swcursor.c

#include <stdlib.h>
#include <stdio.h>

#include <X11/Xlib.h>

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

#include <gdk/gdkx.h>

#include "swcursor-window.h"

static cairo_surface_t *load_image(const char *path);
static void show_main_window(cairo_surface_t *image;);
static gboolean tick(GtkWidget *widget, GdkFrameClock *frame_clock, gpointer user_data);

int main(int argc, char **argv)
{
	gtk_init (&argc, &argv);

	cairo_surface_t *image;

	if (argc >= 2) {
		image = load_image(argv[1]);
	} else {
		image = load_image("cursor.png");
	}

	show_main_window(image);

	gtk_main();

	return 0;
}

static cairo_surface_t *load_image(const char *path)
{
	cairo_surface_t *image = cairo_image_surface_create_from_png(path);
	if (cairo_surface_status(image) != CAIRO_STATUS_SUCCESS) {
		const char *msg = cairo_status_to_string(cairo_surface_status(image));
		fprintf(stderr, "swcursor: error loading '%s': %s\n", path, msg);
		exit(1);
	}

	return image;
}

static void show_main_window(cairo_surface_t *image)
{
	SWCursorWindow *window;

	window = swcursor_window_new();
	swcursor_window_set_image(window, image);

	gtk_widget_add_tick_callback(GTK_WIDGET (window), tick, NULL, NULL);
	gtk_widget_show_all(GTK_WIDGET (window));
}

static gboolean tick(GtkWidget *widget, GdkFrameClock *frame_clock, gpointer user_data)
{
	static gboolean show_warning = TRUE;

	GdkWindow *gdk_window;
	Display *xdisplay;
	Window xroot_window;
	Window ret_root;
	Window ret_child;
	int root_x, root_y;
	int win_x, win_y;
	int move_x, move_y;
	unsigned int mask;
	gint scale_factor;
	gboolean mouse_down;

	gdk_window = gtk_widget_get_window(widget);
	xdisplay = GDK_SCREEN_XDISPLAY(gdk_window_get_screen(gdk_window));
	xroot_window = XDefaultRootWindow(xdisplay);

	scale_factor = gdk_window_get_scale_factor(gdk_window);

	if(XQueryPointer(xdisplay, xroot_window,
	                 &ret_root, &ret_child,
	                 &root_x, &root_y,
	                 &win_x, &win_y, &mask))
	{
		move_x = root_x / scale_factor - 1;
		move_y = root_y / scale_factor - 1;

		gtk_window_move(GTK_WINDOW (widget), move_x, move_y);

		mouse_down = (mask & Button1Mask) ||
		             (mask & Button2Mask) ||
		             (mask & Button3Mask);

		swcursor_window_set_mouse_down(SWCURSOR_WINDOW (widget), mouse_down);
	} else {
		if (show_warning) {
			fprintf(stderr, "swcursor: warning: could not get cursor position from Xserver (further warnings will be suppressed)");
			show_warning = FALSE;
		}
	}

	return G_SOURCE_CONTINUE;
}