From fc58fbaa71895d921f4dffee5424afd0933799e0 Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Wed, 13 Jul 2022 19:41:25 +0300
Subject: [PATCH] Add conversion helpers between xinerama indices and output
 objects

Currently, we implicitly assume that enabled outputs are stored in the
xinerama order, but with ongoing refactorings, it's easy to break that
assumption. Also, we are not going to change the DRM backend so it
stores enabled outputs in the xinerama order.

This change adds xinerama index conversion helpers in order to reduce
the number of potential regressions with output refactorings.
---
 src/activation.cpp |  2 +-
 src/workspace.cpp  |  7 ++++++-
 src/workspace.h    |  2 ++
 src/x11window.cpp  | 10 +++++-----
 4 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/src/activation.cpp b/src/activation.cpp
index ff3f98c2ba..84dbf62055 100644
--- a/src/activation.cpp
+++ b/src/activation.cpp
@@ -768,7 +768,7 @@ void X11Window::startupIdChanged()
         workspace()->sendWindowToDesktop(this, desktop, true);
     }
     if (asn_data.xinerama() != -1) {
-        Output *output = kwinApp()->platform()->findOutput(asn_data.xinerama());
+        Output *output = workspace()->xineramaIndexToOutput(asn_data.xinerama());
         if (output) {
             workspace()->sendWindowToOutput(this, output);
         }
diff --git a/src/workspace.cpp b/src/workspace.cpp
index d59805beca..57b569b73a 100644
--- a/src/workspace.cpp
+++ b/src/workspace.cpp
@@ -2248,7 +2248,7 @@ QRectF Workspace::clientArea(clientAreaOption opt, const Output *output, const V
 
     const Output *effectiveOutput = output;
     if (is_multihead) {
-        effectiveOutput = kwinApp()->platform()->findOutput(screen_number);
+        effectiveOutput = xineramaIndexToOutput(screen_number);
     }
 
     if (auto desktopIt = m_screenAreas.constFind(desktop); desktopIt != m_screenAreas.constEnd()) {
@@ -2352,6 +2352,11 @@ int Workspace::oldDisplayHeight() const
     return olddisplaysize.height();
 }
 
+Output *Workspace::xineramaIndexToOutput(int index) const
+{
+    return kwinApp()->platform()->enabledOutputs().value(index);
+}
+
 Output *Workspace::activeOutput() const
 {
     if (options->activeMouseScreen()) {
diff --git a/src/workspace.h b/src/workspace.h
index 837ca8d21e..9f9b4a6d17 100644
--- a/src/workspace.h
+++ b/src/workspace.h
@@ -151,6 +151,8 @@ public:
 
     bool initializing() const;
 
+    Output *xineramaIndexToOutput(int index) const;
+
     Output *activeOutput() const;
     void setActiveOutput(Output *output);
     void setActiveOutput(const QPointF &pos);
diff --git a/src/x11window.cpp b/src/x11window.cpp
index 6eb0f6daf8..dbf8c66252 100644
--- a/src/x11window.cpp
+++ b/src/x11window.cpp
@@ -619,7 +619,7 @@ bool X11Window::manage(xcb_window_t w, bool isMapped)
     } else {
         Output *output = nullptr;
         if (asn_data.xinerama() != -1) {
-            output = kwinApp()->platform()->findOutput(asn_data.xinerama());
+            output = workspace()->xineramaIndexToOutput(asn_data.xinerama());
         }
         if (!output) {
             output = workspace()->activeOutput();
@@ -4649,16 +4649,16 @@ QRect X11Window::fullscreenMonitorsArea(NETFullscreenMonitors requestedTopology)
 {
     QRect total;
 
-    if (auto output = kwinApp()->platform()->findOutput(requestedTopology.top)) {
+    if (auto output = workspace()->xineramaIndexToOutput(requestedTopology.top)) {
         total = total.united(output->geometry());
     }
-    if (auto output = kwinApp()->platform()->findOutput(requestedTopology.bottom)) {
+    if (auto output = workspace()->xineramaIndexToOutput(requestedTopology.bottom)) {
         total = total.united(output->geometry());
     }
-    if (auto output = kwinApp()->platform()->findOutput(requestedTopology.left)) {
+    if (auto output = workspace()->xineramaIndexToOutput(requestedTopology.left)) {
         total = total.united(output->geometry());
     }
-    if (auto output = kwinApp()->platform()->findOutput(requestedTopology.right)) {
+    if (auto output = workspace()->xineramaIndexToOutput(requestedTopology.right)) {
         total = total.united(output->geometry());
     }