[chronojump] force sensor zoom improvements

[Xavier de Blas <xaviblas src gnome org>]

commit ded9a0db23b45a5de4c667e64028dc36212ac491
Author: Xavier de Blas <xaviblas gmail com>
Date:   Thu Mar 28 15:32:03 2019 +0100

    force sensor zoom improvements

 src/gui/forceSensorAnalyze.cs | 39 ++++++++++++++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 7 deletions(-)
---
diff --git a/src/gui/forceSensorAnalyze.cs b/src/gui/forceSensorAnalyze.cs
index f30a7969..42c69d45 100644
--- a/src/gui/forceSensorAnalyze.cs
+++ b/src/gui/forceSensorAnalyze.cs
@@ -516,19 +516,25 @@ public partial class ChronoJumpWindow
                                Util.IsNumber(label_force_sensor_ai_time_a.Text, true) &&
                                Util.IsNumber(label_force_sensor_ai_time_b.Text, true))
                {
-                       zoomA = fsAI.GetTimeMS(Convert.ToInt32(hscale_force_sensor_ai_a.Value)) * 1000;
-                       zoomB = fsAI.GetTimeMS(Convert.ToInt32(hscale_force_sensor_ai_b.Value)) * 1000;
+                       //invert hscales if needed
+                       int firstValue = Convert.ToInt32(hscale_force_sensor_ai_a.Value);
+                       int secondValue = Convert.ToInt32(hscale_force_sensor_ai_b.Value);
+
+                       if(firstValue > secondValue) {
+                               int temp = firstValue;
+                               firstValue = secondValue;
+                               secondValue = firstValue;
+                       }
+
+                       //-1 and +1 to have the points at the edges to calcule the RFDs
+                       zoomA = fsAI.GetTimeMS(firstValue -1) * 1000;
+                       zoomB = fsAI.GetTimeMS(secondValue +1) * 1000;
 
                        //do not zoom if both are the same
                        if(zoomA == zoomB)
                        {
                                zoomA = -1;
                                zoomB = -1;
-                       } else if(zoomA > zoomB) //invert if needed
-                       {
-                               double temp = zoomA;
-                               zoomA = zoomB;
-                               zoomB = temp;
                        }
                }
 
@@ -756,6 +762,10 @@ public partial class ChronoJumpWindow
        {
                forceSensorZoomApplied = false;
        }
+       private int hscale_force_sensor_ai_a_BeforeZoom = 0;
+       private int hscale_force_sensor_ai_a_AtZoom = 0;
+       private int hscale_force_sensor_ai_b_BeforeZoom = 0;
+       private int hscale_force_sensor_ai_b_AtZoom = 0;
        private void on_button_force_sensor_ai_zoom_clicked (object o, EventArgs args)
        {
                forceSensorZoomApplied = ! forceSensorZoomApplied;
@@ -765,7 +775,22 @@ public partial class ChronoJumpWindow
                else
                        button_force_sensor_ai_zoom.Label = "Zoom [A-B]";
 
+               //store hscale a to help return to position on unzoom
+               if(forceSensorZoomApplied) {
+                       hscale_force_sensor_ai_a_BeforeZoom = Convert.ToInt32(hscale_force_sensor_ai_a.Value);
+                       hscale_force_sensor_ai_b_BeforeZoom = Convert.ToInt32(hscale_force_sensor_ai_b.Value);
+               } else {
+                       hscale_force_sensor_ai_a_AtZoom = Convert.ToInt32(hscale_force_sensor_ai_a.Value);
+                       hscale_force_sensor_ai_b_AtZoom = Convert.ToInt32(hscale_force_sensor_ai_b.Value);
+               }
+
                forceSensorDoGraphAI();
+
+               if(! forceSensorZoomApplied)
+               {
+                       hscale_force_sensor_ai_a.Value = hscale_force_sensor_ai_a_BeforeZoom + 
(hscale_force_sensor_ai_a_AtZoom -1);
+                       hscale_force_sensor_ai_b.Value = hscale_force_sensor_ai_a_BeforeZoom + 
(hscale_force_sensor_ai_b_AtZoom -1);
+               }
        }
 
        private void forceSensorAnalyzeManualGraphDo(Rectangle allocation)