source: sasview/src/sas/perspectives/invariant/invariant_panel.py @ 3db44fb

"""
This module provides the GUI for the invariant perspective panel

"""
import copy
import time
import sys
import os
import wx
import logging
from wx.lib.scrolledpanel import ScrolledPanel
from sas.invariant import invariant
from sas.guiframe.utils import format_number
from sas.guiframe.utils import check_float
from sas.guiframe.events import StatusEvent
from sas.guiframe.events import AppendBookmarkEvent
from sas.perspectives.invariant.invariant_details import InvariantDetailsPanel
from sas.perspectives.invariant.invariant_details import InvariantContainer
from sas.perspectives.invariant.invariant_widgets import OutputTextCtrl
from sas.perspectives.invariant.invariant_widgets import InvTextCtrl
from sas.perspectives.invariant.invariant_state import InvariantState as IState
from sas.guiframe.panel_base import PanelBase
from sas.guiframe.documentation_window import DocumentationWindow

# The minimum q-value to be used when extrapolating
Q_MINIMUM = 1e-5
# The maximum q-value to be used when extrapolating
Q_MAXIMUM = 10
# the ratio of maximum q value/(qmax of data) to plot the theory data
Q_MAXIMUM_PLOT = 3
# the number of points to consider during fit
NPTS = 10
#Default value for background
BACKGROUND = 0.0
#default value for the scale
SCALE = 1.0
#default value of the contrast
CONTRAST = 1.0
#default value of the power used for power law
POWER = 4.0
#Invariant panel size
_BOX_WIDTH = 76


if sys.platform.count("win32") > 0:
    _STATICBOX_WIDTH = 450
    PANEL_WIDTH = 500
    PANEL_HEIGHT = 700
    FONT_VARIANT = 0
else:
    _STATICBOX_WIDTH = 490
    PANEL_WIDTH = 530
    PANEL_HEIGHT = 700
    FONT_VARIANT = 1


class InvariantPanel(ScrolledPanel, PanelBase):
    """
    Main class defining the sizers (wx "panels") used to draw the
    Invariant GUI.
    """
    ## Internal nickname for the window, used by the AUI manager
    window_name = "Invariant"
    ## Name to appear on the window title bar
    window_caption = "Invariant"
    ## Flag to tell the AUI manager to put this panel in the center pane
    CENTER_PANE = True
    def __init__(self, parent, data=None, manager=None, *args, **kwds):
        kwds["size"] = (PANEL_WIDTH, PANEL_HEIGHT)
        kwds["style"] = wx.FULL_REPAINT_ON_RESIZE
        ScrolledPanel.__init__(self, parent=parent, *args, **kwds)
        PanelBase.__init__(self, parent)
        self.SetupScrolling()
        #Font size
        self.SetWindowVariant(variant=FONT_VARIANT)
        #Object that receive status event
        self.parent = parent.parent
        #plug-in using this panel
        self._manager = manager
        #Data uses for computation
        self._data = data
        self._scale = SCALE
        self._background = BACKGROUND
        self._bmark = None
        self.bookmark_num = 0
        self.state = None
        self.popUpMenu = None
        self._set_bookmark_menu()
        #Init state
        self.set_state()
        # default flags for state
        self.new_state = False
        self.is_state_data = False
        self.is_power_out = False

        #container of invariant value
        self.inv_container = None
        #sizers
        self.main_sizer = None
        self.outputs_sizer = None
        self.data_name_boxsizer = None
        self.hint_msg_sizer = None
        self.data_name_sizer = None
        self.data_range_sizer = None
        self.sizer_input = None
        self.inputs_sizer = None
        self.extrapolation_sizer = None
        self.extrapolation_range_sizer = None
        self.extrapolation_low_high_sizer = None
        self.low_extrapolation_sizer = None
        self.low_q_sizer = None
        self.high_extrapolation_sizer = None
        self.high_q_sizer = None
        self.volume_surface_sizer = None
        self.invariant_sizer = None
        self.button_sizer = None
        self.save_button_sizer = None
        self.hint_msg_txt = None
        self.data_name_tcl = None
        self.data_min_tcl = None
        self.data_max_tcl = None
        #Draw the panel
        self._do_layout()
        self.reset_panel()
        self._reset_state_list()
        ## Default file location for save
        self._default_save_location = os.getcwd()
        if self.parent is not None:
            msg = ""
            wx.PostEvent(self.parent, StatusEvent(status=msg, info="info"))
            self._default_save_location = \
                        self.parent.get_save_location()

        self._set_bookmark_flag(False)

    def get_data(self):
        """
        """
        return self._manager.get_data()

    def get_state(self):
        """
        """
        return self.state

    def set_data(self, data):
        """
        Set the data
        """
        self._data = data
        #edit the panel
        if self._data is not None:
            self._delete_bookmark_items()
            self.get_state_by_num(0)
            data_name = self._data.name
            data_qmin = min(self._data.x)
            data_qmax = max(self._data.x)
            self.data_name_tcl.SetValue(str(data_name))
            self.data_min_tcl.SetValue(str(data_qmin))
            self.data_max_tcl.SetValue(str(data_qmax))
            self.reset_panel()
            self.compute_invariant(event=None)
            self.state.file = self._data.name
            #Reset the list of states
            self.state.data = copy.deepcopy(data)
            self._set_save_flag(True)
            self._set_preview_flag(False)
            self._reset_state_list()
            self._set_bookmark_flag(True)
        return True

    def _delete_bookmark_items(self):
        """
        Delete bookmark menu items
        """
        # delete toolbar menu
        self.parent.reset_bookmark_menu(self)
        self.parent._update_toolbar_helper()
        # delete popUpMenu items
        pos = 0
        for item in self.popUpMenu.GetMenuItems():
            pos += 1
            if pos < 3:
                continue
            self.popUpMenu.DestroyItem(item)

    def set_message(self):
        """
        Display warning message if available
        """
        if self.inv_container is not None:
            if self.inv_container.existing_warning:
                msg = "Warning! Computations on invariant require your "
                msg += "attention.\nPlease click on Details button."
                self.hint_msg_txt.SetForegroundColour("red")

                wx.PostEvent(self.parent,
                             StatusEvent(status=msg, info="warning"))
            else:
                msg = "For more information, click on Details button."
                self.hint_msg_txt.SetForegroundColour("black")
                wx.PostEvent(self.parent,
                             StatusEvent(status=msg, info="info"))
            self.hint_msg_txt.SetLabel(msg)
        self.Layout()

    def set_manager(self, manager):
        """
        set value for the manager
        """
        self._manager = manager

    def save_project(self, doc=None):
        """
        return an xml node containing state of the panel
         that guiframe can write to file
        """
        data = self.get_data()
        state = self.get_state()
        if data is not None:
            new_doc = self._manager.state_reader.write_toXML(data, state)
            if new_doc is not None:
                if doc is not None and hasattr(doc, "firstChild"):
                    child = new_doc.getElementsByTagName("SASentry")
                    for item in child:
                        doc.firstChild.appendChild(item)
                else:
                    doc = new_doc
        return doc

    def set_state(self, state=None, data=None):
        """
        set state when loading it from a .inv/.svs file
        """

        if state == None and data == None:
            self.state = IState()
        elif state == None or data == None:
            return
        else:
            new_state = copy.deepcopy(state)
            self.new_state = True
            if not self.set_data(data):
                return

            self.state = new_state
            self.state.file = data.name

            num = self.state.saved_state['state_num']
            if num > 0:
                self._set_undo_flag(True)
            if num < len(state.state_list) - 1:
                self._set_redo_flag(True)

