# Source code for pyqtgraph.console.Console

    import importlib
    import pickle
    import re
    import subprocess
    import sys
    import traceback

    from .. import exceptionHandling as exceptionHandling
    from .. import getConfigOption
    from ..functions import SignalBlock
    from ..Qt import QT_LIB, QtCore, QtGui, QtWidgets

    ui_template = importlib.import_module(
        f'.template_{QT_LIB.lower()}', package=__package__)

    class ConsoleWidget(QtWidgets.QWidget):
        """
        Widget displaying console output and accepting command input.
        Implements:

          - eval python expressions / exec python statements
          - storable history of commands
          - exception handling allowing commands to be interpreted in the context of any level in the exception stack frame

        Why not just use python in an interactive shell (or ipython) ? There are a few reasons:

          - pyside does not yet allow Qt event processing and interactive shell at the same time
          - on some systems, typing in the console _blocks_ the qt event loop until the user presses enter. This can
            be baffling and frustrating to users since it would appear the program has frozen.
          - some terminals (eg windows cmd.exe) have notoriously unfriendly interfaces
          - ability to add extra features like exception stack introspection
          - ability to have multiple interactive prompts, including for spawned sub-processes
        """
        _threadException = QtCore.Signal(object)

        def __init__(self, parent=None, namespace=None, historyFile=None, text=None, editor=None):
            """
            ==============  ============================================================================
            **Arguments:**
            namespace       dictionary containing the initial variables present in the default namespace
            historyFile     optional file for storing command history
            text            initial text to display in the console window
            editor          optional string for invoking code editor (called when stack trace entries are
                            double-clicked). May contain {fileName} and {lineNum} format keys. Example::

                                editorCommand --loadfile {fileName} --gotoline {lineNum}
            ==============  =============================================================================
            """
            QtWidgets.QWidget.__init__(self, parent)
            if namespace is None:
                namespace = {}
            namespace['__console__'] = self
            self.localNamespace = namespace
            self.editor = editor
            self.multiline = None
            self.inCmd = False
            self.frames = []  # stack frames to access when an item in the stack list is selected

            self.ui = ui_template.Ui_Form()
            self.ui.setupUi(self)
            self.output = self.ui.output
            self.input = self.ui.input
            self.input.setFocus()

            if text is not None:
                self.output.setPlainText(text)

            self.historyFile = historyFile

            history = self.loadHistory()
            if history is not None:
                self.input.history = [""] + history
                self.ui.historyList.addItems(history[::-1])
            self.ui.historyList.hide()
            self.ui.exceptionGroup.hide()

            self.input.sigExecuteCmd.connect(self.runCmd)
            self.ui.historyBtn.toggled.connect(self.ui.historyList.setVisible)
            self.ui.historyList.itemClicked.connect(self.cmdSelected)
            self.ui.historyList.itemDoubleClicked.connect(self.cmdDblClicked)
            self.ui.exceptionBtn.toggled.connect(self.ui.exceptionGroup.setVisible)

            self.ui.catchAllExceptionsBtn.toggled.connect(self.catchAllExceptions)
            self.ui.catchNextExceptionBtn.toggled.connect(self.catchNextException)
            self.ui.clearExceptionBtn.clicked.connect(self.clearExceptionClicked)
            self.ui.exceptionStackList.itemClicked.connect(self.stackItemClicked)
            self.ui.exceptionStackList.itemDoubleClicked.connect(self.stackItemDblClicked)
            self.ui.onlyUncaughtCheck.toggled.connect(self.updateSysTrace)

            self.currentTraceback = None

            # send exceptions raised in non-gui threads back to the main thread by signal.
            self._threadException.connect(self._threadExceptionHandler)

        def loadHistory(self):
            """Return the list of previously-invoked command strings (or None)."""
            if self.historyFile is not None:
                with open(self.historyFile, 'rb') as pf:
                    return pickle.load(pf)

        def saveHistory(self, history):
            """Store the list of previously-invoked command strings."""
            if self.historyFile is not None:
                with open(self.historyFile, 'wb') as pf:
                    pickle.dump(pf, history)

        def runCmd(self, cmd):
            #cmd = str(self.input.lastCmd)

            orig_stdout = sys.stdout
            orig_stderr = sys.stderr
            encCmd = re.sub(r'>', '&gt;', re.sub(r'<', '&lt;', cmd))
            encCmd = re.sub(r' ', '&nbsp;', encCmd)

