class WorkHandler(object):
"""
Class to handle threading of "work" (concretely this is just the evaluation of a function of the
form func(*args, **kwargs).
The process ID identifies (uniquely) each instance of a Worker; but the caller also defines
an ID which is then used to identify the Worker through the API.
"""
class WorkListener(metaclass=ABCMeta):
"""
This abstract base class defines methods which must be overriden and which
handle responses to certain worker actions such as raised errors, or completion.
"""
def __init__(self):
pass
@abstractmethod
def on_processing_finished(self, result):
pass
@abstractmethod
def on_processing_error(self, error):
pass
def __init__(self):
self.thread_pool = None
self._listener = {}
self._worker = {}
self.thread_pool = QThreadPool()
def _add_listener(self, listener, process_id, id):
if not isinstance(listener, self.WorkListener):
raise ValueError("The listener is not of type "
"WorkListener but rather {}".format(
type(listener)))
self._listener.update({process_id: {'id': id, 'listener': listener}})
@Slot()
def on_finished(self, process_id):
if process_id not in self._worker:
return
result = self._worker.pop(process_id)['worker'].result
self._listener.pop(process_id)['listener'].on_processing_finished(
result)
@Slot()
def on_error(self, process_id, error):
if process_id not in self._worker:
return
self._listener[process_id]['listener'].on_processing_error(error)
def process(self, caller, func, id, *args, **kwargs):
"""
Process a function call with arbitrary arguments on a new thread.
:param caller: ??
:param func: The function to be evaluated.
:param id: An identifying integer for the task.
:param args: args for func.
:param kwargs: keyword args for func.
"""
self.remove_already_processing(id)
process_id = uuid.uuid4()
# Add the caller
self._add_listener(caller, process_id, id)
finished_callback = functools.partial(self.on_finished, process_id)
error_callback = functools.partial(self.on_error, process_id)
worker = Worker(func, *args, **kwargs)
worker.signals.finished.connect(finished_callback)
worker.signals.error.connect(error_callback)
self._worker.update({process_id: {'id': id, 'worker': worker}})
self.thread_pool.start(self._worker[process_id]['worker'])
def remove_already_processing(self, id):
"""
Remove workers with ID
:param id:
"""
for key, process in list(self._listener.items()):
if process['id'] == id:
self._listener.pop(key)
self._worker.pop(key)
def wait_for_done(self):
self.thread_pool.waitForDone()
def __eq__(self, other):
return self.__dict__ == other.__dict__
def __ne__(self, other):
return self.__dict__ != other.__dict__
class QtViewer(QSplitter):
"""Qt view for the napari Viewer model.
Parameters
----------
viewer : napari.components.ViewerModel
Napari viewer containing the rendered scene, layers, and controls.
Attributes
----------
canvas : vispy.scene.SceneCanvas
Canvas for rendering the current view.
console : QtConsole
iPython console terminal integrated into the napari GUI.
controls : QtControls
Qt view for GUI controls.
dims : napari.qt_dims.QtDims
Dimension sliders; Qt View for Dims model.
dockConsole : QtViewerDockWidget
QWidget wrapped in a QDockWidget with forwarded viewer events.
aboutKeybindings : QtAboutKeybindings
Key bindings for the 'About' Qt dialog.
dockLayerControls : QtViewerDockWidget
QWidget wrapped in a QDockWidget with forwarded viewer events.
dockLayerList : QtViewerDockWidget
QWidget wrapped in a QDockWidget with forwarded viewer events.
layerButtons : QtLayerButtons
Button controls for napari layers.
layers : QtLayerList
Qt view for LayerList controls.
layer_to_visual : dict
Dictionary mapping napari layers with their corresponding vispy_layers.
pool : qtpy.QtCore.QThreadPool
Pool of worker threads.
view : vispy scene widget
View displayed by vispy canvas. Adds a vispy ViewBox as a child widget.
viewer : napari.components.ViewerModel
Napari viewer containing the rendered scene, layers, and controls.
viewerButtons : QtViewerButtons
Button controls for the napari viewer.
