset ("get_size"));
+				*raw_ptr = Marshal.GetFunctionPointerForDelegate ((Delegate) callback);
+			}
+		}
+
+		// We have to implement this VM manually because x_offset, y_offset, width and height params may be NULL and therefore cannot be treated as "out int"
+		[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
+		internal delegate void GetSizeNativeDelegate (IntPtr item, IntPtr widget, IntPtr cell_area_ptr, IntPtr x_offset, IntPtr y_offset, IntPtr width, IntPtr height);
+
+		static void GetSize_cb (IntPtr item, IntPtr widget, IntPtr cell_area_ptr, IntPtr x_offset, IntPtr y_offset, IntPtr width, IntPtr height)
+		{
+			try {
+				CellRenderer obj = GLib.Object.GetObject (item, false) as CellRenderer;
+				Gtk.Widget widg = GLib.Object.GetObject (widget, false) as Gtk.Widget;
+				Gdk.Rectangle cell_area = Gdk.Rectangle.Zero;
+				if (cell_area_ptr != IntPtr.Zero)
+					cell_area = Gdk.Rectangle.New (cell_area_ptr);
+				int a, b, c, d;
+
+				obj.OnGetSize (widg, ref cell_area, out a, out b, out c, out d);
+				if (x_offset != IntPtr.Zero)
+					Marshal.WriteInt32 (x_offset, a);
+				if (y_offset != IntPtr.Zero)
+					Marshal.WriteInt32 (y_offset, b);
+				if (width != IntPtr.Zero)
+					Marshal.WriteInt32 (width, c);
+				if (height != IntPtr.Zero)
+					Marshal.WriteInt32 (height, d);
+			} catch (Exception e) {
+				GLib.ExceptionManager.RaiseUnhandledException (e, false);
+			}
+		}
+
+		[GLib.DefaultSignalHandler (Type = typeof(Gtk.CellRenderer), ConnectionMethod = nameof(OverrideGetSize))]
+		protected virtual void OnGetSize (Gtk.Widget widget, ref Gdk.Rectangle cell_area, out int x_offset, out int y_offset, out int width, out int height)
+		{
+			InternalOnGetSize (widget, ref cell_area, out x_offset, out y_offset, out width, out height);
+		}
+
+		private void InternalOnGetSize (Gtk.Widget widget, ref Gdk.Rectangle cell_area, out int x_offset, out int y_offset, out int width, out int height)
+		{
+			IntPtr native_cell_area = GLib.Marshaller.StructureToPtrAlloc (cell_area);
+			gtksharp_cellrenderer_base_get_size (Handle, widget?.Handle ?? IntPtr.Zero, native_cell_area, out x_offset, out y_offset, out width, out height);
+			cell_area = Gdk.Rectangle.New (native_cell_area);
+			Marshal.FreeHGlobal (native_cell_area);
+		}
+
+		static GetSizeNativeDelegate InternalGetSizeNativeDelegate (GLib.GType gtype)
+		{
+			GetSizeNativeDelegate unmanaged = null;
+			unsafe {
+				IntPtr* raw_ptr = (IntPtr*) (((long) gtype.GetClassPtr ()) + (long) class_abi.GetFieldOffset ("get_size"));
