updated to Gtk+ 3 and revamped the Gtk interface's popup widget

 * depend on Gtk+ 3.10. If necessary older versions should also
   be supportable. GtkOverlay was already introduced in v3.2
 * A fallback for GtkFlowBox is compiled in if the Gtk installation
   is too old. This applies even to Ubuntu 14.04 which still runs
   Gtk v3.10.
 * the threading the Gtk UI is left as it is for the time being
   even though the synchronization mechanism has been deprecated.
   Alternative approaches have to be tried out and benchmarked.
 * Completely revamped the GtkInfoPopup widget.
   It is now as powerful as the Curses UI's popup widget.
   * A GtkOverlay is used instead of the top-level window hack
     in the Gtk2 version.
   * GtkFlowBox is used to lay out the columns of the popup.
   * I had to work around restrictions of GtkScrolledWindow
     by writing my own poor-mans scrolled window which handles
     size requests correctly.
   * The popup window no longer overflows the screen size,
     instead we scroll.
   * Scrolling pagewise is finally supported. Wraps at the
     end of a list just like the Curses UI.
   * Instead of using only two stock icons, we now use
     GIO to get file and directory icons for the current theme.
     This looks even better.
   * The GtkFlowBox allows selections which can be used for mouse
     interaction later. But this is not yet implemented.
 * Theming of the popup widget and command line is still
   not performed correctly.

1 files changed, 187 insertions, 83 deletions

diff --git a/src/gtk-info-popup.gob b/src/gtk-info-popup.gob
index 914647a..5082091 100644
--- a/src/gtk-info-popup.gob
+++ b/src/gtk-info-popup.gob
@@ -1,7 +1,18 @@
-requires 2.0.16
+requires 2.0.20
 
-%privateheader{
-#include <gdk/gdk.h>
+%ctop{
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <math.h>
+
+#include <glib/gprintf.h>
+#include <gio/gio.h>
+
+#ifndef HAVE_GTK_FLOW_BOX_NEW
+#include "gtkflowbox.h"
+#endif
 %}
 
 %h{
@@ -14,114 +25,181 @@ enum GTK_INFO_POPUP {
 	DIRECTORY
 } Gtk:Info:Popup:Entry:Type;
 
-class Gtk:Info:Popup from Gtk:Window {
-	private GtkWidget *parent;
+class Gtk:Info:Popup from Gtk:Event:Box {
+	public GtkAdjustment *hadjustment;
+	public GtkAdjustment *vadjustment;
+
+	private GtkWidget *flow_box;
 
 	init(self)
 	{
-		GtkWidget *vbox;
+		GtkWidget *box, *viewport;
 
-		//gtk_window_set_gravity(GTK_WINDOW(self), GDK_GRAVITY_SOUTH_WEST);
-		gtk_container_set_border_width(GTK_CONTAINER(self), 10);
+		/*
+		 * A box containing a viewport and scrollbar will
+		 * "emulate" a scrolled window.
+		 * We cannot use a scrolled window since it ignores
+		 * the preferred height of its viewport which breaks
+		 * height-for-width management.
+		 */
+		box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
 
-		vbox = gtk_vbox_new(FALSE, 5);
-		gtk_container_set_resize_mode(GTK_CONTAINER(vbox), GTK_RESIZE_PARENT);
-		gtk_container_add(GTK_CONTAINER(self), vbox);
-		gtk_widget_show(vbox);
-	}
+		self->hadjustment = gtk_adjustment_new(0, 0, 0, 0, 0, 0);
+		self->vadjustment = gtk_adjustment_new(0, 0, 0, 0, 0, 0);
 
-	public GtkWidget *
-	new(Gtk:Widget *parent)
-	{
-		Self *widget;
-		GtkWidget *toplevel;
+		GtkWidget *scrollbar = gtk_scrollbar_new(GTK_ORIENTATION_VERTICAL,
+		                                         self->vadjustment);
 
-		widget = GET_NEW_VARG("type", GTK_WINDOW_POPUP, NULL);
-		widget->_priv->parent = parent;
+		self->_priv->flow_box = gtk_flow_box_new();
+		/* take as little height as necessary */
+		gtk_orientable_set_orientation(GTK_ORIENTABLE(self->_priv->flow_box),
+		                               GTK_ORIENTATION_HORIZONTAL);
+		//gtk_flow_box_set_homogeneous(GTK_FLOW_BOX(self->_priv->flow_box), TRUE);
+		/* this for focus handling only, not for scrolling */
+		gtk_flow_box_set_hadjustment(GTK_FLOW_BOX(self->_priv->flow_box),
+		                             self->hadjustment);
+		gtk_flow_box_set_vadjustment(GTK_FLOW_BOX(self->_priv->flow_box),
+		                             self->vadjustment);
 
-		g_signal_connect(parent, "size-allocate",
-				 G_CALLBACK(self_size_allocate_cb), widget);
-		toplevel = gtk_widget_get_toplevel(parent);
-		g_signal_connect(toplevel, "configure-event",
-				 G_CALLBACK(self_configure_cb), widget);
+		gtk_container_set_border_width(GTK_CONTAINER(self->_priv->flow_box), 10);
 
