Source code for pydm.utilities.iconfont

iconfont provides a barebones system to get QIcons from icon fonts (like Font Awesome).
The inspiration and methodology come from the 'QtAwesome' module, which does exactly this, but
is a little too big, complicated, and flexible for PyDM's needs.
import os
import sys
import json
from qtpy.QtGui import QFontDatabase, QIconEngine, QPixmap, QPainter, QColor, QFont, QIcon
from qtpy.QtCore import Qt, QRect, QPoint, qRound

if sys.version_info[0] == 3:
    unichr = chr

[docs]class IconFont(object): """IconFont represents an icon font. Users will generally want to use IconFont.icon() to get a QIcon object for the character they want.""" __instance = None def __init__(self): if self.__initialized: return self.font_file = "fontawesome.ttf" # specify these relative to this file. self.charmap_file = "fontawesome-charmap.json" self.font_name = None self.char_map = None self.loaded_fonts = {} self.load_font(self.font_file, self.charmap_file) self.__initialized = True def __new__(cls, *args, **kwargs): if cls.__instance is None: cls.__instance = object.__new__(IconFont) cls.__instance.__initialized = False return cls.__instance def load_font(self, ttf_filename, charmap_filename): def hook(obj): result = {} for key in obj: result[key] = unichr(int(obj[key], 16)) return result if self.char_map is None: cache_key = ttf_filename + "|" + charmap_filename ttf_fname = os.path.join(os.path.dirname(os.path.realpath(__file__)), ttf_filename) font_id = QFontDatabase.addApplicationFont(ttf_fname) if font_id >= 0: font_families = QFontDatabase.applicationFontFamilies(font_id) else: cache = self.loaded_fonts.get(cache_key, None) if cache is None: raise OSError("Could not load ttf file for icon font.") else: self.char_map = cache['char_map'] self.font_name = cache['font_name'] return self.font_name = font_families[0] with open(os.path.join(os.path.dirname(os.path.realpath(__file__)), charmap_filename), 'r') as codes: self.char_map = json.load(codes, object_hook=hook) self.loaded_fonts[cache_key] = {'char_map': self.char_map, 'font_name': self.font_name} def get_char_for_name(self, name): if name in self.char_map: return self.char_map[name] else: raise ValueError("Invalid icon name for font.") def font(self, size): font = QFont(self.font_name) font.setPixelSize(size) return font
[docs] def icon(self, name, color=None): """ Retrieve the icon given a name and color. Parameters ---------- name : str The Icon string identifier. Icon strings can be found at: color : QColor, Optional The base color to use when constructing the Icon. Default is QColor(90, 90, 90). Returns ------- QIcon The desired Icon. """ char = self.get_char_for_name(name) engine = CharIconEngine(self, char, color) return QIcon(engine)
class CharIconEngine(QIconEngine): """Subclass of QIconEngine that is designed to draw characters from icon fonts.""" def __init__(self, icon_font, char, color=None): super(CharIconEngine, self).__init__() self.icon_font = icon_font self.char = char if color is None: self._base_color = QColor(90, 90, 90) else: self._base_color = color self._disabled_color = QColor.fromHslF(self._base_color.hueF(), self._base_color.saturationF(), max(min(self._base_color.lightnessF() + 0.25, 1.0), 0.0)) def paint(self, painter, rect, mode, state): if mode == QIcon.Disabled: color = self._disabled_color else: color = self._base_color painter.setPen(color) scale_factor = 1.0 draw_size = 0.875 * qRound(rect.height() * scale_factor) painter.setFont(self.icon_font.font(draw_size)) painter.setOpacity(1.0) painter.drawText(rect, Qt.AlignCenter | Qt.AlignVCenter, self.char) painter.restore() def pixmap(self, size, mode, state): pm = QPixmap(size) pm.fill(Qt.transparent) self.paint(QPainter(pm), QRect(QPoint(0, 0), size), mode, state) return pm