lightdm-webkit2-greeter/src/lightdm-webkit2-greeter.c

/*
 * lightdm-webkit2-greeter.c
 *
 * Copyright © 2014-2015 Antergos Developers <dev@antergos.com>
 *
 * Based on code from lightdm-webkit-greeter:
 * Copyright © 2010-2015 Robert Ancell <robert.ancell@canonical.com>
 *
 * This file is part of lightdm-webkit2-greeter.
 *
 * lightdm-webkit2-greeter is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * lightdm-webkit2-greeter is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * The following additional terms are in effect as per Section 7 of the license:
 *
 * The preservation of all legal notices and author attributions in
 * the material or in the Appropriate Legal Notices displayed
 * by works containing it is required.
 *
 * You should have received a copy of the GNU General Public License
 * along with lightdm-webkit2-greeter; If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <stdlib.h>
#include <gtk/gtk.h>
#include <gdk/gdkx.h>
#include <glib.h>
#include <glib-unix.h>
#include <gtk/gtkx.h>
#include <webkit2/webkit2.h>
#include <JavaScriptCore/JavaScript.h>
#include <glib/gi18n.h>

#include <lightdm.h>

#include <config.h>

#include "src/lightdm-webkit2-greeter-css-application.h"

static GtkWidget      *web_view;
static GtkWidget      *window;
static WebKitSettings *webkit_settings;
static GdkDisplay     *default_display;

/* Screensaver values */
static int  timeout, interval, prefer_blanking, allow_exposures;
static gint config_timeout;


static GdkFilterReturn
wm_window_filter(GdkXEvent *gxevent, GdkEvent *event, gpointer data) {

	XEvent *xevent = (XEvent *) gxevent;
	if (xevent->type == MapNotify) {
		GdkDisplay        *display = gdk_x11_lookup_xdisplay(xevent->xmap.display);
		GdkWindow         *win     = gdk_x11_window_foreign_new_for_display(display, xevent->xmap.window);
		GdkWindowTypeHint win_type = gdk_window_get_type_hint(win);

		if (win_type != GDK_WINDOW_TYPE_HINT_COMBO
			&& win_type != GDK_WINDOW_TYPE_HINT_TOOLTIP
			&& win_type != GDK_WINDOW_TYPE_HINT_NOTIFICATION) {

			gdk_window_focus(win, GDK_CURRENT_TIME);
		}

	} else if (xevent->type == UnmapNotify) {
		Window xwin;
		int    revert_to = RevertToNone;

		XGetInputFocus(xevent->xunmap.display, &xwin, &revert_to);
		if (revert_to == RevertToNone) {
			gdk_window_lower(gtk_widget_get_window(gtk_widget_get_toplevel(GTK_WIDGET(window))));
		}
	}

	return GDK_FILTER_CONTINUE;
}


static void
initialize_web_extensions_cb(WebKitWebContext *context, gpointer user_data) {

	webkit_web_context_set_web_extensions_directory(context, LIGHTDM_WEBKIT2_GREETER_EXTENSIONS_DIR);

}


static void
create_new_webkit_settings_object(void) {
	webkit_settings = webkit_settings_new_with_settings(
		"enable-developer-extras", FALSE,
		"enable-fullscreen", TRUE,
		"enable-site-specific-quirks", TRUE,
		"enable-dns-prefetching", TRUE,
		"javascript-can-open-windows-automatically", TRUE,
		"allow-file-access-from-file-urls", TRUE,
		"enable-accelerated-2d-canvas", FALSE,
		"enable-smooth-scrolling", FALSE,
		"enable-webgl", FALSE,
		"enable-write-console-messages-to-stdout", TRUE,
		NULL
	);
}


static gboolean
context_menu_cb(WebKitWebView *view,
				WebKitContextMenu *context_menu,
				GdkEvent *event,
				WebKitHitTestResult *hit_test_result,
				gpointer user_data) {
	return TRUE;
}


static void
greeter_bridge_lock_hint_cb(void) {
	// Make the greeter behave a bit more like a screensaver if used as un/lock-screen by blanking the screen.
	Display *display = gdk_x11_display_get_xdisplay(default_display);
	XGetScreenSaver(display, &timeout, &interval, &prefer_blanking, &allow_exposures);
	XForceScreenSaver(display, ScreenSaverActive);
	XSetScreenSaver(display,
					config_timeout,
					0,
					ScreenSaverActive,
					DefaultExposures);
}


static void
message_received_cb(WebKitUserContentManager *manager,
					WebKitJavascriptResult *message,
					gpointer user_data) {