+				if (*raw_ptr == IntPtr.Zero)
+					return default;
+
+				unmanaged = Marshal.GetDelegateForFunctionPointer<GetSizeNativeDelegate> (*raw_ptr);
+			}
+
+			return unmanaged;
+		}
+
+		static void gtksharp_cellrenderer_base_get_size (IntPtr cell, IntPtr widget, IntPtr cell_area, out int x_offset, out int y_offset, out int width, out int height)
+		{
+			/*
+			const gchar *__gtype_prefix = "__gtksharp_";
+			#define HAS_PREFIX(a) (*((guint64 *)(a)) == *((guint64 *) __gtype_prefix))
+
+			static GObjectClass *
+			get_threshold_class (GObject *obj)
+			{
+				GType gtype = G_TYPE_FROM_INSTANCE (obj);
+				while (HAS_PREFIX (g_type_name (gtype)))
+					gtype = g_type_parent (gtype);
+				GObjectClass *klass = g_type_class_peek (gtype);
+				if (klass == NULL) klass = g_type_class_ref (gtype);
+				return klass;
+			}			 
+			 
+			 void gtksharp_cellrenderer_base_get_size (GtkCellRenderer *cell, GtkWidget *widget, GdkRectangle *cell_area, gint *x_offset, gint *y_offset, gint *width, gint *height)
+			{
+				GtkCellRendererClass *klass = (GtkCellRendererClass *) get_threshold_class (G_OBJECT (cell));
+				if (klass->get_size)
+					(* klass->get_size) (cell, widget, cell_area, x_offset, y_offset, width, height);
+			}
+			 */
+
+			x_offset = 0;
+			y_offset = 0;
+			width = 0;
+			height = 0;
+
+			if (cell == IntPtr.Zero) {
+				return;
+			}
+
+			var obj = TryGetObject (cell);
+			var parent = obj.NativeType;
+			while ((parent = parent.GetBaseType ()) != GLib.GType.None) {
+				
+				if (parent.ToString ().StartsWith ("__gtksharp_")) {
+					continue;
+				}
+
+				var GetSize = InternalGetSizeNativeDelegate (parent);
+				if (GetSize != default) {
+					var a = Marshal.AllocHGlobal (sizeof(int));
+					var b = Marshal.AllocHGlobal (sizeof(int));
+					var c = Marshal.AllocHGlobal (sizeof(int));
+					var d = Marshal.AllocHGlobal (sizeof(int));
+					try {
+						GetSize (cell, widget, cell_area, a, b, c, d);
+						if (a != IntPtr.Zero)
+							Marshal.WriteInt32 (a, x_offset);
+						if (b != IntPtr.Zero)
+							Marshal.WriteInt32 (b, y_offset);
+						if (c != IntPtr.Zero)
+							Marshal.WriteInt32 (c, width);
+						if (d != IntPtr.Zero)
+							Marshal.WriteInt32 (d, height);
+					} finally {
+						Marshal.FreeHGlobal (a);
+						Marshal.FreeHGlobal (b);
+						Marshal.FreeHGlobal (c);
+						Marshal.FreeHGlobal (d);
+					}
+				}
+
+				return;
+			}
+		}
+
+	}
+
+}

