Merge pull request #19 from slapab/manual_control_rts_dtr

Added functionality to manually control state of RTS and DTR lines when port has been opened with no flow control or software flow control enabled.
neundorf · Oct 31, 2016 · 7da86b3 · 7da86b3
2 parents e94ca54 + f9a0b89
commit 7da86b3
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Showing 5 changed files with 114 additions and 5 deletions.
diff --git a/controlpanel.cpp b/controlpanel.cpp
@@ -62,6 +62,9 @@ ControlPanel::ControlPanel(QWidget *parent, Settings *settings)
     setAutoFillBackground(true);
     //    setWindowOpacity(0.1);
     m_bt_open->setCheckable(true);
+    // Disable RTS and CTS checkboxes during construction
+    m_rts_line->setEnabled(false);
+    m_dtr_line->setEnabled(false);
 
     // Connect button signal to slot
     connect(m_bt_settings, &QPushButton::clicked, this, &ControlPanel::toggleMenu);
@@ -129,10 +132,19 @@ void ControlPanel::toggleDevice(bool open)
     if (open) {
         if (m_menuVisible)
             toggleMenu();
+        // Enable RTS and DTR checkboxes when opening device. Note that visibility of these
+        // widgets depends on currently selected type of flow control.
+        m_rts_line->setEnabled(true);
+        m_dtr_line->setEnabled(true);
+
         m_bt_settings->setEnabled(false);
         m_bt_open->setText(tr("Cl&ose"));
         emit openDeviceClicked();
     } else {
+        // Disable RTS and DTR checkboxes when closing device.
+        m_rts_line->setEnabled(false);
+        m_dtr_line->setEnabled(false);
+
         m_bt_settings->setEnabled(true);
         emit closeDeviceClicked();
         m_bt_open->setText(tr("&Open"));
@@ -319,6 +331,11 @@ void ControlPanel::fillFlowCombo()
 
     connect(m_combo_flowControl, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
             [=]() { emit settingChanged(Settings::FlowControl, m_combo_flowControl->currentData()); });
+
+    // Connect flow-control's combobox index changed signal to the slot that sets the visibility of RTS and DTR
+    // checkboxes
+    connect(m_combo_flowControl, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this,
+            &ControlPanel::changeVisibilityOfRTSandDTRCheckboxes);
 }
 
 void ControlPanel::fillParityCombo()
@@ -378,3 +395,19 @@ void ControlPanel::chooseLogFile()
         m_logfile_edit->setText(logFile);
     }
 }
+
+void ControlPanel::changeVisibilityOfRTSandDTRCheckboxes(int index)
+{
+    // if index is valid then retrieve the flow control type and change visibility of RTS and DTR lines. RTS and CTS
+    // checkboxes are invisible only if hardware control is enabled.
+    if (-1 != index) {
+        auto data = static_cast<QSerialPort::FlowControl>(m_combo_flowControl->itemData(index).toInt());
+        if (QSerialPort::FlowControl::HardwareControl == data) {
+            m_rts_line->setVisible(false);
+            m_dtr_line->setVisible(false);
+        } else {
+            m_rts_line->setVisible(true);
+            m_dtr_line->setVisible(true);
+        }
+    }
+}
diff --git a/controlpanel.h b/controlpanel.h
@@ -80,6 +80,15 @@ class ControlPanel : public QFrame, public Ui::ControlPanel
     void customBaudRateSet();
     void chooseLogFile();
 
+    /**
+     * @brief   Designed to catch QComboBox::currentIndexChanged(int) signal. Its roles is to set the
+     *          proper visibility of RTS and DTR checkboxes which depends on selected type of flow control.
+     *          If user selects the hardware flow control, then RTS and DTR checkboxes are being invisible.
+     *          If user selects none or software flow control, then RTS and DTR checkboxes are being visible.
+     * @param   index   QComboBox item's index.
+     */
+    void changeVisibilityOfRTSandDTRCheckboxes(int index);
+
 private:
     int m_x;
     int m_y;

