wmaker: improve support for RandR

This patch is improving the support for RandR.
It uses version 1.3 released in March 2009.
Most of the support is done in randr.c/randr.h
It is built on top of the mature Xinerama structure
but Xinerama lib is not required.
Like for Xinerama, RandR is now auto enabled if the
library is found at compiled time.

RandR support can be used in 2 modes:
A static mode (which is the default) is to define manually
your setup with external tools like xrandr or arandr,
like for example what Openbox is doing.

A dynamic mode, which is triggered on hotplug events,
like for example what GNOME is doing.
If a new monitor is detected, it will select the best mode
available and add it to the right on the existing monitors.

The mode can be switched with a new option available in WindowMaker
conf file (or via WPrefs expert panel):

HotplugMonitor = NO;

WPrefs.app/Expert.c

@@ -132,6 +132,11 @@ static struct expert_option {
 
 	{ N_("Allow windows to take focus using mouse wheel."),
 	  /* default: */ False, OPTION_WMAKER, "MouseWheelFocus"},
+
+#ifdef USE_RANDR
+	{ N_("Automatically (de)activate monitors on hotplug events."),
+	  /* default: */ False, OPTION_WMAKER, "HotplugMonitor"},
+#endif
 };
 
 

configure.ac

@@ -657,11 +657,11 @@ dnl RandR support
 dnl =============
 m4_divert_push([INIT_PREPARE])dnl
 AC_ARG_ENABLE([randr],
-    [AS_HELP_STRING([--enable-randr], [enable RandR extension support (NOT recommended, buggy)])],
+    [AS_HELP_STRING([--enable-randr], [enable RandR extension support for multi-monitor live reconfiguration])],
     [AS_CASE(["$enableval"],
         [yes|no], [],
         [AC_MSG_ERROR([bad value $enableval for --enable-randr]) ]) ],
-    [enable_randr=no])
+    [enable_randr=auto])
 m4_divert_pop([INIT_PREPARE])dnl
 WM_XEXT_CHECK_XRANDR
 

po/Makefile.am

@@ -27,6 +27,7 @@ POTFILES  = \
 	$(top_srcdir)/src/framewin.c \
 	$(top_srcdir)/src/geomview.c \
 	$(top_srcdir)/src/icon.c \
+	$(top_srcdir)/src/keytree.c \
 	$(top_srcdir)/src/main.c \
 	$(top_srcdir)/src/menu.c \
 	$(top_srcdir)/src/misc.c \
@@ -40,6 +41,7 @@ POTFILES  = \
 	$(top_srcdir)/src/pixmap.c \
 	$(top_srcdir)/src/placement.c \
 	$(top_srcdir)/src/properties.c \
+	$(top_srcdir)/src/randr.c \
 	$(top_srcdir)/src/resources.c \
 	$(top_srcdir)/src/rootmenu.c \
 	$(top_srcdir)/src/screen.c \

src/Makefile.am

@@ -61,6 +61,8 @@ wmaker_SOURCES = 	\
 	placement.h \
 	properties.c \
 	properties.h \
+	randr.c \
+	randr.h \
 	resources.c \
 	resources.h \
 	rootmenu.c \
@@ -195,6 +197,5 @@ defaults-callbacks-dynamic:
 		--source "$(srcdir)/defaults.c" --structure "optionList"  \
 		--field-value-ptr 4 --field-callback 5  \
 		--struct-def "wPreferences=$(srcdir)/WindowMaker.h"  \
-		--struct-def "legacy_minipreview_config=$(srcdir)/defaults.c"  \
+		--callback "getBool=char, getEnum=char, getInt=int, getString=char*"  \
-		--callback "getBool=char, getEnum=char, getInt=int"  \
 		--callback "getPathList=char*, getCoord=WCoord"

src/WindowMaker.h

@@ -410,6 +410,9 @@ extern struct WPreferences {
 
 	char dont_blink;                   /* do not blink icon selection */
 	char keep_dock_on_primary_head;    /* keep dock on primary head */
+#ifdef USE_RANDR
+	char hotplug_monitor;              /* auto-(de)activate monitors */
+#endif
 
 	/* Appearance options */
 	char new_style;                    /* Use newstyle buttons */

src/actions.c

@@ -4,7 +4,7 @@
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
  *  Copyright (c) 1998-2003 Dan Pascu
- *  Copyright (c) 2014-2023 Window Maker Team
+ *  Copyright (c) 2014-2026 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -1608,6 +1608,9 @@ void wDeiconifyWindow(WWindow *wwin)
 		}
 	}
 
+	/* Relocate to an active head if the stored position is in dead space */
+	wWindowSnapToHead(wwin);
+
 	/* if the window is in another workspace, do it silently */
 	if (!netwm_hidden) {
 #ifdef USE_ANIMATIONS
@@ -1876,6 +1879,9 @@ static void unhideWindow(WIcon *icon, int icon_x, int icon_y, WWindow *wwin, int
 
 	wwin->flags.hidden = 0;
 
