Show detailed information why an effect cannot be loaded

Effects can specify their minimum requirements in their
desktop file:
* OpenGL
* OpenGL 2 (GLSL required)
* Shaders (either ARB or OpenGL 2)

The configuration module uses this information in combination
with which backend KWin is currently using. So if e.g. OpenGL
is used and an effect requires OpenGL 2 a detailed error
message can be showed that OpenGL 2 is required.

BUG: 209213
FIXED-IN: 4.9.0
REVIEW: 104847

composite.cpp

@@ -556,6 +556,28 @@ bool Workspace::openGLIsBroken() const
     return CompositingPrefs::openGlIsBroken();
 }
 
+QString Workspace::compositingType()
+{
+    // the returned strings are considered as identifiers and may not be translated
+    if (!effects) {
+        return "none";
+    }
+    if (effects->compositingType() == XRenderCompositing) {
+        return "xrender";
+    } else if (effects->compositingType() == OpenGLCompositing) {
+#ifdef KWIN_HAVE_OPENGLES
+        return "gles";
+#else
+        if (ShaderManager::instance()->isValid()) {
+            return "gl2";
+        } else {
+            return "gl1";
+        }
+#endif
+    }
+    return "none";
+}
+
 //****************************************
 // Toplevel
 //****************************************

effects/blur/blur.desktop

@@ -165,4 +165,5 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=true
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=75
-
+X-KWin-Requires-OpenGL=true
+X-KWin-Requires-Shaders=true

effects/coverswitch/coverswitch.desktop

@@ -149,3 +149,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=50
+X-KWin-Requires-OpenGL=true

effects/cube/cube.desktop

@@ -163,3 +163,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=50
+X-KWin-Requires-OpenGL=true

effects/cube/cubeslide.desktop

@@ -143,3 +143,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=50
+X-KWin-Requires-OpenGL=true

effects/explosion/explosion.desktop

@@ -162,3 +162,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=70
+X-KWin-Requires-OpenGL2=true

effects/flipswitch/flipswitch.desktop

@@ -145,3 +145,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=50
+X-KWin-Requires-OpenGL=true

effects/glide/glide.desktop

@@ -130,3 +130,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=50
+X-KWin-Requires-OpenGL=true

effects/invert/invert.desktop

@@ -162,3 +162,4 @@ X-KDE-PluginInfo-Depends=
 X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
+X-KWin-Requires-OpenGL2=true

effects/kwineffect.desktop

@@ -88,3 +88,12 @@ Comment[zh_TW]=KWin 效果
 
 [PropertyDef::X-KDE-Ordering]
 Type=int
+
+[PropertyDef::X-KWin-Requires-OpenGL]
+Type=bool
+
+[PropertyDef::X-KWin-Requires-OpenGL2]
+Type=bool
+
+[PropertyDef::X-KWin-Requires-Shaders]
+Type=bool

effects/lookingglass/lookingglass.desktop

@@ -155,3 +155,4 @@ X-KDE-PluginInfo-Depends=
 X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
+X-KWin-Requires-OpenGL2=true

effects/magiclamp/magiclamp.desktop

@@ -155,3 +155,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=50
+X-KWin-Requires-OpenGL=true

effects/sheet/sheet.desktop

@@ -144,3 +144,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=60
+X-KWin-Requires-OpenGL=true

effects/startupfeedback/startupfeedback.desktop

@@ -118,3 +118,4 @@ X-KDE-PluginInfo-Depends=
 X-KDE-PluginInfo-EnabledByDefault=true
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=90
+X-KWin-Requires-OpenGL=true

effects/wobblywindows/wobblywindows.desktop

@@ -156,3 +156,4 @@ X-KDE-PluginInfo-License=GPL
 X-KDE-PluginInfo-EnabledByDefault=false
 X-KDE-Library=kwin4_effect_builtins
 X-KDE-Ordering=45
+X-KWin-Requires-OpenGL=true

