Polish the modbus client example

- Use modern string literals
- Use QCommandLineParser to switch on verbose mode
- Fix translated texts with arguments
- Streamline some code
- Remove unused member variable
- Use QVariant casts

Pick-to: 6.4
Change-Id: Ie3bdaa82856bfe8df020dc289de9177d098f02d3
Reviewed-by: Karsten Heimrich <karsten.heimrich@qt.io>

1 files changed, 35 insertions, 27 deletions

diff --git a/examples/serialbus/modbus/client/writeregistermodel.cpp b/examples/serialbus/modbus/client/writeregistermodel.cpp
index 6cc62a5..de6ffbd 100644
--- a/examples/serialbus/modbus/client/writeregistermodel.cpp
+++ b/examples/serialbus/modbus/client/writeregistermodel.cpp
@@ -3,6 +3,8 @@
 
 #include "writeregistermodel.h"
 
+using namespace Qt::StringLiterals;
+
 enum { NumColumn = 0, CoilsColumn = 1, HoldingColumn = 2, ColumnCount = 3, RowCount = 10 };
 
 WriteRegisterModel::WriteRegisterModel(QObject *parent)
@@ -11,77 +13,81 @@ WriteRegisterModel::WriteRegisterModel(QObject *parent)
 {
 }
 
-int WriteRegisterModel::rowCount(const QModelIndex &/*parent*/) const
+int WriteRegisterModel::rowCount(const QModelIndex & /* parent */) const
 {
     return RowCount;
 }
 
-int WriteRegisterModel::columnCount(const QModelIndex &/*parent*/) const
+int WriteRegisterModel::columnCount(const QModelIndex & /* parent */) const
 {
     return ColumnCount;
 }
 
 QVariant WriteRegisterModel::data(const QModelIndex &index, int role) const
 {
-    if (!index.isValid() || index.row() >= RowCount || index.column() >= ColumnCount)
-        return QVariant();
+    const int row = index.row();
+    const int column = index.column();
+    if (!index.isValid() || row >= RowCount || column >= ColumnCount)
+        return {};
 
     Q_ASSERT(m_coils.count() == RowCount);
     Q_ASSERT(m_holdingRegisters.count() == RowCount);
 
-    if (index.column() == NumColumn && role == Qt::DisplayRole)
-        return QString::number(index.row());
+    if (column == NumColumn && role == Qt::DisplayRole)
+        return QString::number(row);
 
-    if (index.column() == CoilsColumn && role == Qt::CheckStateRole) // coils
-        return m_coils.at(index.row()) ? Qt::Checked : Qt::Unchecked;
+    if (column == CoilsColumn && role == Qt::CheckStateRole) // coils
+        return m_coils.at(row) ? Qt::Checked : Qt::Unchecked;
 
-    if (index.column() == HoldingColumn && role == Qt::DisplayRole) // holding registers
-        return QString("0x%1").arg(QString::number(m_holdingRegisters.at(index.row()), 16));
+    if (column == HoldingColumn && role == Qt::DisplayRole) // holding registers
+        return QString("0x%1").arg(QString::number(m_holdingRegisters.at(row), 16));
 
-    return QVariant();
+    return {};
 
 }
 
 QVariant WriteRegisterModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
     if (role != Qt::DisplayRole)
-        return QVariant();
+        return {};
 
     if (orientation == Qt::Horizontal) {
         switch (section) {
         case NumColumn:
-            return QStringLiteral("#");
+            return u"#"_s;
         case CoilsColumn:
-            return QStringLiteral("Coils  ");
+            return u"Coils  "_s;
         case HoldingColumn:
-            return QStringLiteral("Holding Registers");
+            return u"Holding Registers"_s;
         default:
             break;
         }
     }
-    return QVariant();
+    return {};
 }
 
 bool WriteRegisterModel::setData(const QModelIndex &index, const QVariant &value, int role)
 {
-    if (!index.isValid() ||  index.row() >= RowCount || index.column() >= ColumnCount)
+    const int row = index.row();
+    const int column = index.column();
+    if (!index.isValid() ||  row >= RowCount || column >= ColumnCount)
         return false;
 
     Q_ASSERT(m_coils.count() == RowCount);
     Q_ASSERT(m_holdingRegisters.count() == RowCount);
 
-    if (index.column() == CoilsColumn && role == Qt::CheckStateRole) { // coils
+    if (column == CoilsColumn && role == Qt::CheckStateRole) { // coils
         auto s = static_cast<Qt::CheckState>(value.toUInt());
-        s == Qt::Checked ? m_coils.setBit(index.row()) : m_coils.clearBit(index.row());
+        s == Qt::Checked ? m_coils.setBit(row) : m_coils.clearBit(row);
         emit dataChanged(index, index);
         return true;
     }
 
-    if (index.column() == HoldingColumn && role == Qt::EditRole) { // holding registers
+    if (column == HoldingColumn && role == Qt::EditRole) { // holding registers
         bool result = false;
         quint16 newValue = value.toString().toUShort(&result, 16);
         if (result)
-            m_holdingRegisters[index.row()] = newValue;
+            m_holdingRegisters[row] = newValue;
 
         emit dataChanged(index, index);
         return result;
@@ -92,16 +98,18 @@ bool WriteRegisterModel::setData(const QModelIndex &index, const QVariant &value
 
 Qt::ItemFlags WriteRegisterModel::flags(const QModelIndex &index) const
 {
-    if (!index.isValid() || index.row() >= RowCount || index.column() >= ColumnCount)
-        return QAbstractTableModel::flags(index);
-
+    const int row = index.row();
+    const int column = index.column();
     Qt::ItemFlags flags = QAbstractTableModel::flags(index);
-    if ((index.row() < m_address) || (index.row() >= (m_address + m_number)))
+    if (!index.isValid() || row >= RowCount || column >= ColumnCount)
+        return flags;
+
+    if ((row < m_address) || (row >= (m_address + m_number)))
         flags &= ~Qt::ItemIsEnabled;
 
-    if (index.column() == CoilsColumn) // coils
+    if (column == CoilsColumn) // coils
         return flags | Qt::ItemIsUserCheckable;
-    if (index.column() == HoldingColumn) // holding registers
+    if (column == HoldingColumn) // holding registers
         return flags | Qt::ItemIsEditable;
 
     return flags;