            self.ui.historyList.addItem(cmd)
            self.saveHistory(self.input.history[1:100])

            try:
                sys.stdout = self
                sys.stderr = self
                if self.multiline is not None:
                    self.write("<br><b>%s</b>\n"%encCmd, html=True, scrollToBottom=True)
                    self.execMulti(cmd)
                else:
                    self.write("<br><div style='background-color: #CCF; color: black'><b>%s</b>\n"%encCmd, html=True, scrollToBottom=True)
                    self.inCmd = True
                    self.execSingle(cmd)

                if not self.inCmd:
                    self.write("</div>\n", html=True, scrollToBottom=True)

            finally:
                sys.stdout = orig_stdout
                sys.stderr = orig_stderr

                sb = self.ui.historyList.verticalScrollBar()
                sb.setValue(sb.maximum())

        def globals(self):
            frame = self.currentFrame()
            if frame is not None and self.ui.runSelectedFrameCheck.isChecked():
                return self.currentFrame().f_globals
            else:
                return self.localNamespace

        def locals(self):
            frame = self.currentFrame()
            if frame is not None and self.ui.runSelectedFrameCheck.isChecked():
                return self.currentFrame().f_locals
            else:
                return self.localNamespace

        def currentFrame(self):
            ## Return the currently selected exception stack frame (or None if there is no exception)
            index = self.ui.exceptionStackList.currentRow()
            if index >= 0 and index < len(self.frames):
                return self.frames[index]
            else:
                return None

        def execSingle(self, cmd):
            try:
                output = eval(cmd, self.globals(), self.locals())
                self.write(repr(output) + '\n')
                return
            except SyntaxError:
                pass
            except:
                self.displayException()
                return

            # eval failed with syntax error; try exec instead
            try:
                exec(cmd, self.globals(), self.locals())
            except SyntaxError as exc:
                if 'unexpected EOF' in exc.msg:
                    self.multiline = cmd
                else:
                    self.displayException()
            except:
                self.displayException()

        def execMulti(self, nextLine):
            if nextLine.strip() != '':
                self.multiline += "\n" + nextLine
                return
            else:
                cmd = self.multiline

            try:
                output = eval(cmd, self.globals(), self.locals())
                self.write(str(output) + '\n')
                self.multiline = None
                return
            except SyntaxError:
                pass
            except:
                self.displayException()
                self.multiline = None
                return

            # eval failed with syntax error; try exec instead
            try:
                exec(cmd, self.globals(), self.locals())
                self.multiline = None
            except SyntaxError as exc:
                if 'unexpected EOF' in exc.msg:
                    self.multiline = cmd
                else:
                    self.displayException()
                    self.multiline = None
            except:
                self.displayException()
                self.multiline = None

        def write(self, strn, html=False, scrollToBottom='auto'):
            """Write a string into the console.

            If scrollToBottom is 'auto', then the console is automatically scrolled
            to fit the new text only if it was already at the bottom.
            """
            isGuiThread = QtCore.QThread.currentThread() == QtCore.QCoreApplication.instance().thread()
            if not isGuiThread:
                sys.__stdout__.write(strn)
                return

            sb = self.output.verticalScrollBar()
            scroll = sb.value()
            if scrollToBottom == 'auto':
                atBottom = scroll == sb.maximum()
                scrollToBottom = atBottom

            self.output.moveCursor(QtGui.QTextCursor.MoveOperation.End)
            if html:
                self.output.textCursor().insertHtml(strn)
            else:
                if self.inCmd:
                    self.inCmd = False
                    self.output.textCursor().insertHtml("</div><br><div style='font-weight: normal; background-color: #FFF; color: black'>")
                self.output.insertPlainText(strn)

            if scrollToBottom:
                sb.setValue(sb.maximum())
            else:
                sb.setValue(scroll)

        def fileno(self):
            # Need to implement this since we temporarily occlude sys.stdout, and someone may be looking for it (faulthandler, for example)
            return 1

        def displayException(self):
            """
            Display the current exception and stack.
            """
            tb = traceback.format_exc()
            lines = []
            indent = 4
            prefix = ''
            for l in tb.split('\n'):
                lines.append(" "*indent + prefix + l)
            self.write('\n'.join(lines))
            self.exceptionHandler(*sys.exc_info())

