/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * MATE Power Manager Brightness Applet
 * Copyright (C) 2006 Benjamin Canou <bookeldor@gmail.com>
 * Copyright (C) 2007 Richard Hughes <richard@hughsie.com>
 * Copyright (C) 2012-2021 MATE Developers
 *
 * Licensed under the GNU General Public License Version 2
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mate-panel-applet.h>
#include <gtk/gtk.h>
#include <glib/gi18n.h>
#include <gdk/gdkkeysyms.h>
#include <glib-object.h>
#include <dbus/dbus-glib.h>

#include "gpm-common.h"

#define GPM_TYPE_BRIGHTNESS_APPLET		(gpm_brightness_applet_get_type ())
#define GPM_BRIGHTNESS_APPLET(o)		(G_TYPE_CHECK_INSTANCE_CAST ((o), GPM_TYPE_BRIGHTNESS_APPLET, GpmBrightnessApplet))
#define GPM_BRIGHTNESS_APPLET_CLASS(k)		(G_TYPE_CHECK_CLASS_CAST((k), GPM_TYPE_BRIGHTNESS_APPLET, GpmBrightnessAppletClass))
#define GPM_IS_BRIGHTNESS_APPLET(o)		(G_TYPE_CHECK_INSTANCE_TYPE ((o), GPM_TYPE_BRIGHTNESS_APPLET))
#define GPM_IS_BRIGHTNESS_APPLET_CLASS(k)	(G_TYPE_CHECK_CLASS_TYPE ((k), GPM_TYPE_BRIGHTNESS_APPLET))
#define GPM_BRIGHTNESS_APPLET_GET_CLASS(o)	(G_TYPE_INSTANCE_GET_CLASS ((o), GPM_TYPE_BRIGHTNESS_APPLET, GpmBrightnessAppletClass))

typedef struct{
	MatePanelApplet parent;
	/* applet state */
	gboolean call_worked; /* g-p-m refusing action */
	gboolean popped; /* the popup is shown */
	/* the popup and its widgets */
	GtkWidget *popup, *slider, *btn_plus, *btn_minus;
	/* the icon and a cache for size*/
	GdkPixbuf *icon;
	gint icon_width, icon_height;
	/* connection to g-p-m */
	DBusGProxy *proxy;
	DBusGConnection *connection;
	guint bus_watch_id;
	guint level;
	/* a cache for panel size */
	gint size;
	/* the slider action delaying */
	guint slider_delay_id;
} GpmBrightnessApplet;

typedef struct{
	MatePanelAppletClass	parent_class;
} GpmBrightnessAppletClass;

GType                gpm_brightness_applet_get_type  (void);


#define	GPM_DBUS_SERVICE		"org.mate.PowerManager"
#define	GPM_DBUS_PATH_BACKLIGHT		"/org/mate/PowerManager/Backlight"
#define	GPM_DBUS_INTERFACE_BACKLIGHT	"org.mate.PowerManager.Backlight"

G_DEFINE_TYPE (GpmBrightnessApplet, gpm_brightness_applet, PANEL_TYPE_APPLET)

static void      gpm_applet_get_icon              (GpmBrightnessApplet *applet);
static void      gpm_applet_check_size            (GpmBrightnessApplet *applet);
static gboolean  gpm_applet_draw_cb               (GpmBrightnessApplet *applet);
static void      gpm_applet_change_background_cb  (GpmBrightnessApplet *applet,
						   MatePanelAppletBackgroundType arg1,
						   cairo_pattern_t *arg2, gpointer data);
static void      gpm_applet_theme_change_cb (GtkIconTheme *icon_theme, gpointer data);
static void      gpm_applet_stop_scroll_events_cb (GtkWidget *widget, GdkEvent  *event);
static gboolean  gpm_applet_destroy_popup_cb      (GpmBrightnessApplet *applet);
static void      gpm_applet_update_tooltip        (GpmBrightnessApplet *applet);
static void      gpm_applet_update_popup_level    (GpmBrightnessApplet *applet);
static gboolean  gpm_applet_plus_cb               (GtkWidget *w, GpmBrightnessApplet *applet);
static gboolean  gpm_applet_minus_cb              (GtkWidget *w, GpmBrightnessApplet *applet);
static gboolean  gpm_applet_key_press_cb          (GtkWidget *popup, GdkEventKey *event, GpmBrightnessApplet *applet);
static gboolean  gpm_applet_scroll_cb             (GpmBrightnessApplet *applet, GdkEventScroll *event);
static gboolean  gpm_applet_slide_cb              (GtkWidget *w, GpmBrightnessApplet *applet);
static void      gpm_applet_create_popup          (GpmBrightnessApplet *applet);
static gboolean  gpm_applet_popup_cb              (GpmBrightnessApplet *applet, GdkEventButton *event);
static void      gpm_applet_dialog_about_cb       (GtkAction *action, gpointer data);
static gboolean  gpm_applet_cb                    (MatePanelApplet *_applet, const gchar *iid, gpointer data);
static void      gpm_applet_destroy_cb            (GtkWidget *widget);

