/*
 * Copyright © 2008 Behdad Esfahbod
 * Copyright © 2009 Chris Wilson
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the name of
 * Chris Wilson not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior
 * permission. Chris Wilson makes no representations about the
 * suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * CHRIS WILSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS, IN NO EVENT SHALL CHRIS WILSON BE LIABLE FOR ANY SPECIAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
 * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Author: Chris Wilson <chris@chris-wilson.co.uk>
 */

#include <gtk/gtk.h>
#include <cairo.h>

struct options {
    const char *text;
    const char *family;
    cairo_font_weight_t weight;
    cairo_font_slant_t slant;
    double size;
    int PAD;
    const char *png;
};

static void
draw (cairo_t *cr, struct options *options)
{
    cairo_text_extents_t extents;
    cairo_font_extents_t font_extents;

    cairo_select_font_face (cr,
			    options->family, options->slant, options->weight);
    cairo_set_font_size (cr, options->size);

    cairo_text_extents (cr, options->text, &extents);
    cairo_translate (cr,
		     options->PAD - extents.x_bearing,
		     options->PAD - extents.y_bearing);

    cairo_font_extents (cr, &font_extents);
    cairo_rectangle (cr, 0, -font_extents.ascent,
		      extents.x_advance, font_extents.height);
    cairo_move_to (cr, -options->PAD, 0);
    cairo_line_to (cr, extents.width + options->PAD, 0);
    cairo_set_source_rgba (cr, 1, 0, 0, .7);
    cairo_stroke (cr);

    cairo_rectangle (cr,
		     extents.x_bearing, extents.y_bearing,
		     extents.width, extents.height);
    cairo_set_source_rgba (cr, 0, 1, 0, .7);
    cairo_stroke (cr);

    cairo_move_to (cr, 0, 0);
    cairo_set_source_rgb (cr, 0, 0, 1);
    cairo_show_text (cr, options->text);
    cairo_fill (cr);
}

static gboolean
expose_event (GtkWidget *w, GdkEventExpose *ev, struct options *options)
{
    cairo_t *cr;

    cr = gdk_cairo_create (w->window);

    cairo_set_source_rgb (cr, 1, 1, 1);
    cairo_paint (cr);

    draw (cr, options);

    cairo_destroy (cr);

    if (options->png) {
	cairo_surface_t *image;

	image = cairo_image_surface_create (CAIRO_FORMAT_RGB24,
		                            w->allocation.width,
					    w->allocation.height);
	cr = cairo_create (image);
	cairo_set_source_rgb (cr, 1, 1, 1);
	cairo_paint (cr);

	draw (cr, options);

	cairo_destroy (cr);
	cairo_surface_write_to_png (image, options->png);
	cairo_surface_destroy (image);
    }

    return TRUE;
}

static void
size_request (GtkWidget *w, GtkRequisition *req , struct options *options)
{
    cairo_surface_t *dummy;
    cairo_t *cr;
    cairo_text_extents_t extents;

    dummy = cairo_image_surface_create (CAIRO_FORMAT_RGB24, 0, 0);
    cr = cairo_create (dummy);
    cairo_surface_destroy (dummy);

    cairo_select_font_face (cr,
			    options->family, options->slant, options->weight);
    cairo_set_font_size (cr, options->size);

    cairo_text_extents (cr, options->text, &extents);
    cairo_destroy (cr);

    req->width = extents.width + 2 * options->PAD;
    req->height = extents.height + 2 * options->PAD;
}

int
main (int argc, char **argv)
{
    GtkWidget *window;
    struct options options = {
	"The Quick Brown Fox Jumps Over The Lazy Dog!",
	"@cairo:small-caps",
	CAIRO_FONT_WEIGHT_NORMAL,
	CAIRO_FONT_SLANT_NORMAL,
	48,
	30,
	"font-view.png"
    };

    gtk_init (&argc, &argv);

    /* rudimentary argument processing */
    if (argc >= 2) {
	options.family = argv[1];
    }
    if (argc >= 3) {
	if (strcmp (argv[2], "italic") == 0)
	    options.slant = CAIRO_FONT_SLANT_ITALIC;
	else if (strcmp (argv[2], "oblique") == 0)
	    options.slant = CAIRO_FONT_SLANT_OBLIQUE;
	else
	    options.slant = atoi (argv[2]);
    }
    if (argc >= 4) {
	if (strcmp (argv[3], "bold") == 0)
	    options.weight = CAIRO_FONT_WEIGHT_BOLD;
	else
	    options.weight = atoi (argv[3]);
    }
    if (argc >= 5) {
	options.size = atof (argv[4]);
    }
    if (argc >= 6) {
	options.text = argv[5];
    }

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    g_signal_connect (window, "size-request",
		      G_CALLBACK (size_request), &options);
    g_signal_connect (window, "expose-event",
		      G_CALLBACK (expose_event), &options);
    g_signal_connect (window, "delete-event",
		      G_CALLBACK (gtk_main_quit), NULL);

    gtk_window_present (GTK_WINDOW (window));
    gtk_main ();

    return 0;
}