"""
raw_stylesheet = combine_stylesheets()
def __init__(self, viewer):
super().__init__()
self.setAttribute(Qt.WA_DeleteOnClose)
self.pool = QThreadPool()
QCoreApplication.setAttribute(
Qt.AA_UseStyleSheetPropagationInWidgetStyles, True)
self.viewer = viewer
self.dims = QtDims(self.viewer.dims)
self.controls = QtControls(self.viewer)
self.layers = QtLayerList(self.viewer.layers)
self.layerButtons = QtLayerButtons(self.viewer)
self.viewerButtons = QtViewerButtons(self.viewer)
self.console = QtConsole({'viewer': self.viewer})
layerList = QWidget()
layerList.setObjectName('layerList')
layerListLayout = QVBoxLayout()
layerListLayout.addWidget(self.layerButtons)
layerListLayout.addWidget(self.layers)
layerListLayout.addWidget(self.viewerButtons)
layerListLayout.setContentsMargins(8, 4, 8, 6)
layerList.setLayout(layerListLayout)
self.dockLayerList = QtViewerDockWidget(
self,
layerList,
name='layer list',
area='left',
allowed_areas=['left', 'right'],
)
self.dockLayerControls = QtViewerDockWidget(
self,
self.controls,
name='layer controls',
area='left',
allowed_areas=['left', 'right'],
)
self.dockConsole = QtViewerDockWidget(
self,
self.console,
name='console',
area='bottom',
allowed_areas=['top', 'bottom'],
shortcut='Ctrl+Shift+C',
)
self.dockConsole.setVisible(False)
self.dockLayerControls.visibilityChanged.connect(self._constrain_width)
self.dockLayerList.setMaximumWidth(258)
self.dockLayerList.setMinimumWidth(258)
# This dictionary holds the corresponding vispy visual for each layer
self.layer_to_visual = {}
if self.console.shell is not None:
self.viewerButtons.consoleButton.clicked.connect(
lambda: self.toggle_console())
else:
self.viewerButtons.consoleButton.setEnabled(False)
self.canvas = SceneCanvas(keys=None, vsync=True, parent=self)
self.canvas.events.ignore_callback_errors = False
self.canvas.events.draw.connect(self.dims.enable_play)
self.canvas.native.setMinimumSize(QSize(200, 200))
self.canvas.context.set_depth_func('lequal')
self.canvas.connect(self.on_mouse_move)
self.canvas.connect(self.on_mouse_press)
self.canvas.connect(self.on_mouse_release)
self.canvas.connect(self.on_key_press)
self.canvas.connect(self.on_key_release)
self.canvas.connect(self.on_draw)
self.view = self.canvas.central_widget.add_view()
self._update_camera()
main_widget = QWidget()
main_layout = QVBoxLayout()
main_layout.setContentsMargins(10, 22, 10, 2)
main_layout.addWidget(self.canvas.native)
main_layout.addWidget(self.dims)
main_layout.setSpacing(10)
main_widget.setLayout(main_layout)
self.setOrientation(Qt.Vertical)
self.addWidget(main_widget)
self._last_visited_dir = str(Path.home())
self._cursors = {
'disabled':
QCursor(
QPixmap(':/icons/cursor/cursor_disabled.png').scaled(20, 20)),
'cross':
Qt.CrossCursor,
'forbidden':
Qt.ForbiddenCursor,
'pointing':
Qt.PointingHandCursor,
'standard':
QCursor(),
}
self._update_palette(viewer.palette)
self._key_release_generators = {}
self.viewer.events.interactive.connect(self._on_interactive)
self.viewer.events.cursor.connect(self._on_cursor)
self.viewer.events.reset_view.connect(self._on_reset_view)
self.viewer.events.palette.connect(
lambda event: self._update_palette(event.palette))
self.viewer.layers.events.reordered.connect(self._reorder_layers)
self.viewer.layers.events.added.connect(self._add_layer)
self.viewer.layers.events.removed.connect(self._remove_layer)
self.viewer.dims.events.camera.connect(
lambda event: self._update_camera())
# stop any animations whenever the layers change
self.viewer.events.layers_change.connect(lambda x: self.dims.stop())
self.setAcceptDrops(True)
def _constrain_width(self, event):
"""Allow the layer controls to be wider, only if floated.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
if self.dockLayerControls.isFloating():
self.controls.setMaximumWidth(700)
else:
self.controls.setMaximumWidth(220)
def _add_layer(self, event):
"""When a layer is added, set its parent and order.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
layers = event.source
layer = event.item
vispy_layer = create_vispy_visual(layer)
vispy_layer.camera = self.view.camera
vispy_layer.node.parent = self.view.scene
vispy_layer.order = len(layers)
self.layer_to_visual[layer] = vispy_layer
def _remove_layer(self, event):
"""When a layer is removed, remove its parent.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
layer = event.item
vispy_layer = self.layer_to_visual[layer]
vispy_layer.node.transforms = ChainTransform()
vispy_layer.node.parent = None
del self.layer_to_visual[layer]
def _reorder_layers(self, event):
"""When the list is reordered, propagate changes to draw order.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
for i, layer in enumerate(self.viewer.layers):
vispy_layer = self.layer_to_visual[layer]
vispy_layer.order = i
self.canvas._draw_order.clear()
self.canvas.update()
def _update_camera(self):
"""Update the viewer camera."""
