access gtk throbber frames through an interface

This changes the gtk throbber frames to be accessed through an API
  This removes teh nsgtk_throbber global and hides the implementation
  details from the rest of the code.

frontends/gtk/scaffolding.c

@@ -349,16 +349,20 @@ static void scaffolding_update_context(struct nsgtk_scaffolding *g)
  */
 static void nsgtk_throb(void *p)
 {
+	nserror res;
+	GdkPixbuf *pixbuf;
 	struct nsgtk_scaffolding *g = p;
 
-	if (g->throb_frame >= (nsgtk_throbber->nframes - 1)) {
+	g->throb_frame++; /* advance to next frame */
+	res = nsgtk_throbber_get_frame(g->throb_frame, &pixbuf);
+	if (res == NSERROR_BAD_SIZE) {
 		g->throb_frame = 1;
-	} else {
-		g->throb_frame++;
+		res = nsgtk_throbber_get_frame(g->throb_frame, &pixbuf);
 	}
 
-	gtk_image_set_from_pixbuf(g->throbber,
-			nsgtk_throbber->framedata[g->throb_frame]);
+	if (res == NSERROR_OK) {
+		gtk_image_set_from_pixbuf(g->throbber, pixbuf);
+	}
 
 	nsgtk_schedule(100, nsgtk_throb, p);
 }
@@ -2358,11 +2362,19 @@ void gui_window_start_throbber(struct gui_window* _g)
 
 void gui_window_stop_throbber(struct gui_window* _g)
 {
+	nserror res;
+	GdkPixbuf *pixbuf;
 	struct nsgtk_scaffolding *g = nsgtk_get_scaffold(_g);
-	if (g == NULL)
+
+	if (g == NULL) {
 		return;
+	}
+
 	scaffolding_update_context(g);
 	nsgtk_schedule(-1, nsgtk_throb, g);
+
+	g->throb_frame = 0;
+
 	if (g->buttons[STOP_BUTTON] != NULL)
 		g->buttons[STOP_BUTTON]->sensitivity = false;
 	if (g->buttons[RELOAD_BUTTON] != NULL)
@@ -2370,11 +2382,11 @@ void gui_window_stop_throbber(struct gui_window* _g)
 
 	nsgtk_scaffolding_set_sensitivity(g);
 
-	if ((g->throbber == NULL) || (nsgtk_throbber == NULL) ||
-			(nsgtk_throbber->framedata == NULL) ||
-			(nsgtk_throbber->framedata[0] == NULL))
-		return;
-	gtk_image_set_from_pixbuf(g->throbber, nsgtk_throbber->framedata[0]);
+	res = nsgtk_throbber_get_frame(g->throb_frame, &pixbuf);
+	if ((res == NSERROR_OK) &&
+	    (g->throbber != NULL)) {
+		gtk_image_set_from_pixbuf(g->throbber, pixbuf);
+	}
 }
 
 

frontends/gtk/throbber.c

@@ -28,7 +28,16 @@
 #include "gtk/resources.h"
 #include "gtk/throbber.h"
 
-struct nsgtk_throbber *nsgtk_throbber = NULL;
+/**
+ * Throbber images context
+ */
+struct nsgtk_throbber
+{
+	int nframes; /**< Number of frames in the throbber */
+	GdkPixbuf **framedata; /* pixbuf data for the frames */
+};
+
+static struct nsgtk_throbber *nsgtk_throbber = NULL;
 
 #define THROBBER_FRAMES 9
 #define THROBBER_FMT "throbber/throbber%d.png"
@@ -36,10 +45,10 @@ struct nsgtk_throbber *nsgtk_throbber = NULL;
 /* exported interface documented in gtk/throbber.h */
 nserror nsgtk_throbber_init(void)
 {
-	struct nsgtk_throbber *throb;		/**< structure we generate */
+	nserror res = NSERROR_OK;
+	struct nsgtk_throbber *throb;
 	int frame;
 	char resname[] = THROBBER_FMT;
-	nserror res = NSERROR_OK;
 
 	throb = malloc(sizeof(*throb));
 	if (throb == NULL) {
@@ -49,7 +58,7 @@ nserror nsgtk_throbber_init(void)
 	throb->framedata = malloc(sizeof(GdkPixbuf *) * THROBBER_FRAMES);
 	if (throb->framedata == NULL) {
 		free(throb);
-		return false;
+		return NSERROR_NOMEM;
 	}
 
 	for (frame = 0; frame < THROBBER_FRAMES; frame++) {
@@ -73,11 +82,9 @@ nserror nsgtk_throbber_init(void)
 	throb->nframes = frame;
 	nsgtk_throbber = throb;
 	return res;
-
-
 }
 