            # get bookmarks
            self.bookmark_num = len(self.state.bookmark_list)
            total_bookmark_num = self.bookmark_num + 1

            for ind in range(1, total_bookmark_num):
                #bookmark_num = ind
                value = self.state.bookmark_list[ind]
                name = "%d] bookmarked at %s on %s" % (ind, value[0], value[1])
                # append it to menu
                id = wx.NewId()
                self.popUpMenu.Append(id, name, str(''))
                wx.EVT_MENU(self, id, self._back_to_bookmark)
                wx.PostEvent(self.parent,
                             AppendBookmarkEvent(title=name,
                                                 hint='',
                                                 handler=self._back_to_bookmark))

            self.get_state_by_num(state_num=str(num))

            self._get_input_list()
            #make sure that the data is reset (especially
            # when loaded from a inv file)
            self.state.data = self._data
            self._set_preview_flag(False)
            self.new_state = False
            self.is_state_data = False

    def clear_panel(self):
        """
        Clear panel to defaults, used by set_state of manager
        """

        self._data = None
        # default data testctrl
        self.hint_msg_txt.SetLabel('')
        data_name = ''
        data_qmin = ''
        data_qmax = ''
        self.data_name_tcl.SetValue(str(data_name))
        self.data_min_tcl.SetValue(str(data_qmin))
        self.data_max_tcl.SetValue(str(data_qmax))
        #reset output textctrl
        self._reset_output()
        #reset panel
        self.reset_panel()
        #reset state w/o data
        self.set_state()
        # default flags for state
        self.new_state = False
        self.is_state_data = False
        self.is_power_out = False

    def get_background(self):
        """
        return the background textcrtl value as a float
        """
        background = self.background_tcl.GetValue().lstrip().rstrip()
        if background == "":
            raise ValueError, "Need a background"
        if check_float(self.background_tcl):
            return float(background)
        else:
            msg = "Receive invalid value for background : %s" % (background)
            raise ValueError, msg

    def get_scale(self):
        """
        return the scale textcrtl value as a float
        """
        scale = self.scale_tcl.GetValue().lstrip().rstrip()
        if scale == "":
            raise ValueError, "Need a background"
        if check_float(self.scale_tcl):
            if float(scale) <= 0.0:
                self.scale_tcl.SetBackgroundColour("pink")
                self.scale_tcl.Refresh()
                msg = "Receive invalid value for scale: %s" % (scale)
                raise ValueError, msg
            return float(scale)
        else:
            raise ValueError, "Receive invalid value for scale : %s" % (scale)

    def get_contrast(self):
        """
        return the contrast textcrtl value as a float
        """
        par_str = self.contrast_tcl.GetValue().strip()
        contrast = None
        if par_str != " " and check_float(self.contrast_tcl):
            contrast = float(par_str)
        return contrast

    def get_extrapolation_type(self, low_q, high_q):
        """
        get extrapolation type
        """
        extrapolation = None
        if low_q  and not high_q:
            extrapolation = "low"
        elif not low_q  and high_q:
            extrapolation = "high"
        elif low_q and high_q:
            extrapolation = "both"
        return extrapolation

    def get_porod_const(self):
        """
        return the porod constant textcrtl value as a float
        """
        par_str = self.porod_constant_tcl.GetValue().strip()
        porod_const = None
        if par_str != "" and check_float(self.porod_constant_tcl):
            porod_const = float(par_str)
        return porod_const

    def get_volume(self, inv, contrast, extrapolation):
        """
        get volume fraction
        """
        if contrast is not None:
            try:
                v, dv = inv.get_volume_fraction_with_error(contrast=contrast,
                                                           extrapolation=extrapolation)
                self.volume_tcl.SetValue(format_number(v))
                self.volume_err_tcl.SetValue(format_number(dv))
            except:
                self.volume_tcl.SetValue(format_number(None))
                self.volume_err_tcl.SetValue(format_number(None))
                msg = "Error occurred computing volume "
                msg += " fraction: %s" % sys.exc_value
                wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                      info="error",
                                                      type="stop"))

    def get_surface(self, inv, contrast, porod_const, extrapolation):
        """
        get surface value
        """
        if contrast is not None and porod_const is not None:
            try:
                s, ds = inv.get_surface_with_error(contrast=contrast,
                                                   porod_const=porod_const,
                                                   extrapolation=extrapolation)
                self.surface_tcl.SetValue(format_number(s))
                self.surface_err_tcl.SetValue(format_number(ds))
            except:
                self.surface_tcl.SetValue(format_number(None))
                self.surface_err_tcl.SetValue(format_number(None))
                msg = "Error occurred computing "
                msg += "specific surface: %s" % sys.exc_value
                wx.PostEvent(self.parent, StatusEvent(status=msg, info="error",
                                                      type="stop"))

    def get_total_qstar(self, inv, extrapolation):
        """
        get total qstar
        """
        try:
            qstar_total, qstar_total_err = \
                                    inv.get_qstar_with_error(extrapolation)
            self.invariant_total_tcl.SetValue(format_number(qstar_total))
            self.invariant_total_err_tcl.SetValue(\
                                    format_number(qstar_total_err))
            self.inv_container.qstar_total = qstar_total
            self.inv_container.qstar_total_err = qstar_total_err
        except:
            self.inv_container.qstar_total = "Error"
            self.inv_container.qstar_total_err = "Error"
            self.invariant_total_tcl.SetValue(format_number(None))
            self.invariant_total_err_tcl.SetValue(format_number(None))
            msg = "Error occurred computing invariant using"
            msg += " extrapolation: %s" % sys.exc_value
            wx.PostEvent(self.parent, StatusEvent(status=msg, type="stop"))

    def get_low_qstar(self, inv, npts_low, low_q=False):
        """
        get low qstar
        """
        if low_q:
            try:
                qstar_low, qstar_low_err = inv.get_qstar_low()
                self.inv_container.qstar_low = qstar_low
                self.inv_container.qstar_low_err = qstar_low_err
                extrapolated_data = inv.get_extra_data_low(npts_in=npts_low)
                power_low = inv.get_extrapolation_power(range='low')
                if self.power_law_low.GetValue():
                    self.power_low_tcl.SetValue(format_number(power_low))
                self._manager.plot_theory(data=extrapolated_data,
                                          name="Low-Q extrapolation")
            except:
                self.inv_container.qstar_low = "ERROR"
                self.inv_container.qstar_low_err = "ERROR"
                self._manager.plot_theory(name="Low-Q extrapolation")
                msg = "Error occurred computing low-Q "
                msg += "invariant: %s" % sys.exc_value
                wx.PostEvent(self.parent,
                             StatusEvent(status=msg, type="stop"))
                raise
        else:
            try:
                self._manager.plot_theory(name="Low-Q extrapolation")
            except:
                logging.error(sys.exc_value)

    def get_high_qstar(self, inv, high_q=False):
        """
        get high qstar
        """
        if high_q:
            try:
                qmax_plot = Q_MAXIMUM_PLOT * max(self._data.x)
                if qmax_plot > Q_MAXIMUM:
                    qmax_plot = Q_MAXIMUM
                qstar_high, qstar_high_err = inv.get_qstar_high()
                self.inv_container.qstar_high = qstar_high
                self.inv_container.qstar_high_err = qstar_high_err
                power_high = inv.get_extrapolation_power(range='high')
                self.power_high_tcl.SetValue(format_number(power_high))
                high_out_data = inv.get_extra_data_high(q_end=qmax_plot,
                                                        npts=500)
                self._manager.plot_theory(data=high_out_data,
                                          name="High-Q extrapolation")
            except:
                #raise
                self.inv_container.qstar_high = "ERROR"
                self.inv_container.qstar_high_err = "ERROR"
                self._manager.plot_theory(name="High-Q extrapolation")
                msg = "Error occurred computing high-Q "
                msg += "invariant: %s" % sys.exc_value
                wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                      type="stop"))
                raise
        else:
            try:
                self._manager.plot_theory(name="High-Q extrapolation")
            except:
                logging.error(sys.exc_value)

    def get_qstar(self, inv):
        """
        get qstar
        """
        qstar, qstar_err = inv.get_qstar_with_error()
        self.inv_container.qstar = qstar
        self.inv_container.qstar_err = qstar_err

    def set_extrapolation_low(self, inv, low_q=False):
        """
        return float value necessary to compute invariant a low q
        """
        #get funtion
        if self.guinier.GetValue():
            function_low = "guinier"
        # get the function
        power_low = None #2.0/3.0
        if self.power_law_low.GetValue():
            function_low = "power_law"
            if self.fit_enable_low.GetValue():
                #set value of power_low to none to allow fitting
                power_low = None
            else:
                power_low = self.power_low_tcl.GetValue().lstrip().rstrip()
                if check_float(self.power_low_tcl):
                    power_low = float(power_low)
                else:
                    if low_q:
                        #Raise error only when qstar at low q is requested
                        msg = "Expect float for power at low q, "
                        msg += " got %s" % (power_low)
                        wx.PostEvent(self.parent,
                                     StatusEvent(status=msg,
                                                 info="error",
                                                 type="stop"))

