[chronojump] Encoder capture Init try/catch on sp.Open()

[Xavier de Blas <xaviblas src gnome org>]

commit 14e10b2e115caccda1c1346d9854abd28ae6a67c
Author: Xavier de Blas <xaviblas gmail com>
Date:   Fri Feb 23 19:00:08 2018 +0100

    Encoder capture Init try/catch on sp.Open()

 src/encoderCapture.cs |   15 ++++++++++++---
 src/gui/encoder.cs    |    8 +++++++-
 2 files changed, 19 insertions(+), 4 deletions(-)
---
diff --git a/src/encoderCapture.cs b/src/encoderCapture.cs
index 5bf2f61..86e9d2f 100644
--- a/src/encoderCapture.cs
+++ b/src/encoderCapture.cs
@@ -112,7 +112,7 @@ public abstract class EncoderCapture
 
 
        //if cont (continuous mode), then will not end when too much time passed before start
-       public void InitGlobal (int widthG, int heightG, int time, int timeEnd,
+       public bool InitGlobal (int widthG, int heightG, int time, int timeEnd,
                        bool cont, string eccon, string port, bool capturingInertialBG, bool showOnlyBars,
                        bool simulated)
        {
@@ -130,12 +130,19 @@ public abstract class EncoderCapture
                        rand = new Random(40);
                        SimulatedReset();
                }
-               else if(! simulated && ! capturingInertialBG) {
+               else if(! simulated && ! capturingInertialBG)
+               {
                        LogB.Debug("runEncoderCaptureCsharp start port:", port);
                        sp = new SerialPort(port);
                        sp.BaudRate = 115200;
                        LogB.Information("sp created");
-                       sp.Open();
+
+                       try {
+                               sp.Open();
+                       } catch {
+                               LogB.Information("Error: Cannot open port");
+                               return false;
+                       }
                        LogB.Information("sp opened");
                }
                
@@ -203,6 +210,8 @@ public abstract class EncoderCapture
 
                cancel = false;
                finish = false;
+
+               return true;
        }
 
        protected virtual void initSpecific()
diff --git a/src/gui/encoder.cs b/src/gui/encoder.cs
index 593a585..453568c 100644
--- a/src/gui/encoder.cs
+++ b/src/gui/encoder.cs
@@ -5340,7 +5340,7 @@ public partial class ChronoJumpWindow
                        else { //action == encoderActions.CAPTURE_IM)
 
                                eCapture = new EncoderCaptureIMCalc();
-                               eCapture.InitGlobal(
+                               bool success = eCapture.InitGlobal(
                                                encoder_capture_signal_drawingarea.Allocation.Width,
                                                encoder_capture_signal_drawingarea.Allocation.Height,
                                                preferences.encoderCaptureTimeIM,
@@ -5351,6 +5351,12 @@ public partial class ChronoJumpWindow
                                                false,
                                                false,
                                                false);
+                               if(! success)
+                               {
+                                       new DialogMessage(Constants.MessageTypes.WARNING,
+                                                       Catalog.GetString("Sorry, cannot start capture."));
+                                       return;
+                               }
 
                                encoderRProcCapture.CutByTriggers = Preferences.TriggerTypes.NO_TRIGGERS; 
//do not cutByTriggers on inertial, yet.