Printing of TSQ ZCE graph

prasopes/zcetools.py

@@ -2,6 +2,7 @@ from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
 from matplotlib.figure import Figure
 from PyQt5 import QtCore
 from PyQt5 import QtWidgets
+from PyQt5 import QtPrintSupport
 import numpy as np
 import prasopes.graphtools as gt
 import prasopes.filetools as ft
@@ -9,12 +10,12 @@ import os.path
 import pkg_resources
 
 
-def pop_dial(zcespec, gradspect, data_set, widget, coff_d, grad_d,
+def pop_dial(zcespec, gradspect, data_set, coff_d, grad_d,
              textfield, fn, parent):
     if fn[0] is None:
         QtWidgets.QMessageBox.warning(
             parent, "ZCE calculation",
-            "No spectrum opened, cancelling request")
+            "No spectrum opened, nothing to display")
         return
     zcespec.clear()
     gradspect.clear()
@@ -51,7 +52,6 @@ def pop_dial(zcespec, gradspect, data_set, widget, coff_d, grad_d,
     gradspect.annotate('{:.2f}'.format(grad_d['gmax']),
                        xy=(grad_d['x'][maxarg], grad_d['y'][maxarg]))
     zcespec.figure.canvas.draw()
-    widget.show()
 
 
 def exp_zce(zce_spec, zcegrad_spec, fn, parent):
@@ -90,6 +90,25 @@ def help_msg(pw):
             pw, "TSQ zce tool help", "{}".format(helpcontent))
 
 
+def print_graph(ds, coff, coffgrad, filename):
+    printfig = Figure(figsize=(5, 2), dpi=100)
+    printplot = printfig.add_subplot(111)
+    printplot_overlay = printplot.twinx()
+    printcanvas = FigureCanvas(printfig)
+    textfield = QtWidgets.QLabel()
+    pop_dial(printplot, printplot_overlay, ds, coff, coffgrad,
+             textfield, filename, None)
+    widget = QtWidgets.QDialog(None, windowTitle='Print preview')
+    layout = QtWidgets.QVBoxLayout(widget)
+    layout.addWidget(printcanvas)
+    widget.resize(600, 400)
+    widget.show()
+    dialog = QtPrintSupport.QPrintDialog()
+    if dialog.exec_() == QtWidgets.QDialog.Accepted:
+        printcanvas.render(dialog.printer())
+    widget.close()
+
+
 def dialog(parent, ds, filename):
     coff = dict(x=[0], y=[0], line=None, name="",
                 xlabel="Voltage (V)", ylabel="ion count")
@@ -114,6 +133,9 @@ def dialog(parent, ds, filename):
     zce_export = QtWidgets.QPushButton("Export ZCE")
     zce_export.clicked.connect(lambda: exp_zce(
         coff, coffgrad, filename, parent))
+    zce_print = QtWidgets.QPushButton("Print ZCE")
+    zce_print.clicked.connect(lambda: print_graph(
+        ds, coff, coffgrad, filename))
     zce_help = QtWidgets.QPushButton("Help")
     zce_help.clicked.connect(lambda: help_msg(parent))
     close_button = QtWidgets.QPushButton("Close")
@@ -125,11 +147,13 @@ def dialog(parent, ds, filename):
     textfield = QtWidgets.QLabel(coffgrad['gmax'])
     butt_layout.addWidget(textfield)
     butt_layout.addStretch(1)
+    butt_layout.addWidget(zce_print)
     butt_layout.addWidget(zce_export)
     butt_layout.addWidget(close_button)
 
     dial_layout = QtWidgets.QVBoxLayout(dial_widget)
     dial_layout.addWidget(graph_canvas)
     dial_layout.addLayout(butt_layout)
-    pop_dial(coffspect, coffspect_grad, ds, dial_widget, coff, coffgrad,
+    dial_widget.show()
+    pop_dial(coffspect, coffspect_grad, ds, coff, coffgrad,
              textfield, filename, parent)