xnest: introduce Xnest screen private structure

Since we've got lots of per-screen information spread across several arrays,
and for future features (eg. mult-upstream support) yet more to come, it's
time to consolidate into a per-screen private structure.

Initially just moving the upstream root window ID into it - others follwing
by subsequent patches. Leaving it as a global array and not assigning
private data to Screen structure yet.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

hw/xnest/Color.c

@@ -32,6 +32,7 @@ is" without express or implied warranty.
 #include "Visual.h"
 #include "XNWindow.h"
 #include "Args.h"
+#include "multiscreen.h"
 
 DevPrivateKeyRec xnestColormapPrivateKeyRec;
 
@@ -54,9 +55,11 @@ xnestCreateColormap(ColormapPtr pCmap)
     pVisual = pCmap->pVisual;
     ncolors = pVisual->ColormapEntries;
 
+    XnestScreenPtr xnscr = xnestScreenPriv(pCmap->pScreen);
+
     xnestColormapPriv(pCmap)->colormap =
         XCreateColormap(xnestDisplay,
-                        xnestDefaultWindows[pCmap->pScreen->myNum],
+                        xnscr->rootWindow,
                         xnestVisual(pVisual),
                         (pVisual->class & DynamicClass) ? AllocAll : AllocNone);
 
@@ -193,6 +196,7 @@ xnestSetInstalledColormapWindows(ScreenPtr pScreen)
 {
     xnestInstalledColormapWindows icws;
     int numWindows;
+    XnestScreenPtr xnscr = xnestScreenPriv(pScreen);
 
     icws.cmapIDs = xallocarray(pScreen->maxInstalledCmaps, sizeof(Colormap));
     icws.numCmapIDs = xnestListInstalledColormaps(pScreen, icws.cmapIDs);
@@ -202,7 +206,7 @@ xnestSetInstalledColormapWindows(ScreenPtr pScreen)
         icws.windows = xallocarray(icws.numWindows + 1, sizeof(Window));
         icws.index = 0;
         WalkTree(pScreen, xnestGetInstalledColormapWindows, (void *) &icws);
-        icws.windows[icws.numWindows] = xnestDefaultWindows[pScreen->myNum];
+        icws.windows[icws.numWindows] = xnscr->rootWindow;
         numWindows = icws.numWindows + 1;
     }
     else {
@@ -215,7 +219,7 @@ xnestSetInstalledColormapWindows(ScreenPtr pScreen)
     if (!xnestSameInstalledColormapWindows(icws.windows, icws.numWindows)) {
         free(xnestOldInstalledColormapWindows);
 
-        XSetWMColormapWindows(xnestDisplay, xnestDefaultWindows[pScreen->myNum],
+        XSetWMColormapWindows(xnestDisplay, xnscr->rootWindow,
                               icws.windows, numWindows);
 
         xnestOldInstalledColormapWindows = icws.windows;
@@ -243,9 +247,7 @@ xnestSetInstalledColormapWindows(ScreenPtr pScreen)
                                         pScreen->defColormap, X11_RESTYPE_COLORMAP,
                                         serverClient, DixUseAccess);
 
-            XSetWindowColormap(xnestDisplay,
+            XSetWindowColormap(xnestDisplay, xnscr->rootWindow, xnestColormap(pCmap));
-                               xnestDefaultWindows[pScreen->myNum],
-                               xnestColormap(pCmap));
         }
 #endif                          /* DUMB_WINDOW_MANAGERS */
     }
@@ -256,9 +258,11 @@ xnestSetInstalledColormapWindows(ScreenPtr pScreen)
 void
 xnestSetScreenSaverColormapWindow(ScreenPtr pScreen)
 {
+    XnestScreenPtr xnscr = xnestScreenPriv(pScreen);
+
     free(xnestOldInstalledColormapWindows);
 
-    XSetWMColormapWindows(xnestDisplay, xnestDefaultWindows[pScreen->myNum],
+    XSetWMColormapWindows(xnestDisplay, xnscr->rootWindow,
                           &xnestScreenSaverWindows[pScreen->myNum], 1);
 
     xnestOldInstalledColormapWindows = NULL;

hw/xnest/Cursor.c

@@ -32,6 +32,7 @@ is" without express or implied warranty.
 #include "Visual.h"
 #include "Keyboard.h"
 #include "Args.h"
+#include "multiscreen.h"
 
 xnestCursorFuncRec xnestCursorFuncs = { NULL };
 
