qml: introduce ChainModel

The ChainModel is responsible for managing the block information
that the gui components need to show. In this case, the ChainModel
will provide a list of ratios for the block times of the last 12 hours
to be rendered on the block clock's dial.

Co-authored-by: shaavan <[email protected]>

Author: johnny9

src/Makefile.qt.include

@@ -36,6 +36,7 @@ QT_FORMS_UI = \
 
 QT_MOC_CPP = \
   qml/moc_appmode.cpp \
+  qml/moc_chainmodel.cpp \
   qml/moc_nodemodel.cpp \
   qml/moc_options_model.cpp \
   qt/moc_addressbookpage.cpp \
@@ -111,6 +112,7 @@ QT_QRC_LOCALE = qt/bitcoin_locale.qrc
 BITCOIN_QT_H = \
   qml/appmode.h \
   qml/bitcoin.h \
+  qml/chainmodel.h \
   qml/imageprovider.h \
   qml/nodemodel.h \
   qml/options_model.h \
@@ -291,6 +293,7 @@ BITCOIN_QT_WALLET_CPP = \
 
 BITCOIN_QML_BASE_CPP = \
   qml/bitcoin.cpp \
+  qml/chainmodel.cpp \
   qml/imageprovider.cpp \
   qml/nodemodel.cpp \
   qml/options_model.cpp \

src/qml/bitcoin.cpp

@@ -6,12 +6,14 @@
 
 #include <chainparams.h>
 #include <init.h>
+#include <interfaces/chain.h>
 #include <interfaces/init.h>
 #include <interfaces/node.h>
 #include <logging.h>
 #include <node/interface_ui.h>
 #include <noui.h>
 #include <qml/appmode.h>
+#include <qml/chainmodel.h>
 #include <qml/imageprovider.h>
 #include <qml/nodemodel.h>
 #include <qml/options_model.h>
@@ -155,6 +157,7 @@ int QmlGuiMain(int argc, char* argv[])
     GUIUtil::LogQtInfo();
 
     std::unique_ptr<interfaces::Node> node = init->makeNode();
+    std::unique_ptr<interfaces::Chain> chain = init->makeChain();
     if (!node->baseInitialize()) {
         // A dialog with detailed error will have been shown by InitError().
         return EXIT_FAILURE;
@@ -170,6 +173,11 @@ int QmlGuiMain(int argc, char* argv[])
     QObject::connect(&init_executor, &InitExecutor::shutdownResult, qGuiApp, &QGuiApplication::quit, Qt::QueuedConnection);
     // QObject::connect(&init_executor, &InitExecutor::runawayException, &node_model, &NodeModel::handleRunawayException);
 
+    ChainModel chain_model{*chain};
+
+    QObject::connect(&node_model, &NodeModel::setTimeRatioList, &chain_model, &ChainModel::setTimeRatioList);
+    QObject::connect(&node_model, &NodeModel::setTimeRatioListInitial, &chain_model, &ChainModel::setTimeRatioListInitial);
+
     qGuiApp->setQuitOnLastWindowClosed(false);
     QObject::connect(qGuiApp, &QGuiApplication::lastWindowClosed, [&] {
         node->startShutdown();
@@ -185,6 +193,7 @@ int QmlGuiMain(int argc, char* argv[])
     engine.addImageProvider(QStringLiteral("images"), new ImageProvider{network_style.data()});
 
     engine.rootContext()->setContextProperty("nodeModel", &node_model);
+    engine.rootContext()->setContextProperty("chainModel", &chain_model);
 
     OptionsQmlModel options_model{*node};
     engine.rootContext()->setContextProperty("optionsModel", &options_model);