-
+/* exported interface documented in gtk/throbber.h */
 void nsgtk_throbber_finalise(void)
 {
 	int i;
@@ -91,3 +98,30 @@ void nsgtk_throbber_finalise(void)
 	nsgtk_throbber = NULL;
 }
 
+
+/* exported interface documented in gtk/throbber.h */
+nserror nsgtk_throbber_get_frame(int frame, GdkPixbuf **pixbuf)
+{
+	nserror res = NSERROR_OK;
+
+	/* ensure initialisation */
+	if (nsgtk_throbber == NULL) {
+		res = nsgtk_throbber_init();
+	}
+	if (res != NSERROR_OK) {
+		return res;
+	}
+
+	/* ensure frame in range */
+	if ((frame < 0) || (frame >= nsgtk_throbber->nframes)) {
+		return NSERROR_BAD_SIZE;
+	}
+
+	/* ensure there is frame data */
+	if (nsgtk_throbber->framedata[frame] == NULL) {
+		return NSERROR_INVALID;
+	}
+
+	*pixbuf = nsgtk_throbber->framedata[frame];
+	return NSERROR_OK;
+}

frontends/gtk/throbber.h

@@ -16,20 +16,27 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __GTK_THROBBER_H__
-#define __GTK_THROBBER_H__
-
-#include <gtk/gtk.h>
-
-struct nsgtk_throbber
-{
-	int		nframes;	/**< Number of frames in the throbber */
-	GdkPixbuf	**framedata;
-};
-
-extern struct nsgtk_throbber *nsgtk_throbber;
+#ifndef NETSURF_GTK_THROBBER_H
+#define NETSURF_GTK_THROBBER_H
 
+/**
+ * Initialise global throbber context
+ */
 nserror nsgtk_throbber_init(void);
+
+/**
+ * release global throbber context
+ */
 void nsgtk_throbber_finalise(void);
 
-#endif /* __GTK_THROBBER_H__ */
+/**
+ * get the pixbuf of a given frame of the throbber
+ *
+ * \param frame The frame number starting at 0 for stopped frame
+ * \param pixbuf updated on success
+ * \return NSERROR_OK and pixbuf updated on success, NSERROR_BAD_SIZE if frame
+ *          is out of range else error code.
+ */
+nserror nsgtk_throbber_get_frame(int frame, GdkPixbuf **pixbuf);
+
+#endif /* NETSURF_GTK_THROBBER_H */

frontends/gtk/toolbar.c

@@ -478,23 +478,23 @@ nsgtk_toolbar_make_widget(struct nsgtk_scaffolding *g,
 	}
 
 	case THROBBER_ITEM: {
-		if ((nsgtk_throbber == NULL) ||
-		    (nsgtk_throbber->framedata == NULL) ||
-		    (nsgtk_throbber->framedata[0] == NULL)) {
+		nserror res;
+		GdkPixbuf *pixbuf;
+		res = nsgtk_throbber_get_frame(0, &pixbuf);
+		if (res != NSERROR_OK) {
 			return NULL;
 		}
 
 		if (edit_mode) {
-			w = GTK_WIDGET(gtk_tool_button_new(GTK_WIDGET(
-					gtk_image_new_from_pixbuf(
-					nsgtk_throbber->framedata[0])),
-							   "[throbber]"));
+			w = GTK_WIDGET(gtk_tool_button_new(
+				GTK_WIDGET(gtk_image_new_from_pixbuf(pixbuf)),
+				"[throbber]"));
 		} else {
 			GtkWidget *image;
 
 			w = GTK_WIDGET(gtk_tool_item_new());
 
-			image = gtk_image_new_from_pixbuf(nsgtk_throbber->framedata[0]);
+			image = gtk_image_new_from_pixbuf(pixbuf);
 			if (image != NULL) {
 				nsgtk_widget_set_alignment(image,
 							   GTK_ALIGN_CENTER,