#define GPM_BRIGHTNESS_APPLET_ID		"BrightnessApplet"
#define GPM_BRIGHTNESS_APPLET_FACTORY_ID	"BrightnessAppletFactory"
#define GPM_BRIGHTNESS_APPLET_ICON		"mate-brightness-applet"
#define GPM_BRIGHTNESS_APPLET_ICON_DISABLED	"gpm-brightness-lcd-disabled"
#define GPM_BRIGHTNESS_APPLET_ICON_INVALID	"gpm-brightness-lcd-invalid"
#define GPM_BRIGHTNESS_APPLET_NAME		_("Power Manager Brightness Applet")
#define GPM_BRIGHTNESS_APPLET_DESC		_("Adjusts laptop panel brightness.")
#define MATE_PANEL_APPLET_VERTICAL(p)					\
	 (((p) == MATE_PANEL_APPLET_ORIENT_LEFT) || ((p) == MATE_PANEL_APPLET_ORIENT_RIGHT))

/* The frequency (in milliseconds) at which update the brightness when the UI
 * slider is moved.  A too short value might lead to freezing the UI, and a
 * too long one will seem unresponsive. */
#define GPM_BRIGHTNESS_APPLET_SLIDER_FREQUENCY	100

/**
 * gpm_applet_get_brightness:
 * Return value: Success value, or zero for failure
 **/
static gboolean
gpm_applet_get_brightness (GpmBrightnessApplet *applet)
{
	GError  *error = NULL;
	gboolean ret;
	guint policy_brightness;

	if (applet->proxy == NULL) {
		g_warning ("not connected\n");
		return FALSE;
	}

	ret = dbus_g_proxy_call (applet->proxy, "GetBrightness", &error,
				 G_TYPE_INVALID,
				 G_TYPE_UINT, &policy_brightness,
				 G_TYPE_INVALID);
	if (error) {
		g_debug ("ERROR: %s\n", error->message);
		g_error_free (error);
	}
	if (ret) {
		applet->level = policy_brightness;
	} else {
		/* abort as the DBUS method failed */
		g_warning ("GetBrightness failed!\n");
	}

	return ret;
}

/**
 * gpm_applet_set_brightness:
 * Return value: Success value, or zero for failure
 **/
static gboolean
gpm_applet_set_brightness (GpmBrightnessApplet *applet)
{
	GError  *error = NULL;
	gboolean ret;

	if (applet->proxy == NULL) {
		g_warning ("not connected");
		return FALSE;
	}

	ret = dbus_g_proxy_call (applet->proxy, "SetBrightness", &error,
				 G_TYPE_UINT, applet->level,
				 G_TYPE_INVALID,
				 G_TYPE_INVALID);
	if (error) {
		g_debug ("ERROR: %s", error->message);
		g_error_free (error);
	}
	if (!ret) {
		/* abort as the DBUS method failed */
		g_warning ("SetBrightness failed!");
	}

	return ret;
}

/**
 * gpm_applet_get_icon:
 * @applet: Brightness applet instance
 *
 * retrieve an icon from stock with a size adapted to panel
 **/
static void
gpm_applet_get_icon (GpmBrightnessApplet *applet)
{
	const gchar *icon;

	/* free */
	if (applet->icon != NULL) {
		g_object_unref (applet->icon);
		applet->icon = NULL;
	}

	if (applet->size <= 2) {
		return;
	}

	/* get icon */
	if (applet->proxy == NULL) {
		icon = GPM_BRIGHTNESS_APPLET_ICON_INVALID;
	} else if (applet->call_worked == FALSE) {
		icon = GPM_BRIGHTNESS_APPLET_ICON_DISABLED;
	} else {
		icon = GPM_BRIGHTNESS_APPLET_ICON;
	}

	applet->icon = gtk_icon_theme_load_icon (gtk_icon_theme_get_default (),
						 icon, applet->size - 2, 0, NULL);

	if (applet->icon == NULL) {
		g_warning ("Cannot find %s!\n", icon);
	} else {
		g_debug ("got icon %s!\n", icon);
		/* update size cache */
		applet->icon_height = gdk_pixbuf_get_height (applet->icon);
		applet->icon_width = gdk_pixbuf_get_width (applet->icon);
	}
}

/**
 * gpm_applet_check_size:
 * @applet: Brightness applet instance
 *
 * check if panel size has changed and applet adapt size
 **/
static void
gpm_applet_check_size (GpmBrightnessApplet *applet)
{
	GtkAllocation allocation;

