[gedit/wip/printing-enhancements: 1/4] print-preview: simplify get_page_at_coords()

[Sébastien Wilmet <swilmet src gnome org>]

commit e5386792edd85f31c443ebaf66e00167420604f2
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sun Jun 28 09:16:32 2015 +0200

    print-preview: simplify get_page_at_coords()
    
    'r' and 'c' actually meant 'row' and 'col'… In the context of math, r
    and c can represent many things, like a radius and center, or rotation.
    
    Since 'r' is the row, the code can be simplified since there is now at
    most one row. Also avoid redundant "+1" and "-1".
    
    A later commit will take into account selected pages for printing (like
    print only pages 1, 5 and 7). And another later commit can fix the FIXME
    comment.

 gedit/gedit-print-preview.c |   28 +++++++++++++++++-----------
 1 files changed, 17 insertions(+), 11 deletions(-)
---
diff --git a/gedit/gedit-print-preview.c b/gedit/gedit-print-preview.c
index 2709745..b41761f 100644
--- a/gedit/gedit-print-preview.c
+++ b/gedit/gedit-print-preview.c
@@ -486,38 +486,44 @@ get_first_page_displayed (GeditPrintPreview *preview)
        return preview->cur_page - (preview->cur_page % preview->n_columns);
 }
 
-/* returns the page number (starting from 0) or -1 if no page */
+/* Returns the page number (starting from 0) or -1 if no page. */
 static gint
 get_page_at_coords (GeditPrintPreview *preview,
                     gint               x,
                     gint               y)
 {
        GtkAdjustment *hadj, *vadj;
-       gint r, c, pg;
+       gint col, page;
 
        if (preview->tile_height <= 0 || preview->tile_width <= 0)
+       {
                return -1;
+       }
 
        get_adjustments (preview, &hadj, &vadj);
 
        x += gtk_adjustment_get_value (hadj);
        y += gtk_adjustment_get_value (vadj);
 
-       r = 1 + y / (preview->tile_height);
-       c = 1 + x / (preview->tile_width);
+       col = x / preview->tile_width;
 
-       if (c > preview->n_columns)
+       if (col >= preview->n_columns ||
+           y > preview->tile_height)
+       {
                return -1;
+       }
 
-       pg = get_first_page_displayed (preview) - 1;
-       pg += (r - 1) * preview->n_columns + c;
+       page = get_first_page_displayed (preview) + col;
 
-       if (pg >= preview->n_pages)
+       if (page >= preview->n_pages)
+       {
                return -1;
+       }
 
-       /* FIXME: we could try to be picky and check
-        * if we actually are inside the page */
-       return pg;
+       /* FIXME: we could try to be picky and check if we actually are inside
+        * the page (i.e. not in the padding or shadow).
+        */
+       return page;
 }
 
 static gboolean