gtk2/demos/gtk-demo/fontrendering.c
Benjamin Otte b025ee428c builder: Connect signals automatically
gtk_builder_connect_signals() is no longer necessary, because all the
setup that made it necessary to have this extra step is now done
automatically via the closure functions.
2019-11-22 17:42:31 +01:00

288 lines
10 KiB
C

/* Pango/Font rendering
*
* Demonstrates various aspects of font rendering.
*/
#include <gtk/gtk.h>
static GtkWidget *window = NULL;
static GtkWidget *font_button = NULL;
static GtkWidget *entry = NULL;
static GtkWidget *image = NULL;
static GtkWidget *hinting = NULL;
static GtkWidget *hint_metrics = NULL;
static GtkWidget *up_button = NULL;
static GtkWidget *down_button = NULL;
static GtkWidget *text_radio = NULL;
static GtkWidget *show_grid = NULL;
static GtkWidget *show_extents = NULL;
static PangoContext *context;
static int scale = 10;
static void
on_destroy (gpointer data)
{
window = NULL;
}
static void
update_image (void)
{
const char *text;
PangoFontDescription *desc;
PangoLayout *layout;
PangoRectangle ink, pink, logical;
int baseline;
cairo_surface_t *surface;
cairo_t *cr;
GdkPixbuf *pixbuf;
GdkPixbuf *pixbuf2;
const char *hint;
cairo_font_options_t *fopt;
cairo_hint_style_t hintstyle;
cairo_hint_metrics_t hintmetrics;
int i;
if (!context)
context = gtk_widget_create_pango_context (image);
text = gtk_editable_get_text (GTK_EDITABLE (entry));
desc = gtk_font_chooser_get_font_desc (GTK_FONT_CHOOSER (font_button));
fopt = cairo_font_options_copy (pango_cairo_context_get_font_options (context));
hint = gtk_combo_box_get_active_id (GTK_COMBO_BOX (hinting));
if (strcmp (hint, "none") == 0)
hintstyle = CAIRO_HINT_STYLE_NONE;
else if (strcmp (hint, "slight") == 0)
hintstyle = CAIRO_HINT_STYLE_SLIGHT;
else if (strcmp (hint, "medium") == 0)
hintstyle = CAIRO_HINT_STYLE_MEDIUM;
else if (strcmp (hint, "full") == 0)
hintstyle = CAIRO_HINT_STYLE_FULL;
else
hintstyle = CAIRO_HINT_STYLE_DEFAULT;
cairo_font_options_set_hint_style (fopt, hintstyle);
if (gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (hint_metrics)))
hintmetrics = CAIRO_HINT_METRICS_ON;
else
hintmetrics = CAIRO_HINT_METRICS_OFF;
cairo_font_options_set_hint_metrics (fopt, hintmetrics);
pango_cairo_context_set_font_options (context, fopt);
cairo_font_options_destroy (fopt);
pango_context_changed (context);
if (gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (text_radio)))
{
layout = pango_layout_new (context);
pango_layout_set_font_description (layout, desc);
pango_layout_set_text (layout, text, -1);
pango_layout_get_extents (layout, &ink, &logical);
pink = ink;
baseline = pango_layout_get_baseline (layout);
pango_extents_to_pixels (&ink, NULL);
surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, ink.width + 20, ink.height + 20);
cr = cairo_create (surface);
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_paint (cr);
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_move_to (cr, 10, 10);
pango_cairo_show_layout (cr, layout);
cairo_destroy (cr);
g_object_unref (layout);
pixbuf = gdk_pixbuf_get_from_surface (surface, 0, 0, cairo_image_surface_get_width (surface), cairo_image_surface_get_height (surface));
pixbuf2 = gdk_pixbuf_scale_simple (pixbuf, gdk_pixbuf_get_width (pixbuf) * scale, gdk_pixbuf_get_height (pixbuf) * scale, GDK_INTERP_NEAREST);
g_object_unref (pixbuf);
cairo_surface_destroy (surface);
surface = cairo_image_surface_create_for_data (gdk_pixbuf_get_pixels (pixbuf2),
CAIRO_FORMAT_ARGB32,
gdk_pixbuf_get_width (pixbuf2),
gdk_pixbuf_get_height (pixbuf2),
gdk_pixbuf_get_rowstride (pixbuf2));
cr = cairo_create (surface);
cairo_set_line_width (cr, 1);
if (gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (show_grid)))
{
cairo_set_source_rgba (cr, 0.2, 0, 0, 0.2);
for (i = 1; i < ink.height + 20; i++)
{
cairo_move_to (cr, 0, scale * i - 0.5);
cairo_line_to (cr, scale * (ink.width + 20), scale * i - 0.5);
cairo_stroke (cr);
}
for (i = 1; i < ink.width + 20; i++)
{
cairo_move_to (cr, scale * i - 0.5, 0);
cairo_line_to (cr, scale * i - 0.5, scale * (ink.height + 20));
cairo_stroke (cr);
}
}
if (gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (show_extents)))
{
cairo_set_source_rgba (cr, 0, 0, 1, 1);
cairo_rectangle (cr,
scale * (10 + pango_units_to_double (logical.x)) - 0.5,
scale * (10 + pango_units_to_double (logical.y)) - 0.5,
scale * pango_units_to_double (logical.width) + 1,
scale * pango_units_to_double (logical.height) + 1);
cairo_stroke (cr);