        def cmdSelected(self, item):
            index = -(self.ui.historyList.row(item)+1)
            self.input.setHistory(index)
            self.input.setFocus()

        def cmdDblClicked(self, item):
            index = -(self.ui.historyList.row(item)+1)
            self.input.setHistory(index)
            self.input.execCmd()

        def flush(self):
            pass

        def catchAllExceptions(self, catch=True):
            """
            If True, the console will catch all unhandled exceptions and display the stack
            trace. Each exception caught clears the last.
            """
            with SignalBlock(self.ui.catchAllExceptionsBtn.toggled, self.catchAllExceptions):
                self.ui.catchAllExceptionsBtn.setChecked(catch)

            if catch:
                with SignalBlock(self.ui.catchNextExceptionBtn.toggled, self.catchNextException):
                    self.ui.catchNextExceptionBtn.setChecked(False)
                self.enableExceptionHandling()
                self.ui.exceptionBtn.setChecked(True)
            else:
                self.disableExceptionHandling()

        def catchNextException(self, catch=True):
            """
            If True, the console will catch the next unhandled exception and display the stack
            trace.
            """
            with SignalBlock(self.ui.catchNextExceptionBtn.toggled, self.catchNextException):
                self.ui.catchNextExceptionBtn.setChecked(catch)
            if catch:
                with SignalBlock(self.ui.catchAllExceptionsBtn.toggled, self.catchAllExceptions):
                    self.ui.catchAllExceptionsBtn.setChecked(False)
                self.enableExceptionHandling()
                self.ui.exceptionBtn.setChecked(True)
            else:
                self.disableExceptionHandling()

        def enableExceptionHandling(self):
            exceptionHandling.register(self.exceptionHandler)
            self.updateSysTrace()

        def disableExceptionHandling(self):
            exceptionHandling.unregister(self.exceptionHandler)
            self.updateSysTrace()

        def clearExceptionClicked(self):
            self.currentTraceback = None
            self.frames = []
            self.ui.exceptionInfoLabel.setText("[No current exception]")
            self.ui.exceptionStackList.clear()
            self.ui.clearExceptionBtn.setEnabled(False)

        def stackItemClicked(self, item):
            pass

        def stackItemDblClicked(self, item):
            editor = self.editor
            if editor is None:
                editor = getConfigOption('editorCommand')
            if editor is None:
                return
            tb = self.currentFrame()
            lineNum = tb.f_lineno
            fileName = tb.f_code.co_filename
            subprocess.Popen(self.editor.format(fileName=fileName, lineNum=lineNum), shell=True)

        def updateSysTrace(self):
            ## Install or uninstall  sys.settrace handler

            if not self.ui.catchNextExceptionBtn.isChecked() and not self.ui.catchAllExceptionsBtn.isChecked():
                if sys.gettrace() == self.systrace:
                    sys.settrace(None)
                return

            if self.ui.onlyUncaughtCheck.isChecked():
                if sys.gettrace() == self.systrace:
                    sys.settrace(None)
            else:
                if sys.gettrace() is not None and sys.gettrace() != self.systrace:
                    self.ui.onlyUncaughtCheck.setChecked(False)
                    raise Exception("sys.settrace is in use; cannot monitor for caught exceptions.")
                else:
                    sys.settrace(self.systrace)

        def exceptionHandler(self, excType, exc, tb, systrace=False, frame=None):
            if frame is None:
                frame = sys._getframe()

            # exceptions raised in non-gui threads must be handled separately
            isGuiThread = QtCore.QThread.currentThread() == QtCore.QCoreApplication.instance().thread()
            if not isGuiThread:
                # sending a frame from one thread to another.. probably not safe, but better than just
                # dropping the exception?
                self._threadException.emit((excType, exc, tb, systrace, frame.f_back))
                return

            if self.ui.catchNextExceptionBtn.isChecked():
                self.ui.catchNextExceptionBtn.setChecked(False)
            elif not self.ui.catchAllExceptionsBtn.isChecked():
                return

            self.currentTraceback = tb

            excMessage = ''.join(traceback.format_exception_only(excType, exc))
            self.ui.exceptionInfoLabel.setText(excMessage)

            if systrace:
                # exceptions caught using systrace don't need the usual
                # call stack + traceback handling
                self.setStack(frame.f_back.f_back)
            else:
                self.setStack(frame=frame.f_back, tb=tb)

        def _threadExceptionHandler(self, args):
            self.exceptionHandler(*args)

        def setStack(self, frame=None, tb=None):
            """Display a call stack and exception traceback.