	/* we don't use the size function here, but the yet allocated size because the
	   size value is false (kind of rounded) */
	gtk_widget_get_allocation (GTK_WIDGET (applet), &allocation);
	if (MATE_PANEL_APPLET_VERTICAL(mate_panel_applet_get_orient (MATE_PANEL_APPLET (applet)))) {
		if (applet->size != allocation.width) {
			applet->size = allocation.width;
			gpm_applet_get_icon (applet);
			gtk_widget_set_size_request (GTK_WIDGET(applet), applet->size, applet->icon_height + 2);
		}
	} else {
		if (applet->size != allocation.height) {
			applet->size = allocation.height;
			gpm_applet_get_icon (applet);
			gtk_widget_set_size_request (GTK_WIDGET(applet), applet->icon_width + 2, applet->size);
		}
	}
}

/**
 * gpm_applet_draw_cb:
 * @applet: Brightness applet instance
 *
 * draws applet content (background + icon)
 **/
static gboolean
gpm_applet_draw_cb (GpmBrightnessApplet *applet)
{
	gint w, h, bg_type;
	GdkRGBA color;
	cairo_t *cr;
	cairo_pattern_t *pattern;
	GtkStyleContext *context;
	GtkAllocation allocation;

	if (gtk_widget_get_window (GTK_WIDGET(applet)) == NULL) {
		return FALSE;
	}

	/* retrieve applet size */
	gpm_applet_get_icon (applet);
	gpm_applet_check_size (applet);
	if (applet->size <= 2) {
		return FALSE;
	}

	/* if no icon, then don't try to display */
	if (applet->icon == NULL) {
		return FALSE;
	}

	gtk_widget_get_allocation (GTK_WIDGET (applet), &allocation);
	w = allocation.width;
	h = allocation.height;

	cr = gdk_cairo_create (gtk_widget_get_window (GTK_WIDGET(applet)));

	/* draw pixmap background */
	bg_type = mate_panel_applet_get_background (MATE_PANEL_APPLET (applet), &color, &pattern);
	if (bg_type == PANEL_PIXMAP_BACKGROUND && !applet->popped) {
		/* fill with given background pixmap */
		cairo_set_source (cr, pattern);
		cairo_rectangle (cr, 0, 0, w, h);
		cairo_fill (cr);
	}

	/* draw color background */
	if (bg_type == PANEL_COLOR_BACKGROUND && !applet->popped) {
		gdk_cairo_set_source_rgba (cr, &color);
		cairo_rectangle (cr, 0, 0, w, h);
		cairo_fill (cr);
	}

	/* fill with selected color if popped */
	if (applet->popped) {
		context = gtk_widget_get_style_context (GTK_WIDGET(applet));
		gtk_style_context_get_color (context, GTK_STATE_FLAG_SELECTED, &color);
		gdk_cairo_set_source_rgba (cr, &color);
		cairo_rectangle (cr, 0, 0, w, h);
		cairo_fill (cr);
	}

	/* draw icon at center */
	gdk_cairo_set_source_pixbuf (cr, applet->icon, (w - applet->icon_width)/2, (h - applet->icon_height)/2);
	cairo_paint (cr);

	cairo_destroy (cr);

	return TRUE;
}

/**
 * gpm_applet_change_background_cb:
 *
 * Enqueues an expose event (don't know why it's not the default behaviour)
 **/
static void
gpm_applet_change_background_cb (GpmBrightnessApplet *applet,
				 MatePanelAppletBackgroundType arg1,
				 cairo_pattern_t *arg2, gpointer data)
{
	gtk_widget_queue_draw (GTK_WIDGET (applet));
}

/**
 * gpm_applet_destroy_popup_cb:
 * @applet: Brightness applet instance
 *
 * destroys the popup (called if orientation has changed)
 **/
static gboolean
gpm_applet_destroy_popup_cb (GpmBrightnessApplet *applet)
{
	if (applet->popup != NULL) {
		gtk_widget_destroy (applet->popup);
		applet->popup = NULL;
		applet->popped = FALSE;
		gpm_applet_update_tooltip (applet);
	}
	return TRUE;
}

/**
 * gpm_applet_update_tooltip:
 * @applet: Brightness applet instance
 *
 * sets tooltip's content (percentage or disabled)
 **/
static void
gpm_applet_update_tooltip (GpmBrightnessApplet *applet)
{
	gchar *buf = NULL;
	if (applet->popped == FALSE) {
		if (applet->proxy == NULL) {
			buf = g_strdup (_("Cannot connect to mate-power-manager"));
		} else if (applet->call_worked == FALSE) {
			buf = g_strdup (_("Cannot get laptop panel brightness"));
		} else {
			buf = g_strdup_printf (_("LCD brightness : %d%%"), applet->level);
		}
		gtk_widget_set_tooltip_text (GTK_WIDGET(applet), buf);
	} else {
		gtk_widget_set_tooltip_text (GTK_WIDGET(applet), NULL);
	}
	g_free (buf);
}