@@ -43,6 +44,7 @@ xnestRealizeCursor(DeviceIntPtr pDev, ScreenPtr pScreen, CursorPtr pCursor)
     XColor fg_color, bg_color;
     unsigned long valuemask;
     XGCValues values;
+    XnestScreenPtr xscr = xnestScreenPriv(pScreen);
 
     valuemask = GCFunction |
         GCPlaneMask | GCForeground | GCBackground | GCClipMask;
@@ -56,11 +58,11 @@ xnestRealizeCursor(DeviceIntPtr pDev, ScreenPtr pScreen, CursorPtr pCursor)
     XChangeGC(xnestDisplay, xnestBitmapGC, valuemask, &values);
 
     source = XCreatePixmap(xnestDisplay,
-                           xnestDefaultWindows[pScreen->myNum],
+                           xscr->rootWindow,
                            pCursor->bits->width, pCursor->bits->height, 1);
 
     mask = XCreatePixmap(xnestDisplay,
-                         xnestDefaultWindows[pScreen->myNum],
+                         xscr->rootWindow,
                          pCursor->bits->width, pCursor->bits->height, 1);
 
     ximage = XCreateImage(xnestDisplay,
@@ -136,8 +138,9 @@ xnestSetCursor(DeviceIntPtr pDev, ScreenPtr pScreen, CursorPtr pCursor, int x,
                int y)
 {
     if (pCursor) {
+        XnestScreenPtr xnscr = xnestScreenPriv(pScreen);
         XDefineCursor(xnestDisplay,
-                      xnestDefaultWindows[pScreen->myNum],
+                      xnscr->rootWindow,
                       xnestCursor(pCursor, pScreen));
     }
 }

hw/xnest/GCOps.c

@@ -34,6 +34,7 @@ is" without express or implied warranty.
 #include "GCOps.h"
 #include "Drawable.h"
 #include "Visual.h"
+#include "multiscreen.h"
 
 void
 xnestFillSpans(DrawablePtr pDrawable, GCPtr pGC, int nSpans, xPoint * pPoints,
@@ -61,12 +62,13 @@ xnestQueryBestSize(int class, unsigned short *pWidth, unsigned short *pHeight,
                    ScreenPtr pScreen)
 {
     unsigned int width, height;
+    XnestScreenPtr xnscr = xnestScreenPriv(pScreen);
 
     width = *pWidth;
     height = *pHeight;
 
     XQueryBestSize(xnestDisplay, class,
-                   xnestDefaultWindows[pScreen->myNum],
+                   xnscr->rootWindow,
                    width, height, &width, &height);
 
     *pWidth = width;

hw/xnest/Keyboard.c

@@ -34,6 +34,7 @@ is" without express or implied warranty.
 #include "Keyboard.h"
 #include "Args.h"
 #include "Events.h"
+#include "multiscreen.h"
 
 #include <X11/extensions/XKB.h>
 #include "xkbsrv.h"
@@ -175,13 +176,17 @@ xnestKeyboardProc(DeviceIntPtr pDev, int onoff)
         break;
     case DEVICE_ON:
         xnestEventMask |= XNEST_KEYBOARD_EVENT_MASK;
-        for (i = 0; i < xnestNumScreens; i++)
+        for (i = 0; i < xnestNumScreens; i++) {
-            XSelectInput(xnestDisplay, xnestDefaultWindows[i], xnestEventMask);
+            XnestScreenPtr xnscr = xnestScreenByIdx(i);
+            XSelectInput(xnestDisplay, xnscr->rootWindow, xnestEventMask);
+        }
         break;
     case DEVICE_OFF:
         xnestEventMask &= ~XNEST_KEYBOARD_EVENT_MASK;
-        for (i = 0; i < xnestNumScreens; i++)
+        for (i = 0; i < xnestNumScreens; i++) {
-            XSelectInput(xnestDisplay, xnestDefaultWindows[i], xnestEventMask);
+            XnestScreenPtr xnscr = xnestScreenByIdx(i);
+            XSelectInput(xnestDisplay, xnscr->rootWindow, xnestEventMask);
+        }
         break;
     case DEVICE_CLOSE:
         break;

hw/xnest/Pixmap.c

@@ -29,6 +29,7 @@ is" without express or implied warranty.
 #include "Display.h"
 #include "Screen.h"
 #include "XNPixmap.h"
+#include "multiscreen.h"
 
 DevPrivateKeyRec xnestPixmapPrivateKeyRec;
 
