c、Xlib 中的 freedesktop XEmbed 系统托盘客户端代码

Question

我一直在尝试使用直接 C 和 Xlib 以及 freedesktop 规范 [0] 来实现系统托盘图标。我似乎无法让我的 Window 嵌入我的桌面管理器的系统托盘 [1]，而其他应用程序似乎能够做到这一点。我不确定如何继续调试它，但我在下面提供了最少的示例代码。

我无法找到任何直接使用 Xlib 和 C 的示例代码，而且我看到的所有建议都是关于 Gtk/Qt/Mono/whatever 等框架的，但我想了解什么应该按照规范在这里发生，而我做错了什么。

#include <X11/Xutil.h>
#include <string.h>

#define MIN(A, B)               ((A) < (B) ? (A) : (B))

/* --------- XEMBED and systray stuff */
#define SYSTEM_TRAY_REQUEST_DOCK   0
#define SYSTEM_TRAY_BEGIN_MESSAGE   1
#define SYSTEM_TRAY_CANCEL_MESSAGE  2

static int trapped_error_code = 0;
static int (*old_error_handler) (Display *, XErrorEvent *);

static int
error_handler(Display     *display, XErrorEvent *error) {
    trapped_error_code = error->error_code;
    return 0;
}

void
trap_errors(void) {
    trapped_error_code = 0;
    old_error_handler = XSetErrorHandler(error_handler);
}

int
untrap_errors(void) {
    XSetErrorHandler(old_error_handler);
    return trapped_error_code;
}

void 
send_systray_message(Display* dpy, Window w, long message, long data1, long data2, long data3) {
    XEvent ev;

    memset(&ev, 0, sizeof(ev));
    ev.xclient.type = ClientMessage;
    ev.xclient.window = w;
    ev.xclient.message_type = XInternAtom (dpy, "_NET_SYSTEM_TRAY_OPCODE", False );
    ev.xclient.format = 32;
    ev.xclient.data.l[0] = CurrentTime;
    ev.xclient.data.l[1] = message;
    ev.xclient.data.l[2] = data1;
    ev.xclient.data.l[3] = data2;
    ev.xclient.data.l[4] = data3;

    trap_errors();
    XSendEvent(dpy, w, False, NoEventMask, &ev);
    XSync(dpy, False);
    if (untrap_errors()) {
        /* Handle errors */
    }
}

/* ------------ Regular X stuff */
int
main(int argc, char **argv) {
    int width, height;
    XWindowAttributes wa;
    XEvent ev;
    Display *dpy;
    int screen;
    Window root, win;

    /* init */
    if (!(dpy=XOpenDisplay(NULL)))
        return 1;
    screen = DefaultScreen(dpy);
    root = RootWindow(dpy, screen);
    if(!XGetWindowAttributes(dpy, root, &wa))
        return 1;
    width = height = MIN(wa.width, wa.height);

    /* create window */
    win = XCreateSimpleWindow(dpy, root, 0, 0, width, height, 0, 0, 0xFFFF9900);

    send_systray_message(dpy, win, SYSTEM_TRAY_REQUEST_DOCK, win, 0, 0);
    XMapWindow(dpy, win);

    XSync(dpy, False);

    /* run */
    while(1) {
        while(XPending(dpy)) {
            XNextEvent(dpy, &ev); /* just waiting until we error because window closed */
        }
    }
}

如有任何帮助，我们将不胜感激。我认为这个问题与语言无关，更多的是我对协议的误解，所以任何语言的答案都是可以接受的，只要它们能帮助我解决这个 XEvent 问题。

[0] https://specifications.freedesktop.org/systemtray-spec/systemtray-spec-0.2.html

[1] 我正在使用带系统托盘补丁的 dwm http://dwm.suckless.org/patches/systray

Answer 1

您正在向错误的人发送消息 window。该文档并不是很有帮助，将托盘嵌入消息发送到您自己的 window! 毫无意义。您需要将其发送到托盘 window.

这是固定的send_systray_message

void
send_systray_message(Display* dpy, long message, long data1, long data2, long data3) {
    XEvent ev;

    Atom selection_atom = XInternAtom (dpy,"_NET_SYSTEM_TRAY_S0",False);
    Window tray = XGetSelectionOwner (dpy,selection_atom);

    if ( tray != None)
        XSelectInput (dpy,tray,StructureNotifyMask);

    memset(&ev, 0, sizeof(ev));
    ev.xclient.type = ClientMessage;
    ev.xclient.window = tray;
    ev.xclient.message_type = XInternAtom (dpy, "_NET_SYSTEM_TRAY_OPCODE", False );
    ev.xclient.format = 32;
    ev.xclient.data.l[0] = CurrentTime;
    ev.xclient.data.l[1] = message;
    ev.xclient.data.l[2] = data1; // <--- your window is only here
    ev.xclient.data.l[3] = data2;
    ev.xclient.data.l[4] = data3;

    trap_errors();
    XSendEvent(dpy, tray, False, NoEventMask, &ev);
    XSync(dpy, False);
    usleep(10000);
    if (untrap_errors()) {
        /* Handle errors */
    }
}

并调用它

send_systray_message(dpy, SYSTEM_TRAY_REQUEST_DOCK, win, 0, 0); // pass win only once

致谢：http://distro.ibiblio.org/vectorlinux/Uelsk8s/GAMBAS/gambas-svn/gambas2/gb.gtk/src/gtrayicon.cpp

c、Xlib 中的 freedesktop XEmbed 系统托盘客户端代码

freedesktop XEmbed systray client code in C, Xlib

x11

systray

xlib

freedesktop.org

xembed