/**
 * gpm_applet_update_popup_level:
 * @applet: Brightness applet instance
 * @get_hw: set UI value from HW value
 * @set_hw: set HW value from UI value
 *
 * updates popup and hardware level of brightness
 * FALSE FAlSE -> set UI from cached value
 * TRUE  FAlSE -> set UI from HW value
 * TRUE  FALSE -> set HW from UI value, then set UI from HW value
 * FALSE TRUE  -> set HW from UI value
 **/
static void
gpm_applet_update_popup_level (GpmBrightnessApplet *applet)
{
	if (applet->popup != NULL) {
		gtk_widget_set_sensitive (applet->btn_plus, applet->level < 100);
		gtk_widget_set_sensitive (applet->btn_minus, applet->level > 0);
		gtk_range_set_value (GTK_RANGE(applet->slider), (guint) applet->level);
	}
	gpm_applet_update_tooltip (applet);
}

/**
 * gpm_applet_plus_cb:
 * @widget: The sending widget (plus button)
 * @applet: Brightness applet instance
 *
 * callback for the plus button
 **/
static gboolean
gpm_applet_plus_cb (GtkWidget *w, GpmBrightnessApplet *applet)
{
	if (applet->level < 100) {
		applet->level++;
	}
	applet->call_worked = gpm_applet_set_brightness (applet);
	gpm_applet_update_popup_level (applet);
	return TRUE;
}

/**
 * gpm_applet_minus_cb:
 * @widget: The sending widget (minus button)
 * @applet: Brightness applet instance
 *
 * callback for the minus button
 **/
static gboolean
gpm_applet_minus_cb (GtkWidget *w, GpmBrightnessApplet *applet)
{
	if (applet->level > 0) {
		applet->level--;
	}
	applet->call_worked = gpm_applet_set_brightness (applet);
	gpm_applet_update_popup_level (applet);
	return TRUE;
}

/**
 * gpm_applet_slide_delayed_cb:
 * @data: Brightness applet instance
 *
 * callback for the delayed slider changes, actually performing the DBus call
 **/
static gboolean
gpm_applet_slide_delayed_cb (gpointer data)
{
	GpmBrightnessApplet *applet = data;

	applet->call_worked = gpm_applet_set_brightness (applet);
	gpm_applet_update_popup_level (applet);
	applet->slider_delay_id = 0;

	return FALSE;
}

/**
 * gpm_applet_slide_cb:
 * @widget: The sending widget (slider)
 * @applet: Brightness applet instance
 *
 * callback for the slider
 **/
static gboolean
gpm_applet_slide_cb (GtkWidget *w, GpmBrightnessApplet *applet)
{
	applet->level = gtk_range_get_value (GTK_RANGE(applet->slider));
	/* we delay applying the new value to improve reactivity, because the
	 * DBus call might be slow (and we don't want to spam the bus either) */
	if (! applet->slider_delay_id)
		applet->slider_delay_id = g_timeout_add (GPM_BRIGHTNESS_APPLET_SLIDER_FREQUENCY,
							 gpm_applet_slide_delayed_cb, applet);
	return TRUE;
}

/**
 * gpm_applet_slide_cb:
 * @applet: Brightness applet instance
 * @event: The key press event
 *
 * callback handling keyboard
 * mainly escape to unpop and arrows to change brightness
 **/
static gboolean
gpm_applet_key_press_cb (GtkWidget *popup, GdkEventKey *event, GpmBrightnessApplet *applet)
{
	int i;

	switch (event->keyval) {
	case GDK_KEY_KP_Enter:
	case GDK_KEY_ISO_Enter:
	case GDK_KEY_3270_Enter:
	case GDK_KEY_Return:
	case GDK_KEY_space:
	case GDK_KEY_KP_Space:
	case GDK_KEY_Escape:
		/* if yet popped, hide */
		if (applet->popped) {
			gtk_widget_hide (applet->popup);
			applet->popped = FALSE;
			gpm_applet_update_tooltip (applet);
			return TRUE;
		} else {
			return FALSE;
		}
		break;
	case GDK_KEY_Page_Up:
		for (i = 0;i < 10;i++) {
			gpm_applet_plus_cb (NULL, applet);
		}
		return TRUE;
		break;
	case GDK_KEY_Left:
	case GDK_KEY_Up:
		gpm_applet_plus_cb (NULL, applet);
		return TRUE;
		break;
	case GDK_KEY_Page_Down:
		for (i = 0;i < 10;i++) {
			gpm_applet_minus_cb (NULL, applet);
		}
		return TRUE;
		break;
	case GDK_KEY_Right:
	case GDK_KEY_Down:
		gpm_applet_minus_cb (NULL, applet);
		return TRUE;
		break;
	default:
		return FALSE;
		break;
	}

	return FALSE;
}

/**
 * gpm_applet_scroll_cb:
 * @applet: Brightness applet instance
 * @event: The scroll event
 *
 * callback handling mouse scrolls, either when the applet
 * is not popped and the mouse is over the applet, or when
 * the applet is popped and no matter where the mouse is.
 **/
static gboolean
gpm_applet_scroll_cb (GpmBrightnessApplet *applet, GdkEventScroll *event)
{
	int i;

	if (event->type == GDK_SCROLL) {
		if (event->direction == GDK_SCROLL_UP) {
			for (i = 0;i < 5;i++) {
				gpm_applet_plus_cb (NULL, applet);
			}

