ExtensionManager: Enable/disable dependencies, inform users accordingly

This instantiates PluginView in order to use setPluginsEnabled. It
enables dependencies of a plugin that is being enabled. Likewise, it
disables dependent plugins when users disable a plugin.

In both cases, the user sees the familiar info dialog.

On confirmation, a "Restart now" button is shown.

Change-Id: Ie74ed377bfdd1ce3cb06289c2aae78377475bc53
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/libs/extensionsystem/pluginview.cpp

@@ -369,6 +369,11 @@ void PluginView::updatePlugins()
     m_categoryView->expandAll();
 }
 
+PluginData &PluginView::data()
+{
+    return m_data;
+}
+
 static QString pluginListString(const QSet<PluginSpec *> &plugins)
 {
     QStringList names = Utils::transform<QList>(plugins, &PluginSpec::name);

src/libs/extensionsystem/pluginview.h

@@ -60,6 +60,8 @@ public:
     void setFilter(const QString &filter);
     void cancelChanges();
 
+    PluginData &data();
+
 signals:
     void currentPluginChanged(ExtensionSystem::PluginSpec *spec);
     void pluginActivated(ExtensionSystem::PluginSpec *spec);

src/plugins/extensionmanager/extensionmanagerwidget.cpp

@@ -16,6 +16,7 @@
 
 #include <extensionsystem/pluginmanager.h>
 #include <extensionsystem/pluginspec.h>
+#include <extensionsystem/pluginview.h>
 
 #include <solutions/tasking/networkquery.h>
 #include <solutions/tasking/tasktree.h>
@@ -279,21 +280,33 @@ public:
     {
         m_label = new InfoLabel;
         m_checkBox = new QCheckBox(Tr::tr("Load on Start"));
+        m_restartButton = new Button("Restart now", Button::MediumPrimary);
+        m_restartButton->setVisible(false);
+        m_pluginView.hide();
 
         using namespace Layouting;
         Column {
             m_label,
             m_checkBox,
+            m_restartButton,
         }.attachTo(this);
 
         connect(m_checkBox, &QCheckBox::clicked, this, [this](bool checked) {
             ExtensionSystem::PluginSpec *spec = ExtensionsModel::pluginSpecForName(m_pluginName);
             if (spec == nullptr)
                 return;
-            spec->setEnabledBySettings(checked);
+            const bool doIt = m_pluginView.data().setPluginsEnabled({spec}, checked);
-            ExtensionSystem::PluginManager::writeSettings();
+            if (doIt) {
+                m_restartButton->show();
+                ExtensionSystem::PluginManager::writeSettings();
+            } else {
+                m_checkBox->setChecked(!checked);
+            }
         });
 
+        connect(m_restartButton, &QAbstractButton::clicked,
+                ICore::instance(), &ICore::restart, Qt::QueuedConnection);
+
         update();
     }
 
@@ -328,7 +341,9 @@ private:
 
     InfoLabel *m_label;
     QCheckBox *m_checkBox;
+    QAbstractButton *m_restartButton;
     QString m_pluginName;
+    ExtensionSystem::PluginView m_pluginView{this};
 };
 
 class TagList : public QWidget