[glade3] * gladeui/glade-widget-adaptor.[ch]: Add a "scrollable" flag on the adaptor class vtable introsp

[Tristan Van Berkom <tvb src gnome org>]

commit b45ddd32b53dc1ab26a4b159427e240935fda692
Author: Tristan Van Berkom <tristan van berkom gmail com>
Date:   Sun Mar 28 16:34:06 2010 -0400

    	* gladeui/glade-widget-adaptor.[ch]: Add a "scrollable" flag on the adaptor class vtable
    	  introspected by checking if (widget_class->set_scroll_adjustments_signal) != 0.
    
    	* gladeui/glade-utils.[ch]: Added glade_util_check_and_warn_scrollable() to check and warn the
    	  user if they are trying to add a non-scrollable widget to a scrolled window.
    
    	* gladeui/glade-app.c, gladeui/glade-popup.c, gladeui/glade-placeholder.c, plugins/gtk+/glade-gtk.c:
    	Consult glade_util_check_and_warn_scrollable() before executing commands that introduce objects
    	to the project.

 ChangeLog                      |   10 ++++++++++
 gladeui/glade-app.c            |    8 +++++++-
 gladeui/glade-placeholder.c    |   27 ++++++++++++++-------------
 gladeui/glade-popup.c          |   18 ++++++++++++------
 gladeui/glade-utils.c          |   25 +++++++++++++++++++++++--
 gladeui/glade-utils.h          |    4 ++++
 gladeui/glade-widget-adaptor.c |    5 +++++
 gladeui/glade-widget-adaptor.h |   16 ++++++++++++++++
 plugins/gtk+/glade-gtk.c       |    5 +++++
 9 files changed, 96 insertions(+), 22 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index b3df831..fc007a6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,16 @@
 	    instead of the property mutator implementation (as the "columns" property is construct-only
 	    and the widget is rebuilt - property reference lists are unavailable at ->set_property time).
 
+	* gladeui/glade-widget-adaptor.[ch]: Add a "scrollable" flag on the adaptor class vtable
+	  introspected by checking if (widget_class->set_scroll_adjustments_signal) != 0.
+
+	* gladeui/glade-utils.[ch]: Added glade_util_check_and_warn_scrollable() to check and warn the
+	  user if they are trying to add a non-scrollable widget to a scrolled window.
+
+	* gladeui/glade-app.c, gladeui/glade-popup.c, gladeui/glade-placeholder.c, plugins/gtk+/glade-gtk.c: 
+	Consult glade_util_check_and_warn_scrollable() before executing commands that introduce objects
+	to the project.
+
 2010-03-27  Tristan Van Berkom <tvb gnome org>
 
 	* gladeui/glade-marshallers.list, gladeui/glade-placeholder.c: 
diff --git a/gladeui/glade-app.c b/gladeui/glade-app.c
index 3fa69b1..3570c40 100644
--- a/gladeui/glade-app.c
+++ b/gladeui/glade-app.c
@@ -1286,8 +1286,14 @@ glade_app_command_paste (GladePlaceholder *placeholder)
 
