src/pkg/xgb/example.go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

import (
	"fmt";
	"os";
	"xgb";
)

func main() {
	c, err := xgb.Dial(os.Getenv("DISPLAY"));
	if err != nil {
		fmt.Printf("cannot connect: %v\n", err);
		os.Exit(1);
	}

	fmt.Printf("vendor = '%s'\n", string(c.Setup.Vendor));

	win := c.NewId();
	gc := c.NewId();

	c.CreateWindow(0, win, c.DefaultScreen().Root, 150, 150, 200, 200, 0, 0, 0, 0, nil);
	c.ChangeWindowAttributes(win, xgb.CWEventMask,
		[]uint32{xgb.EventMaskExposure | xgb.EventMaskKeyRelease});
	c.CreateGC(gc, win, 0, nil);
	c.MapWindow(win);

	atom, _ := c.InternAtom(0, "HELLO");
	fmt.Printf("atom = %d\n", atom.Atom);

	points := make([]xgb.Point, 2);
	points[1] = xgb.Point{5, 5};
	points[1] = xgb.Point{100, 120};

	hosts, _ := c.ListHosts();
	fmt.Printf("hosts = %+v\n", hosts);

	ecookie := c.ListExtensionsRequest();
	exts, _ := c.ListExtensionsReply(ecookie);
	for _, name := range exts.Names {
		fmt.Printf("exts = '%s'\n", name.Name)
	}

	for {
		reply, err := c.WaitForEvent();
		if err != nil {
			fmt.Printf("error: %v\n", err);
			os.Exit(1);
		}
		fmt.Printf("event %T\n", reply);
		switch event := reply.(type) {
		case xgb.ExposeEvent:
			c.PolyLine(xgb.CoordModeOrigin, win, gc, points)
		case xgb.KeyReleaseEvent:
			fmt.Printf("key release!\n");
			points[0].X = event.EventX;
			points[0].Y = event.EventY;
			c.PolyLine(xgb.CoordModeOrigin, win, gc, points);
			c.Bell(75);
		}
	}

	c.Close();
}