+	/* Relocate to an active head if the stored position is in dead space */
+	wWindowSnapToHead(wwin);
+
 #ifdef USE_ANIMATIONS
 	if (!wwin->screen_ptr->flags.startup && !wPreferences.no_animations && animate) {
 		animateResize(wwin->screen_ptr, icon_x, icon_y,

src/defaults.c

@@ -5,7 +5,6 @@
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
  *  Copyright (c) 1998-2003 Dan Pascu
  *  Copyright (c) 2014-2026 Window Maker Team
-
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -527,6 +526,10 @@ WDefaultEntry optionList[] = {
 	{"KeepDockOnPrimaryHead", "NO", NULL,
 	    &wPreferences.keep_dock_on_primary_head, getBool, updateDock,
 	    NULL, NULL},
+#ifdef USE_RANDR
+	{"HotplugMonitor", "NO", NULL,
+	    &wPreferences.hotplug_monitor, getBool, NULL, NULL, NULL},
+#endif
 	{"HotCorners", "NO", NULL,
 	    &wPreferences.hot_corners, getBool, NULL, NULL, NULL},
 	{"HotCornerDelay", "250", (void *)&wPreferences.hot_corner_delay,

src/dock.c

@@ -3054,6 +3054,43 @@ void wDockSwap(WDock *dock)
 	wScreenUpdateUsableArea(scr);
 }
 
+/* Snap a clip back onto a visible head after a RandR reconfiguration,
+ * preserving its relative position within that head */
+void wClipSnapToHead(WDock *clip)
+{
+	WScreen *scr = clip->screen_ptr;
+	WMRect rect, head;
+	float rel_x, rel_y;
+	int x = clip->x_pos;
+	int y = clip->y_pos;
+
+	/* Already fully on a visible head, nothing to do */
+	if (!wScreenKeepInside(scr, &x, &y, ICON_SIZE, ICON_SIZE))
+		return;
+
+	rect.pos.x = clip->x_pos;
+	rect.pos.y = clip->y_pos;
+	rect.size.width  = ICON_SIZE;
+	rect.size.height = ICON_SIZE;
+
+	/* Find the nearest remaining head to the clip's old position */
+	head = wGetRectForHead(scr, wGetHeadForRect(scr, rect));
+
+	/* Compute fractional position within that head and clamp to [0..1] */
+	rel_x = (float)(clip->x_pos - head.pos.x) / (float)head.size.width;
+	rel_y = (float)(clip->y_pos - head.pos.y) / (float)head.size.height;
+
+	if (rel_x < 0.0f) rel_x = 0.0f;
+	else if (rel_x > 1.0f) rel_x = 1.0f;
+	if (rel_y < 0.0f) rel_y = 0.0f;
+	else if (rel_y > 1.0f) rel_y = 1.0f;
+
+	x = head.pos.x + (int)(rel_x * (head.size.width  - ICON_SIZE));
+	y = head.pos.y + (int)(rel_y * (head.size.height - ICON_SIZE));
+
+	moveDock(clip, x, y);
+}
+
 static pid_t execCommand(WAppIcon *btn, const char *command, WSavedState *state)
 {
 	WScreen *scr = btn->icon->core->screen_ptr;

src/dock.h

@@ -92,6 +92,7 @@ WAppIcon *wDockFindIconForWindow(WDock *dock, Window window);
 void wDockDoAutoLaunch(WDock *dock, int workspace);
 void wDockLaunchWithState(WAppIcon *btn, WSavedState *state);
 void wDockSwap(WDock *dock);
+void wClipSnapToHead(WDock *clip);
 
 #ifdef USE_DOCK_XDND
 int wDockReceiveDNDDrop(WScreen *scr, XEvent *event);

src/event.c

@@ -3,7 +3,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
- *  Copyright (c) 2014-2023 Window Maker Team
+ *  Copyright (c) 2014-2026 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -46,7 +46,7 @@
 #endif
 
 #ifdef USE_RANDR
-#include <X11/extensions/Xrandr.h>
+#include "randr.h"
 #endif
 
 #include <X11/XKBlib.h>
@@ -271,10 +271,6 @@ void DispatchEvent(XEvent * event)
 		break;
 
 	case ConfigureNotify:
-#ifdef USE_RANDR
-		if (event->xconfigure.window == DefaultRootWindow(dpy))
-			XRRUpdateConfiguration(event);
-#endif
 		break;
 
 	case SelectionRequest:
@@ -618,14 +614,14 @@ static void handleExtensions(XEvent * event)
 #endif /*KEEP_XKB_LOCK_STATUS */
 	}
 #ifdef USE_RANDR
-	if (w_global.xext.randr.supported && event->type == (w_global.xext.randr.event_base + RRScreenChangeNotify)) {
+	if (w_global.xext.randr.supported &&
-		/* From xrandr man page: "Clients must call back into Xlib using
+	    (event->type == (w_global.xext.randr.event_base + RRScreenChangeNotify) ||
-		 * XRRUpdateConfiguration when screen configuration change notify
+	     event->type == (w_global.xext.randr.event_base + RRNotify))) {
-		 * events are generated */
+		WScreen *randr_scr;
-		XRRUpdateConfiguration(event);
+
-		WCHANGE_STATE(WSTATE_RESTARTING);
+		randr_scr = wScreenForRootWindow(event->xany.window);
-		Shutdown(WSRestartPreparationMode);
+		if (randr_scr)
-		Restart(NULL,True);
+			wRandRHandleNotify(randr_scr, event);
 	}
 #endif
 }

src/moveres.c

@@ -457,11 +457,10 @@ static void drawTransparentFrame(WWindow * wwin, int x, int y, int width, int he
 	GC gc = wwin->screen_ptr->frame_gc;
 	int h = 0;
 	int bottom = 0;
+	int fb = 0;
 