        #Get the number of points to extrapolated
        npts_low = self.npts_low_tcl.GetValue().lstrip().rstrip()
        if check_float(self.npts_low_tcl):
            npts_low = float(npts_low)
        else:
            if low_q:
                msg = "Expect float for number of points at low q,"
                msg += " got %s" % (npts_low)
                wx.PostEvent(self.parent,
                             StatusEvent(status=msg,
                                         info="error",
                                         type="stop"))
        #Set the invariant calculator
        inv.set_extrapolation(range="low", npts=npts_low,
                              function=function_low, power=power_low)
        return inv, npts_low


    def set_extrapolation_high(self, inv, high_q=False):
        """
        return float value necessary to compute invariant a high q
        """
        power_high = None
        #if self.power_law_high.GetValue():
        function_high = "power_law"
        if self.fit_enable_high.GetValue():
            #set value of power_high to none to allow fitting
            power_high = None
        else:
            power_high = self.power_high_tcl.GetValue().lstrip().rstrip()
            if check_float(self.power_high_tcl):
                power_high = float(power_high)
            else:
                if high_q:
                    #Raise error only when qstar at high q is requested
                    msg = "Expect float for power at high q,"
                    msg += " got %s" % (power_high)
                    wx.PostEvent(self.parent,
                                 StatusEvent(status=msg,
                                             info="error",
                                             type="stop"))

        npts_high = self.npts_high_tcl.GetValue().lstrip().rstrip()
        if check_float(self.npts_high_tcl):
            npts_high = float(npts_high)
        else:
            if high_q:
                msg = "Expect float for number of points at high q,"
                msg += " got %s" % (npts_high)
                wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                      info="error",
                                                      type="stop"))
        inv.set_extrapolation(range="high", npts=npts_high,
                              function=function_high, power=power_high)
        return inv, npts_high

    def display_details(self, event):
        """
        open another panel for more details on invariant calculation
        """
        panel = InvariantDetailsPanel(parent=self,
                                      qstar_container=self.inv_container)
        panel.ShowModal()
        panel.Destroy()
        self.button_calculate.SetFocus()

    def compute_invariant(self, event=None):
        """
        compute invariant
        """
        if self._data == None:
            msg = "\n\nData must be loaded first in order"
            msg += " to perform a compution..."
            wx.PostEvent(self.parent, StatusEvent(status=msg))
        # set a state for this computation for saving
        elif event != None:
            self._set_compute_state(state='compute')
            self._set_bookmark_flag(True)
            msg = "\n\nStarting a new invariant computation..."
            wx.PostEvent(self.parent, StatusEvent(status=msg))


        if self._data is None:
            return
        self.button_details.Enable()
        #clear outputs textctrl
        self._reset_output()
        try:
            background = self.get_background()
            scale = self.get_scale()
        except:
            msg = "Invariant Error: %s" % (sys.exc_value)
            wx.PostEvent(self.parent, StatusEvent(status=msg, type="stop"))
            return

        low_q = self.enable_low_cbox.GetValue()
        high_q = self.enable_high_cbox.GetValue()
        temp_data = copy.deepcopy(self._data)

        #set invariant calculator
        inv = invariant.InvariantCalculator(data=temp_data,
                                            background=background,
                                            scale=scale)
        try:
            inv, npts_low = self.set_extrapolation_low(inv=inv, low_q=low_q)
            inv, npts_high = self.set_extrapolation_high(inv=inv, high_q=high_q)
        except:
            msg = "Error occurred computing invariant: %s" % sys.exc_value
            wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                  info="warning", type="stop"))
            return
        #check the type of extrapolation
        extrapolation = self.get_extrapolation_type(low_q=low_q, high_q=high_q)

        #Compute invariant
        try:
            self.get_qstar(inv=inv)
        except:
            msg = "Error occurred computing invariant: %s" % sys.exc_value
            wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                  info="warning",
                                                  type="stop"))
            return
        #self.Show(False)
        r_msg = ''
        try:
            r_msg = 'Low Q: '
            #Compute qstar extrapolated to low q range
            self.get_low_qstar(inv=inv, npts_low=npts_low, low_q=low_q)
            r_msg = 'High Q: '
            #Compute qstar extrapolated to high q range
            self.get_high_qstar(inv=inv, high_q=high_q)
            r_msg = ''
            #Compute qstar extrapolated to total q range
            #and set value to txtcrtl
            self.get_total_qstar(inv=inv, extrapolation=extrapolation)
            # Parse additional parameters
            porod_const = self.get_porod_const()
            contrast = self.get_contrast()
        except:
            msg = r_msg + "Error occurred computing invariant: %s" % \
                                                            sys.exc_value
            wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                  info="error",
                                                  type="stop"))
        try:
            #Compute volume and set value to txtcrtl
            self.get_volume(inv=inv, contrast=contrast,
                            extrapolation=extrapolation)
            #compute surface and set value to txtcrtl
        except:
            msg = "Error occurred computing invariant: %s" % sys.exc_value
            wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                  info="warning",
                                                  type="stop"))
        try:
            self.get_surface(inv=inv, contrast=contrast,
                             porod_const=porod_const,
                             extrapolation=extrapolation)

        except:
            msg = "Error occurred computing invariant: %s" % sys.exc_value
            wx.PostEvent(self.parent, StatusEvent(status=msg,
                                                  info="warning",
                                                  type="stop"))

        #compute percentage of each invariant
        self.inv_container.compute_percentage()

        #display a message
        self.set_message()

        # reset power_out to default to get ready for another '_on_text'
        if self.is_power_out == True:
            self.state.container = copy.deepcopy(self.inv_container)
            self.state.timestamp = self._get_time_stamp()
            msg = self.state.__str__()
            self.state.set_report_string()
            self.is_power_out = False
            wx.PostEvent(self.parent, StatusEvent(status=msg))

        #enable the button_ok for more details
        self._set_preview_flag(True)

        if event != None:
            self._set_preview_flag(True)
            self._set_save_flag(True)
            wx.PostEvent(self.parent,
                         StatusEvent(status='\nFinished invariant computation...'))
        #self.Show(True)
        self.Refresh()

    def on_undo(self, event=None):
        """
        Go back to the previous state

        : param event: undo button event
        """
        if self.state.state_num < 0:
            return
        self.is_power_out = True
        # get the previous state_num
        pre_state_num = int(self.state.saved_state['state_num']) - 1

        self.get_state_by_num(state_num=str(pre_state_num))

        if float(pre_state_num) <= 0:
            self._set_undo_flag(False)
        else:
            self._set_undo_flag(True)
        self._set_redo_flag(True)
        self.is_power_out = False
        self._info_state_num()


    def on_redo(self, event=None):
        """
        Go forward to the previous state

        : param event: redo button event
        """
        self.is_power_out = True
        # get the next state_num
        next_state_num = int(self.state.saved_state['state_num']) + 1

        self.get_state_by_num(state_num=str(next_state_num))

        if float(next_state_num) + 2 > len(self.state.state_list):
            self._set_redo_flag(False)
        else:
            self._set_redo_flag(True)

        self._set_undo_flag(True)
        self.is_power_out = False
        self._info_state_num()

    def on_preview(self, event=None):
        """
        Invoke report dialog panel

        : param event: report button event
        """
        from sas.perspectives.invariant.report_dialog import ReportDialog

        self.state.set_report_string()
        report_html_str = self.state.report_str
        report_text_str = self.state.__str__()
        report_img = self.state.image
        report_list = [report_html_str, report_text_str, report_img]
        dialog = ReportDialog(report_list, None, -1, "")
        dialog.Show()

    def get_state_by_num(self, state_num=None):
        """
        Get the state given by number

        : param state_num: the given state number
        """
        if state_num == None:
            return

        backup_state_list = copy.deepcopy(self.state.state_list)

        # get the previous state
        try:
            current_state = copy.deepcopy(self.state.state_list[str(state_num)])
            # get the previously computed state number
            #(computation before the state changes happened)
            current_compute_num = str(current_state['compute_num'])
        except:
            raise

        # get the state at pre_compute_num
        comp_state = copy.deepcopy(self.state.state_list[current_compute_num])

        # set the parameters
        for key in comp_state:
            value = comp_state[key]
            self._set_property_value(key, value)

        self.compute_invariant(event=None)

        # set the input params at the state at pre_state_num
        for key in current_state:
            # set the inputs and boxes
            value = current_state[key]
            self._set_property_value(key, value)

        self._enable_high_q_section(event=None)
        self._enable_low_q_section(event=None)
        self.state.state_list = backup_state_list
        self.state.saved_state = current_state
        self.state.state_num = state_num

    def _set_property_value(self, key, value):
        """
            Set a property value
            :param key: property name
            :param value: value of the property
        """
        try:
            attr = getattr(self, key)
            attr.SetValue(str(value))
        except:
            logging.error("Invariant state: %s", sys.exc_value)

    def get_bookmark_by_num(self, num=None):
        """
        Get the bookmark state given by number

        : param num: the given bookmark number

        """
        current_state = {}
        comp_state = {}
        backup_state_list = copy.deepcopy(self.state.state_list)

        # get the previous state
        try:
            _, _, current_state, comp_state = self.state.bookmark_list[int(num)]
        except:
            logging.error(sys.exc_value)
            raise ValueError, "No such bookmark exists"

