From 1a81538eb447116993b1519a0d5a40d514c29351 Mon Sep 17 00:00:00 2001
From: "Andrew D. Zonenberg" <azonenberg@drawersteak.com>
Date: Wed, 4 Sep 2024 22:45:29 -0700
Subject: [PATCH] Added a dimmed highlight that follows the timestamp of the
 mouse cursor when mousing over a protocol analyzer view

---
 src/ngscopeclient/MainWindow.cpp             |  1 +
 src/ngscopeclient/Marker.h                   |  8 ++++++++
 src/ngscopeclient/PreferenceSchema.cpp       |  4 ++++
 src/ngscopeclient/ProtocolAnalyzerDialog.cpp |  3 +++
 src/ngscopeclient/Session.cpp                |  1 +
 src/ngscopeclient/Session.h                  |  9 +++++++++
 src/ngscopeclient/WaveformGroup.cpp          | 21 ++++++++++++++++++--
 7 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/ngscopeclient/MainWindow.cpp b/src/ngscopeclient/MainWindow.cpp
index 09b08f7ec..331cdedd5 100644
--- a/src/ngscopeclient/MainWindow.cpp
+++ b/src/ngscopeclient/MainWindow.cpp
@@ -737,6 +737,7 @@ void MainWindow::RenderUI()
 	}
 
 	//Dialog boxes
+	m_session.SetHoveredPacketTimestamp({});
 	set< shared_ptr<Dialog> > dlgsToClose;
 	for(auto& dlg : m_dialogs)
 	{
diff --git a/src/ngscopeclient/Marker.h b/src/ngscopeclient/Marker.h
index a66035533..5bb102c97 100644
--- a/src/ngscopeclient/Marker.h
+++ b/src/ngscopeclient/Marker.h
@@ -58,6 +58,14 @@ class TimePoint : public std::pair<time_t, int64_t>
 	{ second = fs; }
 
 	std::string PrettyPrint() const;
+
+	int64_t operator-(const TimePoint& rhs)
+	{
+		int64_t dsec = first - rhs.first;
+		int64_t dfs = second - rhs.second;
+
+		return dsec*FS_PER_SECOND + dfs;
+	}
 };
 
 /**
diff --git a/src/ngscopeclient/PreferenceSchema.cpp b/src/ngscopeclient/PreferenceSchema.cpp
index 9d0f2c161..693467f4f 100644
--- a/src/ngscopeclient/PreferenceSchema.cpp
+++ b/src/ngscopeclient/PreferenceSchema.cpp
@@ -66,6 +66,10 @@ void PreferenceManager::InitializeDefaults()
 				Preference::Color("marker_color", ColorFromString("#ff00a0"))
 				.Label("Marker color")
 				.Description("Color for markers"));
+			cursors.AddPreference(
+				Preference::Color("hover_color", ColorFromString("#ffffff80"))
+				.Label("Hover color")
+				.Description("Color for the hovered-packet indicator"));
 
 		auto& decodes = appearance.AddCategory("Decodes");
 			decodes.AddPreference(
diff --git a/src/ngscopeclient/ProtocolAnalyzerDialog.cpp b/src/ngscopeclient/ProtocolAnalyzerDialog.cpp
index f4f0fa86e..e24029eee 100644
--- a/src/ngscopeclient/ProtocolAnalyzerDialog.cpp
+++ b/src/ngscopeclient/ProtocolAnalyzerDialog.cpp
@@ -322,6 +322,9 @@ bool ProtocolAnalyzerDialog::DoRender()
 					m_parent.NavigateToTimestamp(offset, len, StreamDescriptor(m_filter, 0));
 				}
 