if self.viewer.dims.ndisplay == 3:
# Set a 3D camera
if not isinstance(self.view.camera, ArcballCamera):
self.view.camera = ArcballCamera(name="ArcballCamera", fov=0)
# flip y-axis to have correct alignment
# self.view.camera.flip = (0, 1, 0)
self.view.camera.viewbox_key_event = viewbox_key_event
self.viewer.reset_view()
else:
# Set 2D camera
if not isinstance(self.view.camera, PanZoomCamera):
self.view.camera = PanZoomCamera(aspect=1,
name="PanZoomCamera")
# flip y-axis to have correct alignment
self.view.camera.flip = (0, 1, 0)
self.view.camera.viewbox_key_event = viewbox_key_event
self.viewer.reset_view()
def screenshot(self, path=None):
"""Take currently displayed screen and convert to an image array.
Parmeters
---------
path : str
Filename for saving screenshot image.
Returns
-------
image : array
Numpy array of type ubyte and shape (h, w, 4). Index [0, 0] is the
upper-left corner of the rendered region.
"""
img = self.canvas.native.grabFramebuffer()
if path is not None:
imsave(path, QImg2array(img)) # scikit-image imsave method
return QImg2array(img)
def _save_screenshot(self):
"""Save screenshot of current display, default .png"""
filename, _ = QFileDialog.getSaveFileName(
parent=self,
caption='',
directory=self._last_visited_dir, # home dir by default
filter=
"Image files (*.png *.bmp *.gif *.tif *.tiff)", # first one used by default
# jpg and jpeg not included as they don't support an alpha channel
)
if (filename != '') and (filename is not None):
# double check that an appropriate extension has been added as the filter
# filter option does not always add an extension on linux and windows
# see https://bugreports.qt.io/browse/QTBUG-27186
image_extensions = ('.bmp', '.gif', '.png', '.tif', '.tiff')
if not filename.endswith(image_extensions):
filename = filename + '.png'
self.screenshot(path=filename)
def _open_images(self):
"""Add image files from the menubar."""
filenames, _ = QFileDialog.getOpenFileNames(
parent=self,
caption='Select image(s)...',
directory=self._last_visited_dir, # home dir by default
)
if (filenames != []) and (filenames is not None):
self._add_files(filenames)
def _open_folder(self):
"""Add a folder of files from the menubar."""
folder = QFileDialog.getExistingDirectory(
parent=self,
caption='Select folder...',
directory=self._last_visited_dir, # home dir by default
)
if folder not in {'', None}:
self._add_files([folder])
def _add_files(self, filenames):
"""Add an image layer to the viewer.
If multiple images are selected, they are stacked along the 0th
axis.
