From ec8f7e1facffa05a95bdb553d91abb915525d4cb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20L=C3=BCbking?= <thomas.luebking@gmail.com>
Date: Thu, 4 Sep 2014 21:13:55 +0200
Subject: [PATCH] ensure disjunct screenedges on overlapping screens

If two or more screens overlap (partially or fully)
we must not create double edges since kwin would
trigger both - since they've the same actions bound
(for sure) the action will called twice (so either
eg. toggle or skip one VD etc.)

BUG: 338381
REVIEW: 120060
---
 screenedge.cpp | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/screenedge.cpp b/screenedge.cpp
index 75035540f1..7f45d762f2 100644
--- a/screenedge.cpp
+++ b/screenedge.cpp
@@ -872,23 +872,27 @@ void ScreenEdges::recreateEdges()
     QList<Edge*> oldEdges(m_edges);
     m_edges.clear();
     const QRect fullArea(0, 0, displayWidth(), displayHeight());
+    QRegion processedRegion;
     for (int i=0; i<screens()->count(); ++i) {
-        const QRect screen = screens()->geometry(i);
-        if (isLeftScreen(screen, fullArea)) {
-            // left most screen
-            createVerticalEdge(ElectricLeft, screen, fullArea);
-        }
-        if (isRightScreen(screen, fullArea)) {
-            // right most screen
-            createVerticalEdge(ElectricRight, screen, fullArea);
-        }
-        if (isTopScreen(screen, fullArea)) {
-            // top most screen
-            createHorizontalEdge(ElectricTop, screen, fullArea);
-        }
-        if (isBottomScreen(screen, fullArea)) {
-            // bottom most screen
-            createHorizontalEdge(ElectricBottom, screen, fullArea);
+        const QRegion screen = QRegion(screens()->geometry(i)).subtracted(processedRegion);
+        processedRegion += screen;
+        Q_FOREACH (const QRect &screenPart, screen.rects()) {
+            if (isLeftScreen(screenPart, fullArea)) {
+                // left most screen
+                createVerticalEdge(ElectricLeft, screenPart, fullArea);
+            }
+            if (isRightScreen(screenPart, fullArea)) {
+                // right most screen
+                createVerticalEdge(ElectricRight, screenPart, fullArea);
+            }
+            if (isTopScreen(screenPart, fullArea)) {
+                // top most screen
+                createHorizontalEdge(ElectricTop, screenPart, fullArea);
+            }
+            if (isBottomScreen(screenPart, fullArea)) {
+                // bottom most screen
+                createHorizontalEdge(ElectricBottom, screenPart, fullArea);
+            }
         }
     }
     // copy over the effect/script reservations from the old edges