src/qml/chainmodel.cpp

@@ -0,0 +1,91 @@
+// Copyright (c) 2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <qml/chainmodel.h>
+
+#include <QDateTime>
+#include <QThread>
+#include <QTime>
+#include <interfaces/chain.h>
+
+ChainModel::ChainModel(interfaces::Chain& chain)
+    : m_chain{chain}
+{
+    QTimer* timer = new QTimer();
+    connect(timer, &QTimer::timeout, this, &ChainModel::setCurrentTimeRatio);
+    timer->start(1000);
+
+    QThread* timer_thread = new QThread;
+    timer->moveToThread(timer_thread);
+    timer_thread->start();
+}
+
+void ChainModel::setTimeRatioList(int new_time)
+{
+    if (m_time_ratio_list.isEmpty()) {
+        setTimeRatioListInitial();
+    }
+    int time_at_meridian = timestampAtMeridian();
+
+    if (new_time < time_at_meridian) {
+        return;
+    }
+    m_time_ratio_list.push_back(double(new_time - time_at_meridian) / SECS_IN_12_HOURS);
+
+    Q_EMIT timeRatioListChanged();
+}
+
+int ChainModel::timestampAtMeridian()
+{
+    int secs_since_meridian = (QTime::currentTime().msecsSinceStartOfDay() / 1000) % SECS_IN_12_HOURS;
+    int current_timestamp = QDateTime::currentSecsSinceEpoch();
+
+    return current_timestamp - secs_since_meridian;
+}
+
+void ChainModel::setTimeRatioListInitial()
+{
+    int time_at_meridian = timestampAtMeridian();
+    m_time_ratio_list.clear();
+    /* m_time_ratio_list[0] = current_time_ratio
+     * m_time_ratio_list[1] = 0
+     * These two positions remain fixed for these
+     * values in m_time_ratio_list */
+    m_time_ratio_list.push_back(double(QDateTime::currentSecsSinceEpoch() - time_at_meridian) / SECS_IN_12_HOURS);
+    m_time_ratio_list.push_back(0);
+
+    int first_block_height;
+    int active_chain_height = m_chain.getHeight().value();
+    bool success = m_chain.findFirstBlockWithTimeAndHeight(/*min_time=*/time_at_meridian, /*min_height=*/0, interfaces::FoundBlock().height(first_block_height));
+
+    if (!success) {
+        Q_EMIT timeRatioListChanged();
+        return;
+    }
+
+    for (int height = first_block_height; height < active_chain_height + 1; height++) {
+        m_time_ratio_list.push_back(double(m_chain.getBlockTime(height) - time_at_meridian) / SECS_IN_12_HOURS);
+    }
+
+    Q_EMIT timeRatioListChanged();
+}
+
+void ChainModel::setCurrentTimeRatio()
+{
+    int secs_since_meridian = (QTime::currentTime().msecsSinceStartOfDay() / 1000) % SECS_IN_12_HOURS;
+    double current_time_ratio = double(secs_since_meridian) / SECS_IN_12_HOURS;
+
+    if (current_time_ratio < m_time_ratio_list[0].toDouble()) { // That means time has crossed a meridian
+        m_time_ratio_list.clear();
+    }
+
+    if (m_time_ratio_list.isEmpty()) {
+        m_time_ratio_list.push_back(current_time_ratio);
+        m_time_ratio_list.push_back(0);
+    } else {
+        m_time_ratio_list[0] = current_time_ratio;
+    }
+
+    Q_EMIT timeRatioListChanged();
+}

src/qml/chainmodel.h

@@ -0,0 +1,54 @@
+// Copyright (c) 2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_QML_CHAINMODEL_H
+#define BITCOIN_QML_CHAINMODEL_H
+
+#include <interfaces/chain.h>
+
+#include <QObject>
+#include <QTimer>
+#include <QVariant>
+
+namespace interfaces {
+class FoundBlock;
+class Chain;
+} // namespace interfaces
+
+static const int SECS_IN_12_HOURS = 43200;
+
+class ChainModel : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QVariantList timeRatioList READ timeRatioList NOTIFY timeRatioListChanged)
+
+public:
+    explicit ChainModel(interfaces::Chain& chain);
+
+    QVariantList timeRatioList() const { return m_time_ratio_list; };
+
+    int timestampAtMeridian();
+
+    void setCurrentTimeRatio();
+
+public Q_SLOTS:
+    void setTimeRatioList(int new_time);
+    void setTimeRatioListInitial();
+
+Q_SIGNALS:
+    void timeRatioListChanged();
+
+private:
+    /* time_ratio: Ratio between the time at which an event
+     * happened and 12 hours. So, for example, if a block is
+     * found at 4 am or pm, the time_ratio would be 0.3.
+     * The m_time_ratio_list stores the time ratio value for
+     * the current_time and the time at which the blocks in
+     * the last 12 hours were mined. */
+    QVariantList m_time_ratio_list{0.0};
+
+    interfaces::Chain& m_chain;
+};
+
+#endif // BITCOIN_QML_CHAINMODEL_H