class QtReader(BaseReader):
"""Image reader using Qt's QImageReader implementation under the hood."""
def __init__(self, path: str, file_format: str):
super().__init__(path, file_format)
self._handler = QImageReader(path, file_format.encode())
self._handler.setAutoTransform(True)
if not self._handler.canRead():
# TODO
raise ValueError(f"'{path}' cannot be read as image")
@classmethod
def supports(cls, file_format: str) -> bool:
return file_format in QImageReader.supportedImageFormats()
@property
def is_animation(self) -> bool:
return self._handler.supportsAnimation()
def get_pixmap(self) -> QPixmap:
"""Retrieve the pixmap directly from the image reader."""
pixmap = QPixmap.fromImageReader(self._handler)
if self._handler.error():
raise ValueError(
f"Error reading image '{self.path}': {self._handler.errorString()}"
)
return pixmap
def get_image(self, size: int) -> QImage:
"""Retrieve the down-scaled image directly from the image reader."""
qsize = self._handler.size()
qsize.scale(size, size, Qt.KeepAspectRatio)
self._handler.setScaledSize(qsize)
return self._handler.read()
def _load(self, path: str, reload_only: bool):
"""Load proper displayable QWidget for a path.
This reads the image using QImageReader and then emits the appropriate
*_loaded signal to tell the image to display a new object.
"""
# Pass file format explicitly as imghdr does a much better job at this than the
# file name based approach of QImageReader
file_format = files.imghdr.what(path)
if file_format is None:
log.error("%s is not a valid image", path)
return
reader = QImageReader(path, file_format.encode("utf-8"))
reader.setAutoTransform(True) # Automatically apply exif orientation
if not reader.canRead():
log.error("Cannot read image %s", path)
return
# SVG
if file_format == "svg" and QSvgWidget:
# Do not store image and only emit with the path as the
# VectorGraphic widget needs the path in the constructor
self.original = None
api.signals.svg_loaded.emit(path, reload_only)
self._image_type = ImageType.Svg
# Gif
elif reader.supportsAnimation():
movie = QMovie(path)
if not movie.isValid() or movie.frameCount() == 0:
log.error("Error reading animation %s: invalid data", path)
return
self.original = movie
api.signals.movie_loaded.emit(self.current, reload_only)
self._image_type = ImageType.Movie
# Regular image
else:
pixmap = QPixmap.fromImageReader(reader)
if reader.error():
log.error("Error reading image %s: %s", path, reader.errorString())
return
self.original = pixmap
api.signals.pixmap_loaded.emit(self.current, reload_only)
self._image_type = ImageType.Pixmap
self._path = path