		} else {
			for (i = 0;i < 5;i++) {
				gpm_applet_minus_cb (NULL, applet);
			}
		}
		return TRUE;
	}

	return FALSE;
}

/**
 * on_popup_button_press:
 * @applet: Brightness applet instance
 * @event: The button press event
 *
 * hide popup on focus loss.
 **/
static gboolean
on_popup_button_press (GtkWidget      *widget,
                       GdkEventButton *event,
                       GpmBrightnessApplet *applet)
{
	GtkWidget *event_widget;

	if (event->type != GDK_BUTTON_PRESS) {
		return FALSE;
	}
	event_widget = gtk_get_event_widget ((GdkEvent *)event);
	g_debug ("Button press: %p dock=%p", event_widget, widget);
	if (event_widget == widget) {
		gtk_widget_hide (applet->popup);
		applet->popped = FALSE;
		gpm_applet_update_tooltip (applet);
		return TRUE;
	}

	return FALSE;
}

/**
 * gpm_applet_create_popup:
 * @applet: Brightness applet instance
 *
 * cretes a new popup according to orientation of panel
 **/
static void
gpm_applet_create_popup (GpmBrightnessApplet *applet)
{
	static GtkWidget *box, *frame;
	gint orientation = mate_panel_applet_get_orient (MATE_PANEL_APPLET (MATE_PANEL_APPLET (applet)));

	gpm_applet_destroy_popup_cb (applet);

	/* slider */
	if (MATE_PANEL_APPLET_VERTICAL(orientation)) {
		applet->slider = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
		gtk_widget_set_size_request (applet->slider, 100, -1);
	} else {
		applet->slider = gtk_scale_new_with_range (GTK_ORIENTATION_VERTICAL, 0, 100, 1);
		gtk_widget_set_size_request (applet->slider, -1, 100);
	}
	gtk_range_set_inverted (GTK_RANGE(applet->slider), TRUE);
	gtk_scale_set_draw_value (GTK_SCALE(applet->slider), FALSE);
	gtk_range_set_value (GTK_RANGE(applet->slider), applet->level);
	g_signal_connect (G_OBJECT(applet->slider), "value-changed", G_CALLBACK(gpm_applet_slide_cb), applet);

	/* minus button */
	applet->btn_minus = gtk_button_new_with_label ("\342\210\222"); /* U+2212 MINUS SIGN */
	gtk_button_set_relief (GTK_BUTTON(applet->btn_minus), GTK_RELIEF_NONE);
	gtk_widget_set_can_focus (applet->btn_minus, FALSE);
	g_signal_connect (G_OBJECT(applet->btn_minus), "pressed", G_CALLBACK(gpm_applet_minus_cb), applet);

	/* plus button */
	applet->btn_plus = gtk_button_new_with_label ("+");
	gtk_button_set_relief (GTK_BUTTON(applet->btn_plus), GTK_RELIEF_NONE);
	gtk_widget_set_can_focus (applet->btn_plus, FALSE);
	g_signal_connect (G_OBJECT(applet->btn_plus), "pressed", G_CALLBACK(gpm_applet_plus_cb), applet);

	/* box */
	if (MATE_PANEL_APPLET_VERTICAL(orientation)) {
		box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 1);
	} else {
		box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 1);
	}
	gtk_box_pack_start (GTK_BOX(box), applet->btn_plus, FALSE, FALSE, 0);
	gtk_box_pack_start (GTK_BOX(box), applet->slider, TRUE, TRUE, 0);
	gtk_box_pack_start (GTK_BOX(box), applet->btn_minus, FALSE, FALSE, 0);

	/* frame */
	frame = gtk_frame_new (NULL);
	gtk_frame_set_shadow_type (GTK_FRAME(frame), GTK_SHADOW_OUT);
	gtk_container_add (GTK_CONTAINER(frame), box);

	/* window */
	applet->popup = gtk_window_new (GTK_WINDOW_POPUP);
	gtk_window_set_type_hint (GTK_WINDOW(applet->popup), GDK_WINDOW_TYPE_HINT_UTILITY);
	gtk_container_add (GTK_CONTAINER(applet->popup), frame);

	/* window events */
	g_signal_connect (G_OBJECT(applet->popup), "button-press-event",
	                  G_CALLBACK (on_popup_button_press), applet);

	g_signal_connect (G_OBJECT(applet->popup), "key-press-event",
	                  G_CALLBACK(gpm_applet_key_press_cb), applet);

	/* Set volume control frame, slider and toplevel window to follow panel volume control theme */
	GtkWidget *toplevel = gtk_widget_get_toplevel (frame);
	GtkStyleContext *context;
	context = gtk_widget_get_style_context (GTK_WIDGET(toplevel));
	gtk_style_context_add_class(context,"mate-panel-applet-slider");
	/*Make transparency possible in gtk3 theme3 */
 	GdkScreen *screen = gtk_widget_get_screen(GTK_WIDGET(toplevel));
	GdkVisual *visual = gdk_screen_get_rgba_visual(screen);
	gtk_widget_set_visual(GTK_WIDGET(toplevel), visual);
}