        # set the parameters
        for key in comp_state:
            value = comp_state[key]
            self._set_property_value(key, value)

        self.compute_invariant(event=None)
        # set the input params at the state of pre_state_num
        for key in current_state:
            value = current_state[key]
            self._set_property_value(key, value)
        self.state.saved_state = copy.deepcopy(current_state)

        self._enable_high_q_section(event=None)
        self._enable_low_q_section(event=None)
        self.state.state_list = backup_state_list
        #self.state.saved_state = current_state
        #self.state.state_num = state_num

    def reset_panel(self):
        """
        set the panel at its initial state.
        """
        self.background_tcl.SetValue(str(BACKGROUND))
        self.scale_tcl.SetValue(str(SCALE))
        self.contrast_tcl.SetValue(str(CONTRAST))
        self.porod_constant_tcl.SetValue('')
        self.npts_low_tcl.SetValue(str(NPTS))
        self.enable_low_cbox.SetValue(False)
        self.fix_enable_low.SetValue(True)
        self.power_low_tcl.SetValue(str(POWER))
        self.guinier.SetValue(True)
        self.power_low_tcl.Disable()
        self.enable_high_cbox.SetValue(False)
        self.fix_enable_high.SetValue(True)
        self.power_high_tcl.SetValue(str(POWER))
        self.npts_high_tcl.SetValue(str(NPTS))
        self.button_details.Disable()
        #Change the state of txtcrtl to enable/disable
        self._enable_low_q_section()
        #Change the state of txtcrtl to enable/disable
        self._enable_high_q_section()
        self._reset_output()
        self._set_undo_flag(False)
        self._set_redo_flag(False)
        self._set_bookmark_flag(False)
        self._set_preview_flag(False)
        self._set_save_flag(False)
        self.button_calculate.SetFocus()
        #self.SetupScrolling()

    def _set_state(self, event):
        """
        Set the state list

        :param event: rb/cb event
        """
        if event == None:
            return
        obj = event.GetEventObject()
        name = str(obj.GetName())
        value = str(obj.GetValue())
        rb_list = [['power_law_low', 'guinier'],
                   ['fit_enable_low', 'fix_enable_low'],
                   ['fit_enable_high', 'fix_enable_high']]

        try:
            if value == None or value.lstrip().rstrip() == '':
                value = 'None'
            setattr(self.state, name, str(value))
            self.state.saved_state[name] = str(value)

            # set the count part of radio button clicked
            #False for the saved_state
            for title, content in rb_list:
                if name == title:
                    name = content
                    value = False
                elif name == content:
                    name = title
                    value = False
            self.state.saved_state[name] = str(value)

            # Instead of changing the future, create a new future.
            max_state_num = len(self.state.state_list) - 1
            self.state.saved_state['state_num'] = max_state_num

            self.state.saved_state['state_num'] += 1
            self.state.state_num = self.state.saved_state['state_num']
            self.state.state_list[str(self.state.state_num)] = \
                    self.state.clone_state()
        except:
            logging.error(sys.exc_value)

        self._set_undo_flag(True)
        self._set_redo_flag(False)
        #event.Skip()

    def _set_compute_state(self, state=None):
        """
        Notify the compute_invariant state to self.state

        : param state: set 'compute' when the computation is
        activated by the 'compute' button, else None

        """
        # reset the default
        if state != 'compute':
            self.new_state = False
            self.is_power_out = False
        else:
            self.is_power_out = True
        # Instead of changing the future, create a new future.
        max_state_num = len(self.state.state_list) - 1
        self.state.saved_state['state_num'] = max_state_num
        # A new computation is also A state
        #copy.deepcopy(self.state.saved_state)
        temp_saved_states = self.state.clone_state()
        temp_saved_states['state_num'] += 1
        self.state.state_num = temp_saved_states['state_num']


        # set the state number of the computation
        if state == 'compute':
            temp_saved_states['compute_num'] = self.state.state_num
        self.state.saved_state = copy.deepcopy(temp_saved_states)
        #copy.deepcopy(self.state.saved_state)
        self.state.state_list[str(self.state.state_num)] = \
                                        self.state.clone_state()

        # A computation is a new state, so delete the states with any higher
        # state numbers
        for i in range(self.state.state_num + 1, len(self.state.state_list)):
            try:
                del self.state.state_list[str(i)]
            except:
                logging.error(sys.exc_value)
        # Enable the undo button if it was not
        self._set_undo_flag(True)
        self._set_redo_flag(False)

    def _reset_state_list(self, data=None):
        """
        Reset the state_list just before data was loading:
        Used in 'set_current_data()'
        """
        #if data == None: return
        #temp_state = self.state.clone_state()
        #copy.deepcopy(self.state.saved_state)
        # Clear the list
        self.state.state_list.clear()
        self.state.bookmark_list.clear()
        # Set defaults
        self.state.saved_state['state_num'] = 0
        self.state.saved_state['compute_num'] = 0
        if self._data != None:
            self.state.saved_state['file'] = str(self._data.name)
        else:
            self.state.saved_state['file'] = 'None'
        self.state.file = self.state.saved_state['file']

        self.state.state_num = self.state.saved_state['state_num']
        self.state.timestamp = "('00:00:00', '00/00/0000')"

        # Put only the current state in the list
        #copy.deepcopy(self.state.saved_state)
        self.state.state_list[str(self.state.state_num)] = \
                                                self.state.clone_state()
        self._set_undo_flag(False)
        self._set_redo_flag(False)
        self._set_bookmark_flag(False)
        self._set_preview_flag(False)
        self._set_save_flag(False)


    def _on_text(self, event):
        """
        Catch text change event to add the state to the state_list

        :param event: txtctr event ; assumes not None

        """
        if self._data == None:
            return
        # check if this event is from do/undo button
        if self.state.saved_state['is_time_machine'] or self.new_state:
            #event.Skip()
            return

        # get the object
        obj = event.GetEventObject()
        name = str(obj.GetName())
        value = str(obj.GetValue())
        state_num = self.state.saved_state['state_num']

        # text event is a new state, so delete the states with higher state_num
        # i.e., change the future
        for i in range(int(state_num) + 1, len(self.state.state_list)):
            try:
                del self.state.state_list[str(i)]
            except:
                logging.error(sys.exc_value)

        # try to add new state of the text changes in the state_list
        try:
            if value.strip() == None:
                value = ''
            setattr(self.state, name, str(value))
            self.state.saved_state[name] = str(value)
            self.state.input_list[name] = str(value)
            if not self.is_power_out:
                if name != 'power_low_tcl' and name != 'power_high_tcl':
                    self.state.saved_state['state_num'] += 1
            self.state.state_num = self.state.saved_state['state_num']
            self.state.state_list[str(self.state.state_num)] = self.state.clone_state()
        except:
            logging.error(sys.exc_value)

        self._set_undo_flag(True)
        self._set_redo_flag(False)
        self._set_bookmark_flag(True)
        self._set_preview_flag(False)

    def _on_out_text(self, event):
        """
        Catch ouput text change to add the state

        :param event: txtctr event ; assumes not None

        """
        # get the object
        obj = event.GetEventObject()
        name = str(obj.GetName())
        value = str(obj.GetValue())
        try:
            self.state.saved_state[name] = str(value)
            self.state.state_list[str(self.state.state_num)] = self.state.clone_state()
        except:
            logging.error(sys.exc_value)

    def _get_input_list(self):
        """
        get input_list; called by set_state
        """
        # get state num of the last compute state
        compute_num = self.state.saved_state['compute_num']
        # find values and put into the input list
        for key1, value1 in self.state.state_list[str(compute_num)].iteritems():
            for key, _ in self.state.input_list.iteritems():
                if key == key1:
                    self.state.input_list[key] = value1
                    break

    def _set_bookmark_menu(self):
        """
        Setup 'bookmark' context menu
        """
        ## Create context menu for page
        self.popUpMenu = wx.Menu()
        id = wx.NewId()
        self._bmark = wx.MenuItem(self.popUpMenu, id, "BookMark",
                                  " Bookmark the panel to recall it later")
        self.popUpMenu.AppendItem(self._bmark)
        self._bmark.Enable(True)
        wx.EVT_MENU(self, id, self.on_bookmark)
        self.popUpMenu.AppendSeparator()
        self.Bind(wx.EVT_CONTEXT_MENU, self._on_context_menu)

    def on_bookmark(self, event):
        """
        Save the panel state in memory and add the list on
        the popup menu on bookmark context menu event
        """
        if self._data == None:
            return
        if event == None:
            return
        self.bookmark_num += 1
        # date and time of the event
        my_time, date = self._get_time_stamp()
        _ = self.state.state_num
        compute_num = self.state.saved_state['compute_num']
        # name and message of the bookmark list
        msg = "State saved at %s on %s" % (my_time, date)
        ## post help message for the selected model
        msg += " Right click on the panel to retrieve this state"
        #wx.PostEvent(self.parent.parent, StatusEvent(status = msg ))
        name = "%d] bookmarked at %s on %s" % (self.bookmark_num, my_time, date)