@@ -58,7 +59,7 @@ xnestCreatePixmap(ScreenPtr pScreen, int width, int height, int depth,
     if (width && height)
         xnestPixmapPriv(pPixmap)->pixmap =
             XCreatePixmap(xnestDisplay,
-                          xnestDefaultWindows[pScreen->myNum],
+                xnestScreenPriv(pScreen)->rootWindow,
                 width, height, depth);
     else
         xnestPixmapPriv(pPixmap)->pixmap = 0;
@@ -83,7 +84,7 @@ xnestModifyPixmapHeader(PixmapPtr pPixmap, int width, int height, int depth,
   if(!xnestPixmapPriv(pPixmap)->pixmap && width > 0 && height > 0) {
     xnestPixmapPriv(pPixmap)->pixmap =
         XCreatePixmap(xnestDisplay,
-                      xnestDefaultWindows[pPixmap->drawable.pScreen->myNum],
+                      xnestScreenPriv(pPixmap->drawable.pScreen)->rootWindow,
                       width, height, depth);
   }
 

hw/xnest/Pointer.c

@@ -28,6 +28,7 @@ is" without express or implied warranty.
 #include "Screen.h"
 #include "Pointer.h"
 #include "Args.h"
+#include "multiscreen.h"
 
 #include "xserver-properties.h"
 #include "exevents.h"           /* For XIGetKnownProperty */
@@ -78,12 +79,12 @@ xnestPointerProc(DeviceIntPtr pDev, int onoff)
     case DEVICE_ON:
         xnestEventMask |= XNEST_POINTER_EVENT_MASK;
         for (i = 0; i < xnestNumScreens; i++)
-            XSelectInput(xnestDisplay, xnestDefaultWindows[i], xnestEventMask);
+            XSelectInput(xnestDisplay, xnestScreenByIdx(i)->rootWindow, xnestEventMask);
         break;
     case DEVICE_OFF:
         xnestEventMask &= ~XNEST_POINTER_EVENT_MASK;
         for (i = 0; i < xnestNumScreens; i++)
-            XSelectInput(xnestDisplay, xnestDefaultWindows[i], xnestEventMask);
+            XSelectInput(xnestDisplay, xnestScreenByIdx(i)->rootWindow, xnestEventMask);
         break;
     case DEVICE_CLOSE:
         break;

hw/xnest/Screen.c

@@ -41,8 +41,8 @@ is" without express or implied warranty.
 #include "mipointer.h"
 #include "Args.h"
 #include "mipointrst.h"
+#include "multiscreen.h"
 
-Window xnestDefaultWindows[MAXSCREENS];
 Window xnestScreenSaverWindows[MAXSCREENS];
 DevPrivateKeyRec xnestScreenCursorFuncKeyRec;
 DevScreenPrivateKeyRec xnestScreenCursorPrivKeyRec;
@@ -53,7 +53,7 @@ xnestScreen(Window window)
     int i;
 
     for (i = 0; i < xnestNumScreens; i++)
-        if (xnestDefaultWindows[i] == window)
+        if (xnestScreenByIdx(i)->rootWindow == window)
             return screenInfo.screens[i];
 
     return NULL;
@@ -340,6 +340,7 @@ xnestOpenScreen(ScreenPtr pScreen, int argc, char *argv[])
 #define POSITION_OFFSET (pScreen->myNum * (xnestWidth + xnestHeight) / 32)
 
     if (xnestDoFullGeneration) {
+        XnestScreenPtr xnscr = xnestScreenPriv(pScreen);
 
         valuemask = CWBackPixel | CWEventMask | CWColormap;
         attributes.background_pixel = xnestWhitePixel;
@@ -348,12 +349,11 @@ xnestOpenScreen(ScreenPtr pScreen, int argc, char *argv[])
             xnestDefaultVisualColormap(xnestDefaultVisual(pScreen));
 
         if (xnestParentWindow != 0) {
-            xnestDefaultWindows[pScreen->myNum] = xnestParentWindow;
+            xnscr->rootWindow = xnestParentWindow;
-            XSelectInput(xnestDisplay, xnestDefaultWindows[pScreen->myNum],
+            XSelectInput(xnestDisplay, xnestParentWindow, xnestEventMask);
-                         xnestEventMask);
         }
         else
-            xnestDefaultWindows[pScreen->myNum] =
+            xnscr->rootWindow =
                 XCreateWindow(xnestDisplay,
                               DefaultRootWindow(xnestDisplay),
                               xnestX + POSITION_OFFSET,
@@ -378,12 +378,12 @@ xnestOpenScreen(ScreenPtr pScreen, int argc, char *argv[])
         if (xnestUserGeometry & WidthValue || xnestUserGeometry & HeightValue)
             sizeHints.flags |= USSize;
         XSetStandardProperties(xnestDisplay,
-                               xnestDefaultWindows[pScreen->myNum],
+                               xnscr->rootWindow,
                                xnestWindowName,
                                xnestWindowName,
                                xnestIconBitmap, argv, argc, &sizeHints);
 
