add xevent.

server/internal/desktop/xevent/xevent.c

@@ -0,0 +1,123 @@
+#include "xevent.h"
+
+static int XEventError(Display *display, XErrorEvent *event) {
+  char message[100];
+
+  int error;
+  error = XGetErrorText(display, event->error_code, message, sizeof(message));
+  if (error) {
+    goXEventError(event, "Could not get error message.");
+  } else {
+    goXEventError(event, message);
+  }
+
+  return 1;
+}
+
+void XEventLoop(char *name) {
+  Display *display = XOpenDisplay(name);
+  Window root = RootWindow(display, 0);
+
+  int xfixes_event_base, xfixes_error_base;
+  if (!XFixesQueryExtension(display, &xfixes_event_base, &xfixes_error_base)) {
+    return;
+  }
+
+  Atom WM_WINDOW_ROLE = XInternAtom(display, "WM_WINDOW_ROLE", 1);
+  Atom XA_CLIPBOARD = XInternAtom(display, "CLIPBOARD", 0);
+  XFixesSelectSelectionInput(display, root, XA_CLIPBOARD, XFixesSetSelectionOwnerNotifyMask);
+  XFixesSelectCursorInput(display, root, XFixesDisplayCursorNotifyMask);
+  XSelectInput(display, root, SubstructureNotifyMask);
+
+  XSync(display, 0);
+  XSetErrorHandler(XEventError);
+
+  while (goXEventActive()) {
+    XEvent event;
+    XNextEvent(display, &event);
+
+    // XFixesDisplayCursorNotify
+    if (event.type == xfixes_event_base + 1) {
+      XFixesCursorNotifyEvent notifyEvent = *((XFixesCursorNotifyEvent *) &event);
+      if (notifyEvent.subtype == XFixesDisplayCursorNotify) {
+        goXEventCursorChanged(notifyEvent);
+        continue;
+      }
+    }
+
+    // XFixesSelectionNotifyEvent
+    if (event.type == xfixes_event_base + XFixesSelectionNotify) {
+      XFixesSelectionNotifyEvent notifyEvent = *((XFixesSelectionNotifyEvent *) &event);
+      if (notifyEvent.subtype == XFixesSetSelectionOwnerNotify && notifyEvent.selection == XA_CLIPBOARD) {
+        goXEventClipboardUpdated();
+        continue;
+      }
+    }
+
+    // ConfigureNotify
+    if (event.type == ConfigureNotify) {
+      Window window = event.xconfigure.window;
+
+      char *name;
+      XFetchName(display, window, &name);
+
+      XTextProperty role;
+      XGetTextProperty(display, window, &role, WM_WINDOW_ROLE);
+
+      goXEventConfigureNotify(display, window, name, role.value);
+      XFree(name);
+      continue;
+    }
+
+    // UnmapNotify
+    if (event.type == UnmapNotify) {
+      Window window = event.xunmap.window;
+      goXEventUnmapNotify(window);
+      continue;
+    }
+  }
+
+  XCloseDisplay(display);
+}
+
+void XFileChooserHide(Display *display, Window window) {
+  Window root = RootWindow(display, 0);
+
+  // The WM_TRANSIENT_FOR property is defined by the [ICCCM] for managed windows.
+  // This specification extends the use of the property to override-redirect windows.
+  // If an override-redirect is a pop-up on behalf of another window, then the Client
+  // SHOULD set WM_TRANSIENT_FOR on the override-redirect to this other window.
+  //
+  // As an example, a Client should set WM_TRANSIENT_FOR on dropdown menus to the
+  // toplevel application window that contains the menubar.
+
+  // Remove WM_TRANSIENT_FOR
+  Atom WM_TRANSIENT_FOR = XInternAtom(display, "WM_TRANSIENT_FOR", 0);
+  XDeleteProperty(display, window, WM_TRANSIENT_FOR);
+
+  // Add _NET_WM_STATE_BELOW
+  XClientMessageEvent clientMessageEvent;
+  memset(&clientMessageEvent, 0, sizeof(clientMessageEvent));
+
+  // window  = the respective client window
+  // message_type = _NET_WM_STATE
+  // format = 32
+  // data.l[0] = the action, as listed below
+  //   _NET_WM_STATE_REMOVE  0 // remove/unset property
+  //   _NET_WM_STATE_ADD     1 // add/set property
+  //   _NET_WM_STATE_TOGGLE  2 // toggle property 
+  // data.l[1] = first property to alter
+  // data.l[2] = second property to alter
+  // data.l[3] = source indication
+  // other data.l[] elements = 0
+
+  clientMessageEvent.type         = ClientMessage;
+  clientMessageEvent.window       = window;
+  clientMessageEvent.message_type = XInternAtom(display, "_NET_WM_STATE", 0);
+  clientMessageEvent.format       = 32;
+  clientMessageEvent.data.l[0]    = 1;
+  clientMessageEvent.data.l[1]    = XInternAtom(display, "_NET_WM_STATE_BELOW", 0);
+  clientMessageEvent.data.l[3]    = 1;
+
+  XSendEvent(display, root, 0, SubstructureRedirectMask | SubstructureNotifyMask, (XEvent *)&clientMessageEvent);
+}