[gedit/wip/printing-enhancements] print-preview: get tile size with a getter

[Sébastien Wilmet <swilmet src gnome org>]

commit 9a178a269e62ffb7f68f9751fc60f02ba910c7aa
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sun Jun 28 12:35:49 2015 +0200

    print-preview: get tile size with a getter
    
    No need to store the value, since it can be computed from other values.
    It simplifies a little the code, since we don't need to call
    update_tile_size() when some other values change.

 gedit/gedit-print-preview.c |   89 ++++++++++++++++++++++++------------------
 1 files changed, 51 insertions(+), 38 deletions(-)
---
diff --git a/gedit/gedit-print-preview.c b/gedit/gedit-print-preview.c
index eb8125c..454d4ee 100644
--- a/gedit/gedit-print-preview.c
+++ b/gedit/gedit-print-preview.c
@@ -61,13 +61,6 @@ struct _GeditPrintPreview
 
        gdouble scale;
 
-       /* 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;
-
        /* multipage support */
        gint n_columns;
 
@@ -145,26 +138,6 @@ gedit_print_preview_class_init (GeditPrintPreviewClass *klass)
        gtk_widget_class_bind_template_child (widget_class, GeditPrintPreview, layout);
 }
 
-static void
-get_adjustments (GeditPrintPreview  *preview,
-                GtkAdjustment     **hadj,
-                GtkAdjustment     **vadj)
-{
-       *hadj = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (preview->layout));
-       *vadj = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (preview->layout));
-}
-
-static void
-update_layout_size (GeditPrintPreview *preview)
-{
-       /* force size of the drawing area to make the scrolled window work */
-       gtk_layout_set_size (preview->layout,
-                            preview->tile_width * preview->n_columns,
-                            preview->tile_height);
-
-       gtk_widget_queue_draw (GTK_WIDGET (preview->layout));
-}
-
 /* Get the paper size in points: these must be used only
  * after the widget has been mapped and the dpi is known.
  */
@@ -180,12 +153,49 @@ get_paper_height (GeditPrintPreview *preview)
        return preview->paper_height * preview->dpi;
 }
 
-/* Updates the tile size to the current zoom and page size. */
+/* 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.
+ */
+static void
+get_tile_size (GeditPrintPreview *preview,
+              gint              *tile_width,
+              gint              *tile_height)
+{
+       if (tile_width != NULL)
+       {
+               *tile_width = 2 * PAGE_PAD + round (preview->scale * get_paper_width (preview));
+       }
+
+       if (tile_height != NULL)
+       {
+               *tile_height = 2 * PAGE_PAD + round (preview->scale * get_paper_height (preview));
+       }
+}
+
 static void
-update_tile_size (GeditPrintPreview *preview)
+get_adjustments (GeditPrintPreview  *preview,
+                GtkAdjustment     **hadj,
+                GtkAdjustment     **vadj)
 {
-       preview->tile_width = 2 * PAGE_PAD + round (preview->scale * get_paper_width (preview));
-       preview->tile_height = 2 * PAGE_PAD + round (preview->scale * get_paper_height (preview));
+       *hadj = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (preview->layout));
+       *vadj = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (preview->layout));
+}
+
+static void
+update_layout_size (GeditPrintPreview *preview)
+{
+       gint tile_width;
+       gint tile_height;
+
+       get_tile_size (preview, &tile_width, &tile_height);
+
+       /* force size of the drawing area to make the scrolled window work */
+       gtk_layout_set_size (preview->layout,
+                            tile_width * preview->n_columns,
+                            tile_height);
+
+       gtk_widget_queue_draw (GTK_WIDGET (preview->layout));
 }
 
 /* Zoom should always be set with one of these two function
@@ -197,8 +207,6 @@ set_zoom_factor (GeditPrintPreview *preview,
                 gdouble            zoom)
 {
        preview->scale = zoom;
-
-       update_tile_size (preview);
        update_layout_size (preview);
 }
 
@@ -488,10 +496,13 @@ get_page_at_coords (GeditPrintPreview *preview,
                     gint               x,
                     gint               y)
 {
+       gint tile_width, tile_height;
        GtkAdjustment *hadj, *vadj;
        gint col, page;
 
-       if (preview->tile_height <= 0 || preview->tile_width <= 0)
+       get_tile_size (preview, &tile_width, &tile_height);
+
+       if (tile_height <= 0 || tile_width <= 0)
        {
                return -1;
        }
@@ -501,10 +512,9 @@ get_page_at_coords (GeditPrintPreview *preview,
        x += gtk_adjustment_get_value (hadj);
        y += gtk_adjustment_get_value (vadj);
 
-       col = x / preview->tile_width;
+       col = x / tile_width;
 
-       if (col >= preview->n_columns ||
-           y > preview->tile_height)
+       if (col >= preview->n_columns || y > tile_height)
        {
                return -1;
        }
@@ -916,6 +926,7 @@ preview_draw (GtkWidget         *widget,
              GeditPrintPreview *preview)
 {
        GdkWindow *bin_window;
+       gint tile_width;
        gint page_num;
        gint col;
 
@@ -930,6 +941,8 @@ preview_draw (GtkWidget         *widget,
 
        gtk_cairo_transform_to_window (cr, widget, bin_window);
 
+       get_tile_size (preview, &tile_width, NULL);
+
        col = 0;
        page_num = get_first_page_displayed (preview);
 
@@ -942,7 +955,7 @@ preview_draw (GtkWidget         *widget,
                }
 
                draw_page (cr,
-                          col * preview->tile_width,
+                          col * tile_width,
                           0,
                           page_num,
                           preview);