Add button to the decoded text window context menu to erase the contents

Right-click  either decoded  text window  to erase  its contents.  The
"Erase" button on the main UI  still operates as before although it is
implemented differently now.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@8090 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

displaytext.cpp

@@ -5,18 +5,39 @@
 #include <QTextCharFormat>
 #include <QTextCursor>
 #include <QTextBlock>
+#include <QMenu>
+#include <QAction>
 
 #include "qt_helpers.hpp"
 
 #include "moc_displaytext.cpp"
 
-DisplayText::DisplayText(QWidget *parent) :
-    QTextEdit(parent)
+DisplayText::DisplayText(QWidget *parent)
+  : QTextEdit(parent)
+  , erase_action_ {new QAction {tr ("&Erase"), this}}
 {
   setReadOnly (true);
   viewport ()->setCursor (Qt::ArrowCursor);
   setWordWrapMode (QTextOption::NoWrap);
-  document ()->setMaximumBlockCount (5000); // max lines to limit heap usage
+
+  // max lines to limit heap usage
+  document ()->setMaximumBlockCount (5000);
+
+  // context menu erase action
+  setContextMenuPolicy (Qt::CustomContextMenu);
+  connect (this, &DisplayText::customContextMenuRequested, [this] (QPoint const& position) {
+      auto * menu = createStandardContextMenu (position);
+      menu->addAction (erase_action_);
+      menu->exec (mapToGlobal (position));
+      delete menu;
+    });
+  connect (erase_action_, &QAction::triggered, this, &DisplayText::erase);
+}
+
+void DisplayText::erase ()
+{
+  clear ();
+  Q_EMIT erased ();
 }
 
 void DisplayText::setContentFont(QFont const& font)

displaytext.h

@@ -8,6 +8,8 @@
 #include "logbook/logbook.h"
 #include "decodedtext.h"
 
+class QAction;
+
 class DisplayText
   : public QTextEdit
 {
@@ -25,8 +27,10 @@ public:
   void displayQSY(QString text);
 
   Q_SIGNAL void selectCallsign (bool alt, bool ctrl);
+  Q_SIGNAL void erased ();
 
   Q_SLOT void appendText (QString const& text, QColor bg = Qt::white);
+  Q_SLOT void erase ();
 
 protected:
   void mouseDoubleClickEvent(QMouseEvent *e);
@@ -36,6 +40,7 @@ private:
 			     QColor color_CQ, QColor color_DXCC, QColor color_NewCall);
 
   QFont char_font_;
+  QAction * erase_action_;
 };
 
 #endif // DISPLAYTEXT_H

mainwindow.cpp

@@ -550,6 +550,7 @@ MainWindow::MainWindow(QDir const& temp_directory, bool multiple,
           SLOT(doubleClickOnCall(bool,bool)));
   connect(ui->decodedTextBrowser,SIGNAL(selectCallsign(bool,bool)),this,
           SLOT(doubleClickOnCall2(bool,bool)));
+  connect (ui->decodedTextBrowser2, &DisplayText::erased, this, &MainWindow::rx_frequency_activity_cleared);
 
   // initialize decoded text font and hook up font change signals
   // defer initialization until after construction otherwise menu
@@ -2897,23 +2898,27 @@ void MainWindow::killFile ()
   }
 }
 
-void MainWindow::on_EraseButton_clicked()                          //Erase
+void MainWindow::on_EraseButton_clicked ()
 {
   qint64 ms=QDateTime::currentMSecsSinceEpoch();
-  ui->decodedTextBrowser2->clear();
+  ui->decodedTextBrowser2->erase ();
   if(m_mode.startsWith ("WSPR") or m_mode=="Echo" or m_mode=="ISCAT") {
-    ui->decodedTextBrowser->clear();
+    ui->decodedTextBrowser->erase ();
   } else {
-    m_QSOText.clear();
     if((ms-m_msErase)<500) {
-      ui->decodedTextBrowser->clear();
-      m_messageClient->clear_decodes ();
-      QFile f(m_config.temp_dir ().absoluteFilePath ("decoded.txt"));
-      if(f.exists()) f.remove();
+      ui->decodedTextBrowser->erase ();
     }
   }
   m_msErase=ms;
-  set_dateTimeQSO(-1);
+}
+
+void MainWindow::rx_frequency_activity_cleared ()
+{
+  m_QSOText.clear();
+  m_messageClient->clear_decodes ();
+  QFile f(m_config.temp_dir ().absoluteFilePath ("decoded.txt"));
+  if(f.exists()) f.remove();
+  set_dateTimeQSO(-1);          // G4WJS: why do we do this?
 }
 
 void MainWindow::decodeBusy(bool b)                             //decodeBusy()

mainwindow.h

@@ -153,6 +153,7 @@ private slots:
   void decode();
   void decodeBusy(bool b);
   void on_EraseButton_clicked();
+  void rx_frequency_activity_cleared ();
   void on_txFirstCheckBox_stateChanged(int arg1);
   void set_dateTimeQSO(int m_ntx);
   void set_ntx(int n);