            This allows the user to probe the contents of any frame in the given stack.

            *frame* may either be a Frame instance or None, in which case the current
            frame is retrieved from ``sys._getframe()``.

            If *tb* is provided then the frames in the traceback will be appended to
            the end of the stack list. If *tb* is None, then sys.exc_info() will
            be checked instead.
            """
            self.ui.clearExceptionBtn.setEnabled(True)

            if frame is None:
                frame = sys._getframe().f_back

            if tb is None:
                tb = sys.exc_info()[2]

            self.ui.exceptionStackList.clear()
            self.frames = []

            # Build stack up to this point
            for index, line in enumerate(traceback.extract_stack(frame)):
                # extract_stack return value changed in python 3.5
                if 'FrameSummary' in str(type(line)):
                    line = (line.filename, line.lineno, line.name, line._line)

                self.ui.exceptionStackList.addItem('File "%s", line %s, in %s()\n  %s' % line)
            while frame is not None:
                self.frames.insert(0, frame)
                frame = frame.f_back

            if tb is None:
                return

            self.ui.exceptionStackList.addItem('-- exception caught here: --')
            item = self.ui.exceptionStackList.item(self.ui.exceptionStackList.count()-1)
            item.setBackground(QtGui.QBrush(QtGui.QColor(200, 200, 200)))
            item.setForeground(QtGui.QBrush(QtGui.QColor(50, 50, 50)))
            self.frames.append(None)

            # And finish the rest of the stack up to the exception
            for index, line in enumerate(traceback.extract_tb(tb)):
                # extract_stack return value changed in python 3.5
                if 'FrameSummary' in str(type(line)):
                    line = (line.filename, line.lineno, line.name, line._line)

                self.ui.exceptionStackList.addItem('File "%s", line %s, in %s()\n  %s' % line)
            while tb is not None:
                self.frames.append(tb.tb_frame)
                tb = tb.tb_next

        def systrace(self, frame, event, arg):
            if event == 'exception' and self.checkException(*arg):
                self.exceptionHandler(*arg, systrace=True)
            return self.systrace

        def checkException(self, excType, exc, tb):
            ## Return True if the exception is interesting; False if it should be ignored.

            filename = tb.tb_frame.f_code.co_filename
            function = tb.tb_frame.f_code.co_name

            filterStr = str(self.ui.filterText.text())
            if filterStr != '':
                if isinstance(exc, Exception):
                    msg = traceback.format_exception_only(type(exc), exc)
                elif isinstance(exc, str):
                    msg = exc
                else:
                    msg = repr(exc)
                match = re.search(filterStr, "%s:%s:%s" % (filename, function, msg))
                return match is not None

            ## Go through a list of common exception points we like to ignore:
            if excType is GeneratorExit or excType is StopIteration:
                return False
            if excType is KeyError:
                if filename.endswith('python2.7/weakref.py') and function in ('__contains__', 'get'):
                    return False
                if filename.endswith('python2.7/copy.py') and function == '_keep_alive':
                    return False
            if excType is AttributeError:
                if filename.endswith('python2.7/collections.py') and function == '__init__':
                    return False
                if filename.endswith('numpy/core/fromnumeric.py') and function in ('all', '_wrapit', 'transpose', 'sum'):
                    return False
                if filename.endswith('numpy/core/arrayprint.py') and function in ('_array2string'):
                    return False
                if filename.endswith('MetaArray.py') and function == '__getattr__':
                    for name in ('__array_interface__', '__array_struct__', '__array__'):  ## numpy looks for these when converting objects to array
                        if name in exc:
                            return False
                if filename.endswith('flowchart/eq.py'):
                    return False
                if filename.endswith('pyqtgraph/functions.py') and function == 'makeQImage':
                    return False
            if excType is TypeError:
                if filename.endswith('numpy/lib/function_base.py') and function == 'iterable':
                    return False
            if excType is ZeroDivisionError:
                if filename.endswith('python2.7/traceback.py'):
                    return False

            return True