From ad44b0f08c9940c70a50216b25781ab5fa2160bd Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Sat, 22 Feb 2020 00:13:08 +0200
Subject: [PATCH] [server] Add some sub-surface life cycle signals

Summary:
These signals can be very useful when one wants to monitor changes in a
sub-surface tree.

Reviewers: #kwin, apol

Reviewed By: apol

Subscribers: apol, kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D27860
---
 src/wayland/surface_interface.cpp |  2 ++
 src/wayland/surface_interface.h   | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/src/wayland/surface_interface.cpp b/src/wayland/surface_interface.cpp
index 3b78664436..e61d5794ba 100644
--- a/src/wayland/surface_interface.cpp
+++ b/src/wayland/surface_interface.cpp
@@ -43,6 +43,7 @@ void SurfaceInterface::Private::addChild(QPointer< SubSurfaceInterface > child)
     subSurfacePending.children.append(child);
     current.children.append(child);
     Q_Q(SurfaceInterface);
+    emit q->childSubSurfaceAdded(child);
     emit q->subSurfaceTreeChanged();
     QObject::connect(child.data(), &SubSurfaceInterface::positionChanged, q, &SurfaceInterface::subSurfaceTreeChanged);
     QObject::connect(child->surface().data(), &SurfaceInterface::damaged, q, &SurfaceInterface::subSurfaceTreeChanged);
@@ -57,6 +58,7 @@ void SurfaceInterface::Private::removeChild(QPointer< SubSurfaceInterface > chil
     subSurfacePending.children.removeAll(child);
     current.children.removeAll(child);
     Q_Q(SurfaceInterface);
+    emit q->childSubSurfaceRemoved(child);
     emit q->subSurfaceTreeChanged();
     QObject::disconnect(child.data(), &SubSurfaceInterface::positionChanged, q, &SurfaceInterface::subSurfaceTreeChanged);
     if (!child->surface().isNull()) {
diff --git a/src/wayland/surface_interface.h b/src/wayland/surface_interface.h
index fb61978fda..ad8f24e415 100644
--- a/src/wayland/surface_interface.h
+++ b/src/wayland/surface_interface.h
@@ -330,6 +330,16 @@ Q_SIGNALS:
      * @since 5.22
      **/
     void subSurfaceTreeChanged();
+    /**
+     * Emitted whenever a new child sub-surface @p subSurface is added.
+     * @since 5.70
+     */
+    void childSubSurfaceAdded(SubSurfaceInterface *subSurface);
+    /**
+     * Emitted whenver the child sub-surface @p subSurface is removed.
+     * @since 5.70
+     */
+    void childSubSurfaceRemoved(SubSurfaceInterface *subSurface);
 
     /**
      * Emitted whenever a pointer constraint get (un)installed on this SurfaceInterface.