From c481bbeff22339095de76fc2bd91b5d6edcae94e Mon Sep 17 00:00:00 2001
From: Jeff Long <willcode4@gmail.com>
Date: Tue, 3 Oct 2023 09:04:50 -0400
Subject: [PATCH 1/2] plotter: clear waterfall using Delete key

The waterfall is not automatically cleared after changes to the many
settings that could cause it to be distorted or invalid. An explicit
clear allows users who do not want to see outdated data to get rid of
it.

Signed-off-by: Jeff Long <willcode4@gmail.com>
---
 resources/kbd-shortcuts.txt          | 1 +
 src/applications/gqrx/mainwindow.cpp | 3 +++
 src/qtgui/plotter.cpp                | 7 +++++++
 src/qtgui/plotter.h                  | 1 +
 4 files changed, 12 insertions(+)

diff --git a/resources/kbd-shortcuts.txt b/resources/kbd-shortcuts.txt
index 1a76518b9..ff8849960 100644
--- a/resources/kbd-shortcuts.txt
+++ b/resources/kbd-shortcuts.txt
@@ -12,6 +12,7 @@ Main window actions:
  F11            Toggle full screen mode
  F              Set focus to the frequency controller
  Z              Zero frequency offset
+ Delete         Clear waterfall
  Ctrl+Q         Quit the program
 
 Receiver modes:
diff --git a/src/applications/gqrx/mainwindow.cpp b/src/applications/gqrx/mainwindow.cpp
index 765347b7b..09403fe78 100644
--- a/src/applications/gqrx/mainwindow.cpp
+++ b/src/applications/gqrx/mainwindow.cpp
@@ -172,6 +172,9 @@ MainWindow::MainWindow(const QString& cfgfile, bool edit_conf, QWidget *parent)
     // toggle markers on/off
     auto *toggle_markers_shortcut = new QShortcut(QKeySequence(Qt::CTRL | Qt::Key_K), this);
     QObject::connect(toggle_markers_shortcut, &QShortcut::activated, this, &MainWindow::toggleMarkers);
+    // clear waterfall
+    auto *clear_waterfall_shortcut = new QShortcut(Qt::Key_Delete, this);
+    QObject::connect(clear_waterfall_shortcut, SIGNAL(activated()), ui->plotter, SLOT(clearWaterfall()));
 
     setCorner(Qt::TopLeftCorner, Qt::LeftDockWidgetArea);
     setCorner(Qt::TopRightCorner, Qt::RightDockWidgetArea);
diff --git a/src/qtgui/plotter.cpp b/src/qtgui/plotter.cpp
index b5d17ae7a..990bba4f0 100644
--- a/src/qtgui/plotter.cpp
+++ b/src/qtgui/plotter.cpp
@@ -2455,6 +2455,13 @@ void CPlotter::setMarkers(qint64 a, qint64 b)
     updateOverlay();
 }
 
+void CPlotter::clearWaterfall()
+{
+    if (!m_WaterfallPixmap.isNull()) {
+        m_WaterfallPixmap.fill(Qt::black);
+    }
+}
+
 void CPlotter::calcDivSize (qint64 low, qint64 high, int divswanted, qint64 &adjlow, qint64 &step, int& divs)
 {
     qCDebug(plotter) << "low:" << low;
diff --git a/src/qtgui/plotter.h b/src/qtgui/plotter.h
index 7d1b04146..7e322440c 100644
--- a/src/qtgui/plotter.h
+++ b/src/qtgui/plotter.h
@@ -181,6 +181,7 @@ public slots:
     void enableBandPlan(bool enable);
     void enableMarkers(bool enabled);
     void setMarkers(qint64 a, qint64 b);
+    void clearWaterfall();
     void updateOverlay();
 
     void setPercent2DScreen(int percent)

From 5397bcc1121c7481d6f0877e184d81965bdb1f07 Mon Sep 17 00:00:00 2001
From: Clayton Smith <argilo@gmail.com>
Date: Tue, 3 Oct 2023 09:16:11 -0400
Subject: [PATCH 2/2] Update news

---
 resources/news.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/resources/news.txt b/resources/news.txt
index 42b76c36e..f9c3e4b3d 100644
--- a/resources/news.txt
+++ b/resources/news.txt
@@ -1,4 +1,9 @@
 
+    2.17.1: In progress...
+
+       NEW: Delete key clears the waterfall.
+
+
       2.17: Released October 1, 2023
 
        NEW: "Avg" plot mode, which displays average of FFT bins.