Source code for validators

'''
Validators

by Patrick Ruoff in 2012
'''

from transfer import CTransfer

import wx


class CValidator(wx.PyValidator):
    """ Generic validator, mediates between dialog_data and the associated control """
    
    dialog_data = None;
    
    def __init__(self, dialog_data = None):
        super(CValidator, self).__init__();
        self.dialog_data = dialog_data;
        
    def SetData(self, dialog_data):
        self.dialog_data = dialog_data;
        
    # PyValidator functions
    def Clone(self):
        return CValidator(self.dialog_data);

    def Validate(self, win):
        return True
    
    def TransferToWindow(self):
        return True
    
    def TransferFromWindow(self):
        return True
    
    # utility functions
    def GetCtrlValueAs(self, t):
        """ Tries to interpret the control's value as type *t* """
        ctrl = self.GetWindow();
        if issubclass(type(ctrl), wx.TextCtrl) or \
           issubclass(type(ctrl), wx.Slider)   or \
           issubclass(type(ctrl), wx.SpinCtrl) or \
           issubclass(type(ctrl), wx.CheckBox):
            return t(ctrl.GetValue());
        elif issubclass(type(ctrl), wx.ControlWithItems):
            return t(ctrl.GetSelection());
        elif issubclass(type(ctrl), wx.RadioBox):
            return t(ctrl.GetSelection());
        
    def SetCtrlValue(self, value):
        """ Tries to set the control's value to *value* """
        ctrl = self.GetWindow(); 
        if issubclass(type(ctrl), wx.Slider) or \
           issubclass(type(ctrl), wx.SpinCtrl):
            ctrl.SetValue(int(value));
        elif issubclass(type(ctrl), wx.TextCtrl):
            ctrl.SetValue(str(value));
        elif issubclass(type(ctrl), wx.ControlWithItems):
            ctrl.SetSelection(int(value));
        elif issubclass(type(ctrl), wx.CheckBox):
            ctrl.SetValue(bool(value));
    
    def ShowError(self, error_string):
        """ Indicate an error, try to present *error_string* to the user """
        ctrl = self.GetWindow();
        ctrl.SetToolTipString(error_string);
        if issubclass(type(ctrl), wx.TextCtrl) or \
           issubclass(type(ctrl), wx.SpinCtrl):
            ctrl.SetBackgroundColour("pink");
        ctrl.SetFocus();
        ctrl.Refresh();
        
    def ResetError(self):  
        """ Reset error status """
        ctrl = self.GetWindow();          
        ctrl.SetToolTipString("");
        if issubclass(type(ctrl), wx.TextCtrl) or \
           issubclass(type(ctrl), wx.SpinCtrl):
            ctrl.SetBackgroundColour(wx.SystemSettings_GetColour(wx.SYS_COLOUR_WINDOW));
        ctrl.Refresh();


class CSingleItemValidator(CValidator):
    """ Validator that mediates between the control and a single data item by using transfer functions """
    
    data_item_key = None;
    transfer = None;
    
    def __init__(self, data_item_key, transfer = None, dialog_data = None):
        """ Use the transfer function *transfer* to mediate between the data item at *data_item_key* 
        and the control's value """
        super(CSingleItemValidator, self).__init__(dialog_data);
        self.data_item_key = data_item_key;
        if transfer == None:
            self.transfer = CTransfer();
        else:
            self.transfer = transfer;
            
    def SetTransfer(self, transfer):
        self.transfer = transfer;         
        
    def Clone(self):
        return CSingleItemValidator(self.data_item_key, self.transfer, self.dialog_data);
    
    def TransferToWindow(self):
        try:
            self.SetCtrlValue(self.transfer.ToWindow(self.dialog_data, self.data_item_key));
        except:
            return False;
        return True;
        
    def TransferFromWindow(self):
        data_type = type(self.dialog_data[self.data_item_key]);
        try:
            cval = self.GetCtrlValueAs(data_type);
        except:
            self.ShowError("Cannot parse entered value as "+str(data_type));
            return False;
        
        ret = self.transfer.FromWindow(self.dialog_data, self.data_item_key ,cval);
        if ret:            
            self.ResetError();
        else:
            self.ShowError("Entered value did not respect the constraints")
        return ret;