/**
 * gpm_applet_popup_cb:
 * @applet: Brightness applet instance
 *
 * pops and unpops
 **/
static gboolean
gpm_applet_popup_cb (GpmBrightnessApplet *applet, GdkEventButton *event)
{
	GtkAllocation allocation, popup_allocation;
	gint orientation, x, y;
	GdkWindow *window;
	GdkDisplay *display;
	GdkSeat *seat;

	/* react only to left mouse button */
	if (event->button != 1) {
		return FALSE;
	}

	/* if yet popped, release focus and hide */
	if (applet->popped) {
		gtk_widget_hide (applet->popup);
		applet->popped = FALSE;
		gpm_applet_update_tooltip (applet);
		return TRUE;
	}

	/* don't show the popup if brightness is unavailable */
	if (applet->level == -1) {
		return FALSE;
	}

	/* otherwise pop */
	applet->popped = TRUE;

	/* create a new popup (initial or if panel parameters changed) */
	if (applet->popup == NULL) {
		gpm_applet_create_popup (applet);
	}

	/* update UI for current brightness */
	gpm_applet_update_popup_level (applet);

	gtk_widget_show_all (applet->popup);

	/* retrieve geometry parameters and move window appropriately */
	orientation = mate_panel_applet_get_orient (MATE_PANEL_APPLET (MATE_PANEL_APPLET (applet)));
	gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET(applet)), &x, &y);

	gtk_widget_get_allocation (GTK_WIDGET (applet), &allocation);
	gtk_widget_get_allocation (GTK_WIDGET (applet->popup), &popup_allocation);
	switch (orientation) {
	case MATE_PANEL_APPLET_ORIENT_DOWN:
		x += allocation.x + allocation.width/2;
		y += allocation.y + allocation.height;
		x -= popup_allocation.width/2;
		break;
	case MATE_PANEL_APPLET_ORIENT_UP:
		x += allocation.x + allocation.width/2;
		y += allocation.y;
		x -= popup_allocation.width/2;
		y -= popup_allocation.height;
		break;
	case MATE_PANEL_APPLET_ORIENT_RIGHT:
		y += allocation.y + allocation.height/2;
		x += allocation.x + allocation.width;
		y -= popup_allocation.height/2;
		break;
	case MATE_PANEL_APPLET_ORIENT_LEFT:
		y += allocation.y + allocation.height/2;
		x += allocation.x;
		x -= popup_allocation.width;
		y -= popup_allocation.height/2;
		break;
	default:
		g_assert_not_reached ();
	}

	gtk_window_move (GTK_WINDOW (applet->popup), x, y);

	/* grab input */
	window = gtk_widget_get_window (GTK_WIDGET (applet->popup));
	display = gdk_window_get_display (window);
	seat = gdk_display_get_default_seat (display);
	gdk_seat_grab (seat,
	               window,
	               GDK_SEAT_CAPABILITY_ALL,
	               TRUE,
	               NULL,
	               NULL,
	               NULL,
	               NULL);

	return TRUE;
}

/**
 * gpm_applet_theme_change_cb:
 *
 * Updtes icon when theme changes
 **/
static void
gpm_applet_theme_change_cb (GtkIconTheme *icon_theme, gpointer data)
{
	GpmBrightnessApplet *applet = GPM_BRIGHTNESS_APPLET (data);
	gpm_applet_get_icon (applet);
}

/**
 * gpm_applet_stop_scroll_events_cb:
 *
 * Prevents scroll events from reaching the tooltip
 **/
static void
gpm_applet_stop_scroll_events_cb (GtkWidget *widget, GdkEvent  *event)
{
	if (event->type == GDK_SCROLL)
		g_signal_stop_emission_by_name (widget, "event-after");
}

/**
 * gpm_applet_dialog_about_cb:
 *
 * displays about dialog
 **/
static void
gpm_applet_dialog_about_cb (GtkAction *action, gpointer data)
{
	static const gchar *authors[] = {
		"Benjamin Canou <bookeldor@gmail.com>",
		"Richard Hughes <richard@hughsie.com>",
		NULL
	};

	const char *documenters [] = {
		NULL
	};

	const char *license[] = {
		 N_("Power Manager 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 2 "
		   "of the License, or (at your option) any later version."),