-	if (HAS_BORDER_WITH_SELECT(wwin)) {
+	if (HAS_BORDER_WITH_SELECT(wwin))
-		x += wwin->screen_ptr->frame_border_width;
+		fb = wwin->screen_ptr->frame_border_width;
-		y += wwin->screen_ptr->frame_border_width;
-	}
 
 	if (HAS_TITLEBAR(wwin) && !wwin->flags.shaded) {
 		h = WMFontHeight(wwin->screen_ptr->title_font) + (wPreferences.window_title_clearance +
@@ -478,13 +477,13 @@ static void drawTransparentFrame(WWindow * wwin, int x, int y, int width, int he
 		   (e.g. interactive placement), frame does not point to anything. */
 		bottom = RESIZEBAR_HEIGHT;
 	}
-	XDrawRectangle(dpy, root, gc, x - 1, y - 1, width + 1, height + 1);
+	XDrawRectangle(dpy, root, gc, x, y, width - 1 + 2 * fb, height - 1 + 2 * fb);
 
 	if (h > 0) {
-		XDrawLine(dpy, root, gc, x, y + h - 1, x + width, y + h - 1);
+		XDrawLine(dpy, root, gc, x, y + fb + h - 1, x + 2 * fb + width, y + fb + h - 1);
 	}
 	if (bottom > 0) {
-		XDrawLine(dpy, root, gc, x, y + height - bottom, x + width, y + height - bottom);
+		XDrawLine(dpy, root, gc, x, y + fb + height - bottom, x + 2 * fb + width, y + fb + height - bottom);
 	}
 }
 
@@ -1200,7 +1199,7 @@ updateWindowPosition(WWindow * wwin, MoveData * data, Bool doResistance,
 static void draw_snap_frame(WWindow *wwin, int direction)
 {
 	WScreen *scr;
-	int head, x, y;
+	int head, x, y, fb;
 	unsigned int width, height;
 	WMRect rect;
 
@@ -1212,6 +1211,7 @@ static void draw_snap_frame(WWindow *wwin, int direction)
 	y = rect.pos.y;
 	width = rect.size.width;
 	height = rect.size.height;
+	fb = HAS_BORDER_WITH_SELECT(wwin) ? 2 * wwin->screen_ptr->frame_border_width : 0;
 
 	switch (direction) {
 	case SNAP_LEFT:
@@ -1258,7 +1258,7 @@ static void draw_snap_frame(WWindow *wwin, int direction)
 		break;
 	}
 
-	drawTransparentFrame(wwin, x, y, width, height);
+	drawTransparentFrame(wwin, x, y, width - fb, height - fb);
 }
 
 static int get_snap_direction(WScreen *scr, int x, int y)