 			return;
 		}
+
 	}
-	
+
+	/* Abort operation when adding a non scrollable widget to any kind of GtkScrolledWindow. */
+	if (parent && widget &&
+	    glade_util_check_and_warn_scrollable (parent, widget->adaptor, glade_app_get_window()))
+		return;
+
 	/* Check if we have anything to paste */
 	if (g_list_length (clipboard->selection) == 0)
 	{
diff --git a/gladeui/glade-placeholder.c b/gladeui/glade-placeholder.c
index b35eabc..593f41c 100644
--- a/gladeui/glade-placeholder.c
+++ b/gladeui/glade-placeholder.c
@@ -362,19 +362,20 @@ glade_placeholder_button_press (GtkWidget *widget, GdkEventButton *event)
 	{
 		if (adaptor != NULL)
 		{
-			/* A widget type is selected in the palette.
-			 * Add a new widget of that type.
-			 */
-			glade_command_create
-				(adaptor, 
-				 glade_placeholder_get_parent (placeholder),
-				 placeholder, project);
-
-			glade_palette_deselect_current_item (glade_app_get_palette(), TRUE);
-
-			/* reset the cursor */
-			glade_cursor_set (event->window, GLADE_CURSOR_SELECTOR);
-
+			GladeWidget *parent = glade_placeholder_get_parent (placeholder);
+
+			if (!glade_util_check_and_warn_scrollable (parent, adaptor, glade_app_get_window()))
+			{
+				/* A widget type is selected in the palette.
+				 * Add a new widget of that type.
+				 */
+				glade_command_create (adaptor, parent, placeholder, project);
+				
+				glade_palette_deselect_current_item (glade_app_get_palette(), TRUE);
+				
+				/* reset the cursor */
+				glade_cursor_set (event->window, GLADE_CURSOR_SELECTOR);
+			}
 			handled = TRUE;
 		}
 	}
diff --git a/gladeui/glade-popup.c b/gladeui/glade-popup.c
index 84f67b7..0163065 100644
--- a/gladeui/glade-popup.c
+++ b/gladeui/glade-popup.c
@@ -83,14 +83,20 @@ static void
 glade_popup_placeholder_add_cb (GtkMenuItem *item, GladePlaceholder *placeholder)
 {
 	GladeWidgetAdaptor *adaptor;
-	
+	GladeWidget        *parent;
+
 	adaptor = glade_palette_get_current_item (glade_app_get_palette ());
 	g_return_if_fail (adaptor != NULL);
-	
-	glade_command_create (adaptor, glade_placeholder_get_parent (placeholder),
-						  placeholder, glade_placeholder_get_project (placeholder));
-						  
-	glade_palette_deselect_current_item (glade_app_get_palette(), TRUE);
+
+	parent = glade_placeholder_get_parent (placeholder);
+
+	if (!glade_util_check_and_warn_scrollable (parent, adaptor, glade_app_get_window()))
+	{
+		glade_command_create (adaptor, parent,
+				      placeholder, glade_placeholder_get_project (placeholder));
+		
+		glade_palette_deselect_current_item (glade_app_get_palette(), TRUE);
+	}
 }
 
 static void
diff --git a/gladeui/glade-utils.c b/gladeui/glade-utils.c
index 16d6a3b..2decba3 100644
--- a/gladeui/glade-utils.c
+++ b/gladeui/glade-utils.c
@@ -272,8 +272,28 @@ glade_util_ui_message (GtkWidget           *parent,
 }
 
 
-
-
+gboolean
+glade_util_check_and_warn_scrollable (GladeWidget        *parent,
+				      GladeWidgetAdaptor *child_adaptor,
+				      GtkWidget          *parent_widget)
+{
+	if (GTK_IS_SCROLLED_WINDOW (parent->object) &&
+	    GWA_SCROLLABLE_WIDGET (child_adaptor) == FALSE)
+	{
+		GladeWidgetAdaptor *vadaptor = 
+			glade_widget_adaptor_get_by_type (GTK_TYPE_VIEWPORT);
+
+		glade_util_ui_message (parent_widget,
+				       GLADE_UI_INFO, NULL,
+				       _("Cannot add non scrollable %s widget to a %s directly.\n"
+					 "Add a %s first."),
+				       child_adaptor->title,
+				       parent->adaptor->title,
+				       vadaptor->title);
+		return TRUE;
+	}
+	return FALSE;
+}
 
 typedef struct {
 	GtkStatusbar *statusbar;
@@ -2327,3 +2347,4 @@ glade_utils_hijack_key_press (GtkWindow          *win,
 	}
 	return FALSE;
 }
+
diff --git a/gladeui/glade-utils.h b/gladeui/glade-utils.h
index f7d314b..f263b06 100644
--- a/gladeui/glade-utils.h
+++ b/gladeui/glade-utils.h
@@ -34,6 +34,10 @@ void		glade_util_flash_message	(GtkWidget *statusbar,
 						 guint context_id,
 						 gchar *format, ...);
 