diff --git a/controlpanel.ui b/controlpanel.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>628</width>
-    <height>129</height>
+    <height>130</height>
    </rect>
   </property>
   <property name="autoFillBackground">
@@ -242,6 +242,32 @@
      <item>
       <widget class="DeviceCombo" name="m_combo_device" native="true"/>
      </item>
+     <item>
+      <widget class="QCheckBox" name="m_rts_line">
+       <property name="toolTip">
+        <string>The RTS line is set to logic HIGH when checked. Note that in RS232C the negative logic is used.</string>
+       </property>
+       <property name="locale">
+        <locale language="English" country="UnitedStates"/>
+       </property>
+       <property name="text">
+        <string>RTS</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <widget class="QCheckBox" name="m_dtr_line">
+       <property name="toolTip">
+        <string>The DTR line is set to logic HIGH when checked. Note that in RS232C the negative logic is used.</string>
+       </property>
+       <property name="locale">
+        <locale language="English" country="UnitedStates"/>
+       </property>
+       <property name="text">
+        <string>DTR</string>
+       </property>
+      </widget>
+     </item>
      <item>
       <spacer name="horizontalSpacer">
        <property name="orientation">

diff --git a/mainwindow.cpp b/mainwindow.cpp
@@ -212,6 +212,9 @@ MainWindow::MainWindow(QWidget *parent, const QString &session)
     connect(m_sessionManager, &SessionManager::sessionRenamed, m_settings, &Settings::renameSession);
     connect(m_sessionManager, &SessionManager::sessionCloned, m_settings, &Settings::cloneSession);
     connect(actionManager, &QAction::triggered, m_sessionManager, &QDialog::show);
+
+    connect(controlPanel->m_rts_line, &QCheckBox::stateChanged, this, &MainWindow::setRTSLineState);
+    connect(controlPanel->m_dtr_line, &QCheckBox::stateChanged, this, &MainWindow::setDTRLineState);
 }
 
 bool MainWindow::eventFilter(QObject *obj, QEvent *event)
@@ -322,10 +325,15 @@ void MainWindow::openDevice()
         m_device->setStopBits(session.stopBits);
         m_device->setFlowControl(session.flowControl);
 
-        /* Disable RTS/DTR when no flow control is used */
-        if (session.flowControl == QSerialPort::NoFlowControl) {
-            m_device->setDataTerminalReady(false);
-            m_device->setRequestToSend(false);
+        /* Disable RTS/DTR when no flow control or software flow control is used */
+        if (QSerialPort::FlowControl::HardwareControl != session.flowControl) {
+            // Force to emit QCheckBox::stateChanged signals to set proper logic levels on DTR/RTS lines.
+            // Note that on Linux when opening serial device even with no flow control, DTR and RTS lines are set to
+            // logic high, in RS232 that means a negative voltage on these lines (or just 0V for TTL based USB-UARTs).
+            // So this applies the same settings after reopen the device, and sets RTS/DTR to logic low when opening for
+            // first time when no flow control or software flow control is set.
+            emit controlPanel->m_dtr_line->stateChanged(controlPanel->m_dtr_line->checkState());
+            emit controlPanel->m_rts_line->stateChanged(controlPanel->m_rts_line->checkState());
         }
 
         m_device->flush();
@@ -922,6 +930,28 @@ void MainWindow::removeSelectedInputItems(bool checked)
     }
 }
 
+void MainWindow::setRTSLineState(int checked)
+{
+    if ((nullptr != m_device) && (true == m_device->isOpen())) {
+        if (Qt::CheckState::Checked == static_cast<Qt::CheckState>(checked)) {
+            m_device->setRequestToSend(true);
+        } else {
+            m_device->setRequestToSend(false);
+        }
+    }
+}
+
+void MainWindow::setDTRLineState(int checked)
+{
+    if ((nullptr != m_device) && (true == m_device->isOpen())) {
+        if (Qt::CheckState::Checked == static_cast<Qt::CheckState>(checked)) {
+            m_device->setDataTerminalReady(true);
+        } else {
+            m_device->setDataTerminalReady(false);
+        }
+    }
+}
+
 MainWindow::~MainWindow()
 {
     if (m_device->isOpen()) {

diff --git a/mainwindow.h b/mainwindow.h
@@ -81,6 +81,17 @@ private slots:
     void sendDone(int exitCode, QProcess::ExitStatus exitStatus);
     void resizeEvent(QResizeEvent *event);
 
+protected slots:
+    /**
+     * @brief Handles QCheckBox::stateChanged signal received from RTS checkbox (placed in control panel).
+     */
+    void setRTSLineState(int checked);
+
+    /**
+     * @brief Handles QCheckBox::stateChanged signal recieved from DTR checkbox (placed in control panel).
+     */
+    void setDTRLineState(int checked);
+
 private:
     void toggleLogging(bool start);
     void fillLineTerminationChooser(const Settings::LineTerminator setting = Settings::LF);