src/randr.c

@@ -0,0 +1,629 @@
+/* randr.c - RandR multi-monitor support
+ *
+ *  Window Maker window manager
+ *
+ *  Copyright (c) 2026 Window Maker Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "wconfig.h"
+
+#ifdef USE_RANDR
+
+#include <string.h>
+#include <X11/Xlib.h>
+
+#include "randr.h"
+#include "window.h"
+#include "framewin.h"
+#include "xinerama.h"
+#include "wmspec.h"
+#include "dock.h"
+#include "workspace.h"
+#include "actions.h"
+
+#define RANDR_MAX_OUTPUTS     32
+#define RANDR_DEBOUNCE_DELAY  100   /* milliseconds */
+
+typedef struct {
+    RROutput xid;
+    RRCrtc crtc;
+    int x, y, w, h;
+    Rotation rotation;     /* current CRTC rotation */
+    Bool connected;        /* RR_Connected */
+    Bool stale;            /* mark-scan scratch flag */
+    char name[64];
+} WRandROutput;
+
+typedef struct {
+    WRandROutput outputs[RANDR_MAX_OUTPUTS];
+    int n_outputs;
+} WRandRState;
+
+/* Initial output scan to populate state from scratch */
+static void wRandR_Scan(WScreen *scr, WRandRState *state)
+{
+    XRRScreenResources *sr;
+    int i;
+
+    state->n_outputs = 0;
+
+    sr = XRRGetScreenResourcesCurrent(dpy, scr->root_win);
+    if (!sr)
+        return;
+
+    for (i = 0; i < sr->noutput && state->n_outputs < RANDR_MAX_OUTPUTS; i++) {
+        XRROutputInfo *oi;
+        WRandROutput *o;
+
+        oi = XRRGetOutputInfo(dpy, sr, sr->outputs[i]);
+        if (!oi)
+            continue;
+
+        o = &state->outputs[state->n_outputs++];
+        memset(o, 0, sizeof(*o));
+        o->xid = sr->outputs[i];
+        o->connected = (oi->connection == RR_Connected);
+        o->crtc = oi->crtc;
+        strncpy(o->name, oi->name, sizeof(o->name) - 1);
+
+        if (oi->crtc != None) {
+            XRRCrtcInfo *ci = XRRGetCrtcInfo(dpy, sr, oi->crtc);
+            if (ci) {
+                o->x = ci->x;
+                o->y = ci->y;
+                o->w = ci->width;
+                o->h = ci->height;
+                o->rotation = ci->rotation;
+                XRRFreeCrtcInfo(ci);
+            }
+        }
+
+        XRRFreeOutputInfo(oi);
+    }
+
+    XRRFreeScreenResources(sr);
+}
+
+/* Primary head detection */
+static int wRandR_PrimaryHeadIndex(Window root, const RROutput *xids, int count)
+{
+    RROutput primary_xid = XRRGetOutputPrimary(dpy, root);
+    int i;
+
+    if (primary_xid != None) {
+        for (i = 0; i < count; i++) {
+            if (xids[i] == primary_xid)
+                return i;
+        }
+    }
+    return 0;
+}
+
+/* Push RandR geometry into the Xinerama head layer */
+static void wRandR_ApplyToXinerama(WScreen *scr, WRandRState *state)
+{
+    WMRect new_screens[RANDR_MAX_OUTPUTS];
+    RROutput new_xids[RANDR_MAX_OUTPUTS];   /* parallel: XID of each head */
+    int count = 0;
+    int old_count;
+    int i;
+
+    for (i = 0; i < state->n_outputs && count < RANDR_MAX_OUTPUTS; i++) {
+        WRandROutput *o = &state->outputs[i];
+        int j, dup = 0;
+
+        /* Collect outputs that are truly active */
+        if (o->crtc == None || o->w == 0 || o->h == 0)
+            continue;
+
+        /* Deduplicate mirrored outputs that share the same CRTC origin */
+        for (j = 0; j < count; j++) {
+            if (new_screens[j].pos.x == o->x && new_screens[j].pos.y == o->y) {
+                dup = 1;
+                break;
+            }
+        }
+        if (dup)
+            continue;
+
+        new_screens[count].pos.x = o->x;
+        new_screens[count].pos.y = o->y;
+        new_screens[count].size.width = o->w;
+        new_screens[count].size.height = o->h;
+        new_xids[count] = o->xid;
+        count++;
+    }
+
+    /* Fallback: if every output disappeared, use the full virtual screen so
+     * we never end up with zero heads */
+    if (count == 0) {
+        new_screens[0].pos.x = 0;
+        new_screens[0].pos.y = 0;
+        new_screens[0].size.width = scr->scr_width;
+        new_screens[0].size.height = scr->scr_height;
+        new_xids[0] = None;
+        count = 1;
+    }
+
+    old_count = wXineramaHeads(scr);
+
+    /* Replace the screens array */
+    if (scr->xine_info.screens)
+        wfree(scr->xine_info.screens);
+
+    scr->xine_info.screens = wmalloc(sizeof(WMRect) * (count + 1));
+    memcpy(scr->xine_info.screens, new_screens, sizeof(WMRect) * count);
+    scr->xine_info.count = count;
+
+    scr->xine_info.primary_head = wRandR_PrimaryHeadIndex(scr->root_win, new_xids, count);
+
+    /* Refresh cached screen dimensions (updated by XRRUpdateConfiguration) */
+    scr->scr_width = WidthOfScreen(ScreenOfDisplay(dpy, scr->screen));
+    scr->scr_height = HeightOfScreen(ScreenOfDisplay(dpy, scr->screen));
+
+    /* Reallocate per-head usable area arrays if the head count changed */
+    if (old_count != count) {
+        wfree(scr->usableArea);
+        wfree(scr->totalUsableArea);
+        scr->usableArea = wmalloc(sizeof(WArea) * count);
+        scr->totalUsableArea = wmalloc(sizeof(WArea) * count);
+    }
+
+    /* Seed usable areas from new geometry */
+    for (i = 0; i < count; i++) {
+        WMRect *r = &scr->xine_info.screens[i];
+
+        scr->usableArea[i].x1 = scr->totalUsableArea[i].x1 = r->pos.x;
+        scr->usableArea[i].y1 = scr->totalUsableArea[i].y1 = r->pos.y;
+        scr->usableArea[i].x2 = scr->totalUsableArea[i].x2 = r->pos.x + r->size.width;
+        scr->usableArea[i].y2 = scr->totalUsableArea[i].y2 = r->pos.y + r->size.height;
+    }
+}
+
+/* Bring any off-screen windows in */
+static void wRandR_BringAllWindowsInside(WScreen *scr)
+{
+    WWindow *wwin;
+    int i;
+
+    for (wwin = scr->focused_window; wwin != NULL; wwin = wwin->prev) {
+        int bw, wx, wy, ww, wh;
+        int fully_inside = 0;
+
+        if (!wwin->flags.mapped || wwin->flags.hidden)
+            continue;
+
+        bw = HAS_BORDER(wwin) ? scr->frame_border_width : 0;
+        wx = wwin->frame_x - bw;
+        wy = wwin->frame_y - bw;
+        ww = (int)wwin->frame->core->width  + 2 * bw;
+        wh = (int)wwin->frame->core->height + 2 * bw;
+
+        /* Skip windows already fully contained within a surviving head */
+        for (i = 0; i < wXineramaHeads(scr); i++) {
+            WMRect r = wGetRectForHead(scr, i);
+            if (wx >= r.pos.x && wy >= r.pos.y &&
+                wx + ww <= r.pos.x + (int)r.size.width &&
+                wy + wh <= r.pos.y + (int)r.size.height) {
+                fully_inside = 1;
+                break;
+            }
+        }
+
+        if (!fully_inside)
+            wWindowSnapToHead(wwin);
+    }
+}
+
+/* Auto-deactivate a physically disconnected output that still holds a CRTC