+gboolean        glade_util_check_and_warn_scrollable (GladeWidget        *parent,
+						      GladeWidgetAdaptor *child_adaptor,
+						      GtkWidget          *parent_widget);
+
 /* This is a GCompareFunc for comparing the labels of 2 stock items, ignoring
    any '_' characters. It isn't particularly efficient. */
 
diff --git a/gladeui/glade-widget-adaptor.c b/gladeui/glade-widget-adaptor.c
index c11f5e7..262d412 100644
--- a/gladeui/glade-widget-adaptor.c
+++ b/gladeui/glade-widget-adaptor.c
@@ -600,6 +600,11 @@ glade_widget_adaptor_constructor (GType                  type,
 		gwa_setup_properties (adaptor, object_class, TRUE);
 	}
 
+	/* Detect scrollability */
+	if (g_type_is_a (adaptor->type, GTK_TYPE_WIDGET) &&
+	    GTK_WIDGET_CLASS (object_class)->set_scroll_adjustments_signal != 0)
+		GLADE_WIDGET_ADAPTOR_GET_CLASS(adaptor)->scrollable = TRUE;
+
 	/* Inherit packing defaults here */
 	adaptor->child_packings = gwa_inherit_child_packing (adaptor);
 
diff --git a/gladeui/glade-widget-adaptor.h b/gladeui/glade-widget-adaptor.h
index 899545c..f4be4ba 100644
--- a/gladeui/glade-widget-adaptor.h
+++ b/gladeui/glade-widget-adaptor.h
@@ -140,6 +140,17 @@ typedef struct _GladeWidgetAdaptorClass   GladeWidgetAdaptorClass;
 #define GWA_DEFAULT_HEIGHT(obj) \
         ((obj) ? GLADE_WIDGET_ADAPTOR_GET_CLASS(obj)->default_height : -1)
 
+
+/**
+ * GWA_SCROLLABLE_WIDGET:
+ * @obj: A #GladeWidgetAdaptor
+ *
+ * Checks whether this is a GtkWidgetClass with scrolling capabilities.
+ */
+#define GWA_SCROLLABLE_WIDGET(obj) \
+        ((obj) ? GLADE_WIDGET_ADAPTOR_GET_CLASS(obj)->scrollable : FALSE)
+
+
 /**
  * GWA_GET_CLASS:
  * @type: A #GType
@@ -636,6 +647,11 @@ struct _GladeWidgetAdaptorClass
 							      * to interface with child widgets.
 							      */
 
+	guint                      scrollable : 1;           /* Whether this is a widget class that has
+							      * klass->set_scroll_adjustments_signal != NULL (i.e.
+							      * can be directly added to a GtkScrolledWindow).
+							      */
+
 	gint                       default_width;  /* Default width in GladeDesignLayout */
 	gint                       default_height; /* Default height in GladeDesignLayout */
 
diff --git a/plugins/gtk+/glade-gtk.c b/plugins/gtk+/glade-gtk.c
index 91c6c56..381bf74 100644
--- a/plugins/gtk+/glade-gtk.c
+++ b/plugins/gtk+/glade-gtk.c
@@ -1285,6 +1285,11 @@ glade_gtk_widget_action_activate (GladeWidgetAdaptor *adaptor,
 			GladeWidgetAdaptor *adaptor = glade_widget_adaptor_get_by_type (new_type);
 			GList              *saved_props, *prop_cmds;
 			GladeProject       *project;
+
+			/* Dont add non-scrollable widgets to scrolled windows... */
+			if (gparent &&
+			    glade_util_check_and_warn_scrollable (gparent, adaptor, glade_app_get_window()))
+				return;
 			
 			glade_command_push_group (_("Adding parent %s for %s"), 
 						  adaptor->title, gwidget->name);