Implemented output file choosing to save png and csv (raw data) on every update

main.kv

@@ -35,6 +35,34 @@
         id: status_message
         size_hint_x: 0.80
 
+<OutputFileDialog>:
+    textinput: text_input
+    BoxLayout:
+        orientation: 'vertical'
+        Label:
+            text: "Select a folder & file name for the output. A csv & png file will be saved."
+            size_hint_y: 0.1
+        FileChooserListView:
+            id: filechooser
+            on_selection: text_input.text = self.selection and self.selection[0] or ''
+        BoxLayout:
+            size_hint_y: 0.1
+            orientation: 'horizontal'
+            Label:
+                text: 'File name:'
+                size_hint_x: 0.2
+            TextInput:
+                id: text_input
+        BoxLayout:
+            size_hint_y: 0.1
+            orientation: 'horizontal'
+            Button:
+                text: 'Cancel'
+                on_press: root.cancel()
+            Button:
+                text: 'Set Output File'
+                on_press: root.set_output(filechooser.path, text_input.text)
+
 <MainWindow>:
     label_wid: "Temperature Monitor"
     current_temperature: current_temperature
@@ -44,6 +72,10 @@
     on_lastTemperature: mainplot.on_lastTemperature(self.lastTemperature)
     on_lastTime: mainplot.on_lastTime(self.lastTime)
     on_lastStatus: status_bar.update_status(self.lastStatus)
+    raw_data_output_file: ''
+    image_output_file: ''
+    on_raw_data_output_file: mainplot.raw_data_output_file = self.raw_data_output_file
+    on_image_output_file: mainplot.image_output_file = self.image_output_file
     BoxLayout:
         orientation: 'vertical'
         BoxLayout:
@@ -53,6 +85,7 @@
             orientation: 'horizontal'
             MyLabel:
                 id: current_temperature
+                text: "Current Temperature: n/a"
             StatusWidget:
                 id: startstop_widget
                 state: 'running'
@@ -66,13 +99,17 @@
                     id: clear_button
                     text: 'Clear'
                     on_press: root.initiate_clear_dialog()
-            Label:
+            Button:
+                id: output_button
                 text: 'No File Chosen'
+                on_press: root.choose_output_file()
             SerialPortButton:
                 id: serial_chooser_button
                 on_serial_port_changed: root.serial_port_changed(self.text)
         PlotWidget:
             id: mainplot
+            on_image_output_file: self.update_image_output_file()
+            on_raw_data_output_file: self.update_raw_data_output_file()
             size_hint_y: 0.8
         StatusBar:
             size_hint_y: 0.1

main.py

@@ -20,11 +20,13 @@ from kivy.uix.modalview import ModalView
 from kivy.uix.popup import Popup
 from kivy.uix.spinner import Spinner
 import kivy.lang
-import numpy
 import matplotlib
 matplotlib.use('Agg')
 import matplotlib.image
 import matplotlib.pyplot
+import numpy
+import os
+import os.path
 import pygame.image
 import Queue
 import StringIO
@@ -63,6 +65,8 @@ class MainWindow(FloatLayout):
     recordingState = StringProperty('')
     state = StringProperty('running')
     lastStatus = DictProperty({})
+    image_output_file = StringProperty('')
+    raw_data_output_file = StringProperty('')
 
     def __init__(self, **kwargs):
         super(MainWindow, self).__init__(**kwargs)
@@ -162,10 +166,93 @@ class MainWindow(FloatLayout):
         Logger.debug('StatusWidget: process_dialog args: ' + str(args))
         if args and args[0]:
             self.ids.mainplot.clear_data()
+            self.image_output_file = ''
+            self.raw_data_output_file = ''
         self.remove_widget(self.modal_view)
         self.modal_view = None
 