+ *
+ * When a cable is pulled or monitor turned off, the X server sets
+ * connection=RR_Disconnected but does NOT free the CRTC automatically.
+ * We must call XRRSetCrtcConfig with mode=None to release it,
+ * which causes the server to fire a fresh batch of RandR events.
+ *
+ * Returns True if at least one CRTC was freed */
+static Bool wRandR_AutoDeactivate(WScreen *scr, WRandRState *state, XRRScreenResources *sr)
+{
+    Bool deactivated = False;
+    int i;
+
+    for (i = 0; i < state->n_outputs; i++) {
+        WRandROutput *o = &state->outputs[i];
+        Status ret;
+
+        if (o->connected || o->crtc == None || o->stale)
+            continue;
+
+        /* Release the CRTC: no mode, no outputs */
+        ret = XRRSetCrtcConfig(dpy, sr, o->crtc, sr->timestamp,
+                               0, 0, None, RR_Rotate_0, NULL, 0);
+        if (ret == RRSetConfigSuccess) {
+            wwarning("RandR: released CRTC for disconnected output %s", o->name);
+            o->crtc = None;
+            o->w = o->h = 0;
+            deactivated = True;
+        } else {
+            wwarning("RandR: failed to release CRTC for output %s", o->name);
+        }
+    }
+
+    /* Compact and shrink the virtual framebuffer to the bounding box of remaining active outputs */
+    if (deactivated) {
+        int min_x = scr->scr_width;
+        int max_x = 0, max_y = 0;
+        int j;
+
+        for (i = 0; i < state->n_outputs; i++) {
+            WRandROutput *a = &state->outputs[i];
+
+            if (a->crtc == None || a->w == 0 || a->h == 0)
+                continue;
+
+            if (a->x < min_x) min_x = a->x;
+            if (a->x + a->w > max_x) max_x = a->x + a->w;
+            if (a->y + a->h > max_y) max_y = a->y + a->h;
+        }
+
+        /* Slide surviving outputs left to eliminate dead space at the origin */
+        if (min_x > 0 && max_x > 0) {
+            for (i = 0; i < state->n_outputs; i++) {
+                WRandROutput *a = &state->outputs[i];
+                XRRCrtcInfo *ci;
+
+                if (a->crtc == None || a->w == 0 || a->h == 0)
+                    continue;
+
+                ci = XRRGetCrtcInfo(dpy, sr, a->crtc);
+                if (!ci)
+                    continue;
+
+                XRRSetCrtcConfig(dpy, sr, a->crtc, sr->timestamp,
+                                 a->x - min_x, a->y,
+                                 ci->mode, ci->rotation,
+                                 ci->outputs, ci->noutput);
+
+                for (j = 0; j < state->n_outputs; j++) {
+                    if (state->outputs[j].crtc == a->crtc)
+                        state->outputs[j].x -= min_x;
+                }
+
+                XRRFreeCrtcInfo(ci);
+            }
+            max_x -= min_x;
+        }
+
+        /* Shrink the virtual framebuffer down to the compacted bounding box */
+        if (max_x > 0 && max_y > 0 &&
+            (max_x < scr->scr_width || max_y < scr->scr_height)) {
+            int mm_w = (int)((long)WidthMMOfScreen(ScreenOfDisplay(dpy, scr->screen))
+                              * max_x / scr->scr_width);
+            int mm_h = (int)((long)HeightMMOfScreen(ScreenOfDisplay(dpy, scr->screen))
+                              * max_y / scr->scr_height);
+            XRRSetScreenSize(dpy, scr->root_win, max_x, max_y, mm_w, mm_h);
+        }
+    }
+
+    return deactivated;
+}
+
+/* Auto-activate a newly connected output that has no CRTC assigned yet
+ *
+ * Mirrors "xrandr --auto": find a free CRTC, pick the preferred mode,
+ * place the new head to the right of all active outputs,
+ * expand the virtual framebuffer if needed, then call XRRSetCrtcConfig.
+ *
+ * Returns True if at least one output was activated */
+static Bool wRandR_AutoActivate(WScreen *scr, WRandRState *state, XRRScreenResources *sr)
+{
+    Bool activated = False;
+    int i, j;
+
+    for (i = 0; i < state->n_outputs; i++) {
+        WRandROutput *o = &state->outputs[i];
+        XRROutputInfo *oi;
+        RRCrtc free_crtc = None;
+        Rotation rotation = RR_Rotate_0;
+        RRMode best_mode = None;
+        int mode_w = 0, mode_h = 0;
+        int new_x = 0;
+        int new_vw, new_vh;
+        Status ret;
+
+        /* Only process newly connected outputs that have no CRTC yet */
+        if (!o->connected || o->crtc != None)
+            continue;
+
+        oi = XRRGetOutputInfo(dpy, sr, o->xid);
+        if (!oi)
+            continue;
+
+        if (oi->ncrtc == 0 || oi->nmode == 0) {
+            XRRFreeOutputInfo(oi);
+            continue;
+        }
+
+        /* Find a free CRTC that is idle and capable of driving this output */
+        for (j = 0; j < oi->ncrtc; j++) {
+            XRRCrtcInfo *ci = XRRGetCrtcInfo(dpy, sr, oi->crtcs[j]);
+            if (ci) {
+                if (ci->noutput == 0) {
+                    int k;
+
+                    for (k = 0; k < (int)ci->npossible; k++) {
+                        if (ci->possible[k] == o->xid) {
+                            free_crtc = oi->crtcs[j];
+                            if (ci->rotations & RR_Rotate_0)
+                                rotation = RR_Rotate_0;
+                            else if (ci->rotations & RR_Rotate_90)
+                                rotation = RR_Rotate_90;
+                            else if (ci->rotations & RR_Rotate_180)
+                                rotation = RR_Rotate_180;
+                            else
+                                rotation = RR_Rotate_270;
+                            break;
+                        }
+                    }
+                }
+                XRRFreeCrtcInfo(ci);
+            }
+            if (free_crtc != None)
+                break;
+        }
+
+        if (free_crtc == None) {
+            wwarning("RandR: no free CRTC for output %s", o->name);
+            XRRFreeOutputInfo(oi);
+            continue;
+        }
+
+        /* Preferred mode is first in the list (per RandR spec) */
+        best_mode = oi->modes[0];
+        XRRFreeOutputInfo(oi);
+
+        /* Look up its pixel dimensions in sr->modes[] */
+        for (j = 0; j < sr->nmode; j++) {
+            if (sr->modes[j].id == best_mode) {
+                mode_w = (int)sr->modes[j].width;
+                mode_h = (int)sr->modes[j].height;
+                break;
+            }
+        }
+
+        if (mode_w == 0 || mode_h == 0)
+            continue;
+
+        /* Position it to the right of all currently active outputs, same as GNOME */
+        for (j = 0; j < state->n_outputs; j++) {
+            WRandROutput *a = &state->outputs[j];
