From a7c396caeb29d465fd7044e2b200a90129627d8a Mon Sep 17 00:00:00 2001
From: Kai Uwe Broulik <kde@privat.broulik.de>
Date: Thu, 28 Sep 2017 10:18:36 +0200
Subject: [PATCH] [ScreenEdgeEffect] Create glow Svg on demand

Keeps it from loading the Svg and all the Plasma stuff (Theme etc) that comes with it on startup.

Differential Revision: https://phabricator.kde.org/D8011
---
 effects/screenedge/screenedgeeffect.cpp | 18 +++++++++++++++---
 effects/screenedge/screenedgeeffect.h   |  5 +++--
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/effects/screenedge/screenedgeeffect.cpp b/effects/screenedge/screenedgeeffect.cpp
index 09ae2891f0..1b8dea068c 100644
--- a/effects/screenedge/screenedgeeffect.cpp
+++ b/effects/screenedge/screenedgeeffect.cpp
@@ -37,10 +37,8 @@ namespace KWin {
 
 ScreenEdgeEffect::ScreenEdgeEffect()
     : Effect()
-    , m_glow(new Plasma::Svg(this))
     , m_cleanupTimer(new QTimer(this))
 {
-    m_glow->setImagePath(QStringLiteral("widgets/glowbar"));
     connect(effects, SIGNAL(screenEdgeApproaching(ElectricBorder,qreal,QRect)), SLOT(edgeApproaching(ElectricBorder,qreal,QRect)));
     m_cleanupTimer->setInterval(5000);
     m_cleanupTimer->setSingleShot(true);
@@ -59,6 +57,14 @@ ScreenEdgeEffect::~ScreenEdgeEffect()
     cleanup();
 }
 
+void ScreenEdgeEffect::ensureGlowSvg()
+{
+    if (!m_glow) {
+        m_glow = new Plasma::Svg(this);
+        m_glow->setImagePath(QStringLiteral("widgets/glowbar"));
+    }
+}
+
 void ScreenEdgeEffect::cleanup()
 {
     for (QHash<ElectricBorder, Glow*>::iterator it = m_borders.begin();
@@ -263,6 +269,8 @@ Glow *ScreenEdgeEffect::createGlow(ElectricBorder border, qreal factor, const QR
 template <typename T>
 T *ScreenEdgeEffect::createCornerGlow(ElectricBorder border)
 {
+    ensureGlowSvg();
+
     switch (border) {
     case ElectricTopLeft:
         return new T(m_glow->pixmap(QStringLiteral("bottomright")).toImage());
@@ -277,8 +285,10 @@ T *ScreenEdgeEffect::createCornerGlow(ElectricBorder border)
     }
 }
 
-QSize ScreenEdgeEffect::cornerGlowSize(ElectricBorder border) const
+QSize ScreenEdgeEffect::cornerGlowSize(ElectricBorder border)
 {
+    ensureGlowSvg();
+
     switch (border) {
     case ElectricTopLeft:
         return m_glow->elementSize(QStringLiteral("bottomright"));
@@ -296,6 +306,8 @@ QSize ScreenEdgeEffect::cornerGlowSize(ElectricBorder border) const
 template <typename T>
 T *ScreenEdgeEffect::createEdgeGlow(ElectricBorder border, const QSize &size)
 {
+    ensureGlowSvg();
+
     QPoint pixmapPosition(0, 0);
     QPixmap l, r, c;
     switch (border) {
diff --git a/effects/screenedge/screenedgeeffect.h b/effects/screenedge/screenedgeeffect.h
index 94e7c6d3f6..d940e61916 100644
--- a/effects/screenedge/screenedgeeffect.h
+++ b/effects/screenedge/screenedgeeffect.h
@@ -48,13 +48,14 @@ private Q_SLOTS:
     void edgeApproaching(ElectricBorder border, qreal factor, const QRect &geometry);
     void cleanup();
 private:
+    void ensureGlowSvg();
     Glow *createGlow(ElectricBorder border, qreal factor, const QRect &geometry);
     template <typename T>
     T *createCornerGlow(ElectricBorder border);
     template <typename T>
     T *createEdgeGlow(ElectricBorder border, const QSize &size);
-    QSize cornerGlowSize(ElectricBorder border) const;
-    Plasma::Svg *m_glow;
+    QSize cornerGlowSize(ElectricBorder border);
+    Plasma::Svg *m_glow = nullptr;
     QHash<ElectricBorder, Glow*> m_borders;
     QTimer *m_cleanupTimer;
 };