使用xlib绘制边框（frame）

Question

是否可以使用 xlib 在没有标题栏、关闭按钮、鼠标按钮响应的情况下绘制透明 window。那么只用特定颜色和宽度的边框？类似于

这个橙色矩形是我需要创建的。此外，我希望有可能以编程方式移动、调整大小、关闭并使其闪烁（在计时器上更改边框的颜色）。

我设法创建了没有标题栏的透明 window，并在 window 的每一侧绘制矩形，使 border-effect:

#define W_WIDTH 640
#define W_HEIGHT 480

#define X_POS 100
#define Y_POS 120
#define BORDER_WIDTH 2

Display *dpy;
Window w;

XRectangle rectangles[4] =
    {
    { X_POS, Y_POS, W_WIDTH, BORDER_WIDTH },
    { X_POS, Y_POS, BORDER_WIDTH, W_HEIGHT },
    { X_POS, W_HEIGHT - BORDER_WIDTH, W_WIDTH, BORDER_WIDTH },
    { W_WIDTH - BORDER_WIDTH, Y_POS, BORDER_WIDTH, W_HEIGHT }
    };

int main(int argc, char *argv[])
{
    GC gc;
    XGCValues gcv;
    int run = 1;

    dpy = XOpenDisplay(NULL);

    XVisualInfo vinfo;
    XMatchVisualInfo(dpy, DefaultScreen(dpy), 32, TrueColor, &vinfo);
    XSetWindowAttributes attr;
    attr.colormap = XCreateColormap(dpy, DefaultRootWindow(dpy), vinfo.visual, AllocNone);

    w = XCreateWindow(dpy, DefaultRootWindow(dpy), X_POS, Y_POS,
                      W_WIDTH, W_HEIGHT, BORDER_WIDTH, vinfo.depth,
                      InputOutput, vinfo.visual, CWColormap | CWBorderPixel | CWBackPixel, &attr);
    XColor color;
    Colormap colormap;
    char orangeDark[] = "#FF8000";
    colormap = DefaultColormap(dpy, 0);
    XParseColor(dpy, colormap, orangeDark, &color);
    XAllocColor(dpy, colormap, &color);

    gcv.line_width = BORDER_WIDTH;
    gc = XCreateGC(dpy, w, GCLineWidth, &gcv);

    XSelectInput(dpy, w, ExposureMask);
    Atom window_type = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE", False);
    long value = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE_DOCK", False);
    XChangeProperty(dpy, w, window_type, XA_ATOM, 32, PropModeReplace, (unsigned char *) &value, 1);
    XMapWindow(dpy, w);
    XSync(dpy, False);

    while(run)
    {
        XEvent xe;
        XNextEvent(dpy, &xe);
        switch (xe.type)
        {
            case Expose:
                XSetForeground(dpy, gc, color.pixel);
                XDrawRectangles(dpy, w, gc, rectangles, 4);
                XFillRectangles(dpy, w, gc, rectangles, 4);
                XSync(dpy, False);
                break;
            default:
                break;
        }
    }

    XDestroyWindow(dpy, w);
    XCloseDisplay(dpy);

    return 0;
}

这段代码几乎可以正常工作，除了我的橙色边框是半透明的并且在光线下几乎不可见 windows：你能告诉我如何改变我的代码来绘制实心橙色矩形吗？我的另一个变体是在橙色 window 内绘制透明矩形。但是我没有在互联网上找到任何关于如何做到这一点的信息。

Answer 1

两个主要错误。

未将 attr 和 gcv 初始化为 0
不使用attr.colormap进行颜色分配

这应该有帮助：

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>

#define W_WIDTH 640
#define W_HEIGHT 480

#define X_POS 100
#define Y_POS 120
#define BORDER_WIDTH 2

int main(int argc, char *argv[]) {
    XRectangle rectangles[4] = {
        { X_POS, Y_POS, W_WIDTH, BORDER_WIDTH },
        { X_POS, Y_POS, BORDER_WIDTH, W_HEIGHT },
        { X_POS, W_HEIGHT - BORDER_WIDTH, W_WIDTH, BORDER_WIDTH },
        { W_WIDTH - BORDER_WIDTH, Y_POS, BORDER_WIDTH, W_HEIGHT }
    };
    Display *dpy = XOpenDisplay(NULL);
    XSetWindowAttributes attr = {0};
    XGCValues gcv = {0};
    XVisualInfo vinfo;
    GC gc;

    Window w;

    int run = 1;

    XMatchVisualInfo(dpy, DefaultScreen(dpy), 32, TrueColor, &vinfo);
    attr.colormap = XCreateColormap(dpy, DefaultRootWindow(dpy), vinfo.visual, AllocNone);

    XColor color;
    char orangeDark[] = "#FF8000";
    XParseColor(dpy, attr.colormap, orangeDark, &color);
    XAllocColor(dpy, attr.colormap, &color);

    w = XCreateWindow(dpy, DefaultRootWindow(dpy), X_POS, Y_POS,
                      W_WIDTH, W_HEIGHT, BORDER_WIDTH, vinfo.depth,
                      InputOutput, vinfo.visual, CWColormap | CWBorderPixel | CWBackPixel, &attr);

    gcv.line_width = BORDER_WIDTH;
    gc = XCreateGC(dpy, w, GCLineWidth, &gcv);

    XSelectInput(dpy, w, ExposureMask);
    long value = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE_DOCK", False);
    XChangeProperty(dpy, w, XInternAtom(dpy, "_NET_WM_WINDOW_TYPE", False),
                    XA_ATOM, 32, PropModeReplace, (unsigned char *) &value, 1);
    XMapWindow(dpy, w);
    XSync(dpy, False);

    while(run) {
        XEvent xe;
        XNextEvent(dpy, &xe);
        switch (xe.type) {
            case Expose:
                XSetForeground(dpy, gc, color.pixel);
                XDrawRectangles(dpy, w, gc, rectangles, 4);
                XFillRectangles(dpy, w, gc, rectangles, 4);
                XSync(dpy, False);
                break;

            default:
                break;
        }
    }

    XDestroyWindow(dpy, w);
    XCloseDisplay(dpy);

    return 0;
}

结果：

使用xlib绘制边框（frame）

Draw border (frame) using xlib

c

x11

xlib