From 7d6ecb51f66b65221a5df56f2e4907f7a65f4ee4 Mon Sep 17 00:00:00 2001
From: Christophe CURIS <christophe.curis@free.fr>
Date: Mon, 15 Dec 2014 23:22:21 +0100
Subject: [PATCH] wmaker: rewrote the update of _NET_WORKAREA property

As reported by Moritz, the Qt toolkit (and maybe a few other ones) are
using the content of this property, but WindowMaker did not set it properly
so for examples the menus in KDE could fail to display in multi-screen
configuration (probably because the toolkit is using the property to make
sure the menu stays in the visible area).

The original code just assumed it was safe to use the usable area of the
1st screen in the list, but unfortunately it is not that simple.

The new code calculates a rectangle that contains the usable region from
all the screens, so the toolkit gets a more accurate value.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>
---
 src/wmspec.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 55 insertions(+), 13 deletions(-)

diff --git a/src/wmspec.c b/src/wmspec.c
index 89d8fac6..9b56f96f 100644
--- a/src/wmspec.c
+++ b/src/wmspec.c
@@ -702,25 +702,67 @@ void wNETWMUpdateActions(WWindow *wwin, Bool del)
 
 void wNETWMUpdateWorkarea(WScreen *scr)
 {
-	long *area;
-	int count, i;
+	WArea total_usable;
+	int nb_workspace;
 
-	if (!scr->netdata || scr->workspace_count == 0 || !scr->usableArea)
+	if (!scr->netdata) {
+		/* If the _NET_xxx were not initialised, it not necessary to do anything */
 		return;
+	}
 
-	count = scr->workspace_count * 4;
-	area = wmalloc(sizeof(long) * count);
+	if (!scr->usableArea) {
+		/* If we don't have any info, we fall back on using the complete screen area */
+		total_usable.x1 = 0;
+		total_usable.y1 = 0;
+		total_usable.x2 = scr->scr_width;
+		total_usable.y2 = scr->scr_height;
+
+	} else {
+		int i;
+
+		/*
+		 * the _NET_WORKAREA is supposed to contain the total area of the screen that
+		 * is usable, so we merge the areas from all xrandr sub-screens
+		 */
+		total_usable = scr->usableArea[0];
+
+		for (i = 1; i < wXineramaHeads(scr); i++) {
+			/* The merge is not subtle because _NET_WORKAREA does not need more */
+			if (scr->usableArea[i].x1 < total_usable.x1)
+				total_usable.x1 = scr->usableArea[i].x1;
+
+			if (scr->usableArea[i].y1 < total_usable.y1)
+				total_usable.y1 = scr->usableArea[i].y1;
+
+			if (scr->usableArea[i].x2 > total_usable.x2)
+				total_usable.x2 = scr->usableArea[i].x2;
+
+			if (scr->usableArea[i].y2 > total_usable.y2)
+				total_usable.y2 = scr->usableArea[i].y2;
+		}
 
-	for (i = 0; i < scr->workspace_count; i++) {
-		area[4 * i + 0] = scr->usableArea[0].x1;
-		area[4 * i + 1] = scr->usableArea[0].y1;
-		area[4 * i + 2] = scr->usableArea[0].x2 - scr->usableArea[0].x1;
-		area[4 * i + 3] = scr->usableArea[0].y2 - scr->usableArea[0].y1;
 	}
 
-	XChangeProperty(dpy, scr->root_win, net_workarea, XA_CARDINAL, 32,
-				PropModeReplace, (unsigned char *)area, count);
-	wfree(area);
+	/* We are expected to repeat the information for each workspace */
+	if (scr->workspace_count == 0)
+		nb_workspace = 1;
+	else
+		nb_workspace = scr->workspace_count;
+
+	{
+		long property_value[nb_workspace * 4];
+		int i;
+
+		for (i = 0; i < nb_workspace; i++) {
+			property_value[4 * i + 0] = total_usable.x1;
+			property_value[4 * i + 1] = total_usable.y1;
+			property_value[4 * i + 2] = total_usable.x2 - total_usable.x1;
+			property_value[4 * i + 3] = total_usable.y2 - total_usable.y1;
+		}
+
+		XChangeProperty(dpy, scr->root_win, net_workarea, XA_CARDINAL, 32, PropModeReplace,
+		                (unsigned char *) property_value, nb_workspace * 4);
+	}
 }
 
 Bool wNETWMGetUsableArea(WScreen *scr, int head, WArea *area)
-- 
2.11.4.GIT