Allow changing of "pages-per-row" variable at runtime

callbacks.c

@@ -78,3 +78,15 @@ cb_view_vadjustment_value_changed(GtkAdjustment *adjustment, gpointer data)
     free(offset);
   }
 }
+
+void
+cb_pages_per_row_value_changed(girara_session_t* session, girara_setting_t* setting)
+{
+  int pages_per_row = setting->value.i;
+  zathura_t* zathura = setting->data;
+
+  if (pages_per_row < 1)
+    pages_per_row = 1;
+
+  page_view_set_mode(zathura, pages_per_row);
+}

callbacks.h

@@ -23,12 +23,20 @@ gboolean cb_destroy(GtkWidget* widget, gpointer data);
 void buffer_changed(girara_session_t* session);
 
 /**
- * This function gets called when the the value of the vertical scrollbars
+ * This function gets called when the value of the vertical scrollbars
  * changes (e.g.: by scrolling, moving to another page)
  *
  * @param adjustment The vadjustment of the page view
  * @param data NULL
  */
 void cb_view_vadjustment_value_changed(GtkAdjustment *adjustment, gpointer data);
+/**
+ * This function gets called when the value of the "pages-per-row"
+ * variable changes
+ *
+ * @param session The current girara session
+ * @param setting The "pages-per-row" setting
+ */
+void cb_pages_per_row_value_changed(girara_session_t* session, girara_setting_t* setting);
 
 #endif // CALLBACKS_H

config.c

@@ -3,6 +3,7 @@
 #include "config.h"
 #include "commands.h"
 #include "completion.h"
+#include "callbacks.h"
 #include "shortcuts.h"
 #include "zathura.h"
 
@@ -32,16 +33,16 @@ config_load_default(zathura_t* zathura)
 
   /* zathura settings */
   int_value = 10;
-  girara_setting_add(gsession, "zoom-step",     &int_value, INT, false, "Zoom step",              NULL);
+  girara_setting_add(gsession, "zoom-step",     &int_value, INT, false, "Zoom step",               NULL, NULL);
   int_value = 1;
-  girara_setting_add(gsession, "page-padding",  &int_value, INT, true,  "Padding between pages",  NULL);
+  girara_setting_add(gsession, "page-padding",  &int_value, INT, true,  "Padding between pages",   NULL, NULL);
   int_value = 2;
-  girara_setting_add(gsession, "pages-per-row", &int_value, INT, false, "Number of pages per row", NULL);
+  girara_setting_add(gsession, "pages-per-row", &int_value, INT, false, "Number of pages per row", cb_pages_per_row_value_changed, zathura);
 
   string_value = "#FFFFFF";
-  girara_setting_add(gsession, "recolor-dark-color",  string_value, STRING, false, "Recoloring (dark color)",  NULL);
+  girara_setting_add(gsession, "recolor-dark-color",  string_value, STRING, false, "Recoloring (dark color)",  NULL, NULL);
   string_value = "#000000";
-  girara_setting_add(gsession, "recolor-light-color", string_value, STRING, false, "Recoloring (light color)", NULL);
+  girara_setting_add(gsession, "recolor-light-color", string_value, STRING, false, "Recoloring (light color)", NULL, NULL);
 
   /* define default shortcuts */
   girara_shortcut_add(gsession, GDK_CONTROL_MASK, GDK_c,          NULL, sc_abort,                    0,                   0,               NULL);

zathura.c

@@ -378,11 +378,24 @@ statusbar_page_number_update(zathura_t* zathura)
 void
 page_view_set_mode(zathura_t* zathura, unsigned int pages_per_row)
 {
+  GList* child;
+
   /* show at least one page */
   if (pages_per_row == 0) {
     pages_per_row = 1;
   }
 
+  if (zathura->document == NULL) {
+    return;
+  }
+
+  child = gtk_container_get_children(GTK_CONTAINER(zathura->ui.page_view));
+  while (child) {
+    g_object_ref(G_OBJECT(child->data));
+    gtk_container_remove(GTK_CONTAINER(zathura->ui.page_view), GTK_WIDGET(child->data));
+    child = g_list_next(child);
+  }
+
   gtk_table_resize(GTK_TABLE(zathura->ui.page_view), zathura->document->number_of_pages / pages_per_row + 1, pages_per_row);
   for (unsigned int i = 0; i < zathura->document->number_of_pages; i++)
   {