-		return GTK_WIDGET(widget);
+		viewport = gtk_viewport_new(self->hadjustment, self->vadjustment);
+		gtk_container_add(GTK_CONTAINER(viewport), self->_priv->flow_box);
+
+		gtk_box_pack_start(GTK_BOX(box), viewport, TRUE, TRUE, 0);
+		gtk_box_pack_start(GTK_BOX(box), scrollbar, FALSE, FALSE, 0);
+		gtk_widget_show_all(box);
+
+		/*
+		 * The top-level widget is a GtkEventBox, so it can have
+		 * a background. We assign a default color since the popup
+		 * will usually be put in an overlay and we don't want it
+		 * to be transparent.
+		 * It can also be styled with rounded corners etc.
+		 * FIXME: This method of setting a background color is
+		 * deprecated. We are supposed to use CSS style providers...
+		 */
+		gtk_container_add(GTK_CONTAINER(self), box);
+		GdkRGBA color = {0.5, 0.5, 0.5, 1.0};
+		gtk_widget_override_background_color(GTK_WIDGET(self), GTK_STATE_FLAG_NORMAL,
+		                                     &color);
 	}
 
-	private void
-	position(self)
-	{
-		GdkWindow *window = gtk_widget_get_window(self->_priv->parent);
-		gint x, y;
-		gint w, h;
+	override (Gtk:Widget) void
+	size_allocate(Gtk:Widget *widget,
+	              Gtk:Allocation *allocation)
+        {
+		GtkWidget *parent = gtk_widget_get_parent(widget);
+		GtkAllocation parent_alloc;
 
-		if (!window)
-			return;
 
-		gdk_window_get_origin(window, &x, &y);
-		gtk_window_get_size(GTK_WINDOW(self), &w, &h);
+		/*
+		 * Adjust the allocation of the popup to be within the
+		 * bounds of its parent widget which GtkOvelay does
+		 * not seem to do automatically.
+		 * Also Gtk does not seem to query this widget's
+		 * preferred height.
+		 * FIXME: Only works if the GtkInfoPopup is added
+		 * directly to the GtkOverlay.
+		 */
+		gtk_widget_get_allocation(parent, &parent_alloc);
+		allocation->width = MIN(allocation->width, parent_alloc.width);
+		if (allocation->height > parent_alloc.height) {
+			allocation->y += allocation->height - parent_alloc.height;
+			allocation->height = parent_alloc.height;
+		}
 
-		gtk_window_move(GTK_WINDOW(self), x, y - h);
+		/*
+		 * Allocate the adjusted/clipped allocation
+		 */
+		PARENT_HANDLER(widget, allocation);
 	}
 
-	private void
-	size_allocate_cb(Gtk:Widget *parent,
-			 Gtk:Allocation *alloc, gpointer user_data)
+	/*
+	 * Adapted from GtkScrolledWindow's gtk_scrolled_window_scroll_event()
+	 * since the viewport does not react to scroll events.
+	 * FIXME: May need to handle non-delta scrolling, i.e. GDK_SCROLL_UP
+	 * and GDK_SCROLL_DOWN.
+	 */
+	override (Gtk:Widget) gboolean
+	scroll_event(Gtk:Widget *widget, GdkEventScroll *event)
 	{
-		self_position(SELF(user_data));
-	}
+		Self *self = GTK_INFO_POPUP(widget);
+		gdouble delta_x, delta_y;
+
+		if (gdk_event_get_scroll_deltas((GdkEvent *)event,
+		                                &delta_x, &delta_y)) {
+			GtkAdjustment *adj = self->vadjustment;
+			gdouble page_size = gtk_adjustment_get_page_size(adj);
+			gdouble scroll_unit = pow(page_size, 2.0 / 3.0);
+			gdouble new_value;
+
+			new_value = CLAMP(gtk_adjustment_get_value(adj) + delta_y * scroll_unit,
+			                  gtk_adjustment_get_lower(adj),
+			                  gtk_adjustment_get_upper(adj) -
+			                  gtk_adjustment_get_page_size(adj));
+
+			gtk_adjustment_set_value(adj, new_value);
+
+			return TRUE;
+		}
 
-	private gboolean
-	configure_cb(Gtk:Widget *toplevel,
-		     Gdk:Event:Configure *event, gpointer user_data)
-	{
-		self_position(SELF(user_data));
 		return FALSE;
 	}
 
-	override (Gtk:Widget) void
-	show(Gtk:Widget *self)
+	public GtkWidget *
+	new(void)
 	{
-		GtkRequisition req;
+		Self *widget = GET_NEW;
+		return GTK_WIDGET(widget);
+	}
 
