[Spice-devel] [PATCH][vdagent] x11-randr: Force a screen resize when a display is disabled

[Fabiano Fidêncio]

When a display is disabled the new monitors config is sent to the agent
who should be responsible for re-arranging the apps on the non-disabled
displays (at least when using the ums driver).

Related: https://bugzilla.redhat.com/show_bug.cgi?id=1111425
---
 src/vdagent-x11-randr.c | 69 ++++++++++++++++++++++++++++++-------------------
 1 file changed, 42 insertions(+), 27 deletions(-)

diff --git a/src/vdagent-x11-randr.c b/src/vdagent-x11-randr.c
index 46367bc..ed63908 100644
--- a/src/vdagent-x11-randr.c
+++ b/src/vdagent-x11-randr.c
@@ -676,6 +676,42 @@ static void dump_monitors_config(struct vdagent_x11 *x11,
     }
 }
 
+static int resize_randr_screen(struct vdagent_x11 *x11,
+                               VDAgentMonitorsConfig *mon_config,
+                               VDAgentMonitorsConfig *curr_config,
+                               int width,
+                               int height,
+                               int fallback)
+{
+    const int dpi = 96; /* FIXME: read settings from desktop or get from client dpi? */
+    int width_mm = (MM_PER_INCH * width) / dpi;
+    int height_mm = (MM_PER_INCH * height) / dpi;
+
+    if (x11->debug)
+        syslog(LOG_DEBUG, "Changing screen size to %dx%d", width, height);
+
+    vdagent_x11_set_error_handler(x11, error_handler);
+    XRRSetScreenSize(x11->display, x11->root_window[0], width, height, width_mm, height_mm);
+    if (vdagent_x11_restore_error_handler(x11)) {
+        syslog(LOG_ERR, "XRRSetScreenSize failed, not enough mem?");
+        if (!fallback && curr_config) {
+            syslog(LOG_WARNING, "Restoring previous config");
+            vdagent_x11_set_monitor_config(x11, curr_config, 1);
+            free(curr_config);
+            /* Remember this config failed, if the client is maximized or
+               fullscreen it will keep sending the failing config. */
+            free(x11->randr.failed_conf);
+            x11->randr.failed_conf =
+                malloc(config_size(mon_config->num_of_monitors));
+            if (x11->randr.failed_conf)
+                memcpy(x11->randr.failed_conf, mon_config,
+                       config_size(mon_config->num_of_monitors));
+            return 0;
+        }
+    }
+    return 1;
+}
+
 /*
  * Set monitor configuration according to client request.
  *
@@ -781,33 +817,8 @@ void vdagent_x11_set_monitor_config(struct vdagent_x11 *x11,
 
     /* Then we can resize the RandR screen. */
     if (primary_w != x11->width[0] || primary_h != x11->height[0]) {
-        const int dpi = 96; /* FIXME: read settings from desktop or get from client dpi? */
-        int width_mm = (MM_PER_INCH * primary_w) / dpi;
-        int height_mm = (MM_PER_INCH * primary_h) / dpi;
-
-        if (x11->debug)
-            syslog(LOG_DEBUG, "Changing screen size to %dx%d",
-                   primary_w, primary_h);
-        vdagent_x11_set_error_handler(x11, error_handler);
-        XRRSetScreenSize(x11->display, x11->root_window[0], primary_w, primary_h,
-                         width_mm, height_mm);
-        if (vdagent_x11_restore_error_handler(x11)) {
-            syslog(LOG_ERR, "XRRSetScreenSize failed, not enough mem?");
-            if (!fallback && curr) {
-                syslog(LOG_WARNING, "Restoring previous config");
-                vdagent_x11_set_monitor_config(x11, curr, 1);
-                free(curr);
-                /* Remember this config failed, if the client is maximized or
-                   fullscreen it will keep sending the failing config. */
-                free(x11->randr.failed_conf);
-                x11->randr.failed_conf =
-                    malloc(config_size(mon_config->num_of_monitors));
-                if (x11->randr.failed_conf)
-                    memcpy(x11->randr.failed_conf, mon_config,
-                           config_size(mon_config->num_of_monitors));
-                return;
-            }
-        }
+        if (!resize_randr_screen(x11, mon_config, curr, primary_w, primary_h, fallback))
+            return;
     }
 
     /* Finally, we set the new resolutions on RandR CRTCs now that the
@@ -832,6 +843,10 @@ void vdagent_x11_set_monitor_config(struct vdagent_x11 *x11,
         }
     }
 
+    /* Force a screen resize to re-arrange apps on non-disabled monitors */
+    if (!resize_randr_screen(x11, mon_config, curr, primary_w, primary_h, fallback))
+        return;
+
     update_randr_res(x11,
         x11->randr.num_monitors != enabled_monitors(mon_config));
     x11->width[0] = primary_w;
-- 
2.1.0