cairo_move_to (cr, scale * (10 + pango_units_to_double (logical.x)) - 0.5,
scale * (10 + pango_units_to_double (baseline)) - 0.5);
cairo_line_to (cr, scale * (10 + pango_units_to_double (logical.x + logical.width)) + 1,
scale * (10 + pango_units_to_double (baseline)) - 0.5);
cairo_stroke (cr);
cairo_set_source_rgba (cr, 1, 0, 0, 1);
cairo_rectangle (cr,
scale * (10 + pango_units_to_double (pink.x)) + 0.5,
scale * (10 + pango_units_to_double (pink.y)) + 0.5,
scale * pango_units_to_double (pink.width) - 1,
scale * pango_units_to_double (pink.height) - 1);
cairo_stroke (cr);
}
cairo_surface_destroy (surface);
cairo_destroy (cr);
}
else
{
PangoLayoutIter *iter;
PangoLayoutRun *run;
PangoGlyphInfo *g;
int i, j;
layout = pango_layout_new (context);
pango_layout_set_font_description (layout, desc);
pango_layout_set_text (layout, "aaaa", -1);
pango_layout_get_extents (layout, &ink, &logical);
pango_extents_to_pixels (&logical, NULL);
surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, logical.width * 3 / 2, 4*logical.height);
cr = cairo_create (surface);
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_paint (cr);
iter = pango_layout_get_iter (layout);
run = pango_layout_iter_get_run (iter);
cairo_set_source_rgb (cr, 0, 0, 0);
for (i = 0; i < 4; i++)
{
g = &(run->glyphs->glyphs[i]);
g->geometry.width = PANGO_UNITS_ROUND (g->geometry.width * 3 / 2);
}
for (j = 0; j < 4; j++)
{
for (i = 0; i < 4; i++)
{
g = &(run->glyphs->glyphs[i]);
g->geometry.x_offset = i * (PANGO_SCALE / 4);
g->geometry.y_offset = j * (PANGO_SCALE / 4);
}
cairo_move_to (cr, 0, j * logical.height);
pango_cairo_show_layout (cr, layout);
}
cairo_destroy (cr);
pango_layout_iter_free (iter);
g_object_unref (layout);
pixbuf = gdk_pixbuf_get_from_surface (surface, 0, 0, cairo_image_surface_get_width (surface), cairo_image_surface_get_height (surface));
pixbuf2 = gdk_pixbuf_scale_simple (pixbuf, gdk_pixbuf_get_width (pixbuf) * scale, gdk_pixbuf_get_height (pixbuf) * scale, GDK_INTERP_NEAREST);
g_object_unref (pixbuf);
cairo_surface_destroy (surface);
}
gtk_picture_set_pixbuf (GTK_PICTURE (image), pixbuf2);
g_object_unref (pixbuf2);
pango_font_description_free (desc);
}
static void
update_buttons (void)
{
gtk_widget_set_sensitive (up_button, scale < 32);
gtk_widget_set_sensitive (down_button, scale > 1);
}
static void
scale_up (void)
{
scale += 1;
update_buttons ();
update_image ();
}
static void
scale_down (void)
{
scale -= 1;
update_buttons ();
update_image ();
}
GtkWidget *
do_fontrendering (GtkWidget *do_widget)
{
if (!window)
{
GtkBuilder *builder;
builder = gtk_builder_new_from_resource ("/fontrendering/fontrendering.ui");
window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
gtk_window_set_display (GTK_WINDOW (window),
gtk_widget_get_display (do_widget));
g_signal_connect (window, "destroy",
G_CALLBACK (on_destroy), NULL);
g_object_set_data_full (G_OBJECT (window), "builder", builder, g_object_unref);
font_button = GTK_WIDGET (gtk_builder_get_object (builder, "font_button"));
up_button = GTK_WIDGET (gtk_builder_get_object (builder, "up_button"));
down_button = GTK_WIDGET (gtk_builder_get_object (builder, "down_button"));
entry = GTK_WIDGET (gtk_builder_get_object (builder, "entry"));
image = GTK_WIDGET (gtk_builder_get_object (builder, "image"));
hinting = GTK_WIDGET (gtk_builder_get_object (builder, "hinting"));
hint_metrics = GTK_WIDGET (gtk_builder_get_object (builder, "hint_metrics"));
text_radio = GTK_WIDGET (gtk_builder_get_object (builder, "text_radio"));
show_grid = GTK_WIDGET (gtk_builder_get_object (builder, "show_grid"));
show_extents = GTK_WIDGET (gtk_builder_get_object (builder, "show_extents"));
g_signal_connect (up_button, "clicked", G_CALLBACK (scale_up), NULL);
g_signal_connect (down_button, "clicked", G_CALLBACK (scale_down), NULL);
g_signal_connect (entry, "notify::text", G_CALLBACK (update_image), NULL);
g_signal_connect (font_button, "notify::font-desc", G_CALLBACK (update_image), NULL);
g_signal_connect (hinting, "notify::active", G_CALLBACK (update_image), NULL);
g_signal_connect (hint_metrics, "notify::active", G_CALLBACK (update_image), NULL);
g_signal_connect (text_radio, "notify::active", G_CALLBACK (update_image), NULL);
g_signal_connect (show_grid, "notify::active", G_CALLBACK (update_image), NULL);
g_signal_connect (show_extents, "notify::active", G_CALLBACK (update_image), NULL);
update_image ();
}
if (!gtk_widget_get_visible (window))
gtk_widget_show (window);
else
gtk_widget_destroy (window);
return window;
}