Parameters
-------
filenames : list
List of filenames to be opened
"""
if len(filenames) > 0:
self.viewer.add_image(path=filenames)
self._last_visited_dir = os.path.dirname(filenames[0])
def _on_interactive(self, event):
"""Link interactive attributes of view and viewer.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
self.view.interactive = self.viewer.interactive
def _on_cursor(self, event):
"""Set the appearance of the mouse cursor.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
cursor = self.viewer.cursor
size = self.viewer.cursor_size
if cursor == 'square':
if size < 10 or size > 300:
q_cursor = self._cursors['cross']
else:
q_cursor = QCursor(
QPixmap(':/icons/cursor/cursor_square.png').scaledToHeight(
size))
else:
q_cursor = self._cursors[cursor]
self.canvas.native.setCursor(q_cursor)
def _on_reset_view(self, event):
"""Reset view of the rendered scene.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
if isinstance(self.view.camera, ArcballCamera):
quat = self.view.camera._quaternion.create_from_axis_angle(
*event.quaternion)
self.view.camera._quaternion = quat
self.view.camera.center = event.center
self.view.camera.scale_factor = event.scale_factor
else:
# Assumes default camera has the same properties as PanZoomCamera
self.view.camera.rect = event.rect
def _update_palette(self, palette):
"""Update the napari GUI theme.
Parameters
----------
palette : dict of str: str
Color palette with which to style the viewer.
Property of napari.components.viewer_model.ViewerModel
"""
# template and apply the primary stylesheet
themed_stylesheet = template(self.raw_stylesheet, **palette)
self.console.style_sheet = themed_stylesheet
self.console.syntax_style = palette['syntax_style']
bracket_color = QtGui.QColor(*str_to_rgb(palette['highlight']))
self.console._bracket_matcher.format.setBackground(bracket_color)
self.setStyleSheet(themed_stylesheet)
self.canvas.bgcolor = palette['canvas']
def toggle_console(self):
"""Toggle console visible and not visible."""
viz = not self.dockConsole.isVisible()
# modulate visibility at the dock widget level as console is docakable
self.dockConsole.setVisible(viz)
if self.dockConsole.isFloating():
self.dockConsole.setFloating(True)
self.viewerButtons.consoleButton.setProperty(
'expanded', self.dockConsole.isVisible())
self.viewerButtons.consoleButton.style().unpolish(
self.viewerButtons.consoleButton)
self.viewerButtons.consoleButton.style().polish(
self.viewerButtons.consoleButton)
def show_keybindings_dialog(self, event=None):
dialog = QtAboutKeybindings(self.viewer, parent=self)
dialog.show()
def on_mouse_press(self, event):
"""Called whenever mouse pressed in canvas.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
if event.pos is None:
return
event = ReadOnlyWrapper(event)
mouse_press_callbacks(self.viewer, event)
layer = self.viewer.active_layer
if layer is not None:
# Line bellow needed until layer mouse callbacks are refactored
self.layer_to_visual[layer].on_mouse_press(event)
mouse_press_callbacks(layer, event)
def on_mouse_move(self, event):
"""Called whenever mouse moves over canvas.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
if event.pos is None:
return
mouse_move_callbacks(self.viewer, event)
layer = self.viewer.active_layer
if layer is not None:
# Line bellow needed until layer mouse callbacks are refactored
self.layer_to_visual[layer].on_mouse_move(event)
mouse_move_callbacks(layer, event)
def on_mouse_release(self, event):
"""Called whenever mouse released in canvas.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
mouse_release_callbacks(self.viewer, event)
layer = self.viewer.active_layer
if layer is not None:
# Line bellow needed until layer mouse callbacks are refactored
self.layer_to_visual[layer].on_mouse_release(event)
mouse_release_callbacks(layer, event)
def on_key_press(self, event):
"""Called whenever key pressed in canvas.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
if (event.native is not None and event.native.isAutoRepeat()
and event.key.name not in ['Up', 'Down', 'Left', 'Right'
]) or event.key is None:
# pass is no key is present or if key is held down, unless the
# key being held down is one of the navigation keys
return
comb = components_to_key_combo(event.key.name, event.modifiers)
layer = self.viewer.active_layer
if layer is not None and comb in layer.keymap:
parent = layer
elif comb in self.viewer.keymap:
parent = self.viewer
else:
return
func = parent.keymap[comb]
gen = func(parent)
if inspect.isgenerator(gen):
try:
next(gen)
except StopIteration: # only one statement
pass
else:
self._key_release_generators[event.key] = gen
def on_key_release(self, event):
"""Called whenever key released in canvas.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
try:
next(self._key_release_generators[event.key])
except (KeyError, StopIteration):
pass
def on_draw(self, event):
"""Called whenever drawn in canvas. Called for all layers, not just top
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
for visual in self.layer_to_visual.values():
visual.on_draw(event)
def keyPressEvent(self, event):
"""Called whenever a key is pressed.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
self.canvas._backend._keyEvent(self.canvas.events.key_press, event)
event.accept()
def keyReleaseEvent(self, event):
"""Called whenever a key is released.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
self.canvas._backend._keyEvent(self.canvas.events.key_release, event)
event.accept()
def dragEnterEvent(self, event):
"""Ignore event if not dragging & dropping a file or URL to open.