+
+            if (a->crtc != None && a->w > 0) {
+                int right = a->x + a->w;
+
+                if (right > new_x)
+                    new_x = right;
+            }
+        }
+
+        /* Expand virtual framebuffer if the new head exceeds current size */
+        new_vw = new_x + mode_w;
+        new_vh = mode_h > scr->scr_height ? mode_h : scr->scr_height;
+
+        if (new_vw > scr->scr_width || new_vh > scr->scr_height) {
+            int mm_w = (int)((long)WidthMMOfScreen(ScreenOfDisplay(dpy, scr->screen))
+                          * new_vw / scr->scr_width);
+            int mm_h = (int)((long)HeightMMOfScreen(ScreenOfDisplay(dpy, scr->screen))
+                          * new_vh / scr->scr_height);
+            XRRSetScreenSize(dpy, scr->root_win, new_vw, new_vh, mm_w, mm_h);
+        }
+
+        ret = XRRSetCrtcConfig(dpy, sr, free_crtc, sr->timestamp,
+                               new_x, 0, best_mode, rotation,
+                               &o->xid, 1);
+        if (ret == RRSetConfigSuccess) {
+            wwarning("RandR: auto-activated output %s at +%d+0", o->name, new_x);
+            activated = True;
+        } else {
+            wwarning("RandR: failed to auto-activate output %s", o->name);
+        }
+    }
+
+    return activated;
+}
+
+/* Synchronize RandR state with the X server */
+static void wRandR_Update(WScreen *scr)
+{
+    WRandRState *state = (WRandRState *)scr->randr_state;
+    XRRScreenResources *sr;
+    int i, j;
+
+    /* Assume all outputs removed until server confirms */
+    for (i = 0; i < state->n_outputs; i++)
+        state->outputs[i].stale = True;
+
+    /* Re-query server, update or add outputs */
+    sr = XRRGetScreenResourcesCurrent(dpy, scr->root_win);
+    if (!sr) {
+        wwarning("wRandR_Update: XRRGetScreenResourcesCurrent failed");
+        return;
+    }
+
+    for (i = 0; i < sr->noutput; i++) {
+        XRROutputInfo *oi;
+        WRandROutput *found = NULL;
+
+        oi = XRRGetOutputInfo(dpy, sr, sr->outputs[i]);
+        if (!oi)
+            continue;
+
+        /* Match by XID (stable across reconfigures) */
+        for (j = 0; j < state->n_outputs; j++) {
+            if (state->outputs[j].xid == sr->outputs[i]) {
+                found = &state->outputs[j];
+                break;
+            }
+        }
+
+        /* Append new output not seen before */
+        if (!found && state->n_outputs < RANDR_MAX_OUTPUTS) {
+            found = &state->outputs[state->n_outputs++];
+            memset(found, 0, sizeof(*found));
+            found->xid = sr->outputs[i];
+            strncpy(found->name, oi->name, sizeof(found->name) - 1);
+        }
+
+        if (found) {
+            found->stale = False;
+            found->connected = (oi->connection == RR_Connected);
+            found->crtc = oi->crtc;
+            found->w = 0;
+            found->h = 0;
+            found->rotation = RR_Rotate_0;
+
+            if (oi->crtc != None) {
+                XRRCrtcInfo *ci = XRRGetCrtcInfo(dpy, sr, oi->crtc);
+                if (ci) {
+                    found->x = ci->x;
+                    found->y = ci->y;
+                    found->w = ci->width;
+                    found->h = ci->height;
+                    found->rotation = ci->rotation;
+                    XRRFreeCrtcInfo(ci);
+                }
+            }
+        }
+
+        XRRFreeOutputInfo(oi);
+    }
+
+    /* When HotplugMonitor is enabled, actively manage CRTC lifecycle */
+    if (wPreferences.hotplug_monitor) {
+        Bool changed;
+
+        changed  = wRandR_AutoDeactivate(scr, state, sr);
+        changed |= wRandR_AutoActivate(scr, state, sr);
+        if (changed) {
+            XRRFreeScreenResources(sr);
+            return;
+        }
+    }
+
+    XRRFreeScreenResources(sr);
+
+    /* Remove outputs not reported by server at all */
+    for (i = 0, j = 0; i < state->n_outputs; i++) {
+        if (!state->outputs[i].stale) {
+            if (j != i)
+                state->outputs[j] = state->outputs[i];
+            j++;
+        }
+    }
+    state->n_outputs = j;
+
+    /* Apply new geometry to the Xinerama head layer */
+    i = scr->xine_info.primary_head;
+    wRandR_ApplyToXinerama(scr, state);
+
+    /* Move the dock if needed */
+    if (scr->dock &&
+        ((scr->xine_info.primary_head != i && wPreferences.keep_dock_on_primary_head) ||
+         scr->dock->x_pos < 0 ||
+         scr->dock->x_pos >= scr->scr_width))
+        wDockSwap(scr->dock);
+
+    /* Snap each workspace clip back onto a visible head if it ended up
+     * outside the (now smaller or rearranged) virtual framebuffer */
+    if (!wPreferences.flags.noclip) {
+        int k;
+
+        for (k = 0; k < scr->workspace_count; k++) {
+            WDock *clip = scr->workspaces[k]->clip;
+
+            if (clip)
+                wClipSnapToHead(clip);
+        }
+    }
+
+    /* Refresh usable areas and EWMH hints */
+    wScreenUpdateUsableArea(scr);
+    wNETWMUpdateWorkarea(scr);
+
+    /* Bring any windows that ended up in dead space to an active head */
+    wRandR_BringAllWindowsInside(scr);
+
+    /* Rearrange miniaturized and appicons into the icon yard */
+    wArrangeIcons(scr, True);
+}
+
+static void wRandRDebounceTimerFired(void *data)
+{
+    WScreen *scr = (WScreen *)data;
+
+    scr->randr_debounce_timer = NULL;
+    wRandR_Update(scr);
+}
+
+/* end of local stuff */
+
+void wRandRInit(WScreen *scr)
+{
+    WRandRState *state;
+
+    if (!w_global.xext.randr.supported)
+        return;
+
+    state = wmalloc(sizeof(WRandRState));
+    memset(state, 0, sizeof(*state));
+    scr->randr_state = state;
+
+    wRandR_Scan(scr, state);
+    wRandR_ApplyToXinerama(scr, state);
+}
+
+void wRandRTeardown(WScreen *scr)
+{
+    if (!scr->randr_state)
+        return;
+
+    if (scr->randr_debounce_timer) {
+        WMDeleteTimerHandler(scr->randr_debounce_timer);
+        scr->randr_debounce_timer = NULL;
+    }
+
+    wfree(scr->randr_state);
+    scr->randr_state = NULL;
+}
+
+void wRandRHandleNotify(WScreen *scr, XEvent *event)
+{
+    if (!scr || !scr->randr_state)
+        return;
+
+    if (event->type == (w_global.xext.randr.event_base + RRScreenChangeNotify))
+        XRRUpdateConfiguration(event);
+
+    /* Debounce: cancel any pending timer, then restart it */
+    if (scr->randr_debounce_timer) {
+        WMDeleteTimerHandler(scr->randr_debounce_timer);
+        scr->randr_debounce_timer = NULL;
+    }
+    scr->randr_debounce_timer =
+        WMAddTimerHandler(RANDR_DEBOUNCE_DELAY, wRandRDebounceTimerFired, scr);
+}
+
+#endif /* USE_RANDR */