		 N_("Power Manager 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."),

		 N_("You should have received a copy of the GNU General Public License "
		   "along with this program; if not, write to the Free Software "
		   "Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA "
		   "02110-1301, USA.")
	};

	char *license_trans;

	license_trans = g_strjoin("\n\n", _(license[0]), _(license[1]), _(license[2]), NULL);

	gtk_show_about_dialog (NULL,
	                       "program-name", GPM_BRIGHTNESS_APPLET_NAME,
	                       "version", VERSION,
	                       "title", _("About Power Manager Brightness Applet"),
	                       "comments", GPM_BRIGHTNESS_APPLET_DESC,
	                       "copyright", _("Copyright \xC2\xA9 2006 Benjamin Canou\n"
	                                      "Copyright \xC2\xA9 2011-2021 MATE developers"),
	                       "icon-name", GPM_BRIGHTNESS_APPLET_ICON,
	                       "logo-icon-name", GPM_BRIGHTNESS_APPLET_ICON,
	                       "license", license_trans,
	                       "authors", authors,
	                       "documenters", documenters,
	                       "translator-credits", _("translator-credits"),
	                       "wrap-license", TRUE,
	                       "website", PACKAGE_URL,
	                       NULL);

	g_free (license_trans);
}

/**
 * gpm_applet_help_cb:
 *
 * open gpm help
 **/
static void
gpm_applet_help_cb (GtkAction *action, gpointer data)
{
	gpm_help_display ("applets-general#applets-brightness");
}

/**
 * gpm_applet_destroy_cb:
 * @widget: Class instance to destroy
 **/
static void
gpm_applet_destroy_cb (GtkWidget *widget)
{
	GpmBrightnessApplet *applet = GPM_BRIGHTNESS_APPLET(widget);

	if (applet->slider_delay_id) {
		g_source_remove (applet->slider_delay_id);
		applet->slider_delay_id = 0;
	}

	g_bus_unwatch_name (applet->bus_watch_id);
	if (applet->icon != NULL)
		g_object_unref (applet->icon);
}

/**
 * gpm_brightness_applet_class_init:
 * @klass: Class instance
 **/
static void
gpm_brightness_applet_class_init (GpmBrightnessAppletClass *class)
{
	/* nothing to do here */
}

static void
brightness_changed_cb (DBusGProxy          *proxy,
		       guint	            brightness,
		       GpmBrightnessApplet *applet)
{
	g_debug ("BrightnessChanged detected: %i\n", brightness);
	applet->level = brightness;
}

/**
 * gpm_brightness_applet_dbus_connect:
 **/
gboolean
gpm_brightness_applet_dbus_connect (GpmBrightnessApplet *applet)
{
	GError *error = NULL;

	if (applet->connection == NULL) {
		g_debug ("get connection\n");
		g_clear_error (&error);
		applet->connection = dbus_g_bus_get (DBUS_BUS_SESSION, &error);
		if (error != NULL) {
			g_warning ("Could not connect to DBUS daemon: %s", error->message);
			g_error_free (error);
			applet->connection = NULL;
			return FALSE;
		}
	}
	if (applet->proxy == NULL) {
		g_debug ("get proxy\n");
		g_clear_error (&error);
		applet->proxy = dbus_g_proxy_new_for_name_owner (applet->connection,
							 GPM_DBUS_SERVICE,
							 GPM_DBUS_PATH_BACKLIGHT,
							 GPM_DBUS_INTERFACE_BACKLIGHT,
							 &error);
		if (error != NULL) {
			g_warning ("Cannot connect, maybe the daemon is not running: %s\n", error->message);
			g_error_free (error);
			applet->proxy = NULL;
			return FALSE;
		}
		dbus_g_proxy_add_signal (applet->proxy, "BrightnessChanged",
					 G_TYPE_UINT, G_TYPE_INVALID);
		dbus_g_proxy_connect_signal (applet->proxy, "BrightnessChanged",
					     G_CALLBACK (brightness_changed_cb),
					     applet, NULL);
		/* reset, we might be starting race */
		applet->call_worked = gpm_applet_get_brightness (applet);
	}
	return TRUE;
}

/**
 * gpm_brightness_applet_dbus_disconnect:
 **/
gboolean
gpm_brightness_applet_dbus_disconnect (GpmBrightnessApplet *applet)
{
	if (applet->proxy != NULL) {
		g_debug ("removing proxy\n");
		g_object_unref (applet->proxy);
		applet->proxy = NULL;
	}
	return TRUE;
}

/**
 * gpm_brightness_applet_name_appeared_cb:
 **/
static void
gpm_brightness_applet_name_appeared_cb (GDBusConnection *connection,
					const gchar *name,
					const gchar *name_owner,
					GpmBrightnessApplet *applet)
{
	gpm_brightness_applet_dbus_connect (applet);
	gpm_applet_update_tooltip (applet);
	gpm_applet_draw_cb (applet);
}

/**
 * gpm_brightness_applet_name_vanished_cb:
 **/
void
gpm_brightness_applet_name_vanished_cb (GDBusConnection *connection,
					 const gchar *name,
					 GpmBrightnessApplet *applet)
{
	gpm_brightness_applet_dbus_disconnect (applet);
	gpm_applet_update_tooltip (applet);
	gpm_applet_draw_cb (applet);
}