Source/Libs/GtkSharp/CellRenderer.cs

@@ -48,10 +48,6 @@ namespace Gtk {
 			gtk_cell_renderer_render2 (Handle, context == null ? IntPtr.Zero : context.Handle, widget == null ? IntPtr.Zero : widget.Handle, ref background_area, ref cell_area, ref expose_area, (int) flags);
 		}
 
-		// We have to implement this VM manually because x_offset, y_offset, width and height params may be NULL and therefore cannot be treated as "out int"
-		// TODO: Implement "nullable" attribute for value type parameters in GAPI
-		[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
-		delegate void OnGetSizeDelegate (IntPtr item, IntPtr widget, IntPtr cell_area_ptr, IntPtr x_offset, IntPtr y_offset, IntPtr width, IntPtr height);
 	}
 }
 

Source/Samples/Sections/Widgets/CellRendererSection.cs

@@ -0,0 +1,53 @@
+using Gtk;
+using System;
+namespace Samples
+{
+
+	[Section (ContentType = typeof(CustomCellRenderer), Category = Category.Widgets)]
+	class CellRendererSection : ListSection
+	{
+		public CellRendererSection ()
+		{
+			AddItem (CreateCellRenderer ());
+         
+		}
+		ListStore liststore;
+
+		public (string, Widget) CreateCellRenderer ()
+		{
+			liststore = new ListStore (typeof (float), typeof (string));
+			liststore.AppendValues (0.5f, "50%");
+
+			TreeView view = new TreeView (liststore);
+
+			view.AppendColumn ("Progress", new CellRendererText (), "text", 1);
+			view.AppendColumn ("Progress", new CustomCellRenderer (), "percent", 0);
+			GLib.Timeout.Add (50, new GLib.TimeoutHandler (update_percent));
+
+			return (nameof(CustomCellRenderer), view);
+		}
+		
+		bool increasing = true;
+		bool update_percent ()
+		{
+			TreeIter iter;
+			liststore.GetIterFirst (out iter);
+			float perc = (float) liststore.GetValue (iter, 0);
+
+			if ((perc > 0.99) || (perc < 0.01 && perc > 0)) {
+				increasing = !increasing;
+			}
+
+			if (increasing)
+				perc += 0.01f;
+			else
+				perc -= 0.01f;
+
+			liststore.SetValue (iter, 0, perc);
+			liststore.SetValue (iter, 1, Convert.ToInt32 (perc * 100) + "%");
+
+			return true;
+		}
+	}
+
+}

Source/Samples/Sections/Widgets/CustomWidgets/CustomCellRenderer.cs

@@ -0,0 +1,77 @@
+// CustomCellRenderer.cs : C# implementation of an example custom cellrenderer
+// from http://scentric.net/tutorial/sec-custom-cell-renderers.html
+//
+// Author: Todd Berman <tberman@sevenl.net>
+//
+// (c) 2004 Todd Berman
+
+// adopted from: https://github.com/mono/gtk-sharp/commits/2.99.3/sample/CustomCellRenderer.cs
+
+using System;
+using Gtk;
+using Gdk;
+using GLib;
+
+namespace Samples
+{
+
+	public class CustomCellRenderer : CellRenderer
+	{
+
+		private float percent;
+
+		[GLib.Property ("percent")]
+		public float Percentage {
+			get { return percent; }
+			set { percent = value; }
+		}
+
+		protected override void OnGetSize (Widget widget, ref Rectangle cell_area, out int x_offset, out int y_offset, out int width, out int height)
+		{
+			base.OnGetSize (widget, ref cell_area, out x_offset, out y_offset, out width, out height);
+
+			int calc_width = (int) this.Xpad * 2 + 100;
+			int calc_height = (int) this.Ypad * 2 + 10;
+
+			width = calc_width;
+			height = calc_height;
+
+			x_offset = 0;
+			y_offset = 0;
+			if (!cell_area.Equals (Rectangle.Zero)) {
+				x_offset = (int) (this.Xalign * (cell_area.Width - calc_width));
+				x_offset = Math.Max (x_offset, 0);
+
+				y_offset = (int) (this.Yalign * (cell_area.Height - calc_height));
+				y_offset = Math.Max (y_offset, 0);
+			}
+		}
+
+		protected override void OnRender (Cairo.Context cr, Widget widget, Rectangle background_area, Rectangle cell_area, CellRendererState flags)
+		{
+			int x = (int) (cell_area.X + this.Xpad);
+			int y = (int) (cell_area.Y + this.Ypad);
+			int width = (int) (cell_area.Width - this.Xpad * 2);
+			int height = (int) (cell_area.Height - this.Ypad * 2);
+
+			widget.StyleContext.Save ();
+			widget.StyleContext.AddClass ("trough");
+			widget.StyleContext.RenderBackground (cr, x, y, width, height);
+			widget.StyleContext.RenderFrame (cr, x, y, width, height);
+
+			Border padding = widget.StyleContext.GetPadding (StateFlags.Normal);
+			x += padding.Left;
+			y += padding.Top;
+			width -= padding.Left + padding.Right;
+			height -= padding.Top + padding.Bottom;
+
+			widget.StyleContext.Restore ();
+
+			widget.StyleContext.Save ();
+			widget.StyleContext.AddClass ("progressbar");
+			widget.StyleContext.RenderActivity (cr, x, y, (int) (width * Percentage), height);
+			widget.StyleContext.Restore ();
+		}
+	}
+
+}