merge callbacks for pages-per-row, first-page-column and page-padding

All of those callbacks are conceptually related (change the page
layout), and depend from one another.

Now the single callback page_layout_value_changed defers to
page_widget_set_mode to change whatever is needed in the GTK widgets.

callbacks.c

@@ -207,61 +207,25 @@ cb_adjustment_track_bounds(GtkAdjustment* adjustment, gpointer data)
 }
 
 void
-cb_pages_per_row_value_changed(girara_session_t* session, const char* UNUSED(name), girara_setting_type_t UNUSED(type), void* value, void* UNUSED(data))
+cb_page_layout_value_changed(girara_session_t* session, const char* UNUSED(name), girara_setting_type_t UNUSED(type), void* value, void* UNUSED(data))
 {
   g_return_if_fail(value != NULL);
   g_return_if_fail(session != NULL);
   g_return_if_fail(session->global.data != NULL);
   zathura_t* zathura = session->global.data;
 
-  int pages_per_row = *(int*) value;
 
-  if (pages_per_row < 1) {
-    pages_per_row = 1;
-  }
+  unsigned int pages_per_row = 1;
+  girara_setting_get(session, "pages-per-row", &pages_per_row);
 
   unsigned int first_page_column = 1;
   girara_setting_get(session, "first-page-column", &first_page_column);
 
   unsigned int page_padding = 1;
-  girara_setting_get(session, "page-padding", &page_padding);
-
-  page_widget_set_mode(zathura, page_padding, pages_per_row, first_page_column);
-  zathura_document_set_page_layout(zathura->document, page_padding, pages_per_row, first_page_column);
-
-  if (zathura->document != NULL) {
-    unsigned int current_page = zathura_document_get_current_page_number(zathura->document);
-    page_set_delayed(zathura, current_page);
-  }
-}
-
-void
-cb_first_page_column_value_changed(girara_session_t* session, const char* UNUSED(name), girara_setting_type_t UNUSED(type), void* value, void* UNUSED(data))
-{
-  g_return_if_fail(value != NULL);
-  g_return_if_fail(session != NULL);
-  g_return_if_fail(session->global.data != NULL);
-  zathura_t* zathura = session->global.data;
-
-  int first_page_column = *(int*) value;
-
-  if (first_page_column < 1) {
-    first_page_column = 1;
-  }
-
-  unsigned int pages_per_row = 1;
-  girara_setting_get(session, "pages-per-row", &pages_per_row);
-
-  unsigned int page_padding = 1;
-  girara_setting_get(session, "page-padding", &page_padding);
+  girara_setting_get(zathura->ui.session, "page-padding", &page_padding);
 
   page_widget_set_mode(zathura, page_padding, pages_per_row, first_page_column);
   zathura_document_set_page_layout(zathura->document, page_padding, pages_per_row, first_page_column);
-
-  if (zathura->document != NULL) {
-    unsigned int current_page = zathura_document_get_current_page_number(zathura->document);
-    page_set_delayed(zathura, current_page);
-  }
 }
 
 void

callbacks.h

@@ -92,19 +92,7 @@ void cb_adjustment_track_bounds(GtkAdjustment* adjustment, gpointer data);
  * @param value The value
  * @param data Custom data
  */
-void cb_pages_per_row_value_changed(girara_session_t* session, const char* name,
-    girara_setting_type_t type, void* value, void* data);
-/**
- * This function gets called when the value of the "first-page-column"
- * variable changes
- *
- * @param session The current girara session
- * @param name The name of the row
- * @param type The settings type
- * @param value The value
- * @param data Custom data
- */
-void cb_first_page_column_value_changed(girara_session_t* session, const char* name,
+void cb_page_layout_value_changed(girara_session_t* session, const char* name,
     girara_setting_type_t type, void* value, void* data);
 
 /**

config.c

@@ -73,27 +73,6 @@ cb_color_change(girara_session_t* session, const char* name,
   render_all(zathura);
 }
 
-static void
-cb_page_padding_changed(girara_session_t* session, const char* UNUSED(name),
-                        girara_setting_type_t UNUSED(type), void* value, void* UNUSED(data))
-{
-  g_return_if_fail(value != NULL);
-  g_return_if_fail(session != NULL);
-  g_return_if_fail(session->global.data != NULL);
-  zathura_t* zathura = session->global.data;
-
-  int val = *(int*) value;
-  if (GTK_IS_TABLE(zathura->ui.page_widget) == TRUE) {
-#if (GTK_MAJOR_VERSION == 3)
-    gtk_grid_set_row_spacing(GTK_GRID(zathura->ui.page_widget), val);
-    gtk_grid_set_column_spacing(GTK_GRID(zathura->ui.page_widget), val);
-#else
-    gtk_table_set_row_spacings(GTK_TABLE(zathura->ui.page_widget), val);
-    gtk_table_set_col_spacings(GTK_TABLE(zathura->ui.page_widget), val);
-#endif
-  }
-}
-
 static void
 cb_nohlsearch_changed(girara_session_t* session, const char* UNUSED(name),
                       girara_setting_type_t UNUSED(type), void* value, void* UNUSED(data))
@@ -153,11 +132,11 @@ config_load_default(zathura_t* zathura)
   int_value = 10;
   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,    false, _("Padding between pages"),   cb_page_padding_changed, NULL);
+  girara_setting_add(gsession, "page-padding",          &int_value,   INT,    false, _("Padding between pages"),   cb_page_layout_value_changed, NULL);
   int_value = 1;
-  girara_setting_add(gsession, "pages-per-row",         &int_value,   INT,    false, _("Number of pages per row"), cb_pages_per_row_value_changed, NULL);
+  girara_setting_add(gsession, "pages-per-row",         &int_value,   INT,    false, _("Number of pages per row"), cb_page_layout_value_changed, NULL);
   int_value = 1;
-  girara_setting_add(gsession, "first-page-column",     &int_value,   INT,    false, _("Column of the first page"),cb_first_page_column_value_changed, NULL);
+  girara_setting_add(gsession, "first-page-column",     &int_value,   INT,    false, _("Column of the first page"),cb_page_layout_value_changed, NULL);
   float_value = 40;
   girara_setting_add(gsession, "scroll-step",           &float_value, FLOAT,  false, _("Scroll step"),             NULL, NULL);
   float_value = 40;