/**
 * gpm_brightness_applet_init:
 * @applet: Brightness applet instance
 **/
static void
gpm_brightness_applet_init (GpmBrightnessApplet *applet)
{
	/* initialize fields */
	applet->size = 0;
	applet->call_worked = TRUE;
	applet->popped = FALSE;
	applet->popup = NULL;
	applet->icon = NULL;
	applet->connection = NULL;
	applet->proxy = NULL;
	applet->slider_delay_id = 0;

	/* Add application specific icons to search path */
	gtk_icon_theme_append_search_path (gtk_icon_theme_get_default (),
	                                   GPM_ICONS_DATA);

	/* monitor the daemon */
	applet->bus_watch_id =
		g_bus_watch_name (G_BUS_TYPE_SESSION,
				  GPM_DBUS_SERVICE,
				  G_BUS_NAME_WATCHER_FLAGS_NONE,
				  (GBusNameAppearedCallback) gpm_brightness_applet_name_appeared_cb,
				  (GBusNameVanishedCallback) gpm_brightness_applet_name_vanished_cb,
				  applet, NULL);

	/* coldplug */
	applet->call_worked = gpm_applet_get_brightness (applet);
	gpm_applet_update_popup_level (applet);

	/* prepare */
	mate_panel_applet_set_flags (MATE_PANEL_APPLET (applet), MATE_PANEL_APPLET_EXPAND_MINOR);
	gtk_widget_set_events (GTK_WIDGET (applet), GDK_SCROLL_MASK);

	/* show */
	gtk_widget_show_all (GTK_WIDGET(applet));

	/* set appropriate size and load icon accordingly */
	gpm_applet_draw_cb (applet);

	/* connect */
	g_signal_connect (G_OBJECT(applet), "button-press-event",
			  G_CALLBACK(gpm_applet_popup_cb), NULL);

	g_signal_connect (G_OBJECT(applet), "scroll-event",
			  G_CALLBACK(gpm_applet_scroll_cb), NULL);

	/* We use g_signal_connect_after because letting the panel draw
	 * the background is the only way to have the correct
	 * background when a theme defines a background picture. */
	g_signal_connect_after (G_OBJECT(applet), "draw",
				G_CALLBACK(gpm_applet_draw_cb), NULL);

	g_signal_connect (G_OBJECT(applet), "change-background",
			  G_CALLBACK(gpm_applet_change_background_cb), NULL);

	g_signal_connect (G_OBJECT(applet), "change-orient",
			  G_CALLBACK(gpm_applet_draw_cb), NULL);

	g_signal_connect (G_OBJECT(applet), "change-orient",
			  G_CALLBACK(gpm_applet_destroy_popup_cb), NULL);

	g_signal_connect (G_OBJECT(applet), "destroy",
			  G_CALLBACK(gpm_applet_destroy_cb), NULL);

	/* prevent scroll events from reaching the tooltip */
	g_signal_connect (G_OBJECT (applet), "event-after", G_CALLBACK (gpm_applet_stop_scroll_events_cb), NULL);

	g_signal_connect (gtk_icon_theme_get_default (), "changed", G_CALLBACK (gpm_applet_theme_change_cb), applet);
}

/**
 * gpm_applet_cb:
 * @_applet: GpmBrightnessApplet instance created by the applet factory
 * @iid: Applet id
 *
 * the function called by libmate-panel-applet factory after creation
 **/
static gboolean
gpm_applet_cb (MatePanelApplet *_applet, const gchar *iid, gpointer data)
{
	GpmBrightnessApplet *applet = GPM_BRIGHTNESS_APPLET(_applet);
	GtkActionGroup *action_group;

	static const GtkActionEntry menu_actions [] = {
		{ "About", "help-about", N_("_About"),
		  NULL, NULL,
		  G_CALLBACK (gpm_applet_dialog_about_cb) },
		{ "Help", "help-browser", N_("_Help"),
		  NULL, NULL,
		  G_CALLBACK (gpm_applet_help_cb) }
	};

	if (strcmp (iid, GPM_BRIGHTNESS_APPLET_ID) != 0) {
		return FALSE;
	}

	action_group = gtk_action_group_new ("Brightness Applet Actions");
	gtk_action_group_set_translation_domain (action_group, GETTEXT_PACKAGE);
	gtk_action_group_add_actions (action_group,
				      menu_actions,
				      G_N_ELEMENTS (menu_actions),
				      applet);
	mate_panel_applet_setup_menu_from_file (MATE_PANEL_APPLET (applet),
	                                        BRIGHTNESS_MENU_UI_DIR "/brightness-applet-menu.xml",
	                                        action_group);
	g_object_unref (action_group);

	gpm_applet_draw_cb (applet);
	return TRUE;
}

/**
 * this generates a main with a applet factory
 **/
MATE_PANEL_APPLET_OUT_PROCESS_FACTORY
 (/* the factory iid */
 GPM_BRIGHTNESS_APPLET_FACTORY_ID,
 /* generates brighness applets instead of regular mate applets  */
 GPM_TYPE_BRIGHTNESS_APPLET,
 /* the applet name */
 "BrightnessApplet",
 /* our callback (with no user data) */
 gpm_applet_cb, NULL);