+				if(ImGui::IsItemHovered())
+					m_session.SetHoveredPacketTimestamp(packtime);
+
 				if(pack)
 				{
 					//Headers
diff --git a/src/ngscopeclient/Session.cpp b/src/ngscopeclient/Session.cpp
index c4f22ab30..0970f2826 100644
--- a/src/ngscopeclient/Session.cpp
+++ b/src/ngscopeclient/Session.cpp
@@ -235,6 +235,7 @@ void Session::Clear()
 	//Reset state
 	m_triggerOneShot = false;
 	m_multiScope = false;
+	m_hoverTime = {};
 }
 
 vector<TimePoint> Session::GetMarkerTimes()
diff --git a/src/ngscopeclient/Session.h b/src/ngscopeclient/Session.h
index 428d46768..cc778c19f 100644
--- a/src/ngscopeclient/Session.h
+++ b/src/ngscopeclient/Session.h
@@ -502,7 +502,16 @@ class Session
 	void RemovePackets(TimePoint t);
 
 	std::set<FlowGraphNode*> GetAllGraphNodes();
+
+	///@brief Returns the timestamp of the protocol analyzer event that the mouse is over, if any
+	std::optional<TimePoint> GetHoveredPacketTimestamp()
+	{ return m_hoverTime; }
+
+	void SetHoveredPacketTimestamp(std::optional<TimePoint> t)
+	{ m_hoverTime = t; }
+
 protected:
+	std::optional<TimePoint> m_hoverTime;
 
 	////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 	// End user preferences (persistent across sessions)
diff --git a/src/ngscopeclient/WaveformGroup.cpp b/src/ngscopeclient/WaveformGroup.cpp
index 88f77a8ea..b755077db 100644
--- a/src/ngscopeclient/WaveformGroup.cpp
+++ b/src/ngscopeclient/WaveformGroup.cpp
@@ -480,7 +480,7 @@ float WaveformGroup::GetInBandPower(WaveformBase* wfm, Unit yunit, int64_t t1, i
 }
 
 /**
-	@brief Render our markers
+	@brief Render our markers (and the hovered-packet indicator if any)
  */
 void WaveformGroup::RenderMarkers(ImVec2 pos, ImVec2 size)
 {
@@ -496,7 +496,11 @@ void WaveformGroup::RenderMarkers(ImVec2 pos, ImVec2 size)
 	if(m_areas.empty())
 		return;
 
-	auto& markers = m_parent->GetSession().GetMarkers(m_areas[0]->GetWaveformTimestamp());
+	auto& session = m_parent->GetSession();
+	auto wavetime = m_areas[0]->GetWaveformTimestamp();
+	auto& markers = session.GetMarkers(wavetime);
+
+	auto packetHover = session.GetHoveredPacketTimestamp();
 
 	//Create a child window for all of our drawing
 	//(this is needed so we're above the WaveformArea's in z order, but behind popup windows)
@@ -507,8 +511,10 @@ void WaveformGroup::RenderMarkers(ImVec2 pos, ImVec2 size)
 
 		auto& prefs = m_parent->GetSession().GetPreferences();
 		auto color = prefs.GetColor("Appearance.Cursors.marker_color");
+		auto hcolor = prefs.GetColor("Appearance.Cursors.hover_color");
 		auto font = m_parent->GetFontPref("Appearance.Cursors.label_font");
 		auto fontSize = font->FontSize * ImGui::GetIO().FontGlobalScale;
+
 		//Draw the markers
 		for(auto& m : markers)
 		{
@@ -535,6 +541,17 @@ void WaveformGroup::RenderMarkers(ImVec2 pos, ImVec2 size)
 				color,
 				str.c_str());
 		}
+
+		//Draw the hovered packet, if any
+		if(packetHover)
+		{
+			//Calculate the delta between the times
+			auto offset = packetHover.value() - wavetime;
+
+			//Lines
+			auto xpos = round(XAxisUnitsToXPosition(offset));
+			list->AddLine(ImVec2(xpos, pos.y), ImVec2(xpos, pos.y + size.y), hcolor);
+		}
 	}
 	ImGui::EndChild();