exception_viewer.py

# Exception Test
import sys
import traceback
from collections import namedtuple
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *

def connect(signal, slot):
    signal.connect(slot)

class ConsoleFunctions:
    """Functions to be used in console for convience"""

    @staticmethod
    def clear():
        """Clears console"""
        #_app_.processEvents()
        _exceptConsole_.clearExceptions()
        #_app_.processEvents()

    @staticmethod
    def show():
        """Shows console"""
        _exceptConsole_.show()
        _exceptConsole_.raise_()
        #_app_.processEvents()
    
    @staticmethod
    def hide():
        """Hides console"""
        _exceptConsole_.hide()
        #_app_.processEvents()
    
    @staticmethod
    def doc(object):
        """Prints docstring of object
        for now just prints to console.
        TODO: make a widget that displays docstring"""
        color = '\033[36m'
        endColor = '\033[0m'
        print(color + str(object.__doc__) + endColor)


class ViewerWidget(QWidget):
    """Viewer widget that displays exception detailed
    information preformatted and with convience set methods.
    
       Expected to show format:
    label -> title text like: str(cls.__name__)+': '+str(err)
    textBrowser -> shows traceback text
    
    """
    def __init__(self, parent=None):
        super(ViewerWidget, self).__init__(parent)
        
        # Declare and intilize component widgets
        self.label = QLabel()
        self.textBrowser = QTextBrowser()
        
        # Configure component widgets
        font = self.label.font()
        font.setPointSize(15)
        self.label.setFont(font)
        self.label.setWordWrap(True)
        
        # Configure layout
        self.layout = QVBoxLayout()
        self.layout.addWidget(self.label)
        self.layout.addWidget(self.textBrowser)
        self.setLayout(self.layout)
    
    def setText(self, title='', body=''):
        self.label.setText(title)
        self.textBrowser.setText(body)
    
    def clear(self):
        """Convience method"""
        self.setText()
        

class ExceptionWindow(QMainWindow):
    """Exception console to be used in Interactive Environment.
    Used in conjunction with custom except hook in startup file,
    where except hook calls addException to add and exception
    to the listWidget, and user can viewer each one of these
    in for more detail instead of traceback filling up entire
    dam output.
    (excepthook will print atleast exception type and error
    in console)"""
    ExceptionDataRole = Qt.UserRole + 1
    ExceptionData = namedtuple('ExceptionData', ['cls', 'err', 'tb'])
    #ExceptionClsRole = Qt.UserRole + 1
    #ExceptionErrRole = Qt.UserRole + 2
    #xceptionTbRole  = Qt.UserRole + 3
    
    def __init__(self, parent=None):
        super(ExceptionWindow, self).__init__(parent)
        self.setWindowTitle("Exception Console")
        self.setUnifiedTitleAndToolBarOnMac(True)
        
        # Declare and initilze component widgets
        self.listWidget = QListWidget()
        self.viewerWidget = ViewerWidget()
        self.toolbar = QToolBar()
        
        ## Actions
        self.actionClear = QAction("Clear", self)
        self.actionClear.triggered.connect(self.clearExceptions)
        #TODO: add behavior for clear enabled/disabled handling
        #      (make another connection from currentItemChanged to handling method)
        #      (and if set based on if current item is None or not)
        #TODO: add checkable toolbar action for always show on top
        
        #TODO: fix splitter resize handling
        #TODO: fix margin on listWidget and containter
        #TODO: add title or placeholder label when viewer is empty
        
        # Configure component widgets
        self.toolbar.setMovable(False)
        self.toolbar.setFloatable(False)
        self.toolbar.addAction(self.actionClear)
        self.addToolBar(self.toolbar)

        self.listWidget.setAttribute(Qt.WA_MacShowFocusRect, False)
        ##
        
        # Configure layout
        self.splitter = QSplitter()
        self.splitter.addWidget(self.listWidget)
        self.splitter.addWidget(self.viewerWidget)
        self.setCentralWidget(self.splitter)
        
        # Make Connections
        connect(self.listWidget.currentItemChanged, self.showCurrentItem)
        
        # Aditional config + logic setup
        self.tbReverse = True
        self.counter = 1
        
    def addException(self, cls, err, tb):
        errorMessage = str(self.counter)+' '+cls+': '+err
        exceptionData = ExceptionWindow.ExceptionData(cls, err, tb)
        
        item = QListWidgetItem(errorMessage)
        item.setData(ExceptionWindow.ExceptionDataRole, exceptionData)
        
        self.listWidget.insertItem(0, item)
        #self.listWidget.scrollToItem(item)
        self.listWidget.setCurrentItem(item)
        self.counter += 1 # increament after added
        
    def clearExceptions(self):
        self.listWidget.clear()
        self.counter = 1
        
    def showCurrentItem(self, current, previous):
        if current is None:
            # Set self.textBrowser text to '' ''
            self.viewerWidget.clear()
        else:
            # Get the current item's data
            exceptionData = current.data(ExceptionWindow.ExceptionDataRole)
            titleText = exceptionData.cls+': '+exceptionData.err
            tb = list(exceptionData.tb)
            if self.tbReverse is True:
                tb.reverse()
            bodyText = "".join(tb)
            
            # Then set the new text of the viewerWidget
            self.viewerWidget.setText(titleText, bodyText)
    
    def excepthook(self, cls, err, tb):
        CLS = str(cls.__name__)
        ERR = str(err)
        TBLIST = list(traceback.format_tb(tb))
        # print minimal error code for console
        print('\033[91m'+CLS+'\033[0m: \033[92m'+ERR+'\033[0m')
        
        self.addException(CLS, ERR, TBLIST)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    _app_ = app # save originals incase user modifies
    exceptConsole = ExceptionWindow()
    _exceptConsole_ = exceptConsole # save originals
    exceptConsole.show()
    exceptConsole.raise_()
    
    # Provide name console functions
    clear = ConsoleFunctions.clear
    show = ConsoleFunctions.show
    hide = ConsoleFunctions.hide
    doc = ConsoleFunctions.doc
    
    #TODO: ps Colors might be breaking previous command up arrow
    #sys.ps1 = '\033[92m>>> \033[0m'
    #sys.ps2 = '\033[42m   \033[0m '

    sys.excepthook = exceptConsole.excepthook
    
    print('Try making exceptions and testing console.')
    print("Traceback for exceptions will appear in the 'exceptConsole'")
    print('TODO: add clear button in console')
    