added logging and help section

Added logging using the logging module for the user, added help section with info on how to use the GUI. Closes #91 (closed)

b_asic/GUI/simulate_sfg_window.py

 from PySide2.QtWidgets import QDialog, QLineEdit, QPushButton, QVBoxLayout, QHBoxLayout,\
-QLabel, QCheckBox, QSpinBox, QGroupBox, QFrame, QFormLayout, QGridLayout, QSizePolicy
+QLabel, QCheckBox, QSpinBox, QGroupBox, QFrame, QFormLayout, QGridLayout, QSizePolicy, QFileDialog, QShortcut
 from PySide2.QtCore import Qt, Signal
-from PySide2.QtGui import QIntValidator
+from PySide2.QtGui import QIntValidator, QKeySequence
 
 from matplotlib.backends import qt_compat
 from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
@@ -52,10 +52,11 @@ class SimulateSFGWindow(QDialog):
                 x += 1
                 y = 0
 
-            _input_value = QLineEdit()
-            _input_value.setValidator(QIntValidator())
-            _input_value.setFixedWidth(50)
-            input_grid.addWidget(_input_value, x, y)
+            input_value = QLineEdit()
+            input_value.setPlaceholderText(str(i))
+            input_value.setValidator(QIntValidator())
+            input_value.setFixedWidth(50)
+            input_grid.addWidget(input_value, x, y)
             y += 1
 
         input_layout.addLayout(input_grid)
@@ -93,9 +94,11 @@ class SimulateSFGWindow(QDialog):
 
 
 class Plot(FigureCanvas):
-    def __init__(self, simulation, sfg, parent=None, width=5, height=4, dpi=100):
+    def __init__(self, simulation, sfg, window, parent=None, width=5, height=4, dpi=100):
         self.simulation = simulation
         self.sfg = sfg
+        self.dpi = dpi
+        self._window = window
 
         fig = Figure(figsize=(width, height), dpi=dpi)
         fig.suptitle(sfg.name, fontsize=20)
@@ -106,8 +109,22 @@ class Plot(FigureCanvas):
 
         FigureCanvas.setSizePolicy(self, QSizePolicy.Expanding, QSizePolicy.Expanding)
         FigureCanvas.updateGeometry(self)
+        self.save_figure = QShortcut(QKeySequence("Ctrl+S"), self)
+        self.save_figure.activated.connect(self._save_plot_figure)
         self._plot_values_sfg()
 
+    def _save_plot_figure(self):
+        self._window.logger.info(f"Saving plot of figure: {self.sfg.name}.")
+        file_choices = "PNG (*.png)|*.png"
+        path, ext = QFileDialog.getSaveFileName(self, "Save file", "", file_choices)
+        path = path.encode("utf-8")
+        if not path[-4:] == file_choices[-4:].encode("utf-8"):
+            path += file_choices[-4:].encode("utf-8")
+
+        if path:
+            self.print_figure(path.decode(), dpi=self.dpi)
+            self._window.logger.info(f"Saved plot: {self.sfg.name} to path: {path}.")
+
     def _plot_values_sfg(self):
         x_axis = list(range(len(self.simulation.results.keys())))
         for _output in range(self.sfg.output_count):