        # append it to menu
        id = wx.NewId()
        self.popUpMenu.Append(id, name, str(msg))
        wx.EVT_MENU(self, id, self._back_to_bookmark)
        state = self.state.clone_state()
        comp_state = copy.deepcopy(self.state.state_list[str(compute_num)])
        self.state.bookmark_list[self.bookmark_num] = [my_time, date,
                                                       state, comp_state]
        self.state.toXML(self, doc=None, entry_node=None)

        wx.PostEvent(self.parent, StatusEvent(status=msg, info="info"))
        wx.PostEvent(self.parent,
                     AppendBookmarkEvent(title=name,
                                         hint=str(msg),
                                         handler=self._back_to_bookmark))

    def _back_to_bookmark(self, event):
        """
        Bring the panel back to the state of bookmarked requested by
        context menu event
        and set it as a new state
        """
        self._manager.on_perspective(event)
        menu = event.GetEventObject()
        ## post help message for the selected model
        msg = menu.GetHelpString(event.GetId())
        msg += " reloaded"
        wx.PostEvent(self.parent, StatusEvent(status=msg))

        name = menu.GetLabel(event.GetId())

        num, _ = name.split(']')
        current_state_num = self.state.state_num
        self.get_bookmark_by_num(num)
        state_num = int(current_state_num) + 1

        self.state.saved_state['state_num'] = state_num
        #copy.deepcopy(self.state.saved_state)
        self.state.state_list[str(state_num)] = self.state.clone_state()
        self.state.state_num = state_num

        self._set_undo_flag(True)
        self._info_bookmark_num(event)

    def _info_bookmark_num(self, event=None):
        """
        print the bookmark number in info

        : event: popUpMenu event
        """
        if event == None:
            return
        # get the object
        menu = event.GetEventObject()
        item = menu.FindItemById(event.GetId())
        text = item.GetText()
        num = text.split(']')[0]
        msg = "bookmark num = %s " % num

        wx.PostEvent(self.parent, StatusEvent(status=msg))

    def _info_state_num(self):
        """
        print the current state number in info
        """
        msg = "state num = "
        msg += self.state.state_num

        wx.PostEvent(self.parent, StatusEvent(status=msg))

    def _get_time_stamp(self):
        """
        return time and date stings
        """
        # date and time
        year, month, day, hour, minute, second, _, _, _ = \
                                    time.localtime()
        my_time = str(hour) + ":" + str(minute) + ":" + str(second)
        date = str(month) + "/" + str(day) + "/" + str(year)
        return my_time, date


    def on_save(self, evt=None):
        """
        Save invariant state into a file
        """
        # Ask the user the location of the file to write to.
        path = None
        if self.parent != None:
            self._default_save_location = self.parent.get_save_location()
        if self._default_save_location == None:
            self._default_save_location = os.getcwd()
        dlg = wx.FileDialog(self, "Choose a file",
                            self._default_save_location, \
                            self.window_caption, "*.inv", wx.SAVE)
        if dlg.ShowModal() == wx.ID_OK:
            path = dlg.GetPath()
            self._default_save_location = os.path.dirname(path)
            if self.parent != None:
                self.parent._default_save_location = \
                    self._default_save_location
        else:
            return None

        dlg.Destroy()
        # MAC always needs the extension for saving
        extens = ".inv"
        # Make sure the ext included in the file name
        fName = os.path.splitext(path)[0] + extens
        self._manager.save_file(filepath=fName, state=self.state)

    def _show_message(self, mssg='', msg='Warning'):
        """
        Show warning message when resetting data
        """
        # no message for now
        return True

    def _reset_output(self):
        """
        clear outputs textcrtl
        """
        self.invariant_total_tcl.Clear()
        self.invariant_total_err_tcl.Clear()
        self.volume_tcl.Clear()
        self.volume_err_tcl.Clear()
        self.surface_tcl.Clear()
        self.surface_err_tcl.Clear()
        #prepare a new container to put result of invariant
        self.inv_container = InvariantContainer()


    def _on_context_menu(self, event):
        """
        On context menu
        """
        pos = event.GetPosition()
        pos = self.ScreenToClient(pos)

        self.PopupMenu(self.popUpMenu, pos)

    def _define_structure(self):
        """
        Define main sizers needed for this panel
        """
        ## Box sizers must be defined first before
        #defining buttons/textctrls (MAC).
        self.main_sizer = wx.BoxSizer(wx.VERTICAL)
        #Sizer related to outputs
        outputs_box = wx.StaticBox(self, -1, "Outputs")
        self.outputs_sizer = wx.StaticBoxSizer(outputs_box, wx.VERTICAL)
        self.outputs_sizer.SetMinSize((_STATICBOX_WIDTH, -1))
        #Sizer related to data
        data_name_box = wx.StaticBox(self, -1, "I(q) Data Source")
        self.data_name_boxsizer = wx.StaticBoxSizer(data_name_box, wx.VERTICAL)
        self.data_name_boxsizer.SetMinSize((_STATICBOX_WIDTH, -1))
        self.hint_msg_sizer = wx.BoxSizer(wx.HORIZONTAL)
        self.data_name_sizer = wx.BoxSizer(wx.HORIZONTAL)

        self.data_range_sizer = wx.BoxSizer(wx.HORIZONTAL)
        #Sizer related to inputs
        self.sizer_input = wx.FlexGridSizer(2, 6, 0, 0)
        #Sizer related to inputs
        inputs_box = wx.StaticBox(self, -1, "Customized Inputs")
        self.inputs_sizer = wx.StaticBoxSizer(inputs_box, wx.VERTICAL)
        self.inputs_sizer.SetMinSize((_STATICBOX_WIDTH, -1))
        #Sizer related to extrapolation
        extrapolation_box = wx.StaticBox(self, -1, "Extrapolation")
        self.extrapolation_sizer = wx.StaticBoxSizer(extrapolation_box,
                                                     wx.VERTICAL)
        self.extrapolation_sizer.SetMinSize((_STATICBOX_WIDTH, -1))
        self.extrapolation_range_sizer = wx.BoxSizer(wx.HORIZONTAL)
        self.extrapolation_low_high_sizer = wx.BoxSizer(wx.HORIZONTAL)
        #Sizer related to extrapolation at low q range
        low_q_box = wx.StaticBox(self, -1, "Low Q")
        self.low_extrapolation_sizer = wx.StaticBoxSizer(low_q_box, wx.VERTICAL)

        self.low_q_sizer = wx.GridBagSizer(5, 5)
        #Sizer related to extrapolation at low q range
        high_q_box = wx.StaticBox(self, -1, "High Q")
        self.high_extrapolation_sizer = wx.StaticBoxSizer(high_q_box,
                                                          wx.VERTICAL)
        self.high_q_sizer = wx.GridBagSizer(5, 5)
        #sizer to define outputs
        self.volume_surface_sizer = wx.GridBagSizer(5, 5)
        #Sizer related to invariant output
        self.invariant_sizer = wx.GridBagSizer(5, 5)
        #Sizer related to button
        self.button_sizer = wx.BoxSizer(wx.HORIZONTAL)
        self.button_sizer.SetMinSize((_STATICBOX_WIDTH, -1))
        #Sizer related to save button
        self.save_button_sizer = wx.BoxSizer(wx.HORIZONTAL)

    def _layout_data_name(self):
        """
        Draw widgets related to data's name
        """
        #Sizer hint
        hint_msg = ""

        self.hint_msg_txt = wx.StaticText(self, -1, hint_msg)
        self.hint_msg_txt.SetForegroundColour("red")
        msg = "Highlight = mouse the mouse's cursor on the data until"
        msg += " the plot's color changes to yellow"
        self.hint_msg_txt.SetToolTipString(msg)
        self.hint_msg_sizer.Add(self.hint_msg_txt)
        #Data name [string]
        data_name_txt = wx.StaticText(self, -1, 'Name:')

        self.data_name_tcl = OutputTextCtrl(self, -1, size=(_BOX_WIDTH * 4, 20),
                                            style=0)
        self.data_name_tcl.SetToolTipString("Data's name.")
        self.data_name_sizer.AddMany([(data_name_txt, 0, wx.LEFT | wx.RIGHT, 10),
                                      (self.data_name_tcl, 0, wx.EXPAND)])
        #Data range [string]
        data_range_txt = wx.StaticText(self, -1, 'Total Q Range (1/A): ')
        data_min_txt = wx.StaticText(self, -1, 'Min : ')
        self.data_min_tcl = OutputTextCtrl(self, -1, size=(_BOX_WIDTH, 20),
                                           style=0, name='data_min_tcl')
        self.data_min_tcl.SetToolTipString("The minimum value of q range.")
        data_max_txt = wx.StaticText(self, -1, 'Max : ')
        self.data_max_tcl = OutputTextCtrl(self, -1, size=(_BOX_WIDTH, 20),
                                           style=0, name='data_max_tcl')
        self.data_max_tcl.SetToolTipString("The maximum value of q range.")
        self.data_range_sizer.AddMany([(data_range_txt, 0, wx.RIGHT, 5),
                                       (data_min_txt, 0, wx.RIGHT, 5),
                                       (self.data_min_tcl, 0, wx.RIGHT, 20),
                                       (data_max_txt, 0, wx.RIGHT, 5),
                                       (self.data_max_tcl, 0, wx.RIGHT, 10)])
        self.data_name_boxsizer.AddMany([(self.hint_msg_sizer, 0, wx.ALL, 5),
                                         (self.data_name_sizer, 0, wx.ALL, 10),
                                         (self.data_range_sizer, 0, wx.ALL, 10)])