-        XMapWindow(xnestDisplay, xnestDefaultWindows[pScreen->myNum]);
+        XMapWindow(xnestDisplay, xnscr->rootWindow);
 
         valuemask = CWBackPixmap | CWColormap;
         attributes.background_pixmap = xnestScreenSaverPixmap;
@@ -391,7 +391,7 @@ xnestOpenScreen(ScreenPtr pScreen, int argc, char *argv[])
             DefaultColormap(xnestDisplay, DefaultScreen(xnestDisplay));
         xnestScreenSaverWindows[pScreen->myNum] =
             XCreateWindow(xnestDisplay,
-                          xnestDefaultWindows[pScreen->myNum],
+                          xnscr->rootWindow,
                           0, 0, xnestWidth, xnestHeight, 0,
                           DefaultDepth(xnestDisplay,
                                        DefaultScreen(xnestDisplay)),

hw/xnest/Screen.h

@@ -18,7 +18,6 @@ is" without express or implied warranty.
 #include <X11/X.h>
 #include <X11/Xdefs.h>
 
-extern Window xnestDefaultWindows[MAXSCREENS];
 extern Window xnestScreenSaverWindows[MAXSCREENS];
 
 ScreenPtr xnestScreen(Window window);

hw/xnest/Window.c

@@ -36,6 +36,7 @@ is" without express or implied warranty.
 #include "Visual.h"
 #include "Events.h"
 #include "Args.h"
+#include "multiscreen.h"
 
 DevPrivateKeyRec xnestWindowPrivateKeyRec;
 

hw/xnest/XNWindow.h

@@ -47,7 +47,7 @@ extern DevPrivateKeyRec xnestWindowPrivateKeyRec;
 #define xnestWindowParent(pWin) \
   ((pWin)->parent ? \
    xnestWindow((pWin)->parent) : \
-   xnestDefaultWindows[pWin->drawable.pScreen->myNum])
+   xnestScreenPriv(pWin->drawable.pScreen)->rootWindow)
 
 #define xnestWindowSiblingAbove(pWin) \
   ((pWin)->prevSib ? xnestWindow((pWin)->prevSib) : None)

hw/xnest/meson.build

@@ -15,6 +15,7 @@ srcs = [
     'Screen.c',
     'Visual.c',
     'Window.c',
+    'multiscreen.c',
     '../../mi/miinitext.c',
     '../../mi/miinitext.h',
 ]

hw/xnest/multiscreen.c

@@ -0,0 +1,15 @@
+
+#include "multiscreen.h"
+#include "scrnintstr.h"
+
+XnestScreenRec xnestScreens[MAXSCREENS] = { 0 };
+
+XnestScreenPtr xnestScreenPriv(ScreenPtr pScreen)
+{
+    return &xnestScreens[pScreen->myNum];
+}
+
+XnestScreenPtr xnestScreenByIdx(int idx)
+{
+    return &xnestScreens[idx];
+}

hw/xnest/multiscreen.h

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: MIT OR X11
+ *
+ * Copyright © 2024 Enrico Weigelt, metux IT consult <info@metux.net>
+ */
+#ifndef _XNEST_MULTISCREEN_H
+#define _XNEST_MULTISCREEN_H
+
+#include <X11/X.h>
+#include <X11/Xdefs.h>
+#include <X11/Xlib.h>
+
+#include "screenint.h"
+
+typedef struct xnest_screen {
+    Window rootWindow;
+} XnestScreenRec, *XnestScreenPtr;
+
+/* retrieve private screen structure by ScreenPtr */
+XnestScreenPtr xnestScreenPriv(ScreenPtr pScreen);
+
+/* retrieve private screen structure by global index */
+XnestScreenPtr xnestScreenByIdx(int idx);
+
+#endif /* _XSERVER_CALLBACK_PRIV_H */