eric6/Preferences/HighlightingStylesFile.py

# -*- coding: utf-8 -*-

# Copyright (c) 2021 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a class representing the highlighting styles JSON file.
"""

import json
import time

from PyQt5.QtCore import QObject
from PyQt5.QtGui import QColor, QFont

from E5Gui import E5MessageBox
from E5Gui.E5OverrideCursor import E5OverridenCursor

import Preferences


class HighlightingStylesFile(QObject):
    """
    Class representing the highlighting styles JSON file.
    """
    def __init__(self, parent: QObject = None):
        """
        Constructor
        
        @param parent reference to the parent object (defaults to None)
        @type QObject (optional)
        """
        super(HighlightingStylesFile, self).__init__(parent)
    
    def writeFile(self, filename: str, lexers: list) -> bool:
        """
        Public method to write the highlighting styles data to a highlighting
        styles JSON file.
        
        @param filename name of the highlighting styles file
        @type str
        @param lexers list of lexers for which to export the styles
        @type list of PreferencesLexer
        @return flag indicating a successful write
        @rtype bool
        """
        stylesDict = {}
        # step 0: header
        stylesDict["header"] = {
            "comment": "eric highlighting styles file",
            "saved": time.strftime('%Y-%m-%d, %H:%M:%S'),
            "author": Preferences.getUser("Email"),
        }
        
        # step 1: add the lexer style data
        stylesDict["lexers"] = []
        for lexer in lexers:
            lexerDict = {
                "name": lexer.language(),
                "styles": [],
            }
            for description, style, substyle in lexer.getStyles():
                lexerDict["styles"].append({
                    "description": description,
                    "style": style,
                    "substyle": substyle,
                    "color": lexer.color(style, substyle).name(),
                    "paper": lexer.paper(style, substyle).name(),
                    "font": lexer.font(style, substyle).toString(),
                    "eolfill": lexer.eolFill(style, substyle),
                    "words": lexer.words(style, substyle).strip(),
                })
            stylesDict["lexers"].append(lexerDict)
        
        try:
            jsonString = json.dumps(stylesDict, indent=2)
            with open(filename, "w") as f:
                f.write(jsonString)
        except (TypeError, EnvironmentError) as err:
            with E5OverridenCursor():
                E5MessageBox.critical(
                    None,
                    self.tr("Export Highlighting Styles"),
                    self.tr(
                        "<p>The highlighting styles file <b>{0}</b> could not"
                        " be written.</p><p>Reason: {1}</p>"
                    ).format(filename, str(err))
                )
                return False
        
        return True
    
    def readFile(self, filename: str, lexers: dict) -> bool:
        """
        Public method to read the highlighting styles data from a highlighting
        styles JSON file.
        
        @param filename name of the highlighting styles file
        @type str
        @param lexers dictionary of lexer objects for which to import the
            styles
        @type dict of {str: PreferencesLexer}
        @return flag indicating a successful read
        @rtype bool
        """
        try:
            with open(filename, "r") as f:
                jsonString = f.read()
            stylesDict = json.loads(jsonString)
        except (EnvironmentError, json.JSONDecodeError) as err:
            E5MessageBox.critical(
                None,
                self.tr("Import Highlighting Styles"),
                self.tr(
                    "<p>The highlighting styles file <b>{0}</b> could not be"
                    " read.</p><p>Reason: {1}</p>"
                ).format(filename, str(err))
            )
            return False
        
        for lexerDict in stylesDict["lexers"]:
            if lexerDict["name"] in lexers:
                lexer = lexers[lexerDict["name"]]
                for styleDict in lexerDict["styles"]:
                    style = styleDict["style"]
                    substyle = styleDict["substyle"]
                    lexer.setColor(QColor(styleDict["color"]), style, substyle)
                    lexer.setPaper(QColor(styleDict["paper"]), style, substyle)
                    font = QFont()
                    font.fromString(styleDict["font"])
                    lexer.setFont(font, style, substyle)
                    lexer.setEolFill(styleDict["eolfill"], style, substyle)
                    if substyle >= 0:
                        # description and words can only be set for sub-styles
                        lexer.setDescription(styleDict["description"],
                                             style, substyle)
                        lexer.setWords(styleDict["words"], style, substyle)
        
        return True