    def _enable_fit_power_law_low(self, event=None):
        """
        Enable and disable the power value editing
        """
        if event != None:
            self._set_bookmark_flag(True)
            self._set_preview_flag(False)

        if self.fix_enable_low.IsEnabled():

            if self.fix_enable_low.GetValue():
                self.fit_enable_low.SetValue(False)
                self.power_low_tcl.Enable()
            else:
                self.fit_enable_low.SetValue(True)
                self.power_low_tcl.Disable()
        self._set_state(event=event)

    def _enable_low_q_section(self, event=None):
        """
        Disable or enable some button if the user enable low q extrapolation
        """
        if event != None:
            self._set_bookmark_flag(True)
            self._set_preview_flag(False)

        if self.enable_low_cbox.GetValue():
            self.npts_low_tcl.Enable()
            self.fix_enable_low.Enable()
            self.fit_enable_low.Enable()
            self.guinier.Enable()
            self.power_law_low.Enable()

        else:
            self.npts_low_tcl.Disable()
            self.fix_enable_low.Disable()
            self.fit_enable_low.Disable()
            self.guinier.Disable()
            self.power_law_low.Disable()

        self._enable_power_law_low()
        self._enable_fit_power_law_low()
        self._set_state(event=event)
        self.button_calculate.SetFocus()

    def _enable_power_law_low(self, event=None):
        """
        Enable editing power law section at low q range
        """
        if event != None:
            self._set_bookmark_flag(True)
            self._set_preview_flag(False)
        if self.guinier.GetValue():
            self.power_law_low.SetValue(False)
            self.fix_enable_low.Disable()
            self.fit_enable_low.Disable()
            self.power_low_tcl.Disable()
        else:
            self.power_law_low.SetValue(True)
            self.fix_enable_low.Enable()
            self.fit_enable_low.Enable()
            self.power_low_tcl.Enable()
        self._enable_fit_power_law_low()
        self._set_state(event=event)

    def _layout_extrapolation_low(self):
        """
        Draw widgets related to extrapolation at low q range
        """
        self.enable_low_cbox = wx.CheckBox(self, -1,
                                           "Enable Extrapolate Low Q",
                                           name='enable_low_cbox')
        wx.EVT_CHECKBOX(self, self.enable_low_cbox.GetId(),
                        self._enable_low_q_section)
        self.fix_enable_low = wx.RadioButton(self, -1, 'Fix',
                                             (10, 10), style=wx.RB_GROUP,
                                             name='fix_enable_low')
        self.Bind(wx.EVT_RADIOBUTTON, self._enable_fit_power_law_low,
                  id=self.fix_enable_low.GetId())
        self.fit_enable_low = wx.RadioButton(self, -1, 'Fit', (10, 10),
                                             name='fit_enable_low')
        self.Bind(wx.EVT_RADIOBUTTON, self._enable_fit_power_law_low,
                  id=self.fit_enable_low.GetId())
        self.guinier = wx.RadioButton(self, -1, 'Guinier',
                                      (10, 10), style=wx.RB_GROUP,
                                      name='guinier')
        self.Bind(wx.EVT_RADIOBUTTON, self._enable_power_law_low,
                  id=self.guinier.GetId())
        self.power_law_low = wx.RadioButton(self, -1, 'Power Law',
                                            (10, 10), name='power_law_low')
        self.Bind(wx.EVT_RADIOBUTTON, self._enable_power_law_low,
                  id=self.power_law_low.GetId())

        npts_low_txt = wx.StaticText(self, -1, 'Npts')
        self.npts_low_tcl = InvTextCtrl(self, -1,
                                        size=(_BOX_WIDTH * 2 / 3, -1),
                                        name='npts_low_tcl')
        wx.EVT_TEXT(self, self.npts_low_tcl.GetId(), self._on_text)
        msg_hint = "Number of Q points to consider"
        msg_hint += "while extrapolating the low-Q region"
        self.npts_low_tcl.SetToolTipString(msg_hint)
        power_txt = wx.StaticText(self, -1, 'Power')
        self.power_low_tcl = InvTextCtrl(self, -1, size=(_BOX_WIDTH * 2 / 3, -1),
                                         name='power_low_tcl')
        wx.EVT_TEXT(self, self.power_low_tcl.GetId(), self._on_text)

        power_hint_txt = "Exponent to apply to the Power_law function."
        self.power_low_tcl.SetToolTipString(power_hint_txt)
        iy = 0
        ix = 0
        self.low_q_sizer.Add(self.enable_low_cbox, (iy, ix), (1, 5),
                             wx.TOP | wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        iy += 1
        ix = 0
        self.low_q_sizer.Add(npts_low_txt, (iy, ix), (1, 1),
                             wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        ix += 1
        self.low_q_sizer.Add(self.npts_low_tcl, (iy, ix), (1, 1),
                             wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        iy += 1
        ix = 0
        self.low_q_sizer.Add(self.guinier, (iy, ix), (1, 2),
                             wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        iy += 1
        ix = 0
        self.low_q_sizer.Add(self.power_law_low, (iy, ix), (1, 2),
                             wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        # Parameter controls for power law
        ix = 1
        iy += 1
        self.low_q_sizer.Add(self.fix_enable_low, (iy, ix), (1, 1),
                             wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        ix += 1
        self.low_q_sizer.Add(self.fit_enable_low, (iy, ix), (1, 1),
                             wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        ix = 1
        iy += 1
        self.low_q_sizer.Add(power_txt, (iy, ix), (1, 1),
                             wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        ix += 1
        self.low_q_sizer.Add(self.power_low_tcl, (iy, ix), (1, 1),
                             wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        self.low_extrapolation_sizer.Add(self.low_q_sizer)

    def _enable_fit_power_law_high(self, event=None):
        """
        Enable and disable the power value editing
        """
        if event != None:
            self._set_bookmark_flag(True)

            self._set_preview_flag(False)
        if self.fix_enable_high.IsEnabled():
            if self.fix_enable_high.GetValue():
                self.fit_enable_high.SetValue(False)
                self.power_high_tcl.Enable()
            else:
                self.fit_enable_high.SetValue(True)
                self.power_high_tcl.Disable()
        self._set_state(event=event)

    def _enable_high_q_section(self, event=None):
        """
        Disable or enable some button if the user enable high q extrapolation
        """
        if event != None:
            self._set_bookmark_flag(True)
            self._set_preview_flag(False)
        if self.enable_high_cbox.GetValue():
            self.npts_high_tcl.Enable()
            self.power_law_high.Enable()
            self.power_high_tcl.Enable()
            self.fix_enable_high.Enable()
            self.fit_enable_high.Enable()
        else:
            self.npts_high_tcl.Disable()
            self.power_law_high.Disable()
            self.power_high_tcl.Disable()
            self.fix_enable_high.Disable()
            self.fit_enable_high.Disable()
        self._enable_fit_power_law_high()
        self._set_state(event=event)
        self.button_calculate.SetFocus()

    def _layout_extrapolation_high(self):
        """
        Draw widgets related to extrapolation at high q range
        """
        self.enable_high_cbox = wx.CheckBox(self, -1,
                                            "Enable Extrapolate high-Q",
                                            name='enable_high_cbox')
        wx.EVT_CHECKBOX(self, self.enable_high_cbox.GetId(),
                        self._enable_high_q_section)
        self.fix_enable_high = wx.RadioButton(self, -1, 'Fix',
                                              (10, 10), style=wx.RB_GROUP,
                                              name='fix_enable_high')
        self.Bind(wx.EVT_RADIOBUTTON, self._enable_fit_power_law_high,
                  id=self.fix_enable_high.GetId())
        self.fit_enable_high = wx.RadioButton(self, -1, 'Fit', (10, 10),
                                              name='fit_enable_high')
        self.Bind(wx.EVT_RADIOBUTTON, self._enable_fit_power_law_high,
                  id=self.fit_enable_high.GetId())

        self.power_law_high = wx.StaticText(self, -1, 'Power Law')
        msg_hint = "Check to extrapolate data at high-Q"
        self.power_law_high.SetToolTipString(msg_hint)
        npts_high_txt = wx.StaticText(self, -1, 'Npts')
        self.npts_high_tcl = InvTextCtrl(self, -1, size=(_BOX_WIDTH * 2 / 3, -1),
                                         name='npts_high_tcl')
        wx.EVT_TEXT(self, self.npts_high_tcl.GetId(), self._on_text)
        msg_hint = "Number of Q points to consider"
        msg_hint += "while extrapolating the high-Q region"
        self.npts_high_tcl.SetToolTipString(msg_hint)
        power_txt = wx.StaticText(self, -1, 'Power')
        self.power_high_tcl = InvTextCtrl(self, -1, size=(_BOX_WIDTH * 2 / 3, -1),
                                          name='power_high_tcl')
        wx.EVT_TEXT(self, self.power_high_tcl.GetId(), self._on_text)
        power_hint_txt = "Exponent to apply to the Power_law function."
        self.power_high_tcl.SetToolTipString(power_hint_txt)
        iy = 0
        ix = 0
        self.high_q_sizer.Add(self.enable_high_cbox, (iy, ix), (1, 5),
                              wx.TOP | wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        iy += 1
        ix = 0
        self.high_q_sizer.Add(npts_high_txt, (iy, ix), (1, 1),
                              wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        ix += 1
        self.high_q_sizer.Add(self.npts_high_tcl, (iy, ix), (1, 1),
                              wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        iy += 1
        ix = 0
        self.high_q_sizer.Add(self.power_law_high, (iy, ix), (1, 2),
                              wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)

