[PATCH] Fix the overprinting of gas name and pressure value on the profile

[Linus Torvalds]

From: Linus Torvalds <torvalds at linux-foundation.org>
Date: Wed, 2 Aug 2017 08:53:10 -0700
Subject: [PATCH] Fix the overprinting of gas name and pressure value on the profile

When I massaged the code to do multiple gas pressures in commit e1b880f4
("Profile support for multiple concurrent pressure sensors") some of the
Y offsetting code got cut out as being too specific to the old
o2pressure code.

But I removed a bit too much, leaving the label (gas name) and number
(gas pressure) overlapping.

This should fix it.

If we really care about multiple gas pressure labels overlapping each
other, we'll have to revisit this code, but the old two-gas case didn't
do a very good job either (both that old code - and this new version -
can look very good in particular cases, but there are cases where it
won't work so well).

So we may need to revisit this eventually, but this gets it looking fine
for the normal cases.

Reported-by: Miika Turkia <miika.turkia at gmail.com>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
---
 profile-widget/diveprofileitem.cpp | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/profile-widget/diveprofileitem.cpp b/profile-widget/diveprofileitem.cpp
index 6f2bf98b..02a0745e 100644
--- a/profile-widget/diveprofileitem.cpp
+++ b/profile-widget/diveprofileitem.cpp
@@ -736,12 +736,13 @@ void DiveGasPressureItem::modelDataChanged(const QModelIndex &topLeft, const QMo
 	int last_pressure[MAX_CYLINDERS] = { 0, };
 	int last_time[MAX_CYLINDERS] = { 0, };
 
-	double print_y_offset[8][2] = { { 0, -0.5 }, { 0, -0.5 }, { 0, -0.5 }, { 0, -0.5 }, { 0, -0.5 } ,{ 0, -0.5 }, { 0, -0.5 }, { 0, -0.5 } };
 	// These are offset values used to print the gas lables and pressures on a
-	// dive profile at appropriate Y-coordinates: One doublet of values for each
-	// of 8 cylinders.
-	// Order of offsets within a doublet: gas lable offset; gas pressure offset.
-	// The array is initialised with default values that apply to non-CCR dives.
+	// dive profile at appropriate Y-coordinates. We alternate aligning the
+	// label and the gas pressure above and under the pressure line.
+	// The values are historical, and we could try to pick the over/under
+	// depending on whether this pressure is higher or lower than the average.
+	// Right now it's just strictly alternating when you have multiple gas
+	// pressures.
 
 	QFlags<Qt::AlignmentFlag> alignVar = Qt::AlignTop;
 	QFlags<Qt::AlignmentFlag> align[MAX_CYLINDERS];
@@ -759,8 +760,19 @@ void DiveGasPressureItem::modelDataChanged(const QModelIndex &topLeft, const QMo
 				continue;
 
 			if (!seen_cyl[cyl]) {
-				plotPressureValue(mbar, entry->sec, alignVar, print_y_offset[cyl][1]);
-				plotGasValue(mbar, entry->sec, displayed_dive.cylinder[cyl].gasmix, alignVar, print_y_offset[cyl][0]);
+				double value_y_offset, label_y_offset;
+
+				// Magic Y offset depending on whether we're aliging
+				// the top of the text or the bottom of the text to
+				// the pressure line.
+				value_y_offset = -0.5;
+				if (alignVar & Qt::AlignTop) {
+					label_y_offset = 5 * axisLog;
+				} else {
+					label_y_offset = -7 * axisLog;
+				}
+				plotPressureValue(mbar, entry->sec, alignVar, value_y_offset);
+				plotGasValue(mbar, entry->sec, displayed_dive.cylinder[cyl].gasmix, alignVar, label_y_offset);
 				seen_cyl[cyl] = true;
 
 				/* Alternate alignment as we see cylinder use.. */
@@ -775,7 +787,8 @@ void DiveGasPressureItem::modelDataChanged(const QModelIndex &topLeft, const QMo
 	// For each cylinder, on right hand side of profile, write cylinder pressure
 	for (int cyl = 0; cyl < MAX_CYLINDERS; cyl++) {
 		if (last_time[cyl]) {
-			plotPressureValue(last_pressure[cyl], last_time[cyl], align[cyl] | Qt::AlignLeft, print_y_offset[cyl][1]);
+			double value_y_offset = -0.5;
+			plotPressureValue(last_pressure[cyl], last_time[cyl], align[cyl] | Qt::AlignLeft, value_y_offset);
 		}
 	}
 }
-- 
2.14.0.rc1.2.g4c8247ec3