[chronojump] blankRunIntervalRealtimeCaptureGraph blank screen at start capture and at change person

[Xavier de Blas <xaviblas src gnome org>]

commit 4a75d67987312bad55c3614b1aa99102e63bbe85
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Sep 28 16:33:06 2021 +0200

    blankRunIntervalRealtimeCaptureGraph blank screen at start capture and at change person

 src/gui/app1/chronojump.cs |  3 +++
 src/gui/eventExecute.cs    | 13 +++++++++++++
 2 files changed, 16 insertions(+)
---
diff --git a/src/gui/app1/chronojump.cs b/src/gui/app1/chronojump.cs
index 48b416a54..d35cba579 100644
--- a/src/gui/app1/chronojump.cs
+++ b/src/gui/app1/chronojump.cs
@@ -1407,7 +1407,9 @@ public partial class ChronoJumpWindow
                }
                else if(current_mode == Constants.Modes.RUNSINTERVALLIC)
                {
+                       blankRunIntervalRealtimeCaptureGraph ();
                        updateGraphRunsInterval();
+
                        if(currentPerson != null)
                                label_sprint_person_name.Text = string.Format(Catalog.GetString("Sprints of 
{0}"), currentPerson.Name);
                        createTreeView_runs_interval_sprint (treeview_runs_interval_sprint);
@@ -5415,6 +5417,7 @@ public partial class ChronoJumpWindow
                event_execute_button_cancel.Sensitive = true;
 
                ExecutingGraphData egd = event_execute_prepareForTest ();
+               blankRunIntervalRealtimeCaptureGraph ();
 
                event_execute_ButtonCancel.Clicked += new EventHandler(on_cancel_clicked);
                event_execute_ButtonFinish.Clicked += new EventHandler(on_finish_clicked);
diff --git a/src/gui/eventExecute.cs b/src/gui/eventExecute.cs
index a0d04f615..39c53a355 100644
--- a/src/gui/eventExecute.cs
+++ b/src/gui/eventExecute.cs
@@ -782,6 +782,13 @@ public partial class ChronoJumpWindow
                cairoPaintBarsPre.Paint();
        }
 
+       public void blankRunIntervalRealtimeCaptureGraph ()
+       {
+               //constructor for showing a blank graph
+               cairoPaintBarsPreRealTime = new CairoPaintBarsPreRunIntervalRealtimeCapture(
+                               event_execute_drawingarea_realtime_capture_cairo, 
preferences.fontType.ToString());
+       }
+
        public void PrepareRunIntervalRealtimeCaptureGraph (double distance, double lastTime, string 
timesString, double distanceTotal, string distancesString, string type)
        {
                if(currentPerson == null)
@@ -3163,6 +3170,12 @@ public class CairoPaintBarsPreRunIntervalRealtimeCapture : CairoPaintBarsPre
        private List<double> time_l;
        private List<double> speed_l;
 
+       //just blank the screen
+       public CairoPaintBarsPreRunIntervalRealtimeCapture (DrawingArea darea, string fontStr)
+       {
+               blankScreen(darea, fontStr);
+       }
+
        public CairoPaintBarsPreRunIntervalRealtimeCapture (DrawingArea darea, string fontStr,
                        Constants.Modes mode, string personName, string testName, int pDN,// bool 
heightPreferred,
                        bool isRelative,