kcmkwin/kwincompositing/main.cpp

@@ -79,6 +79,8 @@ KWinCompositingConfig::KWinCompositingConfig(QWidget *parent, const QVariantList
     : KCModule(KWinCompositingConfigFactory::componentData(), parent)
     , mKWinConfig(KSharedConfig::openConfig("kwinrc"))
     , m_showConfirmDialog(false)
+    , m_showDetailedErrors(new QAction(i18nc("Action to open a dialog showing detailed information why an effect could not be loaded",
+                                             "Details"), this))
 {
     KGlobal::locale()->insertCatalog("kwin_effects");
     ui.setupUi(this);
@@ -86,6 +88,9 @@ KWinCompositingConfig::KWinCompositingConfig(QWidget *parent, const QVariantList
     ui.tabWidget->setCurrentIndex(0);
     ui.statusTitleWidget->hide();
     ui.rearmGlSupport->hide();
+    ui.messageBox->setVisible(false);
+    ui.messageBox->addAction(m_showDetailedErrors);
+    ui.messageBox->setMessageType(KMessageWidget::Warning);
 
     // For future use
     (void) I18N_NOOP("Use GLSL shaders");
@@ -124,6 +129,7 @@ KWinCompositingConfig::KWinCompositingConfig(QWidget *parent, const QVariantList
 
     connect(ui.glVSync, SIGNAL(toggled(bool)), this, SLOT(changed()));
     connect(ui.glShaders, SIGNAL(toggled(bool)), this, SLOT(changed()));
+    connect(m_showDetailedErrors, SIGNAL(triggered(bool)), SLOT(showDetailedEffectLoadingInformation()));
 
     // Open the temporary config file
     // Temporary conf file is used to synchronize effect checkboxes with effect
@@ -584,14 +590,15 @@ void KWinCompositingConfig::checkLoadedEffects()
 {
     // check for effects not supported by Backend or hardware
     // such effects are enabled but not returned by DBus method loadedEffects
-    QDBusMessage message = QDBusMessage::createMethodCall("org.kde.kwin", "/KWin", "org.kde.KWin", "loadedEffects");
-    QDBusMessage reply = QDBusConnection::sessionBus().call(message);
+    OrgKdeKWinInterface kwin("org.kde.kwin", "/KWin", QDBusConnection::sessionBus());
     KConfigGroup effectConfig = KConfigGroup(mKWinConfig, "Compositing");
     bool enabledAfter = effectConfig.readEntry("Enabled", true);
 
-    if (reply.type() == QDBusMessage::ReplyMessage && enabledAfter && !getenv("KDE_FAILSAFE")) {
+    QDBusPendingReply< QStringList > reply = kwin.loadedEffects();
+
+    if (!reply.isError() && enabledAfter && !getenv("KDE_FAILSAFE")) {
         effectConfig = KConfigGroup(mKWinConfig, "Plugins");
-        QStringList loadedEffects = reply.arguments()[0].toStringList();
+        QStringList loadedEffects = reply.value();
         QStringList effects = effectConfig.keyList();
         QStringList disabledEffects = QStringList();
         foreach (QString effect, effects) { // krazy:exclude=foreach
@@ -602,25 +609,108 @@ void KWinCompositingConfig::checkLoadedEffects()
             }
         }
         if (!disabledEffects.isEmpty()) {
-            KServiceTypeTrader* trader = KServiceTypeTrader::self();
-            KService::List services;
-            QString message = i18n("The following desktop effects could not be activated:");
-            message.append("<ul>");
-            foreach (const QString & effect, disabledEffects) {
-                services = trader->query("KWin/Effect", "[X-KDE-PluginInfo-Name] == '" + effect + '\'');
-                message.append("<li>");
-                if (!services.isEmpty())
-                    message.append(services.first()->name());
-                else
-                    message.append(effect);
-                message.append("</li>");
-            }
-            message.append("</ul>");
-            KNotification::event("effectsnotsupported", message, QPixmap(), NULL, KNotification::CloseOnTimeout, KComponentData("kwin"));
+            m_showDetailedErrors->setData(disabledEffects);
+            ui.messageBox->setText(i18ncp("Error Message shown when a desktop effect could not be loaded",
+                                          "A desktop effect could not be loaded.",
+                                          "%1 desktop effects could not be loaded", disabledEffects.count()));
+            ui.messageBox->animatedShow();
         }
     }
 }
 