	/* TODO:
	 * Abstract this by using JSON for exchanging messages so the handler can be used for more than one task/event.
	 */
	greeter_bridge_lock_hint_cb();

}


static gboolean
fade_timer_cb(gpointer data) {
	gdouble opacity;

	opacity = gtk_widget_get_opacity(web_view);
	opacity -= 0.1;
	if (opacity <= 0) {
		gtk_main_quit();
		return FALSE;
	}
	gtk_widget_set_opacity(web_view, opacity);

	return TRUE;
}


static void
quit_cb(void) {
	// Fade out the greeter
	g_timeout_add(40, (GSourceFunc) fade_timer_cb, NULL);

}


int
main(int argc, char **argv) {
	GdkScreen                *screen;
	GdkWindow                *root_window;
	GdkRectangle             geometry;
	GKeyFile                 *keyfile;
	gchar                    *theme;
	GdkRGBA                  bg_color;
	WebKitUserContentManager *manager;
	WebKitWebContext         *context;
	GtkCssProvider           *css_provider;

	g_unix_signal_add(SIGTERM, (GSourceFunc) quit_cb, /* is_callback */ GINT_TO_POINTER(TRUE));

	gtk_init(&argc, &argv);

	// Apply greeter settings from conf file
	keyfile = g_key_file_new();
	g_key_file_load_from_file(keyfile, "/etc/lightdm/lightdm-webkit2-greeter.conf", G_KEY_FILE_NONE, NULL);
	theme          = g_key_file_get_string(keyfile, "greeter", "webkit-theme", NULL);
	config_timeout = g_key_file_get_integer(keyfile, "greeter", "screensaver-timeout", NULL);

	// Setup the main window
	window          = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	screen          = gtk_window_get_screen(GTK_WINDOW(window));
	root_window     = gdk_get_default_root_window();
	default_display = gdk_display_get_default();

	gtk_window_set_decorated(GTK_WINDOW(window), FALSE);
	gdk_screen_get_monitor_geometry(screen, gdk_screen_get_primary_monitor(screen), &geometry);
	gtk_window_set_default_size(GTK_WINDOW(window), geometry.width, geometry.height);
	gtk_window_move(GTK_WINDOW(window), geometry.x, geometry.y);
	gdk_window_set_cursor(root_window, gdk_cursor_new_for_display(default_display, GDK_LEFT_PTR));

	// There is no window manager, so we need to implement some of its functionality
	gdk_window_set_events(root_window, gdk_window_get_events(root_window) | GDK_SUBSTRUCTURE_MASK);
	gdk_window_add_filter(root_window, wm_window_filter, NULL);

	// Setup CSS provider
	css_provider = gtk_css_provider_new();
	gtk_css_provider_load_from_data(css_provider,
									lightdm_webkit2_greeter_css_application,
									lightdm_webkit2_greeter_css_application_length, NULL);
	gtk_style_context_add_provider_for_screen(screen,
											  GTK_STYLE_PROVIDER(css_provider),
											  GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);

	// Register and connect handler for setting the web extensions directory so webkit can find our extension
	context = webkit_web_context_get_default();
	g_signal_connect(context, "initialize-web-extensions", G_CALLBACK(initialize_web_extensions_cb), NULL);

	// Register and connect handler for messages sent from our web extension
	manager = webkit_user_content_manager_new();
	webkit_user_content_manager_register_script_message_handler(manager, "GreeterBridge");
	g_signal_connect(manager, "script-message-received::GreeterBridge", G_CALLBACK(message_received_cb), NULL);

	// Create the web_view
	web_view = webkit_web_view_new_with_user_content_manager(manager);

	// Set the web_view's settings.
	create_new_webkit_settings_object();
	webkit_web_view_set_settings(WEBKIT_WEB_VIEW(web_view), webkit_settings);

	// The default background is white which causes a flash effect when the greeter starts. Make it black instead.
	gdk_rgba_parse(&bg_color, "#000000");
	webkit_web_view_set_background_color(WEBKIT_WEB_VIEW(web_view), gdk_rgba_copy(&bg_color));

	// Disable the context (right-click) menu.
	g_signal_connect(web_view, "context-menu", G_CALLBACK(context_menu_cb), NULL);

	gtk_container_add(GTK_CONTAINER(window), web_view);
	webkit_web_view_load_uri(WEBKIT_WEB_VIEW(web_view), g_strdup_printf("file://%s/%s/index.html", THEME_DIR, theme));
	gtk_widget_show_all(window);


	gtk_main();

	return 0;
}