[chronojump] Disposing after button_press graph, if not it hangs on win/mac

[Xavier de Blas <xaviblas src gnome org>]

commit b7d2a49299dd56e4f0630a52e446adc7f26ad61e
Author: Xavier de Blas <xaviblas gmail com>
Date:   Fri Sep 4 11:58:48 2020 +0200

    Disposing after button_press graph, if not it hangs on win/mac

 src/gui/cairo/jumpsDjOptimalFall.cs   |  4 ++--
 src/gui/cairo/jumpsEvolution.cs       |  4 ++--
 src/gui/cairo/jumpsRjFatigue.cs       |  4 ++--
 src/gui/cairo/jumpsWeightFVProfile.cs |  4 ++--
 src/gui/cairo/xy.cs                   | 14 ++++++++++++--
 5 files changed, 20 insertions(+), 10 deletions(-)
---
diff --git a/src/gui/cairo/jumpsDjOptimalFall.cs b/src/gui/cairo/jumpsDjOptimalFall.cs
index a9a64da8..30cd8c73 100644
--- a/src/gui/cairo/jumpsDjOptimalFall.cs
+++ b/src/gui/cairo/jumpsDjOptimalFall.cs
@@ -39,7 +39,7 @@ public class JumpsDjOptimalFallGraph : CairoXY
                printText(area.Allocation.Width /2, area.Allocation.Height /2, 24, textHeight,
                                needToExecuteJumpsStr + " " + jumpType + ".", g, alignTypes.CENTER);
 
-               endGraph();
+               endGraphDisposing();
        }
 
        //regular constructor
@@ -103,7 +103,7 @@ public class JumpsDjOptimalFallGraph : CairoXY
                }
                writeTitle();
 
-               endGraph();
+               endGraphDisposing();
        }
 
        protected override void writeTitle()
diff --git a/src/gui/cairo/jumpsEvolution.cs b/src/gui/cairo/jumpsEvolution.cs
index d98a27af..c38735a3 100644
--- a/src/gui/cairo/jumpsEvolution.cs
+++ b/src/gui/cairo/jumpsEvolution.cs
@@ -38,7 +38,7 @@ public class JumpsEvolutionGraph : CairoXY
                printText(area.Allocation.Width /2, area.Allocation.Height /2, 24, textHeight,
                                needToExecuteJumpsStr + " " + jumpType + ".", g, alignTypes.CENTER);
 
-               endGraph();
+               endGraphDisposing();
        }
 
        //regular constructor
@@ -77,7 +77,7 @@ public class JumpsEvolutionGraph : CairoXY
 
                writeTitle();
 
-               endGraph();
+               endGraphDisposing();
        }
 
        //here X is year, add/subtract third of a year
diff --git a/src/gui/cairo/jumpsRjFatigue.cs b/src/gui/cairo/jumpsRjFatigue.cs
index 316d2424..f540b394 100644
--- a/src/gui/cairo/jumpsRjFatigue.cs
+++ b/src/gui/cairo/jumpsRjFatigue.cs
@@ -40,7 +40,7 @@ public class JumpsRjFatigueGraph : CairoXY
                //printText(area.Allocation.Width /2, area.Allocation.Height /2, 24, textHeight,
                //              string.Format("Need to execute jumps: {0}.", jumpType), g, true);
 
-               endGraph();
+               endGraphDisposing();
        }
        public JumpsRjFatigueGraph (
                        List<PointF> point_l, double slope, double intercept,
@@ -91,7 +91,7 @@ public class JumpsRjFatigueGraph : CairoXY
 
                writeTitle();
 
-               endGraph();
+               endGraphDisposing();
        }
 
        //here X is year, add/subtract third of a year
diff --git a/src/gui/cairo/jumpsWeightFVProfile.cs b/src/gui/cairo/jumpsWeightFVProfile.cs
index 903badd0..dca7f4a2 100644
--- a/src/gui/cairo/jumpsWeightFVProfile.cs
+++ b/src/gui/cairo/jumpsWeightFVProfile.cs
@@ -47,7 +47,7 @@ public class JumpsWeightFVProfileGraph : CairoXY
 
                plotError();
 
-               endGraph();
+               endGraphDisposing();
        }
 
        //regular constructor
@@ -162,7 +162,7 @@ public class JumpsWeightFVProfileGraph : CairoXY
                if(errorMessage != ErrorAtStart.ALLOK)
                        plotError();
 
-               endGraph();
+               endGraphDisposing();
        }
 
        protected override void writeTitle()
diff --git a/src/gui/cairo/xy.cs b/src/gui/cairo/xy.cs
index bc30e1b8..a99d3583 100644
--- a/src/gui/cairo/xy.cs
+++ b/src/gui/cairo/xy.cs
@@ -530,7 +530,11 @@ public abstract class CairoXY
                                4*pointsRadius, 4*pointsRadius);
                g.Stroke();
                g.Color = black;
-               LogB.Information("writeCoordinatesOfMouseClick done!");
+               LogB.Information("writeCoordinatesOfMouseClick done! disposing");
+
+               endGraphDisposing();
+
+               LogB.Information("writeCoordinatesOfMouseClick disposed!");
        }
 
        /*
@@ -568,7 +572,13 @@ public abstract class CairoXY
                writeTextAtRight(line +2, string.Format("- {0}: {1} {2}", yVariable, 
Util.TrimDecimals(pClosest.Y, 2), yUnits), false);
        }
 
-       protected void endGraph()
+       /*
+          need to dispose because Cairo does not clean ok on win and mac:
+          Don’t forget to manually dispose the Context and the target Surface at the end of the expose 
event. Automatic garbage collecting is not yet 100% working in Cairo.
+               https://www.mono-project.com/docs/tools+libraries/libraries/Mono.Cairo/
+               eg. on Linux can do the writeCoordinatesOfMouseClick() without disposing, but on win and mac 
does not work, so dispose always.
+        */
+       protected void endGraphDisposing()
        {
                g.GetTarget().Dispose ();
                g.Dispose ();