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 sourceFile(self, value):
self._sourceFile = value
p = QImageReader(self._sourceFile)
if (p.canRead()):
p.setAutoTransform(True)
self._image = p.read()
self._transform = QTransform()
print("loaded image "+value)
else:
self._image = None
self.changed.emit()
def _can_write(self):
"""Check if it is possible to save the current path.
Raises:
WriteError if writing is not possible.
"""
if not isinstance(self._pixmap, QPixmap):
raise WriteError("Cannot write animations")
if os.path.exists(self._path): # Override current path
reader = QImageReader(self._path)
if not reader.canRead():
raise WriteError("Path '%s' exists and is not an image" %
(self._path))
def __display_result_image(self, file_path):
image_reader = QImageReader(file_path)
if image_reader.canRead() is True:
widget_height = self.resultView.height()
widget_width = self.resultView.width()
image = image_reader.read().scaled(widget_width, widget_height, Qt.KeepAspectRatio)
item = QGraphicsPixmapItem(QPixmap.fromImage(image))
scene = QGraphicsScene()
scene.addItem(item)
self.resultView.setScene(scene)
else:
scene = QGraphicsScene()
self.resultView.setScene(scene)
def __display_result_image(self, file_path):
image_reader = QImageReader(file_path)
if image_reader.canRead() is True:
widget_height = self.resultView.height()
widget_width = self.resultView.width()
image = image_reader.read().scaled(widget_width, widget_height, Qt.KeepAspectRatio)
item = QGraphicsPixmapItem(QPixmap.fromImage(image))
scene = QGraphicsScene()
scene.addItem(item)
self.resultView.setScene(scene)
else:
scene = QGraphicsScene()
self.resultView.setScene(scene)
def _can_write(pixmap, path):
"""Check if it is possible to save the current path.
See write_pixmap for the args description.
Raises:
WriteError if writing is not possible.
"""
if not isinstance(pixmap, QPixmap):
raise WriteError("Cannot write animations")
if os.path.exists(path): # Override current path
reader = QImageReader(path)
if not reader.canRead():
raise WriteError(f"Path '{path}' exists and is not an image")
def __changed_image_line_edit(self):
file_path = self.lineEdit_image.text()
image_reader = QImageReader(file_path)
if image_reader.canRead() is True:
widget_height = self.queryView.height()
widget_width = self.queryView.width()
image = image_reader.read().scaled(widget_width, widget_height, Qt.KeepAspectRatio)
item = QGraphicsPixmapItem(QPixmap.fromImage(image))
scene = QGraphicsScene()
scene.addItem(item)
self.queryView.setScene(scene)
else:
scene = QGraphicsScene()
self.queryView.setScene(scene)
def __changed_image_line_edit(self):
file_path = self.lineEdit_image.text()
image_reader = QImageReader(file_path)
if image_reader.canRead() is True:
widget_height = self.queryView.height()
widget_width = self.queryView.width()
image = image_reader.read().scaled(widget_width, widget_height, Qt.KeepAspectRatio)
item = QGraphicsPixmapItem(QPixmap.fromImage(image))
scene = QGraphicsScene()
scene.addItem(item)
self.queryView.setScene(scene)
else:
scene = QGraphicsScene()
self.queryView.setScene(scene)
def load_image_data(self) -> QImage:
"""
Loads the image data from disk. This has to be called when the file content needs to be accessed.
:return:
"""
logger.debug(
f"Requested loading image data from the hard disk. File: {self.image_path}"
)
image_reader = QImageReader(str(self.image_path))
if image_reader.canRead():
logger.debug("Image data can be read, performing file reading…")
self.image_data = image_reader.read()
logger.info(
f"File reading done. Loaded image dimensions: "
f"x={self.image_data.width()}, y={self.image_data.height()}, format={self.image_data.format()}"
)
return self.image_data
else:
raise RuntimeError(f"Image {self.image_path} cannot be 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
def dropEvent(self, event):
# # 方法一：针对小图片
# pixmap = QPixmap(event.mimeData().urls()[0].toLocalFile())
# self.ui.LabPic.setPixmap(pixmap)
#
# # 方法二：小图片和PNG格式的大图片
# img = QImage()
# print(event.mimeData().urls()[0].toLocalFile())
# img.load(event.mimeData().urls()[0].toLocalFile())
# pixmap = QPixmap.fromImage(img.scaled(self.ui.LabPic.size(), Qt.KeepAspectRatio))
# self.ui.LabPic.setPixmap(pixmap)
# 方法三：小图片和大图片
reader = QImageReader()
print(event.mimeData().urls()[0].toLocalFile())
reader.setFileName(event.mimeData().urls()[0].toLocalFile())
reader.setDecideFormatFromContent(True)
if reader.canRead():
img = QImage(reader.read())
pixmap = QPixmap.fromImage(
img.scaled(self.ui.LabPic.size(), Qt.KeepAspectRatio))
self.ui.LabPic.setPixmap(pixmap)
def _create_thumbnail(self, path: str, thumbnail_path: str) -> QPixmap:
"""Create thumbnail for an image.
Args:
path: Path to the image for which the thumbnail is created.
thumbnail_path: Path to which the thumbnail is stored.
Returns:
The created QPixmap.
"""
# Cannot access source
if not os.access(path, os.R_OK):
return self._manager.fail_pixmap
size = 256 if self._manager.large else 128
reader = QImageReader(path)
reader.setAutoTransform(True) # Automatically apply exif orientation
if reader.canRead():
qsize = reader.size()
qsize.scale(size, size, Qt.KeepAspectRatio)
reader.setScaledSize(qsize)
image = reader.read()
# Image was deleted in the time between reader.read() and now
try:
attributes = self._get_thumbnail_attributes(path, image)
except FileNotFoundError:
return self._manager.fail_pixmap
for key, value in attributes.items():
image.setText(key, value)
# First create temporary file and then move it. This avoids
# problems with concurrent access of the thumbnail cache, since
# "move" is an atomic operation
handle, tmp_filename = tempfile.mkstemp(
dir=self._manager.directory)
os.close(handle)
os.chmod(tmp_filename, 0o600)
image.save(tmp_filename, format="png")
os.replace(tmp_filename, thumbnail_path)
return QPixmap(image)
return self._manager.fail_pixmap