gtk/demos/gtk-demo/css_basics.c
Matthias Clasen d732c869c2 gtk-demo: Add keywords to demos
Add the names of the main widgets as keywords to
our demos, but also things like "game". This helps
finding relevant demos in our growing list. You
can now for example type "label", and find the
"error states" and "links" demos showing GtkLabel
features.
2020-09-13 15:00:14 -04:00

122 lines
3.9 KiB
C

/* Theming/CSS Basics
*
* GTK themes are written using CSS. Every widget is build of multiple items
* that you can style very similarly to a regular website.
*/
#include <gtk/gtk.h>
static void
show_parsing_error (GtkCssProvider *provider,
GtkCssSection *section,
const GError *error,
GtkTextBuffer *buffer)
{
const GtkCssLocation *start_location, *end_location;
GtkTextIter start, end;
const char *tag_name;
start_location = gtk_css_section_get_start_location (section);
gtk_text_buffer_get_iter_at_line_index (buffer,
&start,
start_location->lines,
start_location->line_bytes);
end_location = gtk_css_section_get_end_location (section);
gtk_text_buffer_get_iter_at_line_index (buffer,
&end,
end_location->lines,
end_location->line_bytes);
if (error->domain == GTK_CSS_PARSER_WARNING)
tag_name = "warning";
else
tag_name = "error";
gtk_text_buffer_apply_tag_by_name (buffer, tag_name, &start, &end);
}
static void
css_text_changed (GtkTextBuffer *buffer,
GtkCssProvider *provider)
{
GtkTextIter start, end;
char *text;
gtk_text_buffer_get_start_iter (buffer, &start);
gtk_text_buffer_get_end_iter (buffer, &end);
gtk_text_buffer_remove_all_tags (buffer, &start, &end);
text = gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
gtk_css_provider_load_from_data (provider, text, -1);
g_free (text);
}
static void
apply_css (GtkWidget *widget, GtkStyleProvider *provider)
{
GtkWidget *child;
gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
for (child = gtk_widget_get_first_child (widget);
child != NULL;
child = gtk_widget_get_next_sibling (child))
apply_css (child, provider);
}
GtkWidget *
do_css_basics (GtkWidget *do_widget)
{
static GtkWidget *window = NULL;
if (!window)
{
GtkWidget *container, *child;
GtkStyleProvider *provider;
GtkTextBuffer *text;
GBytes *bytes;
window = gtk_window_new ();
gtk_window_set_title (GTK_WINDOW (window), "CSS Basics");
gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
text = gtk_text_buffer_new (NULL);
gtk_text_buffer_create_tag (text,
"warning",
"underline", PANGO_UNDERLINE_SINGLE,
NULL);
gtk_text_buffer_create_tag (text,
"error",
"underline", PANGO_UNDERLINE_ERROR,
NULL);
provider = GTK_STYLE_PROVIDER (gtk_css_provider_new ());
container = gtk_scrolled_window_new ();
gtk_window_set_child (GTK_WINDOW (window), container);
child = gtk_text_view_new_with_buffer (text);
gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (container), child);
g_signal_connect (text, "changed",
G_CALLBACK (css_text_changed), provider);
bytes = g_resources_lookup_data ("/css_basics/css_basics.css", 0, NULL);
gtk_text_buffer_set_text (text, g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes));
g_bytes_unref (bytes);
g_signal_connect (provider,
"parsing-error",
G_CALLBACK (show_parsing_error),
gtk_text_view_get_buffer (GTK_TEXT_VIEW (child)));
apply_css (window, provider);
}
if (!gtk_widget_get_visible (window))
gtk_widget_show (window);
else
gtk_window_destroy (GTK_WINDOW (window));
return window;
}