        # Parameter controls for power law
        ix = 1
        iy += 1
        self.high_q_sizer.Add(self.fix_enable_high, (iy, ix), (1, 1),
                              wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        ix += 1
        self.high_q_sizer.Add(self.fit_enable_high, (iy, ix), (1, 1),
                              wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        ix = 1
        iy += 1
        self.high_q_sizer.Add(power_txt, (iy, ix), (1, 1),
                              wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        ix += 1
        self.high_q_sizer.Add(self.power_high_tcl, (iy, ix), (1, 1),
                              wx.EXPAND | wx.ADJUST_MINSIZE, 0)
        self.high_extrapolation_sizer.Add(self.high_q_sizer, 0,
                                          wx.BOTTOM, 20)

    def _layout_extrapolation(self):
        """
        Draw widgets related to extrapolation
        """
        extra_hint = "Extrapolation \nMaximum Q Range [1/A]:"
        extra_hint_txt = wx.StaticText(self, -1, extra_hint)
        #Extrapolation range [string]
        extrapolation_min_txt = wx.StaticText(self, -1, 'Min:')
        self.extrapolation_min_tcl = OutputTextCtrl(self, -1,
                                                    size=(_BOX_WIDTH, 20), style=0,
                                                    name='extrapolation_min_tcl')
        self.extrapolation_min_tcl.SetValue(str(Q_MINIMUM))
        hint_msg = "The minimum extrapolated q value."
        self.extrapolation_min_tcl.SetToolTipString(hint_msg)
        extrapolation_max_txt = wx.StaticText(self, -1, 'Max:')
        self.extrapolation_max_tcl = OutputTextCtrl(self, -1,
                                                    size=(_BOX_WIDTH, 20),
                                                    style=0,
                                                    name='extrapolation_max_tcl')
        self.extrapolation_max_tcl.SetValue(str(Q_MAXIMUM))
        hint_msg = "The maximum extrapolated q value."
        self.extrapolation_max_tcl.SetToolTipString(hint_msg)
        self.extrapolation_range_sizer.AddMany([(extra_hint_txt, 0,
                                                 wx.LEFT, 5),
                                                (extrapolation_min_txt, 0,
                                                 wx.LEFT, 10),
                                                (self.extrapolation_min_tcl,
                                                 0, wx.LEFT, 5),
                                                (extrapolation_max_txt, 0,
                                                 wx.LEFT, 20),
                                                (self.extrapolation_max_tcl,
                                                 0, wx.LEFT, 5)])
        self._layout_extrapolation_low()
        self._layout_extrapolation_high()
        self.extrapolation_low_high_sizer.AddMany([(self.low_extrapolation_sizer,
                                                    0, wx.LEFT | wx.BOTTOM | wx.TOP, 5),
                                                   (self.high_extrapolation_sizer,
                                                    0, wx.LEFT | wx.BOTTOM | wx.TOP, 5)])
        self.extrapolation_sizer.AddMany([(self.extrapolation_range_sizer),
                                          (self.extrapolation_low_high_sizer)])

    def _layout_volume_surface_sizer(self):
        """
        Draw widgets related to volume and surface
        """
        unit_volume = ''
        unit_surface = '[1/A]'
        uncertainty = "+/-"
        volume_txt = wx.StaticText(self, -1, 'Volume Fraction')
        self.volume_tcl = OutputTextCtrl(self, -1, size=(_BOX_WIDTH, -1),
                                         name='volume_tcl')
        wx.EVT_TEXT(self, self.volume_tcl.GetId(), self._on_out_text)
        self.volume_tcl.SetToolTipString("Volume fraction.")
        self.volume_err_tcl = OutputTextCtrl(self, -1, size=(_BOX_WIDTH, -1),
                                             name='volume_err_tcl')
        wx.EVT_TEXT(self, self.volume_err_tcl.GetId(), self._on_out_text)
        hint_msg = "Uncertainty on the volume fraction."
        self.volume_err_tcl.SetToolTipString(hint_msg)
        volume_units_txt = wx.StaticText(self, -1, unit_volume)

        surface_txt = wx.StaticText(self, -1, 'Specific Surface')
        self.surface_tcl = OutputTextCtrl(self, -1, size=(_BOX_WIDTH, -1),
                                          name='surface_tcl')
        wx.EVT_TEXT(self, self.surface_tcl.GetId(), self._on_out_text)
        self.surface_tcl.SetToolTipString("Specific surface value.")
        self.surface_err_tcl = OutputTextCtrl(self, -1, size=(_BOX_WIDTH, -1),
                                              name='surface_err_tcl')
        wx.EVT_TEXT(self, self.surface_err_tcl.GetId(), self._on_out_text)
        hint_msg = "Uncertainty on the specific surface."
        self.surface_err_tcl.SetToolTipString(hint_msg)
        surface_units_txt = wx.StaticText(self, -1, unit_surface)
        iy = 0
        ix = 0
        self.volume_surface_sizer.Add(volume_txt, (iy, ix), (1, 1),
                                      wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        ix += 1
        self.volume_surface_sizer.Add(self.volume_tcl, (iy, ix), (1, 1),
                                      wx.EXPAND | wx.ADJUST_MINSIZE, 20)
        ix += 1
        self.volume_surface_sizer.Add(wx.StaticText(self, -1, uncertainty),
                                      (iy, ix), (1, 1), wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        ix += 1
        self.volume_surface_sizer.Add(self.volume_err_tcl, (iy, ix), (1, 1),
                                      wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        ix += 1
        self.volume_surface_sizer.Add(volume_units_txt, (iy, ix), (1, 1),
                                      wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        iy += 1
        ix = 0
        self.volume_surface_sizer.Add(surface_txt, (iy, ix), (1, 1),
                                      wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        ix += 1
        self.volume_surface_sizer.Add(self.surface_tcl, (iy, ix), (1, 1),
                                      wx.EXPAND | wx.ADJUST_MINSIZE, 20)
        ix += 1
        self.volume_surface_sizer.Add(wx.StaticText(self, -1, uncertainty),
                                      (iy, ix), (1, 1), wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        ix += 1
        self.volume_surface_sizer.Add(self.surface_err_tcl, (iy, ix), (1, 1),
                                      wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        ix += 1
        self.volume_surface_sizer.Add(surface_units_txt, (iy, ix), (1, 1),
                                      wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        static_line = wx.StaticLine(self, -1)
        iy += 1
        ix = 0

    def _layout_invariant_sizer(self):
        """
        Draw widgets related to invariant
        """
        uncertainty = "+/-"
        unit_invariant = '[1/(cm*A^3)]'
        invariant_total_txt = wx.StaticText(self, -1, 'Invariant Total [Q*]')
        self.invariant_total_tcl = OutputTextCtrl(self, -1,
                                                  size=(_BOX_WIDTH, -1),
                                                  name='invariant_total_tcl')
        msg_hint = "Total invariant [Q*], including extrapolated regions."
        self.invariant_total_tcl.SetToolTipString(msg_hint)
        self.invariant_total_err_tcl = OutputTextCtrl(self, -1,
                                                      size=(_BOX_WIDTH, -1),
                                                      name='invariant_total_err_tcl')
        hint_msg = "Uncertainty on invariant."
        self.invariant_total_err_tcl.SetToolTipString(hint_msg)
        invariant_total_units_txt = wx.StaticText(self, -1, unit_invariant,
                                                  size=(80, -1))

