From 9a3d9feb308d734b4fcbfa4438211433d42331dd Mon Sep 17 00:00:00 2001
From: Adriaan de Groot <groot@kde.org>
Date: Fri, 15 Apr 2022 12:13:16 +0200
Subject: [PATCH] [libcalamaresui] Add a countdown widget for limited waiting.

---
 src/libcalamaresui/widgets/WaitingWidget.cpp | 91 ++++++++++++++++++++
 src/libcalamaresui/widgets/WaitingWidget.h   | 49 ++++++++++-
 2 files changed, 139 insertions(+), 1 deletion(-)

diff --git a/src/libcalamaresui/widgets/WaitingWidget.cpp b/src/libcalamaresui/widgets/WaitingWidget.cpp
index aef5aecf5..671f140c5 100644
--- a/src/libcalamaresui/widgets/WaitingWidget.cpp
+++ b/src/libcalamaresui/widgets/WaitingWidget.cpp
@@ -16,6 +16,7 @@
 
 #include <QBoxLayout>
 #include <QLabel>
+#include <QTimer>
 
 WaitingWidget::WaitingWidget( const QString& text, QWidget* parent )
     : QWidget( parent )
@@ -55,3 +56,93 @@ WaitingWidget::setText( const QString& text )
 {
     m_waitingLabel->setText( text );
 }
+
+struct CountdownWaitingWidget::Private
+{
+    std::chrono::seconds duration;
+    // int because we count down, need to be able to show a 0,
+    // and then wrap around to duration a second later.
+    int count = 0;
+    WaitingSpinnerWidget* spinner = nullptr;
+    QLabel* label = nullptr;
+    QTimer* timer = nullptr;
+
+    Private( std::chrono::seconds seconds, QWidget* parent )
+        : duration( seconds )
+        , spinner( new WaitingSpinnerWidget( parent ) )
+        , label( new QLabel( parent ) )
+        , timer( new QTimer( parent ) )
+    {
+    }
+};
+
+CountdownWaitingWidget::CountdownWaitingWidget( std::chrono::seconds duration, QWidget* parent )
+    : QWidget( parent )
+    , d( std::make_unique< Private >( duration, this ) )
+{
+    // Set up the label first for sizing
+    const int labelHeight = d->label->fontMetrics().height() * 3 / 2;
+
+    // Set up the spinner
+    d->spinner->setFixedSize( labelHeight, labelHeight );
+
+    // Overall UI layout
+    QBoxLayout* box = new QHBoxLayout;
+    box->addWidget( d->spinner );
+    box->addWidget( d->label );
+    setLayout( box );
+
+    // Last because it updates the text
+    setInterval( duration );
+
+    d->timer->setInterval( std::chrono::seconds( 1 ) );
+    connect( d->timer, &QTimer::timeout, this, &CountdownWaitingWidget::tick );
+}
+
+CountdownWaitingWidget::~CountdownWaitingWidget()
+{
+    d->timer->stop();
+}
+
+void
+CountdownWaitingWidget::setInterval( std::chrono::seconds duration )
+{
+    d->duration = duration;
+    d->count = int( duration.count() );
+    tick();
+}
+
+void
+CountdownWaitingWidget::start()
+{
+    // start it from the top
+    if ( d->count <= 0 )
+    {
+        d->count = int( d->duration.count() );
+        tick();
+    }
+    d->timer->start();
+}
+
+void
+CountdownWaitingWidget::stop()
+{
+    d->timer->stop();
+}
+
+void
+CountdownWaitingWidget::tick()
+{
+    // We do want to **display** a 0 which is why we wrap around only
+    // after counting down from 0.
+    d->count--;
+    if ( d->count < 0 )
+    {
+        d->count = int( d->duration.count() );
+    }
+    d->label->setText( QString::number( d->count ) );
+    if ( d->count == 0 )
+    {
+        timeout();
+    }
+}
diff --git a/src/libcalamaresui/widgets/WaitingWidget.h b/src/libcalamaresui/widgets/WaitingWidget.h
index 850b81ca9..867529641 100644
--- a/src/libcalamaresui/widgets/WaitingWidget.h
+++ b/src/libcalamaresui/widgets/WaitingWidget.h
@@ -12,18 +12,65 @@
 
 #include <QWidget>
 
-class QLabel;
+#include <chrono>
+#include <memory>
 
+class QLabel;
+class QTimer;
+
+/** @brief A spinner and a label below it
+ *
+ * The spinner has a fixed size of 4* the font height,
+ * and the text is displayed centered below it. Use this
+ * to display a long-term waiting situation with a status report.
+ */
 class WaitingWidget : public QWidget
 {
     Q_OBJECT
 public:
+    /// Create a WaitingWidget with initial @p text label.
     explicit WaitingWidget( const QString& text, QWidget* parent = nullptr );
 
+    /// Update the @p text displayed in the label.
     void setText( const QString& text );
 
 private:
     QLabel* m_waitingLabel;
 };
 
+/** @brief A spinner and a countdown next to it
+ *
+ * The spinner is sized to the text-height and displays a
+ * numeric countdown next to it. The countdown is updated
+ * every second. The signal timeout() is sent every time
+ * the countdown reaches 0.
+ */
+class CountdownWaitingWidget : public QWidget
+{
+    Q_OBJECT
+public:
+    /// Create a countdown widget with a given @p duration
+    explicit CountdownWaitingWidget( std::chrono::seconds duration = std::chrono::seconds( 5 ),
+                                     QWidget* parent = nullptr );
+    ~CountdownWaitingWidget() override;
+
+    /// Changes the duration used and resets the countdown
+    void setInterval( std::chrono::seconds duration );
+
+    /// Start the countdown, resets to the full duration
+    void start();
+    /// Stop the countdown
+    void stop();
+
+Q_SIGNALS:
+    void timeout();
+
+protected Q_SLOTS:
+    void tick();
+
+private:
+    struct Private;
+    std::unique_ptr< Private > d;
+};
+
 #endif  // WAITINGWIDGET_H