From df746047553e635d3cd8dd68b961d9909ee44033 Mon Sep 17 00:00:00 2001
From: Adriaan de Groot <groot@kde.org>
Date: Wed, 13 May 2020 16:35:09 +0200
Subject: [PATCH] [libcalamaresui] Implement non-QML Slideshow

---
 src/libcalamaresui/viewpages/Slideshow.cpp | 91 +++++++++++++++++++++-
 src/libcalamaresui/viewpages/Slideshow.h   | 41 +++++++++-
 2 files changed, 129 insertions(+), 3 deletions(-)

diff --git a/src/libcalamaresui/viewpages/Slideshow.cpp b/src/libcalamaresui/viewpages/Slideshow.cpp
index 5b264a5dd..a6c4c952c 100644
--- a/src/libcalamaresui/viewpages/Slideshow.cpp
+++ b/src/libcalamaresui/viewpages/Slideshow.cpp
@@ -26,11 +26,15 @@
 #include "utils/Qml.h"
 #include "utils/Retranslator.h"
 
+#include <QLabel>
 #include <QMutexLocker>
 #include <QQmlComponent>
 #include <QQmlEngine>
 #include <QQuickItem>
 #include <QQuickWidget>
+#include <QTimer>
+
+#include <chrono>
 
 namespace Calamares
 {
@@ -61,9 +65,13 @@ SlideshowQML::SlideshowQML( QWidget* parent )
 
 SlideshowQML::~SlideshowQML()
 {
+    delete m_qmlObject;
+    delete m_qmlComponent;
+    delete m_qmlShow;
 }
 
-QWidget * SlideshowQML::widget()
+QWidget*
+SlideshowQML::widget()
 {
     return m_qmlShow;
 }
@@ -166,4 +174,83 @@ SlideshowQML::changeSlideShowState( Action state )
     m_state = state;
 }
 
-}  // namespace
+SlideshowPictures::SlideshowPictures( QWidget* parent )
+    : Slideshow( parent )
+    , m_label( new QLabel( parent ) )
+    , m_timer( new QTimer( this ) )
+    , m_imageIndex( 0 )
+    , m_images { QStringLiteral( ":/data/images/yes.svgz" ), QStringLiteral( ":/data/images/no.svgz" ) }
+{
+    m_timer->setInterval( std::chrono::milliseconds( 2000 ) );
+    connect( m_timer, &QTimer::timeout, this, &SlideshowPictures::next );
+}
+
+SlideshowPictures::~SlideshowPictures()
+{
+    delete m_timer;
+    delete m_label;
+}
+
+QWidget*
+SlideshowPictures::widget()
+{
+    return m_label;
+}
+
+void
+SlideshowPictures::changeSlideShowState( Calamares::Slideshow::Action a )
+{
+    QMutexLocker l( &m_mutex );
+    m_state = a;
+    if ( a == Slideshow::Start )
+    {
+        m_imageIndex = -1;
+        if ( m_images.count() < 1 )
+        {
+            m_label->setPixmap( QPixmap( ":/data/images/squid.svg" ) );
+        }
+        else
+        {
+
+            m_timer->start();
+            QTimer::singleShot( 0, this, &SlideshowPictures::next );
+        }
+    }
+    else
+    {
+        m_timer->stop();
+    }
+}
+
+void
+SlideshowPictures::next()
+{
+    QMutexLocker l( &m_mutex );
+
+    if ( m_imageIndex < 0 )
+    {
+        // Initialization, don't do the advance-by-one
+        m_imageIndex = 0;
+    }
+    else
+    {
+        m_imageIndex++;
+        if ( m_imageIndex >= m_images.count() )
+        {
+            m_imageIndex = 0;
+        }
+    }
+
+    if ( m_imageIndex >= m_images.count() )
+    {
+        // Unusual case: timer is running, but we have 0 images to display.
+        // .. this would have been caught in changeSlideShowState(), which
+        // .. special-cases 0 images.
+        return;
+    }
+
+    m_label->setPixmap( QPixmap( m_images.at( m_imageIndex ) ) );
+}
+
+
+}  // namespace Calamares
diff --git a/src/libcalamaresui/viewpages/Slideshow.h b/src/libcalamaresui/viewpages/Slideshow.h
index 428422db5..2296c6d23 100644
--- a/src/libcalamaresui/viewpages/Slideshow.h
+++ b/src/libcalamaresui/viewpages/Slideshow.h
@@ -22,8 +22,11 @@
 #define LIBCALAMARESUI_SLIDESHOW_H
 
 #include <QMutex>
+#include <QStringList>
 #include <QWidget>
 
+class QLabel;
+class QTimer;
 class QQmlComponent;
 class QQuickItem;
 class QQuickWidget;
@@ -31,6 +34,14 @@ class QQuickWidget;
 namespace Calamares
 {
 
+/** @brief API for Slideshow objects
+ *
+ * A Slideshow (subclass) object is created by the ExecutionViewStep
+ * and needs to manage its own configuration (e.g. from Branding).
+ * The slideshow is started and stopped when it becomes visible
+ * and when installation is over, by calling changeSlideShowState()
+ * as appropriate.
+ */
 class Slideshow : public QObject
 {
     Q_OBJECT
@@ -48,7 +59,7 @@ public:
     }
     virtual ~Slideshow();
 
-    ///@brief Is the slideshow being shown **right now**?
+    /// @brief Is the slideshow being shown **right now**?
     bool isActive() const { return m_state == Start; }
 
     /** @brief The actual widget to show the user.
@@ -70,6 +81,15 @@ protected:
     Action m_state = Stop;
 };
 
+/** @brief Slideshow using a QML file
+ *
+ * This is the "classic" slideshow in Calamares, which runs some QML
+ * while the installation is in progress. It is configured through
+ * Branding settings *slideshow* and *slideshowAPI*, showing the QML
+ * file from *slideshow*. The API version influences when and how the
+ * QML is loaded; version 1 does so only when the slideshow is activated,
+ * while version 2 does so asynchronously.
+ */
 class SlideshowQML : public Slideshow
 {
     Q_OBJECT
@@ -90,13 +110,32 @@ private:
     QQuickItem* m_qmlObject;  ///< The actual show
 };
 
+/** @brief Slideshow using images
+ *
+ * This is an "oldschool" slideshow, but new in Calamares, which
+ * displays static image files one-by-one. It is for systems that
+ * do not use QML at all. It is configured through the Branding
+ * setting *slideshow*. When using this widget, the setting must
+ * be a list of filenames; the API is set to -1.
+ */
 class SlideshowPictures : public Slideshow
 {
+    Q_OBJECT
 public:
     SlideshowPictures( QWidget* parent );
     virtual ~SlideshowPictures() override;
 
     QWidget* widget() override;
+    virtual void changeSlideShowState( Action a ) override;
+
+public slots:
+    void next();
+
+private:
+    QLabel* m_label;
+    QTimer* m_timer;
+    int m_imageIndex;
+    QStringList m_images;
 };
 
 }  // namespace Calamares