src/randr.h

@@ -0,0 +1,36 @@
+/* randr.h - RandR multi-monitor support
+ *
+ *  Window Maker window manager
+ *
+ *  Copyright (c) 2026 Window Maker Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _WMRANDR_H_
+#define _WMRANDR_H_
+
+#ifdef USE_RANDR
+
+#include <X11/extensions/Xrandr.h>
+#include "screen.h"
+
+void wRandRInit(WScreen *scr);
+void wRandRTeardown(WScreen *scr);
+void wRandRHandleNotify(WScreen *scr, XEvent *event);
+
+#endif /* USE_RANDR */
+
+#endif /* _WMRANDR_H_ */

src/screen.c

@@ -34,7 +34,7 @@
 #include <X11/Xatom.h>
 #include <X11/XKBlib.h>
 #ifdef USE_RANDR
-#include <X11/extensions/Xrandr.h>
+#include "randr.h"
 #endif
 
 #include <wraster.h>
@@ -642,6 +642,10 @@ WScreen *wScreenInit(int screen_number)
 		scr->usableArea[i].y2 = scr->totalUsableArea[i].y2 = rect.pos.y + rect.size.height;
 	}
 
+#ifdef USE_RANDR
+	wRandRInit(scr);
+#endif
+
 	scr->fakeGroupLeaders = WMCreateArray(16);
 
 	CantManageScreen = 0;
@@ -669,7 +673,10 @@ WScreen *wScreenInit(int screen_number)
 