+void KWinCompositingConfig::showDetailedEffectLoadingInformation()
+{
+    QStringList disabledEffects = m_showDetailedErrors->data().toStringList();
+    OrgKdeKWinInterface kwin("org.kde.kwin", "/KWin", QDBusConnection::sessionBus());
+    QDBusPendingReply< QString > pendingCompositingType = kwin.compositingType();
+    QString compositingType = pendingCompositingType.isError() ? "none" : pendingCompositingType.value();
+    KServiceTypeTrader* trader = KServiceTypeTrader::self();
+    KService::List services;
+    const KLocalizedString unknownReason = ki18nc("Effect with given name could not be activated due to unknown reason",
+                                                    "%1 Effect failed to load due to unknown reason.");
+    const KLocalizedString requiresShaders = ki18nc("Effect with given name could not be activated as it requires hardware shaders",
+                                                    "%1 Effect requires hardware support.");
+    const KLocalizedString requiresOpenGL = ki18nc("Effect with given name could not be activated as it requires OpenGL",
+                                                    "%1 Effect requires OpenGL.");
+    const KLocalizedString requiresOpenGL2 = ki18nc("Effect with given name could not be activated as it requires OpenGL 2",
+                                                    "%1 effect requires OpenGL 2.");
+    KDialog *dialog = new KDialog(this);
+    dialog->setWindowTitle(i18nc("Window title", "List of Effects which could not be loaded"));
+    dialog->setButtons(KDialog::Ok);
+    QWidget *mainWidget = new QWidget(dialog);
+    dialog->setMainWidget(mainWidget);
+    QVBoxLayout *vboxLayout = new QVBoxLayout(mainWidget);
+    mainWidget->setLayout(vboxLayout);
+    KTitleWidget *titleWidget = new KTitleWidget(mainWidget);
+    titleWidget->setText(i18n("For technical reasons it is not possible to determine all possible error causes."),
+                         KTitleWidget::InfoMessage);
+    QLabel *label = new QLabel(mainWidget);
+    label->setOpenExternalLinks(true);
+    vboxLayout->addWidget(titleWidget);
+    vboxLayout->addWidget(label);
+    if (compositingType != "none") {
+        QString text;
+        if (disabledEffects.count() > 1) {
+            text = "<ul>";
+        }
+        foreach (const QString & effect, disabledEffects) {
+            QString message;
+            services = trader->query("KWin/Effect", "[X-KDE-PluginInfo-Name] == '" + effect + '\'');
+            if (!services.isEmpty()) {
+                KService::Ptr service = services.first();
+                if (compositingType == "xrender") {
+                    // XRender compositing
+                    QVariant openGL = service->property("X-KWin-Requires-OpenGL");
+                    QVariant openGL2 = service->property("X-KWin-Requires-OpenGL2");
+                    if ((openGL.isValid() && openGL.toBool()) ||
+                            (openGL2.isValid() && openGL2.toBool())) {
+                        // effect requires OpenGL
+                        message = requiresOpenGL.subs(service->name()).toString();
+                    } else {
+                        // effect does not require OpenGL, unknown reason
+                        message = unknownReason.subs(service->name()).toString();
+                    }
+                } else if (compositingType == "gl1") {
+                    // OpenGL 1 compositing
+                    QVariant openGL2 = service->property("X-KWin-Requires-OpenGL2");
+                    QVariant shaders = service->property("X-KWin-Requires-Shaders");
+                    if (openGL2.isValid() && openGL2.toBool()) {
+                        // effect requires OpenGL 2
+                        message = requiresOpenGL2.subs(service->name()).toString();
+                    } else if (shaders.isValid() && shaders.toBool()) {
+                        // effect requires hardware shaders
+                        message = requiresShaders.subs(service->name()).toString();
+                    } else {
+                        // unknown reason
+                        message = unknownReason.subs(service->name()).toString();
+                    }
+                } else {
+                    // OpenGL 2 compositing - unknown reason
+                    message = unknownReason.subs(service->name()).toString();
+                }
+            } else {
+                message = unknownReason.subs(effect).toString();
+            }
+            if (disabledEffects.count() > 1) {
+                text.append("<li>");
+                text.append(message);
+                text.append("</li>");
+            } else {
+                text = message;
+            }
+        }
+        if (disabledEffects.count() > 1) {
+            text.append("</ul>");
+        }
+        label->setText(text);
+    } else {
+        // compositing is not active - no effect can be active
+        label->setText(i18nc("Error Message shown when Compositing is not active after tried activation",
+                             "Desktop Effect system is not running."));
+    }
+    dialog->show();
+}
+
 void KWinCompositingConfig::configChanged(bool reinitCompositing)
 {
     // Send signal to kwin

