Merge branch 'issue-1152'

CHANGES

@@ -7,6 +7,10 @@ website will have to do for older versions.
 
 This release contains contributions from (alphabetically by first name):
 
+Distributions are **advised** to check the slideshow they use for the
+installation step; changes in loading and translation mechanisms may
+require changes in the slideshow.
+
 ## Core ##
 
  - With this release, option *WITH_PYTHONQT* changes default to **off**.
@@ -18,6 +22,14 @@ This release contains contributions from (alphabetically by first name):
    configured after the last *exec* section of the sequence has been
    solved. The *finished* page can be left out (but then you don't get
    the restart-now functionality). #1168
+ - The *slideshow* which is run during installation is now loaded on
+   startup (while requirements checking is being done). This should
+   improve responsiveness when the slideshow starts. If the slideshow
+   has methods `onActivate()` and `onLeave()` those will be called
+   when the installation step is activated (e.g. the installation
+   starts and the slideshow becomes visible) or is finished (and the
+   slideshow becomes hidden).
+ - The example slideshow now starts its timers when it becomes visible.
 
 ## Modules ##
 

src/branding/default/branding.desc

@@ -93,6 +93,17 @@ images:
 # The slideshow is displayed during execution steps (e.g. when the
 # installer is actually writing to disk and doing other slow things).
 slideshow:               "show.qml"
+# There are two available APIs for the slideshow:
+#  - 1 (the default) loads the entire slideshow when the installation-
+#      slideshow page is shown and starts the QML then. The QML
+#      is never stopped (after installation is done, times etc.
+#      continue to fire).
+#  - 2 loads the slideshow on startup and calls onActivate() and
+#      onLeave() in the root object. After the installation is done,
+#      the show is stopped (first by calling onLeave(), then destroying
+#      the QML components).
+slideshowAPI: 2
+
 
 # Colors for text and background components.
 #

src/branding/default/show.qml

@@ -68,8 +68,9 @@ Presentation
         centeredText: qsTr("This is a third Slide element.")
     }
 
-    Component.onCompleted: {
-        advanceTimer.running = true;
-        console.log("Component complete");
+    function onActivate() {
+        presentation.currentSlide = 0;
+        advanceTimer.running = true
+        console.log("Component activated");
     }
 }

src/libcalamaresui/Branding.cpp

@@ -127,6 +127,7 @@ Branding::Branding( const QString& brandingFilePath,
     , m_descriptorPath( brandingFilePath )
     , m_welcomeStyleCalamares( false )
     , m_welcomeExpandingLogo( true )
+    , m_slideshowAPI( 1 )
 {
     cDebug() << "Using Calamares branding file at" << brandingFilePath;
 
@@ -234,6 +235,14 @@ Branding::Branding( const QString& brandingFilePath,
             }
             else
                 bail( "Syntax error in slideshow sequence." );
+
+            int api = doc[ "slideshowAPI" ].IsScalar() ? doc[ "slideshowAPI" ].as<int>() : -1;
+            if ( ( api < 1 ) || ( api > 2 ) )
+            {
+                cWarning() << "Invalid or missing *slideshowAPI* in branding file.";
+                api = 1;
+            }
+            m_slideshowAPI = api;
         }
         catch ( YAML::Exception& e )
         {

src/libcalamaresui/Branding.h

@@ -118,6 +118,7 @@ public:
 
     /** @brief Path to the slideshow QML file, if any. */
     QString slideshowPath() const { return m_slideshowPath; }
+    int slideshowAPI() const { return m_slideshowAPI; }
 
     QString string( Branding::StringEntry stringEntry ) const;
     QString styleString( Branding::StyleEntry styleEntry ) const;
@@ -172,6 +173,7 @@ private:
     QMap< QString, QString > m_images;
     QMap< QString, QString > m_style;
     QString m_slideshowPath;
+    int m_slideshowAPI;
     QString m_translationsPathPrefix;
 