 #ifdef USE_RANDR
 	if (w_global.xext.randr.supported)
-		XRRSelectInput(dpy, scr->root_win, RRScreenChangeNotifyMask);
+		XRRSelectInput(dpy, scr->root_win,
+		               RRScreenChangeNotifyMask |
+		               RRCrtcChangeNotifyMask   |
+		               RROutputChangeNotifyMask);
 #endif
 
 	XSync(dpy, False);
@@ -1367,3 +1374,13 @@ void ScreenCapture(WScreen *scr, int mode)
 	wfree(filepath);
 	wfree(screenshot_dir);
 }
+
+void wScreenDestroy(WScreen *scr)
+{
+#ifdef USE_RANDR
+	wRandRTeardown(scr);
+#else
+	/* Parameter not used, but tell the compiler that it is ok */
+	(void) scr;
+#endif
+}

src/screen.h

@@ -299,6 +299,11 @@ typedef struct _WScreen {
     /* for hot-corners delay */
     WMHandlerID *hot_corner_timer;
 
+#ifdef USE_RANDR
+    WMHandlerID *randr_debounce_timer;
+    void *randr_state;
+#endif
+
     /* for window shortcuts */
     WMArray *shortcutWindows[MAX_WINDOW_SHORTCUTS];
 
@@ -345,7 +350,7 @@ WScreen *wScreenWithNumber(int i);
 WScreen *wScreenForRootWindow(Window window);   /* window must be valid */
 WScreen *wScreenForWindow(Window window);   /* slower than above functions */
 
-void wScreenFinish(WScreen *scr);
+void wScreenDestroy(WScreen *scr);
 void wScreenUpdateUsableArea(WScreen *scr);
 
 void create_logo_image(WScreen *scr);

src/shutdown.c

@@ -36,6 +36,7 @@
 #include "winspector.h"
 #include "wmspec.h"
 #include "colormap.h"
+#include "screen.h"
 #include "shutdown.h"
 
 
@@ -81,6 +82,7 @@ void Shutdown(WShutdownMode mode)
 					wipeDesktop(scr);
 				else
 					RestoreDesktop(scr);
+				wScreenDestroy(scr);
 			}
 		}
 		ExecExitScript();
@@ -103,6 +105,7 @@ void Shutdown(WShutdownMode mode)
 					kill(scr->helper_pid, SIGKILL);
 				wScreenSaveState(scr);
 				RestoreDesktop(scr);
+				wScreenDestroy(scr);
 			}
 		}
 		break;

src/startup.c

@@ -600,7 +600,23 @@ void StartUp(Bool defaultScreenOnly)
 #endif
 
 #ifdef USE_RANDR
-	w_global.xext.randr.supported = XRRQueryExtension(dpy, &w_global.xext.randr.event_base, &j);
+	{
+		int rr_major = 0, rr_minor = 0;
+		Bool rr_ext = XRRQueryExtension(dpy, &w_global.xext.randr.event_base, &j);
+		Bool rr_ver = rr_ext && XRRQueryVersion(dpy, &rr_major, &rr_minor);
+
+		if (rr_ver && (rr_major > 1 || (rr_major == 1 && rr_minor >= 3))) {
+			w_global.xext.randr.supported = 1;
+		} else {
+			w_global.xext.randr.supported = 0;
+			if (!rr_ext)
+				wwarning(_("RandR extension is not available"));
+			else if (!rr_ver)
+				wwarning(_("RandR version check failed, RandR disabled"));
+			else
+				wwarning(_("RandR version %d.%d found but RandR version >=1.3 required"), rr_major, rr_minor);
+		}
+	}
 #endif
 
 	w_global.xext.xkb.supported = XkbQueryExtension(dpy, NULL, &w_global.xext.xkb.event_base, NULL, NULL, NULL);

src/window.c

@@ -2294,6 +2294,26 @@ void wWindowMove(WWindow *wwin, int req_x, int req_y)
 #endif
 }
 
+/* Move the window to the nearest on-screen position if its stored
+ * frame origin falls in dead space (for example when a RandR monitor
+ * was removed while the window was miniaturized or hidden) */
+void wWindowSnapToHead(WWindow *wwin)
+{
+#ifdef USE_RANDR
+	int bw = HAS_BORDER(wwin) ? wwin->screen_ptr->frame_border_width : 0;
+	int rx = wwin->frame_x - bw;
+	int ry = wwin->frame_y - bw;
+
+	if (wScreenBringInside(wwin->screen_ptr, &rx, &ry,
+	                       wwin->frame->core->width  + 2 * bw,
+	                       wwin->frame->core->height + 2 * bw))
+		wWindowMove(wwin, rx + bw, ry + bw);
+#else
+	/* Parameter not used, but tell the compiler that it is ok */
+	(void) wwin;
+#endif
+}
+
 void wWindowUpdateButtonImages(WWindow *wwin)
 {
 	WScreen *scr = wwin->screen_ptr;

src/window.h

@@ -362,6 +362,7 @@ void wWindowConfigure(WWindow *wwin, int req_x, int req_y,
                       int req_width, int req_height);
 
 void wWindowMove(WWindow *wwin, int req_x, int req_y);
+void wWindowSnapToHead(WWindow *wwin);
 
 void wWindowSynthConfigureNotify(WWindow *wwin);