BFM demod: RDS: radio text on two lines with the bottom one keeping the previously decoded text

plugins/channelrx/demodbfm/bfmdemodgui.cpp

@@ -213,6 +213,8 @@ void BFMDemodGUI::on_clearData_clicked(bool checked)
 	{
 		m_bfmDemod->getRDSParser().clearAllFields();
 
+		ui->go2Text->clear();
+		ui->go2PrevText->clear();
 		ui->g14ProgServiceNames->clear();
 		ui->g14MappedFrequencies->clear();
 		ui->g14AltFrequencies->clear();
@@ -277,6 +279,11 @@ void BFMDemodGUI::on_g00AltFrequenciesBox_activated(int index)
 	changeFrequency(f);
 }
 
+void BFMDemodGUI::on_go2ClearPrevText_clicked()
+{
+	ui->go2PrevText->clear();
+}
+
 void BFMDemodGUI::on_g14MappedFrequencies_activated(int index)
 {
     (void) index;
@@ -353,6 +360,7 @@ BFMDemodGUI::BFMDemodGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISet, Baseban
 	m_deviceUISet(deviceUISet),
 	m_channelMarker(this),
 	m_rdsTimerCount(0),
+    m_radiotext_AB_flag(false),
 	m_rate(625000)
 {
 	ui->setupUi(this);
@@ -684,7 +692,16 @@ void BFMDemodGUI::rdsUpdate(bool force)
 	{
 		ui->g02Label->setStyleSheet("QLabel { background-color : green; }");
 		ui->g02CountText->setNum((int) m_bfmDemod->getRDSParser().m_g2_count);
+        bool radiotext_AB_flag = m_bfmDemod->getRDSParser().m_radiotext_AB_flag;
+
+        if (!m_radiotext_AB_flag && radiotext_AB_flag) // B -> A transiition is start of new text
+        {
+            QString oldText = ui->go2Text->text();
+            ui->go2PrevText->setText(oldText);
+        }
+
 		ui->go2Text->setText(QString(m_bfmDemod->getRDSParser().m_g2_radiotext));
+        m_radiotext_AB_flag = radiotext_AB_flag;
 	}
 	else
 	{

plugins/channelrx/demodbfm/bfmdemodgui.h

@@ -62,6 +62,7 @@ private:
 	BFMDemodSettings m_settings;
 	bool m_doApplySettings;
 	int m_rdsTimerCount;
+    bool m_radiotext_AB_flag;
 
 	SpectrumVis* m_spectrumVis;
 
@@ -99,6 +100,7 @@ private slots:
 	void on_g14ProgServiceNames_currentIndexChanged(int index);
 	void on_clearData_clicked(bool checked);
 	void on_g00AltFrequenciesBox_activated(int index);
+	void on_go2ClearPrevText_clicked();
 	void on_g14MappedFrequencies_activated(int index);
 	void on_g14AltFrequencies_activated(int index);
 	void onWidgetRolled(QWidget* widget, bool rollDown);

plugins/channelrx/demodbfm/bfmdemodgui.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>798</width>
-    <height>472</height>
+    <height>755</height>
    </rect>
   </property>
   <property name="sizePolicy">
@@ -551,7 +551,7 @@
      <x>10</x>
      <y>170</y>
      <width>791</width>
-     <height>301</height>
+     <height>281</height>
     </rect>
    </property>
    <property name="minimumSize">
@@ -565,7 +565,7 @@
    </property>
    <layout class="QVBoxLayout" name="rdsLayout">
     <property name="spacing">
-     <number>3</number>
+     <number>1</number>
     </property>
     <item>
      <layout class="QHBoxLayout" name="reportLayout">
@@ -1602,8 +1602,52 @@
       </item>
       <item>
        <widget class="QLabel" name="go2Text">
+        <property name="toolTip">
+         <string>Current radio text</string>
+        </property>
         <property name="text">
-         <string>Radiotext</string>
+         <string/>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </item>
+    <item>
+     <layout class="QHBoxLayout" name="row4pDataLayout">
+      <item>
+       <widget class="QPushButton" name="go2ClearPrevText">
+        <property name="maximumSize">
+         <size>
+          <width>30</width>
+          <height>16777215</height>
+         </size>
+        </property>
+        <property name="toolTip">
+         <string>Clear previous text</string>
+        </property>
+        <property name="text">
+         <string/>
+        </property>
+        <property name="icon">
+         <iconset resource="../../../sdrgui/resources/res.qrc">
+          <normaloff>:/sweep.png</normaloff>:/sweep.png</iconset>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="Line" name="row4Separator1_2">
+        <property name="orientation">
+         <enum>Qt::Vertical</enum>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QLabel" name="go2PrevText">
+        <property name="toolTip">
+         <string>Previous radio text</string>
+        </property>
+        <property name="text">
+         <string/>
         </property>
        </widget>
       </item>

plugins/channelrx/demodbfm/rdsparser.h

@@ -80,6 +80,7 @@ public:
 	bool           m_g2_updated;
 	unsigned int   m_g2_count;
 	char           m_g2_radiotext[64+1];
+	bool           m_radiotext_AB_flag;
 
 	// G3 data
 	bool           m_g3_updated;
@@ -193,7 +194,6 @@ private:
 	unsigned char  pi_country_identification;
 	unsigned char  pi_program_reference_number;
 
-	bool           m_radiotext_AB_flag;
 	bool           debug;
 	bool           log;