From: Soeren Apel <redacted>
Date: Mon, 22 Oct 2018 20:01:22 +0000 (+0200)
Subject: Ruler: Add "Set as zero point" context menu entry
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=e23567ed84aa55e2a0c48252080058186f6b80e7;p=pulseview.git

Ruler: Add "Set as zero point" context menu entry
---

diff --git a/pv/views/trace/ruler.cpp b/pv/views/trace/ruler.cpp
index 1204559c..6e74ddd0 100644
--- a/pv/views/trace/ruler.cpp
+++ b/pv/views/trace/ruler.cpp
@@ -129,6 +129,10 @@ void Ruler::contextMenuEvent(QContextMenuEvent *event)
 	connect(create_marker, SIGNAL(triggered()), this, SLOT(on_createMarker()));
 	menu->addAction(create_marker);
 
+	QAction *const set_zero_position = new QAction(tr("Set as zero point"), this);
+	connect(set_zero_position, SIGNAL(triggered()), this, SLOT(on_setZeroPosition()));
+	menu->addAction(set_zero_position);
+
 	QAction *const toggle_hover_marker = new QAction(this);
 	connect(toggle_hover_marker, SIGNAL(triggered()), this, SLOT(on_toggleHoverMarker()));
 	menu->addAction(toggle_hover_marker);
@@ -322,6 +326,11 @@ void Ruler::on_createMarker()
 	view_.add_flag(get_time_from_x_pos(mouse_down_point_.x()));
 }
 
+void Ruler::on_setZeroPosition()
+{
+	view_.set_zero_position(get_time_from_x_pos(mouse_down_point_.x()));
+}
+
 void Ruler::on_toggleHoverMarker()
 {
 	GlobalSettings settings;
diff --git a/pv/views/trace/ruler.hpp b/pv/views/trace/ruler.hpp
index d7cab4d7..b1414872 100644
--- a/pv/views/trace/ruler.hpp
+++ b/pv/views/trace/ruler.hpp
@@ -176,6 +176,7 @@ private Q_SLOTS:
 	void invalidate_tick_position_cache();
 
 	void on_createMarker();
+	void on_setZeroPosition();
 	void on_toggleHoverMarker();
 
 private:
diff --git a/pv/views/trace/view.cpp b/pv/views/trace/view.cpp
index fa911f0b..79277b4e 100644
--- a/pv/views/trace/view.cpp
+++ b/pv/views/trace/view.cpp
@@ -495,9 +495,12 @@ const Timestamp& View::ruler_offset() const
 	return ruler_offset_;
 }
 
-void View::set_zero_position(pv::util::Timestamp& position)
+void View::set_zero_position(const pv::util::Timestamp& position)
 {
-	ruler_shift_ = -position;
+	// ruler shift is a negative offset and the new zero position is relative
+	// to the current offset. Hence, we adjust the ruler shift only by the
+	// difference.
+	ruler_shift_ = -(position + (-ruler_shift_));
 
 	// Force an immediate update of the offsets
 	set_offset(offset_, true);
diff --git a/pv/views/trace/view.hpp b/pv/views/trace/view.hpp
index 7e1122a4..a6655d2f 100644
--- a/pv/views/trace/view.hpp
+++ b/pv/views/trace/view.hpp
@@ -173,7 +173,7 @@ public:
 	 */
 	const pv::util::Timestamp& ruler_offset() const;
 
-	void set_zero_position(pv::util::Timestamp& position);
+	void set_zero_position(const pv::util::Timestamp& position);
 
 	void reset_zero_position();