We perform lots of gadget allocations that require allocating a
GtkBuiltinIcon. One notable example is the scrollbar for a scrolled
window.
In the process of doing this, we often calculate baseline information that
isn't necessary. With how much this code path gets exercised, its worth
catching the result for the common case, which is that the font-description
has not changed and we are using the default language the application
was started with.
This simply caches the previous result and verifies that we can reuse it
with pango_font_description_hash() and a simple language check.
Numbers below are scrolling through a textview with GDK_KEY_Down.
Before:
SELF CUMULATIVE FUNCTION
[ 0.08%] [ 9.26%] gtk_builtin_icon_get_preferred_size
[ 0.01%] [ 8.82%] pango_context_get_metrics
[ 0.02%] [ 0.16%] gtk_widget_get_pango_context
[ 0.06%] [ 0.06%] pango_context_get_language
[ 0.01%] [ 0.02%] g_type_check_instance_cast
[ 0.02%] [ 0.02%] strlen
[ 0.02%] [ 0.02%] pango_context_get_font_description
[ 0.02%] [ 0.02%] g_list_foreach
[ 0.01%] [ 0.01%] gtk_css_style_get_value
[ 0.01%] [ 0.01%] itemize_with_font
[ 0.01%] [ 0.01%] pango_context_get_type
[ 0.01%] [ 0.01%] get_base_metrics
[ 0.00%] [ 0.01%] pango_font_metrics_unref
[ 0.01%] [ 0.01%] g_list_free
[ 0.01%] [ 0.01%] gtk_builtin_icon_get_type
After:
SELF CUMULATIVE FUNCTION
[ 0.08%] [ 0.18%] gtk_builtin_icon_get_preferred_size
[ 0.02%] [ 0.02%] pango_font_description_hash
[ 0.00%] [ 0.02%] gtk_widget_get_pango_context
[ 0.00%] [ 0.02%] g_object_get_qdata
[ 0.00%] [ 0.02%] g_datalist_id_get_data
[ 0.02%] [ 0.02%] gtk_builtin_icon_get_type
[ 0.01%] [ 0.01%] pango_context_get_font_description
[ 0.00%] [ 0.01%] - - kernel - -
[ 0.01%] [ 0.01%] pango_context_get_language
[ 0.00%] [ 0.01%] gtk_css_style_get_value
[ 0.00%] [ 0.01%] gtk_css_gadget_get_style
https://bugzilla.gnome.org/show_bug.cgi?id=765486
Most uses of builtin icons (check and radio buttons,
expanders, etc) are placed next to labels, so they should
be properly positioned wrt to the baseline. Lacking anything
better, give the builtin icons a baseline that places the
center of the icon at the strikethrough position.
The gtk_builtin_icon_get_default_size_property returns a const char *,
in a way such that some compilers insist that something that is of a
pointer value be returned, so fix that by replacing 0 with NULL.
Make min-width/height have preference over the set default size. This
allows shrinking the widget. The default size is only used if min-width
is not set (or explicitly set to 0.
