// Minimal X11 window — the irreducible Xlib sequence that GLFW/SDL/winit wrap on
// Linux: XOpenDisplay -> XCreateSimpleWindow -> XMapWindow -> XNextEvent. All
// types and functions come from the real <X11/Xlib.h> via the ImportC shim
// (`c.c`); nothing is hand-declared. See ../index.md (the X11 OS-API survey).
//
// Headless-safe: if no X server is reachable, XOpenDisplay returns null, we print
// `SKIP:` and exit 0. With a live $DISPLAY it opens a real window, draws on the
// first Expose, and exits (a real app loops until WM_DELETE_WINDOW).
module 
(module) appapp;

import 
(module) cc; // ImportC: <X11/Xlib.h>
C preprocess command `cpp` failed for file `/home/runner/work/sparkles/sparkles/docs/research/window-system-integration/os-apis/x11/example/c.c`, exit status 1
import 
(package) corecore.
(package) core.stdcstdc.
(module) core.stdc.config
D compatible types that correspond to various basic types in associated
C and C++ compilers.
Source
core/stdc/config.d
@copyrightCopyright Sean Kelly 2005 - 2009.@licenseDistributed under the
Boost Software License 1.0.
(See accompanying file LICENSE)@authorsSean Kelly@standardsISO/IEC 9899:1999 (E)config : c_long;
import 
(package) corecore.
(package) core.stdcstdc.
(module) core.stdc.stdio
D header file for C99 <stdio.h>
pubs.opengroup.org/onlinepubs/009695399/basedefs/stdio.h.html, stdio.h
Source
core/stdc/stdio.d
@copyrightCopyright Sean Kelly 2005 - 2009.@licenseDistributed under the
Boost Software License 1.0.
(See accompanying file LICENSE)@authorsSean Kelly,
Alex Rønne Petersen@standardsISO/IEC 9899:1999 (E)stdio : 
(alias) app.printf = int core.stdc.stdio.printf(scope const(char*) format, scope const ...) nothrow @nogcprintf;

// Xlib exposes these as expression/object-like macros (e.g. `(1L<<15)`), which
// ImportC does not reliably import — re-declare the few we use, per the ImportC
// guide. (Function macros DefaultScreen/RootWindow/BlackPixel are likewise
// avoided in favour of their real function forms XDefaultScreen/XRootWindow/….)
enum : c_long
{
    
(enum value) app.ExposureMask = 32768LExposureMask = 1L << 15,
    
(enum value) app.KeyPressMask = 1LKeyPressMask = 1L << 0,
    
(enum value) app.StructureNotifyMask = 131072LStructureNotifyMask = 1L << 17,
}

enum
{
    
(enum value) app.Expose = 12Expose = 12,
    
(enum value) app.KeyPress = 2KeyPress = 2,
    
(enum value) app.ClientMessage = 33ClientMessage = 33,
}

int 
int D main()main()
{
    // 1. Connect to the X server named by $DISPLAY (null = default).
    Display* 
(local variable) _error_ dpydpy = XOpenDisplay(null);
undefined identifier `Display`
undefined identifier `XOpenDisplay`
    if (dpy is null)
    {
        
int core.stdc.stdio.printf(scope const(char*) format, scope const ...) nothrow @nogcprintf("SKIP: no X11 display (XOpenDisplay returned null)\n");
        return 0; // green on a headless runner
    }
    scope (exit)
        XCloseDisplay(dpy);
undefined identifier `XCloseDisplay`

    const 
(local variable) const(_error_) screenscreen = XDefaultScreen(dpy);
undefined identifier `XDefaultScreen`
    const 
(local variable) const(_error_) rootroot = XRootWindow(dpy, screen);
undefined identifier `XRootWindow`

    // 2. Create a top-level window as a child of the root window.
    Window 
(local variable) _error_ winwin = XCreateSimpleWindow(dpy, root,
undefined identifier `Window`
undefined identifier `XCreateSimpleWindow`
        0, 0, 480, 320, // x, y, width, height
        1, // border width
        XBlackPixel(dpy, screen), XWhitePixel(dpy, screen));
    XStoreName(dpy, win, "Sparkles · X11 (Xlib)");
undefined identifier `XStoreName`

    // 3. Route the window-manager close button to us as a ClientMessage.
    Atom 
(local variable) _error_ wmDeletewmDelete = XInternAtom(dpy, "WM_DELETE_WINDOW", False);
undefined identifier `Atom`
undefined identifier `XInternAtom`
    XSetWMProtocols(dpy, win, &wmDelete, 1);
undefined identifier `XSetWMProtocols`

    // 4. Subscribe to events, then map (show) the window.
    XSelectInput(dpy, win, ExposureMask | KeyPressMask | StructureNotifyMask);
undefined identifier `XSelectInput`
    XMapWindow(dpy, win);
undefined identifier `XMapWindow`

    // 5. Event loop. A real app loops until WM_DELETE_WINDOW / a key; here we draw
    //    once on the first Expose and exit so CI never blocks.
    GC 
(local variable) _error_ gcgc = XDefaultGC(dpy, screen);
undefined identifier `GC`
undefined identifier `XDefaultGC`
    XEvent 
(local variable) _error_ evev;
undefined identifier `XEvent`
    while (true)
    {
        XNextEvent(dpy, &ev);
undefined identifier `XNextEvent`
        if (ev.type == 
(enum value) app.Expose = 12Expose)
        {
            XSetForeground(dpy, gc, XBlackPixel(dpy, screen));
undefined identifier `XSetForeground`
            XFillRectangle(dpy, win, gc, 190, 130, 100, 60);
undefined identifier `XFillRectangle`
            XFlush(dpy);
undefined identifier `XFlush`
            
int core.stdc.stdio.printf(scope const(char*) format, scope const ...) nothrow @nogcprintf("ok: mapped a 480x320 window and drew on Expose\n");
            return 0;
        }
        if (ev.type == 
(enum value) app.KeyPress = 2KeyPress || ev.type == 
(enum value) app.ClientMessage = 33ClientMessage)
            return 0;
    }
}