[gedit/wip/printing-improvements: 2/3] print-preview: various small code enhancements

[Sébastien Wilmet <swilmet src gnome org>]

commit 36753e47417c41f8a5abdd55375947720dab7f6a
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sat Jun 27 17:45:43 2015 +0200

    print-preview: various small code enhancements
    
    - have all the #defines at the top, to know what is configurable (a
    previous commit fixed two identical #defines, so it's a sign that it's
    better to have them all at the top).
    
    - other various minor stuff

 gedit/gedit-print-preview.c |   54 +++++++++++++++---------------------------
 1 files changed, 19 insertions(+), 35 deletions(-)
---
diff --git a/gedit/gedit-print-preview.c b/gedit/gedit-print-preview.c
index 9c90505..c3cf9b2 100644
--- a/gedit/gedit-print-preview.c
+++ b/gedit/gedit-print-preview.c
@@ -27,6 +27,10 @@
 
 #define PRINTER_DPI (72.0)
 #define TOOLTIP_THRESHOLD 20
+#define PAGE_PAD 12
+#define PAGE_SHADOW_OFFSET 5
+#define ZOOM_IN_FACTOR (1.2)
+#define ZOOM_OUT_FACTOR (1.0 / ZOOM_IN_FACTOR)
 
 struct _GeditPrintPreview
 {
@@ -56,8 +60,10 @@ struct _GeditPrintPreview
 
        gdouble scale;
 
-       /* size of the tile of a page (including padding
-        * and drop shadow) in pixels */
+       /* The tile size is the size in pixels of the area where a page will be
+        * drawn, including the padding. The size is independent of the
+        * orientation.
+        */
        gint tile_width;
        gint tile_height;
 
@@ -65,7 +71,7 @@ struct _GeditPrintPreview
        gint n_columns;
 
        guint n_pages;
-       guint cur_page;
+       guint cur_page; /* starts at 0 */
        gint cursor_x;
        gint cursor_y;
 
@@ -125,17 +131,9 @@ update_layout_size (GeditPrintPreview *preview)
        gtk_widget_queue_draw (GTK_WIDGET (preview->layout));
 }
 
-static void
-set_n_columns (GeditPrintPreview *preview,
-              gint               n_columns)
-{
-       preview->n_columns = n_columns;
-       update_layout_size (preview);
-}
-
-/* get the paper size in points: these must be used only
- * after the widget has been mapped and the dpi is known */
-
+/* Get the paper size in points: these must be used only
+ * after the widget has been mapped and the dpi is known.
+ */
 static gdouble
 get_paper_width (GeditPrintPreview *preview)
 {
@@ -148,24 +146,12 @@ get_paper_height (GeditPrintPreview *preview)
        return preview->paper_height * preview->dpi;
 }
 
-#define PAGE_PAD 12
-#define PAGE_SHADOW_OFFSET 5
-
-/* The tile size is the size of the area where a page
- * will be drawn including the padding and idependent
- * of the orientation */
-
-/* updates the tile size to the current zoom and page size */
+/* Updates the tile size to the current zoom and page size. */
 static void
 update_tile_size (GeditPrintPreview *preview)
 {
-       gint w, h;
-
-       w = 2 * PAGE_PAD + floor (preview->scale * get_paper_width (preview) + 0.5);
-       h = 2 * PAGE_PAD + floor (preview->scale * get_paper_height (preview) + 0.5);
-
-       preview->tile_width = w;
-       preview->tile_height = h;
+       preview->tile_width = 2 * PAGE_PAD + floor (preview->scale * get_paper_width (preview) + 0.5);
+       preview->tile_height = 2 * PAGE_PAD + floor (preview->scale * get_paper_height (preview) + 0.5);
 }
 
 /* Zoom should always be set with one of these two function
@@ -218,9 +204,6 @@ set_zoom_fit_to_size (GeditPrintPreview *preview)
        update_layout_size (preview);
 }
 
-#define ZOOM_IN_FACTOR (1.2)
-#define ZOOM_OUT_FACTOR (1.0 / ZOOM_IN_FACTOR)
-
 static void
 zoom_in (GeditPrintPreview *preview)
 {
@@ -378,14 +361,15 @@ static void
 on_1x1_clicked (GtkMenuItem       *item,
                GeditPrintPreview *preview)
 {
-       set_n_columns (preview, 1);
+       preview->n_columns = 1;
+       update_layout_size (preview);
 }
 
 static void
 on_1x2_clicked (GtkMenuItem       *item,
                GeditPrintPreview *preview)
 {
-       set_n_columns (preview, 2);
+       preview->n_columns = 2;
        set_zoom_fit_to_size (preview);
 }
 
@@ -482,7 +466,7 @@ scroll_event_activated (GtkWidget         *widget,
 static gint
 get_first_page_displayed (GeditPrintPreview *preview)
 {
-       return preview->cur_page - preview->cur_page % preview->n_columns;
+       return preview->cur_page - (preview->cur_page % preview->n_columns);
 }
 
 /* returns the page number (starting from 0) or -1 if no page */