main.c

#include <gtk/gtk.h>
#include "main.h"

GtkWidget *window, *grid, *drawing_area, *spn_percent, *chk_critical, *chk_charging;

gboolean toggle_callback (GtkWidget *widget, gpointer data)
{
	(void)(data);
	(void)(widget);

	gtk_widget_queue_draw(drawing_area);
	return FALSE;
}

gboolean update_spinner (GtkWidget *widget, gpointer data)
{
	(void)(data);
	(void)(widget);

	gtk_widget_queue_draw(drawing_area);
	return FALSE;
}

gboolean battery_get_critical()
{
	return gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(chk_critical));
}

gboolean battery_get_charging()
{
	return gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(chk_charging));
}

gdouble battery_get_percent()
{
	return gtk_spin_button_get_value_as_int(GTK_SPIN_BUTTON(spn_percent)) / 100.0;
}

gboolean draw_callback (GtkWidget *widget, cairo_t *cr, gpointer data)
{
	(void)(data);
	guint width, height;
	cairo_pattern_t *color;

	// Grab our widget size
	width = gtk_widget_get_allocated_width(widget);
	height = gtk_widget_get_allocated_height(widget);

	// Decide on a color
	color = cairo_pattern_create_rgb(COLOR_DEFAULT);
	if (battery_get_charging())
		color = cairo_pattern_create_rgb(COLOR_CHARGING);
	if (battery_get_critical())
		color = cairo_pattern_create_rgb(COLOR_CRITICAL);

	// Draw the main border of the battery
	cairo_rectangle(cr, CENTERED(width, BATTERY_WIDTH),
	                    CENTERED(height, BATTERY_HEIGHT),
	                    BATTERY_WIDTH,
	                    BATTERY_HEIGHT);

	cairo_set_source(cr, color);
	cairo_set_line_width(cr, STROKE_WIDTH);
	cairo_stroke(cr);

	// Draw the peg on the positive end of the battery
	cairo_rectangle(cr, CENTERED(width, BATTERY_WIDTH) + BATTERY_WIDTH + (STROKE_WIDTH / 2),
	                    CENTERED(height, PEG_HEIGHT),
	                    PEG_WIDTH,
	                    PEG_HEIGHT);

	cairo_fill(cr);

	// Draw the delicious cream filling
	cairo_rectangle(cr, CENTERED(width, BATTERY_WIDTH),
	                    CENTERED(height, BATTERY_HEIGHT),
	                    (int)(BATTERY_WIDTH * battery_get_percent()),
	                    BATTERY_HEIGHT);

	cairo_fill(cr);
	
	return FALSE;
}

static void activate (GtkApplication *app, gpointer user_data)
{
	(void)(user_data);
	GtkAdjustment *stepper_adjustment;

	// Initialize the widgets
	window = gtk_application_window_new(app);
	gtk_window_set_title(GTK_WINDOW(window), "Battery Indicator");
	gtk_window_set_resizable(GTK_WINDOW(window), FALSE);

	grid = gtk_grid_new();
	gtk_container_add(GTK_CONTAINER(window), grid);

	drawing_area = gtk_drawing_area_new();
	gtk_grid_attach(GTK_GRID(grid), drawing_area, 0, 0, 1, 1);
	gtk_widget_set_size_request(drawing_area, BATTERY_WIDTH + MARGIN, BATTERY_HEIGHT + MARGIN);
	g_signal_connect(G_OBJECT(drawing_area), "draw", G_CALLBACK(draw_callback), NULL);

	stepper_adjustment = gtk_adjustment_new(50, 0, 100, 1, 0, 0);
	spn_percent = gtk_spin_button_new(stepper_adjustment, 1.0, 0);
	gtk_grid_attach(GTK_GRID(grid), spn_percent, 0, 1, 1, 1);
	g_signal_connect(G_OBJECT(spn_percent), "value-changed", G_CALLBACK(update_spinner), NULL);

	chk_critical = gtk_check_button_new_with_label("Critical");
	gtk_grid_attach(GTK_GRID(grid), chk_critical, 0, 2, 1, 1);
	g_signal_connect(G_OBJECT(chk_critical), "toggled", G_CALLBACK(toggle_callback), NULL);

	chk_charging = gtk_check_button_new_with_label("Charging");
	gtk_grid_attach(GTK_GRID(grid), chk_charging, 0, 3, 1, 1);
	g_signal_connect(G_OBJECT(chk_charging), "toggled", G_CALLBACK(toggle_callback), NULL);
	
	// Display it
	gtk_widget_show_all(window);
}

int main (int argc, char **argv)
{
	GtkApplication *app;
	int status;

	app = gtk_application_new("org.gtk.gtkapplicationwindow-example", G_APPLICATION_FLAGS_NONE);
	g_signal_connect(app, "activate", G_CALLBACK(activate), NULL);
	status = g_application_run(G_APPLICATION(app), argc, argv);
	g_object_unref (app);
	return status;
}