     /** @brief Initialize the simple settings below */

src/libcalamaresui/ExecutionViewStep.cpp

@@ -36,10 +36,40 @@
 #include <QDir>
 #include <QLabel>
 #include <QProgressBar>
-#include <QVBoxLayout>
-#include <QtQuickWidgets/QQuickWidget>
+#include <QQmlComponent>
 #include <QQmlEngine>
+#include <QQuickItem>
+#include <QQuickWidget>
+#include <QVBoxLayout>
+
+/** @brief Calls the QML method @p method()
+ *
+ * Pass in only the name of the method (e.g. onActivate). This function
+ * checks if the method exists (with no arguments) before trying to
+ * call it, so that no warnings are printed due to missing methods.
+ *
+ * If there is a return value from the QML method, it is logged (but not otherwise used).
+ */
+static void
+callQMLFunction( QQuickItem* qmlObject, const char* method )
+{
+    QByteArray methodSignature( method );
+    methodSignature.append( "()" );
 
+    if ( qmlObject && qmlObject->metaObject()->indexOfMethod( methodSignature )  >= 0 )
+    {
+        QVariant returnValue;
+        QMetaObject::invokeMethod( qmlObject, method, Q_RETURN_ARG( QVariant, returnValue ) );
+        if ( !returnValue.isNull() )
+        {
+            cDebug() << "QML" << methodSignature << "returned" << returnValue;
+        }
+    }
+    else if ( qmlObject )
+    {
+        cDebug() << "QML" << methodSignature << "is missing.";
+    }
+}
 
 namespace Calamares
 {
@@ -47,31 +77,38 @@ namespace Calamares
 ExecutionViewStep::ExecutionViewStep( QObject* parent )
     : ViewStep( parent )
     , m_widget( new QWidget )
+    , m_progressBar( new QProgressBar )
+    , m_label( new QLabel )
+    , m_qmlShow( new QQuickWidget )
+    , m_qmlComponent( nullptr )
+    , m_qmlObject( nullptr )
 {
-    m_progressBar = new QProgressBar;
-    m_progressBar->setMaximum( 10000 );
-    m_label = new QLabel;
     QVBoxLayout* layout = new QVBoxLayout( m_widget );
     QVBoxLayout* innerLayout = new QVBoxLayout;
 
-    m_slideShow = new QQuickWidget;
-    layout->addWidget( m_slideShow );
-    CalamaresUtils::unmarginLayout( layout );
+    m_progressBar->setMaximum( 10000 );
 
-    layout->addLayout( innerLayout );
-    m_slideShow->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
-    m_slideShow->setResizeMode( QQuickWidget::SizeRootObjectToView );
+    m_qmlShow->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
+    m_qmlShow->setResizeMode( QQuickWidget::SizeRootObjectToView );
+    m_qmlShow->engine()->addImportPath( CalamaresUtils::qmlModulesDir().absolutePath() );
 
-    m_slideShow->engine()->addImportPath( CalamaresUtils::qmlModulesDir().absolutePath() );
+    layout->addWidget( m_qmlShow );
+    CalamaresUtils::unmarginLayout( layout );
+    layout->addLayout( innerLayout );
 
     innerLayout->addSpacing( CalamaresUtils::defaultFontHeight() / 2 );
     innerLayout->addWidget( m_progressBar );
     innerLayout->addWidget( m_label );
 
-    cDebug() << "QML import paths:" << Logger::DebugList( m_slideShow->engine()->importPathList() );
+    cDebug() << "QML import paths:" << Logger::DebugList( m_qmlShow->engine()->importPathList() );
+    if ( Branding::instance()->slideshowAPI() == 2 )
+    {
+        cDebug() << "QML load on startup, API 2.";
+        loadQmlV2();
+    }
 
-    connect( JobQueue::instance(), &JobQueue::progress,
-             this, &ExecutionViewStep::updateFromJobQueue );
+    connect( JobQueue::instance(), &JobQueue::progress, this, &ExecutionViewStep::updateFromJobQueue );
+    CALAMARES_RETRANSLATE( m_qmlShow->engine()->retranslate(); )
 }
 
