如何在X Windows上将进程窗口置于前台？(C++)

Question

我有进程的PID(和名称),我想把它带到linux(ubuntu)的前面.在Mac上,我只是这样做SetFrontProcess(pid),在Windows上我会枚举窗口,选择我想要的那个,然后打电话,SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);但我不知道在linux上做什么.我已经看了一下X Lib,但是大多数/所有这些函数似乎都在你进程中的窗口上运行.

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编辑:使用bdk的答案我将这些助手添加到我的代码中以获取Window

bool searchHelper(Display* display, Window w, Atom& atomPID, unsigned long pid, Window& result)
{
    bool ret = false;

    Atom atomType;
    int format;
    unsigned long nItems;
    unsigned long bytesAfter;
    unsigned char* propPID = 0;
    if (Success == XGetWindowProperty(display,w,atomPID,0,1,False,XA_CARDINAL,&atomType,&format,&nItems,&bytesAfter,&propPID))
    {
        if (propPID != 0)
        {
            if (pid == *((unsigned long *)propPID))
            {
                result = w;
                ret = true;
            }
            XFree(propPID);
        }
    }

    if (ret)
        return ret; //we found we can stop

    //check the children of the window
    Window wRoot;
    Window wParent;
    Window *wChild=NULL;
    unsigned nChildren=0;
    if (XQueryTree(display, w, &wRoot, &wParent, &wChild, &nChildren) != 0 )
    {
        for (unsigned i=0; i<nChildren; ++i)
        {
            ret = searchHelper(display, wChild[i], atomPID, pid, result);
            if (ret)
                break;
        }
    }
    return ret;
}

bool getWindowFromPid(unsigned long pid, Display* display, Window& result)
{
    Window window = XDefaultRootWindow(display);
    Atom atomPID = XInternAtom(display, "_NET_WM_PID", true);
    if (atomPID == None)
    {
        qDebug("XInternAtom failure");
        return false;
    }
    return searchHelper(display, window, atomPID, pid, result);
}

现在我成功地获得了窗口,但是当我执行以下操作时

if (getWindowFromPid(pid,display,window))
{
    qDebug("Found window ID:%d", window);
    int result = XRaiseWindow(display,window);
    qDebug("XRaiseWindow returned:%d", result);
}

XRaiseWindow返回1(BadRequest).XRaiseWindow的文档没有提到BadRequest的返回代码是可能的结果.我不确定是什么问题.我不允许在不同的进程中为它调用它吗？这种重点钢铁预防是否会妨碍我？有什么想法吗？

编辑编辑:

所以看看xwininfo.c在用-frame调用它时的作用我根据bdk的建议改变了我的代码如下.

if (getWindowFromPid(pid,display,window))
    {
        qDebug("Found window ID:%d", window);

        //Need the windowmanger frame (or parent) id not window id
        Window root, parent;
        Window *childlist;
        unsigned int ujunk;
        int status = XQueryTree(display, window, &root, &parent, &childlist, &ujunk);
        if (status && parent && parent != root)
        {
            qDebug("Found frame window ID:%d",parent);
            window = parent;
        }

        XSetWindowAttributes xswa;
        xswa.override_redirect=True;
        int result = XChangeWindowAttributes (display,window,CWOverrideRedirect,&xswa);
        qDebug("XChangeWindowAttributes returned:%d", result);
        result = XRaiseWindow(display,window);
        qDebug("XRaiseWindow returned:%d", result);
    }
    else
        qDebug("unable to find the window for the pid");

此时我确实找到了窗口框架ID,但是我从XChangeWindowAttributes和XRaiseWindow获得了返回码"1".我不允许修改另一个进程的窗口吗？

Answer 1

我的应用程序中也有这个问题,所以这是解决方案.

要抬高窗口,您不仅需要提高窗口,还需要通知WM它.可以使用以下代码:

        // This is how to get it in Qt; if you don't use it,
        // you can call XOpenDisplay and get it from there;
        Display * display = x11Info().display();

        // Main window identifier of your application
        WId win = winId();

        XEvent event = { 0 };
        event.xclient.type = ClientMessage;
        event.xclient.serial = 0;
        event.xclient.send_event = True;
        event.xclient.message_type = XInternAtom( display, "_NET_ACTIVE_WINDOW", False);
        event.xclient.window = win;
        event.xclient.format = 32;

        XSendEvent( display, DefaultRootWindow(display), False, SubstructureRedirectMask | SubstructureNotifyMask, &event );
        XMapRaised( display, win );

Answer 2

我自己没有尝试过,但将这两种方法放在一起可能有效:

如果您知道窗口ID,则xlib中的XRaiseWindow API调用允许您将窗口提升到前面.

http://www.unix.com/man-page/Linux/3/XRaiseWindow/

此stackoverflow答案解释了如何从PID获取窗口ID:

如何从进程ID获取X11窗口？

编辑:

我在XRaiseWindow上的成功有限.以下程序在twm窗口管理器下工作,但不是我通常使用的离子.窗口管理器必须有办法阻止应用程序"弹出".为了使这个工作,我还必须传递窗口管理器的窗口的窗口ID,而不是窗口本身.运行xwininfo -frame并单击窗口,然后获取帧ID,使用gcc test.c -lX编译该程序,并在命令行上传递该hexid,它将引发窗口.

 #include <stdio.h>
 #include <stdlib.h>
 #include <X11/Xlib.h>

 int main(int argc, char **argv)
 {
   Display *dsp = XOpenDisplay(NULL);
   long id = strtol(argv[1], NULL, 16);
   XSetWindowAttributes xswa;
   xswa.override_redirect=True;
   XChangeWindowAttributes (dsp,id,CWOverrideRedirect, &xswa);
   XRaiseWindow ( dsp, id );
   XCloseDisplay ( dsp );
 }