zathura-page-right-to-left.patch

diff --git a/zathura/callbacks.c b/zathura/callbacks.c
index 7db22f8..a8db4ed 100644
--- a/zathura/callbacks.c
+++ b/zathura/callbacks.c
@@ -254,7 +254,10 @@ cb_page_layout_value_changed(girara_session_t* session, const char* name, girara
   unsigned int page_padding = 1;
   girara_setting_get(zathura->ui.session, "page-padding", &page_padding);
 
-  page_widget_set_mode(zathura, page_padding, pages_per_row, first_page_column);
+  bool page_right_to_left = false;
+  girara_setting_get(zathura->ui.session, "page-right-to-left", &page_right_to_left);
+
+  page_widget_set_mode(zathura, page_padding, pages_per_row, first_page_column, page_right_to_left);
   zathura_document_set_page_layout(zathura->document, page_padding, pages_per_row, first_page_column);
 }
 
diff --git a/zathura/config.c b/zathura/config.c
index d3fe43a..094e37e 100644
--- a/zathura/config.c
+++ b/zathura/config.c
@@ -152,6 +152,8 @@ config_load_default(zathura_t* zathura)
   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",     "1:2",        STRING, false, _("Column of the first page"), cb_page_layout_value_changed, NULL);
+  bool_value = false;
+  girara_setting_add(gsession, "page-right-to-left",    &bool_value,  BOOLEAN, false, _("Render pages from right to left"),  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;
diff --git a/zathura/database-plain.c b/zathura/database-plain.c
index 6c933fd..d3149e3 100644
--- a/zathura/database-plain.c
+++ b/zathura/database-plain.c
@@ -27,6 +27,7 @@
 #define KEY_SCALE                 "scale"
 #define KEY_ROTATE                "rotate"
 #define KEY_PAGES_PER_ROW         "pages-per-row"
+#define KEY_PAGE_RIGHT_TO_LEFT    "page-right-to-left"
 #define KEY_FIRST_PAGE_COLUMN     "first-page-column"
 #define KEY_POSITION_X            "position-x"
 #define KEY_POSITION_Y            "position-y"
@@ -554,6 +555,7 @@ plain_set_fileinfo(zathura_database_t* db, const char* file, zathura_fileinfo_t*
   g_key_file_set_integer(priv->history, name, KEY_ROTATE,            file_info->rotation);
   g_key_file_set_integer(priv->history, name, KEY_PAGES_PER_ROW,     file_info->pages_per_row);
   g_key_file_set_string(priv->history, name, KEY_FIRST_PAGE_COLUMN,  file_info->first_page_column_list);
+  g_key_file_set_boolean(priv->history, name, KEY_PAGE_RIGHT_TO_LEFT,file_info->page_right_to_left);
   g_key_file_set_double (priv->history, name, KEY_POSITION_X,        file_info->position_x);
   g_key_file_set_double (priv->history, name, KEY_POSITION_Y,        file_info->position_y);
   g_key_file_set_integer(priv->history, name, KEY_TIME,              time(NULL));
@@ -596,6 +598,9 @@ plain_get_fileinfo(zathura_database_t* db, const char* file, zathura_fileinfo_t*
   if (g_key_file_has_key(priv->history, name, KEY_FIRST_PAGE_COLUMN, NULL) == TRUE) {
     file_info->first_page_column_list = g_key_file_get_string(priv->history, name, KEY_FIRST_PAGE_COLUMN, NULL);
   }
+  if (g_key_file_has_key(priv->history, name, KEY_PAGE_RIGHT_TO_LEFT, NULL) == TRUE) {
+    file_info->page_right_to_left = g_key_file_get_boolean(priv->history, name, KEY_PAGE_RIGHT_TO_LEFT, NULL);
+  }
   if (g_key_file_has_key(priv->history, name, KEY_POSITION_X, NULL) == TRUE) {
     file_info->position_x        = g_key_file_get_double(priv->history, name, KEY_POSITION_X, NULL);
   }
diff --git a/zathura/database.h b/zathura/database.h
index 7c76407..f60c163 100644
--- a/zathura/database.h
+++ b/zathura/database.h
@@ -15,6 +15,7 @@ typedef struct zathura_fileinfo_s {
   double scale;
   unsigned int rotation;
   unsigned int pages_per_row;
+  bool page_right_to_left;
   char* first_page_column_list;
   double position_x;
   double position_y;
diff --git a/zathura/zathura.c b/zathura/zathura.c
index 938aed3..4d8c73a 100644
--- a/zathura/zathura.c
+++ b/zathura/zathura.c
@@ -806,6 +806,7 @@ document_open(zathura_t* zathura, const char* path, const char* uri, const char*
     .rotation = 0,
     .pages_per_row = 0,
     .first_page_column_list = NULL,
+    .page_right_to_left = false,
     .position_x = 0,
     .position_y = 0
   };
@@ -995,6 +996,7 @@ document_open(zathura_t* zathura, const char* path, const char* uri, const char*
   unsigned int pages_per_row = 1;
   char* first_page_column_list = NULL;
   unsigned int page_padding = 1;
+  bool page_right_to_left = false;
 