-		gtk_widget_size_request(self, &req);
-		gtk_window_resize(GTK_WINDOW(self), req.width, req.height);
-		self_position(SELF(self));
+	private GIcon *
+	get_icon_for_path(const gchar *path, const gchar *fallback_name)
+	{
+		GFile *file;
+		GFileInfo *info;
+		GIcon *icon = NULL;
+
+		file = g_file_new_for_path(path);
+		info = g_file_query_info(file, "standard::icon", 0, NULL, NULL);
+		if (info) {
+			icon = g_file_info_get_icon(info);
+			g_object_ref(icon);
+			g_object_unref(info);
+		} else {
+			/* fall back to standard icon, but this can still return NULL! */
+			icon = g_icon_new_for_string(fallback_name, NULL);
+		}
+		g_object_unref(file);
 
-		PARENT_HANDLER(self);
+		return icon;
 	}
 
 	public void
 	add(self, Gtk:Info:Popup:Entry:Type type,
 	    const gchar *name, gboolean highlight)
 	{
-		static const gchar *type2stock[] = {
-			[GTK_INFO_POPUP_PLAIN]		= NULL,
-			[GTK_INFO_POPUP_FILE]		= GTK_STOCK_FILE,
-			[GTK_INFO_POPUP_DIRECTORY]	= GTK_STOCK_DIRECTORY
-		};
-
-		GtkWidget *vbox = gtk_bin_get_child(GTK_BIN(self));
-		GdkScreen *screen = gtk_window_get_screen(GTK_WINDOW(self));
-		GtkRequisition req;
-
 		GtkWidget *hbox;
 		GtkWidget *label;
 		gchar *markup;
 
-		gtk_widget_size_request(GTK_WIDGET(self), &req);
-		if (req.height > gdk_screen_get_height(screen))
-			return;
+		hbox = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 5);
 
-		hbox = gtk_hbox_new(FALSE, 5);
+		if (type == GTK_INFO_POPUP_FILE || type == GTK_INFO_POPUP_DIRECTORY) {
+			const gchar *fallback = type == GTK_INFO_POPUP_FILE ? "text-x-generic"
+			                                                    : "folder";
+			GIcon *icon;
 
-		if (type2stock[type]) {
-			GtkWidget *image;
+			icon = self_get_icon_for_path(name, fallback);
+			if (icon) {
+				GtkWidget *image;
 
-			image = gtk_image_new_from_stock(type2stock[type],
-							 GTK_ICON_SIZE_MENU);
-			gtk_box_pack_start(GTK_BOX(hbox), image,
-					   FALSE, FALSE, 0);
+				image = gtk_image_new_from_gicon(icon, GTK_ICON_SIZE_MENU);
+				g_object_unref(icon);
+				gtk_box_pack_start(GTK_BOX(hbox), image,
+				                   FALSE, FALSE, 0);
+			}
 		}
 
 		/*
@@ -137,25 +215,51 @@ class Gtk:Info:Popup from Gtk:Window {
 		gtk_misc_set_alignment(GTK_MISC(label), 0., 0.5);
 		gtk_box_pack_start(GTK_BOX(hbox), label, TRUE, TRUE, 0);
 
-		gtk_box_pack_start(GTK_BOX(vbox), hbox, FALSE, FALSE, 0);
 		gtk_widget_show_all(hbox);
+		gtk_container_add(GTK_CONTAINER(self->_priv->flow_box), hbox);
+	}
 
-		gtk_widget_size_request(GTK_WIDGET(self), &req);
-		if (req.height > gdk_screen_get_height(screen)) {
-			label = gtk_label_new("...");
-			gtk_box_pack_start(GTK_BOX(vbox), label,
-					   FALSE, FALSE, 0);
-			gtk_widget_show(label);
+	public void
+	scroll_page(self)
+	{
+		GtkAdjustment *adj = self->vadjustment;
+		gdouble new_value;
+
+		if (gtk_adjustment_get_value(adj) + gtk_adjustment_get_page_size(adj) ==
+		    gtk_adjustment_get_upper(adj)) {
+			/* wrap and scroll back to the top */
+			new_value = gtk_adjustment_get_lower(adj);
+		} else {
+			/* scroll one page */
+			GList *child_list;
+
+			new_value = gtk_adjustment_get_value(adj) +
+			            gtk_adjustment_get_page_size(adj);
+
+			/*
+			 * Adjust this so only complete entries are shown.
+			 * Effectively, this rounds down to the line height.
+			 */
+			child_list = gtk_container_get_children(GTK_CONTAINER(self->_priv->flow_box));
+			if (child_list) {
+				new_value -= (gint)new_value %
+				             gtk_widget_get_allocated_height(GTK_WIDGET(child_list->data));
+				g_list_free(child_list);
+			}
+
+			/* clip to the maximum possible value */
+			new_value = MIN(new_value, gtk_adjustment_get_upper(adj));
 		}
+
+		gtk_adjustment_set_value(adj, new_value);
 	}
 
 	public void
 	clear(self)
 	{
-		GtkWidget *vbox = gtk_bin_get_child(GTK_BIN(self));
 		GList *children;
 
-		children = gtk_container_get_children(GTK_CONTAINER(vbox));
+		children = gtk_container_get_children(GTK_CONTAINER(self->_priv->flow_box));
 		for (GList *cur = g_list_first(children);
 		     cur != NULL;
 		     cur = g_list_next(cur))