[gui][grainplot] Disable button to export maps until maps are computed

darfix/gui/grainPlotWidget.py

@@ -91,7 +91,8 @@ class GrainPlotWidget(qt.QMainWindow):
         levelsLayout.addWidget(self._contoursPlot, 2, 0, 1, 3)
         self._levelsWidget.setLayout(levelsLayout)
         self._mosaicityPlot = Plot2D(parent=self)
-        self._exportButton = qt.QPushButton("Export")
+        self._exportButton = qt.QPushButton("Export maps")
+        self._exportButton.setEnabled(False)
         self._exportButton.clicked.connect(self.exportMaps)
         layout.addWidget(self._methodCB)
         layout.addWidget(self._levelsWidget)
@@ -126,6 +127,7 @@ class GrainPlotWidget(qt.QMainWindow):
             self.origin = (px, py)
             self.scale = (xscale, yscale)
         if self.dataset.dims.ndim > 1:
+            self._curves = {}
             self.ori_dist, self.hsv_key = self.dataset.compute_mosaicity_colorkey()
             xdim = self.dataset.dims.get(1)
             ydim = self.dataset.dims.get(0)
@@ -167,6 +169,7 @@ class GrainPlotWidget(qt.QMainWindow):
             for i in range(rg):
                 self._methodCB.model().item(i).setEnabled(True)
             self._methodCB.setCurrentIndex(0)
+            self._exportButton.setEnabled(True)
         else:
             print("\nComputation aborted")
 
@@ -286,7 +289,7 @@ class GrainPlotWidget(qt.QMainWindow):
 
     def exportMaps(self):
         """
-        Loads the file from a FileDialog.
+        Creates dictionay with maps information and exports it to a nexus file
         """
         if self.dataset and self.dataset.dims.ndim > 1:
             nx = {
@@ -327,7 +330,6 @@ class GrainPlotWidget(qt.QMainWindow):
                         Method.KURTOSIS.name: self._moments[axis][3]
                     }
                 )
-
         else:
             nx = {
                 "entry": {