   girara_setting_get(zathura->ui.session, "page-padding", &page_padding);
 
@@ -1020,7 +1022,10 @@ document_open(zathura_t* zathura, const char* path, const char* uri, const char*
   g_free(file_info.first_page_column_list);
   g_free(first_page_column_list);
 
-  page_widget_set_mode(zathura, page_padding, pages_per_row, first_page_column);
+  //girara_setting_get(zathura->ui.session, "page-right-to-left", &page_right_to_left);
+  page_right_to_left = file_info.page_right_to_left;
+
+  page_widget_set_mode(zathura, page_padding, pages_per_row, first_page_column, page_right_to_left);
   zathura_document_set_page_layout(zathura->document, page_padding, pages_per_row, first_page_column);
 
   girara_set_view(zathura->ui.session, zathura->ui.page_widget);
@@ -1185,6 +1190,7 @@ save_fileinfo_to_db(zathura_t* zathura)
     .rotation = zathura_document_get_rotation(zathura->document),
     .pages_per_row = 1,
     .first_page_column_list = "1:2",
+    .page_right_to_left = false,
     .position_x = zathura_document_get_position_x(zathura->document),
     .position_y = zathura_document_get_position_y(zathura->document)
   };
@@ -1193,6 +1199,8 @@ save_fileinfo_to_db(zathura_t* zathura)
                      &(file_info.pages_per_row));
   girara_setting_get(zathura->ui.session, "first-page-column",
                      &(file_info.first_page_column_list));
+  girara_setting_get(zathura->ui.session, "page-right-to-left",
+                     &(file_info.page_right_to_left));
 
   /* save file info */
   zathura_db_set_fileinfo(zathura->database, path, &file_info);
@@ -1334,7 +1342,8 @@ statusbar_page_number_update(zathura_t* zathura)
 
 void
 page_widget_set_mode(zathura_t* zathura, unsigned int page_padding,
-                     unsigned int pages_per_row, unsigned int first_page_column)
+                     unsigned int pages_per_row, unsigned int first_page_column,
+                     bool page_right_to_left)
 {
   /* show at least one page */
   if (pages_per_row == 0) {
@@ -1365,6 +1374,9 @@ page_widget_set_mode(zathura_t* zathura, unsigned int page_padding,
     int y = (i + first_page_column - 1) / pages_per_row;
 
     GtkWidget* page_widget = zathura->pages[i];
+    if (page_right_to_left) {
+      x = pages_per_row - 1 - x;
+    }
 
     gtk_grid_attach(GTK_GRID(zathura->ui.page_widget), page_widget, x, y, 1, 1);
   }
diff --git a/zathura/zathura.h b/zathura/zathura.h
index 84e0cb6..c2dad88 100644
--- a/zathura/zathura.h
+++ b/zathura/zathura.h
@@ -387,9 +387,11 @@ bool adjust_view(zathura_t* zathura);
  * @param page_padding padding in pixels between pages
  * @param pages_per_row Number of shown pages per row
  * @param first_page_column Column on which first page start
+ * @param page_right_to_left Render pages right to left
  */
 void page_widget_set_mode(zathura_t* zathura, unsigned int page_padding,
-                          unsigned int pages_per_row, unsigned int first_page_column);
+                          unsigned int pages_per_row, unsigned int first_page_column,
+                          bool page_right_to_left);
 
 /**
  * Updates the page number in the statusbar. Note that 1 will be added to the

Can you tell me if this serves to split Zathura's screen or what does this do?

No. This patch is about placing the first page on the right side and the second page on the left side in the dual page view, which is inverse of the default rendering.