 
@@ -130,22 +167,67 @@ ExecutionViewStep::isAtEnd() const
     return true;
 }
 
+void
+ExecutionViewStep::loadQmlV2()
+{
+    if ( !m_qmlComponent && !Calamares::Branding::instance()->slideshowPath().isEmpty() )
+    {
+        m_qmlComponent = new QQmlComponent( m_qmlShow->engine(),
+                                            QUrl::fromLocalFile( Calamares::Branding::instance()->slideshowPath() ),
+                                            QQmlComponent::CompilationMode::Asynchronous
+                                          );
+        connect( m_qmlComponent, &QQmlComponent::statusChanged, this, &ExecutionViewStep::loadQmlV2Complete );
+    }
+}
+
+void
+ExecutionViewStep::loadQmlV2Complete()
+{
+    if ( m_qmlComponent && m_qmlComponent->isReady() && !m_qmlObject )
+    {
+        cDebug() << "QML loading complete, API 2";
+        // Don't do this again
+        disconnect( m_qmlComponent, &QQmlComponent::statusChanged, this, &ExecutionViewStep::loadQmlV2Complete );
+
+        QObject* o = m_qmlComponent->create();
+        m_qmlObject = qobject_cast< QQuickItem* >( o );
+        if ( !m_qmlObject )
+            delete o;
+        else
+        {
+            // setContent() is public API, but not documented publicly.
+            // It is marked \internal in the Qt sources, but does exactly
+            // what is needed: sets up visual parent by replacing the root
+            // item, and handling resizes.
+            m_qmlShow->setContent( QUrl::fromLocalFile( Calamares::Branding::instance()->slideshowPath() ), m_qmlComponent, m_qmlObject );
+            if ( ViewManager::instance()->currentStep() == this )
+            {
+                // We're alreay visible! Must have been slow QML loading, and we
+                // passed onActivate already.
+                callQMLFunction( m_qmlObject, "onActivate" );
+            }
+        }
+    }
+}
 
 void
 ExecutionViewStep::onActivate()
 {
-    CALAMARES_RETRANSLATE_WIDGET( m_widget,
-        if ( !Calamares::Branding::instance()->slideshowPath().isEmpty() )
-            m_slideShow->setSource( QUrl::fromLocalFile( Calamares::Branding::instance()
-                                                         ->slideshowPath() ) );
-    )
-
+    if ( Branding::instance()->slideshowAPI() == 2 )
+    {
+        // The QML was already loaded in the constructor, need to start it
+        callQMLFunction( m_qmlObject, "onActivate" );
+    }
+    else if ( !Calamares::Branding::instance()->slideshowPath().isEmpty() )
+    {
+        // API version 1 assumes onCompleted is the trigger
+        m_qmlShow->setSource( QUrl::fromLocalFile( Calamares::Branding::instance()->slideshowPath() ) );
+    }
 
     JobQueue* queue = JobQueue::instance();
     foreach ( const QString& instanceKey, m_jobInstanceKeys )
     {
-        Calamares::Module* module = Calamares::ModuleManager::instance()
-                                    ->moduleInstance( instanceKey );
+        Calamares::Module* module = Calamares::ModuleManager::instance()->moduleInstance( instanceKey );
         if ( module )
         {
             auto jl = module->jobs();
@@ -183,4 +265,16 @@ ExecutionViewStep::updateFromJobQueue( qreal percent, const QString& message )
     m_label->setText( message );
 }
 
+void
+ExecutionViewStep::onLeave()
+{
+    // API version 2 is explicitly stopped; version 1 keeps running
+    if ( Branding::instance()->slideshowAPI() == 2 )
+    {
+        callQMLFunction( m_qmlObject, "onLeave" );
+        delete m_qmlObject;
+        m_qmlObject = nullptr;
+    }
+}
+
 } // namespace

src/libcalamaresui/ExecutionViewStep.h

@@ -25,7 +25,10 @@
 #include <QStringList>
 
 class QLabel;
+class QObject;
 class QProgressBar;
+class QQmlComponent;
+class QQuickItem;
 class QQuickWidget;
 
 namespace Calamares
@@ -51,19 +54,26 @@ public:
     bool isAtEnd() const override;
 
     void onActivate() override;
+    void onLeave() override;
 
     JobList jobs() const override;
 
     void appendJobModuleInstanceKey( const QString& instanceKey );
 
+public slots:
+    void loadQmlV2Complete();
+
 private:
     QWidget* m_widget;
     QProgressBar* m_progressBar;
     QLabel* m_label;
-    QQuickWidget* m_slideShow;
+    QQuickWidget* m_qmlShow;
+    QQmlComponent* m_qmlComponent;
+    QQuickItem* m_qmlObject;  //< The actual show
 
     QStringList m_jobInstanceKeys;
 
+    void loadQmlV2();  //< Loads the slideshow QML (from branding) for API version 2
     void updateFromJobQueue( qreal percent, const QString& message );
 };