profile: implement animation of the tooltip item

To do so, generalize the animation routine.

This seems to expose a QtQuick bug: we get spurious
hover-events when the tooltip item is updated in the
animation. We have to check for that to prevent
en endless loop (until the user moves the mouse out
of the profile window).

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

profile-widget/profileview.cpp

@@ -17,33 +17,52 @@
 #include <QDebug>
 #include <QElapsedTimer>
 
-// Class for animations (if any). Might want to do our own.
+// Class templates for animations (if any). Might want to do our own.
+// Calls the function object passed in the constructor with a time argument,
+// where 0.0 = start at 1.0 = end..
+// On the last invocation, a 1.0 literal is passed, so floating-point
+// comparison is OK.
 class ProfileAnimation : public QAbstractAnimation {
-	ProfileView &view;
-	// For historical reasons, speed is actually the duration
-	// (i.e. the reciprocal of speed). Ouch, that hurts.
-	int speed;
-
 	int duration() const override
 	{
 		return speed;
 	}
+protected:
+	// For historical reasons, speed is actually the duration
+	// (i.e. the reciprocal of speed). Ouch, that hurts.
+	int speed;
+public:
+	ProfileAnimation(int animSpeed) : speed(animSpeed)
+	{
+	}
+};
+
+template <typename FUNC>
+class ProfileAnimationTemplate : public ProfileAnimation {
 	void updateCurrentTime(int time) override
 	{
 		// Note: we explicitly pass 1.0 at the end, so that
 		// the callee can do a simple float comparison for "end".
-		view.anim(time == speed ? 1.0
-					: static_cast<double>(time) / speed);
+		func(time == speed ? 1.0
+				   : static_cast<double>(time) / speed);
 	}
+	FUNC func;
 public:
-	ProfileAnimation(ProfileView &view, int animSpeed) :
-		view(view),
-		speed(animSpeed)
+	ProfileAnimationTemplate(FUNC func, int animSpeed) :
+		ProfileAnimation(animSpeed),
+		func(func)
 	{
 		start();
 	}
 };
 
+// Helper function to make creation of animations somewhat more palatable
+template <typename FUNC>
+std::unique_ptr<ProfileAnimationTemplate<FUNC>> make_anim(FUNC func, int animSpeed)
+{
+	return std::make_unique<ProfileAnimationTemplate<FUNC>>(func, animSpeed);
+}
+
 ProfileView::ProfileView(QQuickItem *parent) : ChartView(parent, ProfileZValue::Count),
 	d(nullptr),
 	dc(0),
@@ -201,7 +220,7 @@ void ProfileView::plotDive(const struct dive *dIn, int dcIn, int flags)
 	if (prefs.infobox) {
 		QPoint pos = mapFromGlobal(QCursor::pos()).toPoint();
 		tooltip->setVisible(true);
-		updateTooltip(pos, flags & RenderFlags::PlanMode);
+		updateTooltip(pos, flags & RenderFlags::PlanMode, animSpeed);
 	} else {
 		tooltip->setVisible(false);
 	}
@@ -210,7 +229,7 @@ void ProfileView::plotDive(const struct dive *dIn, int dcIn, int flags)
 	if (animSpeed <= 0)
 		animation.reset();
 	else
-		animation = std::make_unique<ProfileAnimation>(*this, animSpeed);
+		animation = make_anim([this](double progress) { anim(progress); }, animSpeed);
 }
 
 void ProfileView::anim(double fraction)
@@ -375,15 +394,30 @@ void ProfileView::hoverMoveEvent(QHoverEvent *event)
 {
 	if (!profileScene)
 		return;
+
+	// This is incredibly stupid: For some weird reason (a bug?), when
+	// resizing the ToolTipItem we get spurious hoverMoveEvents, which
+	// restarts the animation, giving an infinite loop.
+	// Prevent this by comparing to the old mouse position.
+	if (std::exchange(previousHoveMovePosition, event->pos()) == previousHoveMovePosition)
+		return;
+
 	if (tooltip && prefs.infobox) {
-		updateTooltip(event->pos(), false); // TODO: plan mode
+		updateTooltip(event->pos(), false, qPrefDisplay::animation_speed()); // TODO: plan mode
 		update();
 	}
 }
 
-void ProfileView::updateTooltip(QPointF pos, bool plannerMode)
+void ProfileView::updateTooltip(QPointF pos, bool plannerMode, int animSpeed)
 {
 	int time = profileScene->timeAt(pos);
 	auto events = profileScene->eventsAt(pos);
-	tooltip->update(d, dpr, time, profileScene->getPlotInfo(), events, plannerMode);
+	tooltip->update(d, dpr, time, profileScene->getPlotInfo(), events, plannerMode, animSpeed);
+
+	// Reset animation.
+	if (animSpeed <= 0)
+		tooltip_animation.reset();
+	else
+		tooltip_animation = make_anim([this](double progress)
+			{ if (tooltip) tooltip->anim(progress); update(); }, animSpeed);
 }