        #Invariant total
        iy = 0
        ix = 0
        self.invariant_sizer.Add(invariant_total_txt, (iy, ix), (1, 1),
                                 wx.LEFT | wx.EXPAND | wx.ADJUST_MINSIZE, 15)
        ix += 1
        self.invariant_sizer.Add(self.invariant_total_tcl, (iy, ix), (1, 1),
                                 wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        ix += 1
        self.invariant_sizer.Add(wx.StaticText(self, -1, uncertainty),
                                 (iy, ix), (1, 1), wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        ix += 1
        self.invariant_sizer.Add(self.invariant_total_err_tcl, (iy, ix), (1, 1),
                                 wx.EXPAND | wx.ADJUST_MINSIZE, 10)
        ix += 1
        self.invariant_sizer.Add(invariant_total_units_txt, (iy, ix), (1, 1),
                                 wx.EXPAND | wx.ADJUST_MINSIZE, 10)

    def _layout_inputs_sizer(self):
        """
        Draw widgets related to inputs
        """
        contrast_txt = wx.StaticText(self, -1, 'Contrast:')
        self.contrast_tcl = InvTextCtrl(self, -1, size=(_BOX_WIDTH, 20),
                                        style=0, name='contrast_tcl')
        wx.EVT_TEXT(self, self.contrast_tcl.GetId(), self._on_text)
        contrast_hint_txt = "Contrast"
        self.contrast_tcl.SetToolTipString(contrast_hint_txt)
        contrast_unit_txt = wx.StaticText(self, -1, '[1/A^2]', size=(40, -1))
        porod_const_txt = wx.StaticText(self, -1,
                                        'Porod\nConstant:\n(optional)\n')
        porod_unit_txt = wx.StaticText(self, -1, '[1/(cm*A^4)]', size=(80, -1))
        self.porod_constant_tcl = InvTextCtrl(self, -1,
                                              size=(_BOX_WIDTH, 20), style=0,
                                              name='porod_constant_tcl')
        wx.EVT_TEXT(self, self.porod_constant_tcl.GetId(), self._on_text)
        porod_const_hint_txt = "Porod Constant"
        self.porod_constant_tcl.SetToolTipString(porod_const_hint_txt)

        background_txt = wx.StaticText(self, -1, 'Background:')
        self.background_tcl = InvTextCtrl(self, -1, size=(_BOX_WIDTH, 20),
                                          style=0, name='background_tcl')
        wx.EVT_TEXT(self, self.background_tcl.GetId(), self._on_text)
        background_hint_txt = "Background"
        self.background_tcl.SetToolTipString(background_hint_txt)
        background_unit_txt = wx.StaticText(self, -1, '[1/cm]')
        scale_txt = wx.StaticText(self, -1, 'Scale:')
        self.scale_tcl = InvTextCtrl(self, -1, size=(_BOX_WIDTH, 20), style=0,
                                     name='scale_tcl')
        wx.EVT_TEXT(self, self.scale_tcl.GetId(), self._on_text)
        scale_hint_txt = "Scale"
        self.scale_tcl.SetToolTipString(scale_hint_txt)
        self.sizer_input.AddMany([(background_txt, 0, wx.LEFT | wx.BOTTOM, 5),
                                  (self.background_tcl, 0, wx.LEFT | wx.BOTTOM, 5),
                                  (background_unit_txt, 0, wx.LEFT | wx.BOTTOM, 5),
                                  (scale_txt, 0, wx.LEFT | wx.BOTTOM, 10),
                                  (self.scale_tcl, 0, wx.LEFT | wx.BOTTOM | wx.RIGHT, 5),
                                  (10, 10),
                                  (contrast_txt, 0, wx.LEFT | wx.BOTTOM, 5),
                                  (self.contrast_tcl, 0, wx.LEFT | wx.BOTTOM, 5),
                                  (contrast_unit_txt, 0, wx.LEFT | wx.BOTTOM, 5),
                                  (porod_const_txt, 0, wx.LEFT, 10),
                                  (self.porod_constant_tcl, 0, wx.LEFT | wx.BOTTOM | wx.RIGHT, 5),
                                  (porod_unit_txt, 0, wx.LEFT | wx.BOTTOM, 5)])
        self.inputs_sizer.Add(self.sizer_input)

    def _layout_outputs_sizer(self):
        """
        Draw widgets related to outputs
        """
        self._layout_volume_surface_sizer()
        self._layout_invariant_sizer()
        static_line = wx.StaticLine(self, -1)
        self.outputs_sizer.AddMany([(self.volume_surface_sizer,
                                     0, wx.TOP | wx.BOTTOM, 10),
                                    (static_line, 0, wx.EXPAND, 0),
                                    (self.invariant_sizer, 0, wx.TOP | wx.BOTTOM, 10)])
    def _layout_button(self):
        """
        Do the layout for the button widgets
        """
        #compute button
        id = wx.NewId()
        self.button_calculate = wx.Button(self, id, "Compute",
                                          name='compute_invariant')
        self.button_calculate.SetToolTipString("Compute invariant")
        self.Bind(wx.EVT_BUTTON, self.compute_invariant, id=id)
        #detail button
        id = wx.NewId()
        self.button_details = wx.Button(self, id, "Details?")
        hint_msg = "Get more details of computation such as fraction from extrapolation"
        self.button_details.SetToolTipString(hint_msg)
        self.Bind(wx.EVT_BUTTON, self.display_details, id=id)
        #help button
        id = wx.NewId()
        self.button_help = wx.Button(self, id, "HELP")
        self.button_help.SetToolTipString("Invariant Documentation")
        self.Bind(wx.EVT_BUTTON, self.on_help, id=id)
        self.button_sizer.AddMany([((20, 20), 1, wx.EXPAND | wx.ADJUST_MINSIZE, 0),
                                   (self.button_details, 0, wx.ALL, 10),
                                   (self.button_calculate, 0,
                                    wx.RIGHT | wx.TOP | wx.BOTTOM, 10),
                                   (self.button_help, 0, 
                                    wx.RIGHT | wx.TOP | wx.BOTTOM, 10),])
    def _do_layout(self):
        """
        Draw window content
        """
        self._define_structure()
        self._layout_data_name()
        self._layout_extrapolation()
        self._layout_inputs_sizer()
        self._layout_outputs_sizer()
        self._layout_button()
        self.main_sizer.AddMany([(self.data_name_boxsizer, 0, wx.ALL, 10),
                                 (self.outputs_sizer, 0,
                                  wx.LEFT | wx.RIGHT | wx.BOTTOM, 10),
                                 (self.button_sizer, 0, wx.LEFT | wx.RIGHT, 15),
                                 (self.inputs_sizer, 0,
                                  wx.LEFT | wx.RIGHT | wx.BOTTOM, 10),
                                 (self.extrapolation_sizer, 0,
                                  wx.LEFT | wx.RIGHT | wx.BOTTOM, 10)])
        self.SetSizer(self.main_sizer)
        self.SetAutoLayout(True)
        
    def on_help(self, event):
        """
        Bring up the Invariant Documentation whenever the HELP button is 
        clicked.

        Calls DocumentationWindow with the path of the location within the
        documentation tree (after /doc/ ....".  Note that when using old
        versions of Wx (before 2.9) and thus not the release version of
        installers, the help comes up at the top level of the file as
        webbrowser does not pass anything past the # to the browser when it is
        running "file:///...."

    :param evt: Triggers on clicking the help button
    """

        _TreeLocation = "user/perspectives/invariant/invariant_help.html"
        _doc_viewer = DocumentationWindow(self, -1, _TreeLocation, "",
                                          "Invariant Help")


class InvariantDialog(wx.Dialog):
    """
    Invariant Dialog
    """
    def __init__(self, parent=None, id=1, graph=None,
                 data=None, title="Invariant", base=None):
        wx.Dialog.__init__(self, parent, id, title, size=(PANEL_WIDTH,
                                                          PANEL_HEIGHT))
        self.panel = InvariantPanel(self)
        self.Centre()
        self.Show(True)

class InvariantWindow(wx.Frame):
    """
    Invariant Window
    """
    def __init__(self, parent=None, id=1, graph=None,
                 data=None, title="Invariant", base=None):

        wx.Frame.__init__(self, parent, id, title, size=(PANEL_WIDTH + 100,
                                                         PANEL_HEIGHT + 100))
        from sas.dataloader.loader import  Loader
        self.loader = Loader()
        path = "C:/ECLPS/workspace/trunk/sasdataloader/test/ascii_test_3.txt"
        data = self.loader.load(path)
        self.panel = InvariantPanel(self)

        data.name = data.filename
        self.panel.set_data(data)
        self.Centre()
        self.Show(True)

class MyApp(wx.App):
    """
    Test App
    """
    def OnInit(self):
        """
        Init
        """
        wx.InitAllImageHandlers()
        frame = InvariantWindow()
        frame.Show(True)
        self.SetTopWindow(frame)

        return True

# end of class MyApp

if __name__ == "__main__":
    app = MyApp(0)
    app.MainLoop()