Using event.ignore() here allows the event to pass through the
parent widget to its child widget, otherwise the parent widget
would catch the event and not pass it on to the child widget.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
if event.mimeData().hasUrls():
event.accept()
else:
event.ignore()
def dropEvent(self, event):
"""Add local files and web URLS with drag and drop.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
filenames = []
for url in event.mimeData().urls():
if url.isLocalFile():
filenames.append(url.toLocalFile())
else:
filenames.append(url.toString())
self._add_files(filenames)
def closeEvent(self, event):
"""Clear pool of worker threads and close.
Parameters
----------
event : qtpy.QtCore.QEvent
Event from the Qt context.
"""
# if the viewer.QtDims object is playing an axis, we need to terminate
# the AnimationThread before close, otherwise it will cauyse a segFault
# or Abort trap. (calling stop() when no animation is occuring is also
# not a problem)
self.dims.stop()
self.canvas.native.deleteLater()
self.console.close()
self.dockConsole.deleteLater()
if not self.pool.waitForDone(10000):
raise TimeoutError("Timed out waiting for QtViewer.pool to finish")
event.accept()
class WorkHandler(object):
"""
Class to handle threading of "work" (concretely this is just the evaluation of a function of the
form func(*args, **kwargs).
The process ID identifies (uniquely) each instance of a Worker; but the caller also defines
an ID which is then used to identify the Worker through the API.
"""
class WorkListener(with_metaclass(ABCMeta, object)):
"""
This abstract base class defines methods which must be overriden and which
handle responses to certain worker actions such as raised errors, or completion.
"""
def __init__(self):
pass
@abstractmethod
def on_processing_finished(self, result):
pass
@abstractmethod
def on_processing_error(self, error):
pass
def __init__(self):
self.thread_pool = None
self._listener = {}
self._worker = {}
self.thread_pool = QThreadPool()
def _add_listener(self, listener, process_id, id):
if not isinstance(listener, WorkHandler.WorkListener):
raise ValueError("The listener is not of type "
"WorkListener but rather {}".format(type(listener)))
self._listener.update({process_id: {'id': id, 'listener': listener}})
@Slot()
def on_finished(self, process_id):
if process_id not in self._worker:
return
result = self._worker.pop(process_id)['worker'].result
self._listener.pop(process_id)['listener'].on_processing_finished(result)
@Slot()
def on_error(self, process_id, error):
if process_id not in self._worker:
return
self._listener[process_id]['listener'].on_processing_error(error)
def process(self, caller, func, id, *args, **kwargs):
"""
Process a function call with arbitrary arguments on a new thread.
:param caller: ??
:param func: The function to be evaluated.
:param id: An identifying integer for the task.
:param args: args for func.
:param kwargs: keyword args for func.
"""
self.remove_already_processing(id)
process_id = uuid.uuid4()
# Add the caller
self._add_listener(caller, process_id, id)
finished_callback = functools.partial(self.on_finished, process_id)
error_callback = functools.partial(self.on_error, process_id)
worker = Worker(func, *args, **kwargs)
worker.signals.finished.connect(finished_callback)
worker.signals.error.connect(error_callback)
self._worker.update({process_id: {'id': id, 'worker': worker}})
self.thread_pool.start(self._worker[process_id]['worker'])
def remove_already_processing(self, id):
"""
Remove workers with ID
:param id:
"""
for key, process in list(self._listener.items()):
if process['id'] == id:
self._listener.pop(key)
self._worker.pop(key)
def wait_for_done(self):
self.thread_pool.waitForDone()
def __eq__(self, other):
return self.__dict__ == other.__dict__
def __ne__(self, other):
return self.__dict__ != other.__dict__