kcmkwin/kwincompositing/main.h

@@ -81,6 +81,7 @@ private slots:
     void toogleSmoothScaleUi(int compositingType);
     void toggleEffectShortcutChanged(const QKeySequence &seq);
     void updateStatusUI(bool compositingIsPossible);
+    void showDetailedEffectLoadingInformation();
 
 private:
     bool effectEnabled(const QString& effect, const KConfigGroup& cfg) const;
@@ -94,6 +95,7 @@ private:
     bool m_showConfirmDialog;
     KActionCollection* m_actionCollection;
     QString originalGraphicsSystem;
+    QAction *m_showDetailedErrors;
 };
 
 } // namespace

kcmkwin/kwincompositing/main.ui

@@ -6,15 +6,25 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>552</width>
-    <height>483</height>
+    <width>557</width>
+    <height>530</height>
    </rect>
   </property>
-  <layout class="QVBoxLayout">
+  <layout class="QVBoxLayout" name="verticalLayout_5">
+   <item>
+    <widget class="KMessageWidget" name="messageBox">
+     <property name="frameShape">
+      <enum>QFrame::StyledPanel</enum>
+     </property>
+     <property name="frameShadow">
+      <enum>QFrame::Raised</enum>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QTabWidget" name="tabWidget">
      <property name="currentIndex">
-      <number>2</number>
+      <number>0</number>
      </property>
      <widget class="QWidget" name="tab">
       <attribute name="title">
@@ -859,6 +869,12 @@ On legacy hardware disabling Shaders can improve the performance.</string>
    <header>kpluginselector.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>KMessageWidget</class>
+   <extends>QFrame</extends>
+   <header>kmessagewidget.h</header>
+   <container>1</container>
+  </customwidget>
  </customwidgets>
  <tabstops>
   <tabstop>tabWidget</tabstop>

org.kde.KWin.xml

@@ -95,5 +95,15 @@
     <method name="openGLIsBroken">
         <arg type="b" direction="out"/>
     </method>
+    <method name="compositingType">
+        <!--
+            none: No Compositing
+            xrender: XRender
+            gl1: OpenGL 1
+            gl2: OpenGL 2
+            gles: OpenGL ES 2
+        -->
+        <arg type="s" direction="out"/>
+    </method>
   </interface>
 </node>

workspace.h

@@ -455,6 +455,15 @@ public:
     bool compositingPossible() const;
     QString compositingNotPossibleReason() const;
     bool openGLIsBroken() const;
+    /**
+     * Returns the currently used Compositor (Scene):
+     * @li @c none No Compositing
+     * @li @c xrender XRender
+     * @li @c gl1 OpenGL 1
+     * @li @c gl2 OpenGL 2
+     * @li @c gles OpenGL ES 2
+     **/
+    QString compositingType();
 
     void setCurrentScreen(int new_screen);