 
+    def choose_output_file(self, *args, **kwargs):
+        Logger.debug('Choose Output File pressed')
+        output_file_dialog = OutputFileDialog(cancel = self.dismiss_popup,
+                                              set_output_file = self.set_output_file)
+        self._popup = Popup(title="Choose outputfile", content = output_file_dialog)
+        self._popup.open()
+
+
+    def set_output_file(self, path, file_name, *args, **kwargs):
+        #Logger.debug('Setouput file: ', str((path, file_name, args, kwargs)))
+        # If we're oaky with writing path + file_name + (.csv|.png)
+        files = {
+            'image_file' : os.path.join(path, file_name + '.png'),
+            'raw_data_file' : os.path.join(path, file_name + '.csv'),
+        }
+        errors = {}
+        has_errors = False
+        for k, file_name in files.iteritems():
+            errors[k] = self.validate_output_file(file_name)
+            if errors[k]:
+                has_errors = True
+        if not has_errors:
+            Logger.debug('MainWindow: Set output files: ' + str(files))
+            self.raw_data_output_file = files['raw_data_file']
+            self.image_output_file = files['image_file']
+            self.dismiss_popup()
+        else:
+            # UI Feedback in the popup dialog
+            Logger.debug('MainWindow: Set output file errors: ' + str(errors))
+
+
+    def validate_output_file(self, file_name):
+        errors = []
+        # File doesn't exist, parent dir is writable
+        exists = os.path.exists(file_name)
+        # Note, the access check isn't for security, but usability here.
+        access = os.access(os.path.dirname(file_name), os.W_OK)
+        Logger.debug('MainWindow: validate_ouput_file file: ' + str(file_name))
+        Logger.debug('MainWindow: validate_output_file stat: ' + str(exists))
+        Logger.debug('MainWindow: validate_output_file parent dir write access: ' + str(access))
+        if exists:
+            errors.append('File already exists')
+        if not access:
+            errors.append('No write access to parent directory')
+        return errors
+
+
+    def dismiss_popup(self, *args, **kwargs):
+        self._popup.dismiss()
+
+
+    def clear_output_files(self):
+        self.raw_data_output_file = ''
+        self.image_output_file = ''
+
+
+    def on_raw_data_output_file(self, *args, **kwargs):
+        if self.raw_data_output_file:
+            root = self.raw_data_output_file.rsplit('.', 1)
+            Logger.debug('MainWindow: ' + str(root))
+            self.ids.output_button.text = root[0] + '[.csv|.png]'
+        else:
+            self.ids.output_button.text = 'No File Chosen'
+
+
+class OutputFileDialog(FloatLayout):
+
+    def __init__(self, *args, **kwargs):
+        super(OutputFileDialog, self).__init__(*args, **kwargs)
+        self.cancel = kwargs['cancel']
+        self.set_output = kwargs['set_output_file']
+
+
+    def cancel(self, *args, **kwargs):
+        self.cancel(*args, **kwargs)
+
+
+    def set_output(self, *args, **kwargs):
+        self.set_output(*args, **kwargs)
+
+
 class SerialPortButton(Spinner):
 
     __events__ = ('on_serial_port_changed',)
@@ -229,6 +316,9 @@ class StatusWidget(BoxLayout):
 
 class PlotWidget(Image):
 
+    image_output_file = StringProperty('')
+    raw_data_output_file = StringProperty('')
+
     def __init__(self, **kwargs):
         super(PlotWidget, self).__init__(**kwargs)
         self.data = numpy.array([], dtype=float);
@@ -250,22 +340,7 @@ class PlotWidget(Image):
 
 
     def do_update(self):
-        if not self.data.any():
+        image_data = self.to_image_data()
-            return
-        #Logger.debug('self.data: ' + str(self.data))
-        #Logger.debug('self.data shape: ' + str(self.data.shape))
-        data = numpy.copy(self.data)
-        data = data.transpose()
-        #Logger.debug('transpoed data: ' + str(data))
-        #Logger.debug('transposed data shape: ' + str(data.shape))
-        t, temperature = numpy.split(data, 2, axis = 0)
-        #Logger.debug('time: ' + str(t[0]))
-        #Logger.debug('temperature: ' + str(temperature[0]))
-        self.plot_axes.plot(t[0], temperature[0])
-        image_data = StringIO.StringIO()
-        self.figure.savefig(image_data, format = 'png')
-        image_data.seek(0)
-        self._image_raw_data = image_data
         # We can't use ImageLoaders since they assume it's a file on disk.
         # This replicates code from ImageLoaderPygame.load() and ImageLoaderBase.populate()
         try:
@@ -282,6 +357,44 @@ class PlotWidget(Image):
         self.image_data = ImageData(im.get_width(), im.get_height(), fmt, data)
         self.texture = Texture.create_from_data(self.image_data)
         self.texture.flip_vertical()
+        # Update output files, if any
+        # @TODO Add in an update interval so the disk isn't hammered on every single update
+        self.update_image_output_file()
+        self.update_raw_data_output_file()
+
+
+    def to_image_data(self):
+        if not self.data.any():
+            return
+        #Logger.debug('self.data: ' + str(self.data))
+        #Logger.debug('self.data shape: ' + str(self.data.shape))
+        data = numpy.copy(self.data)
+        data = data.transpose()
+        #Logger.debug('transpoed data: ' + str(data))
+        #Logger.debug('transposed data shape: ' + str(data.shape))
+        t, temperature = numpy.split(data, 2, axis = 0)
+        #Logger.debug('time: ' + str(t[0]))
+        #Logger.debug('temperature: ' + str(temperature[0]))
+        self.plot_axes.plot(t[0], temperature[0])
+        image_data = StringIO.StringIO()
+        self.figure.savefig(image_data, format = 'png')
+        image_data.seek(0)
+        self._image_raw_data = image_data
+        return self._image_raw_data
+
+
+    def update_raw_data_output_file(self):
+        if self.raw_data_output_file and self.data.any():
+            numpy.savetxt(self.raw_data_output_file, self.data, delimiter=',')
+
+
+    def update_image_output_file(self, image_data = None):
+        if not image_data:
+            image_data = self.to_image_data()
+        if self.image_output_file and image_data:
+            f = open(self.image_output_file, 'w')
+            f.write(image_data.read())
+            f.close()
 
 
     def on_lastTemperature(self, value):