From 5a8c6b596a36e8c07fee234aa208ef23c8520c92 Mon Sep 17 00:00:00 2001
From: Soeren Apel <soeren@apelpie.net>
Date: Sat, 16 May 2020 23:46:02 +0200
Subject: [PATCH] Fix view setting restoration

---
 pv/views/trace/view.cpp | 32 +++++++++++++++-----------------
 pv/views/trace/view.hpp | 10 ++--------
 2 files changed, 17 insertions(+), 25 deletions(-)

diff --git a/pv/views/trace/view.cpp b/pv/views/trace/view.cpp
index ee4a4042..cfafdc08 100644
--- a/pv/views/trace/view.cpp
+++ b/pv/views/trace/view.cpp
@@ -286,7 +286,7 @@ void View::reset_view_state()
 	zero_offset_ = 0;
 	custom_zero_offset_set_ = false;
 	updating_scroll_ = false;
-	settings_restored_ = false;
+	restoring_state_ = false;
 	always_zoom_to_fit_ = false;
 	tick_period_ = 0;
 	tick_prefix_ = pv::util::SIPrefix::yocto;
@@ -300,10 +300,8 @@ void View::reset_view_state()
 	grabbed_widget_ = nullptr;
 	hover_point_ = QPoint(-1, -1);
 	scroll_needs_defaults_ = true;
-	saved_v_offset_ = 0;
 	scale_at_acq_start_ = 0;
 	offset_at_acq_start_ = 0;
-	suppress_zoom_to_fit_after_acq_ = false;
 
 	show_cursors_ = false;
 	cursor_state_changed(show_cursors_);
@@ -314,6 +312,8 @@ void View::reset_view_state()
 
 	// Make sure the standard bar's segment selector is in sync
 	set_segment_display_mode(segment_display_mode_);
+
+	scrollarea_->verticalScrollBar()->setRange(-100000000, 100000000);
 }
 
 Session& View::session()
@@ -541,14 +541,12 @@ void View::restore_settings(QSettings &settings)
 	}
 
 	if (settings.contains("v_offset")) {
+		// Note: see eventFilter() for additional information
 		saved_v_offset_ = settings.value("v_offset").toInt();
-		set_v_offset(saved_v_offset_);
 		scroll_needs_defaults_ = false;
-		// Note: see eventFilter() for additional information
 	}
 
-	settings_restored_ = true;
-	suppress_zoom_to_fit_after_acq_ = true;
+	restoring_state_ = true;
 
 	// Update the ruler so that it uses the new scale
 	calculate_tick_spacing();
@@ -888,7 +886,7 @@ void View::set_scale_offset(double scale, const Timestamp& offset)
 	// Disable sticky scrolling / always zoom to fit when acquisition runs
 	// and user drags the viewport
 	if ((scale_ == scale) && (offset_ != offset) &&
-			(session_.get_capture_state() == Session::Running)) {
+		(session_.get_capture_state() == Session::Running)) {
 
 		if (sticky_scrolling_) {
 			sticky_scrolling_ = false;
@@ -1565,7 +1563,7 @@ bool View::eventFilter(QObject *object, QEvent *event)
 		// resized to their final sizes.
 		update_layout();
 
-		if (settings_restored_)
+		if (restoring_state_)
 			determine_if_header_was_shrunk();
 		else
 			resize_header_to_fit();
@@ -1575,10 +1573,8 @@ bool View::eventFilter(QObject *object, QEvent *event)
 			scroll_needs_defaults_ = false;
 		}
 
-		if (saved_v_offset_) {
+		if (restoring_state_)
 			set_v_offset(saved_v_offset_);
-			saved_v_offset_ = 0;
-		}
 	}
 
 	return QObject::eventFilter(object, event);
@@ -1963,13 +1959,14 @@ void View::capture_state_updated(int state)
 		// the main view of this session (other trace views may be used for
 		// zooming and we don't want to mess them up)
 		bool state = settings.value(GlobalSettings::Key_View_ZoomToFitDuringAcq).toBool();
-		if (is_main_view_ && state) {
+		if (is_main_view_ && state && !restoring_state_) {
 			always_zoom_to_fit_ = true;
 			always_zoom_to_fit_changed(always_zoom_to_fit_);
 		}
 
 		// Enable sticky scrolling if the setting is enabled
-		sticky_scrolling_ = settings.value(GlobalSettings::Key_View_StickyScrolling).toBool();
+		sticky_scrolling_ = !restoring_state_ &&
+			settings.value(GlobalSettings::Key_View_StickyScrolling).toBool();
 
 		// Reset all traces to segment 0
 		current_segment_ = 0;
@@ -1995,12 +1992,13 @@ void View::capture_state_updated(int state)
 		// Only perform zoom-to-fit if the user hasn't altered the viewport and
 		// we didn't restore settings in the meanwhile
 		if (zoom_to_fit_after_acq &&
-			!suppress_zoom_to_fit_after_acq_ &&
+			!restoring_state_ &&
 			(scale_ == scale_at_acq_start_) &&
-			(offset_ == offset_at_acq_start_))
+			(sticky_scrolling_ || (offset_ == offset_at_acq_start_))) {
 			zoom_fit(false);  // We're stopped, so the GUI state doesn't matter
+		}
 
-		suppress_zoom_to_fit_after_acq_ = false;
+		restoring_state_ = false;
 	}
 }
 
diff --git a/pv/views/trace/view.hpp b/pv/views/trace/view.hpp
index 63bafbfe..b4c946d6 100644
--- a/pv/views/trace/view.hpp
+++ b/pv/views/trace/view.hpp
@@ -536,7 +536,7 @@ private:
 	bool custom_zero_offset_set_;
 
 	bool updating_scroll_;
-	bool settings_restored_;
+	bool restoring_state_;
 	bool header_was_shrunk_;
 
 	bool sticky_scrolling_;
@@ -569,18 +569,12 @@ private:
 	// This is true when the defaults couldn't be set due to insufficient info
 	bool scroll_needs_defaults_;
 
-	// A nonzero value indicates the v offset to restore. See View::resizeEvent()
+	// The v offset to restore. See View::eventFilter()
 	int saved_v_offset_;
 
 	// These are used to determine whether the view was altered after acq started
 	double scale_at_acq_start_;
 	pv::util::Timestamp offset_at_acq_start_;
-
-	// Used to suppress performing a "zoom to fit" when the session stops. This
-	// is needed when the view's settings are restored before acquisition ends.
-	// In that case we want to keep the restored settings, not have a "zoom to fit"
-	// mess them up.
-	bool suppress_zoom_to_fit_after_acq_;
 };
 
 } // namespace trace
-- 
2.30.2