When using scikit CollectionViewer (simple image browser) I'd like pressing arrow keys not to trigger going to prev/next image after slider got focus. I used eventFilter for that
from skimage.viewer import ImageViewer
from skimage.viewer.qt import Qt
from skimage.viewer.widgets import Slider
class SilentViewer(ImageViewer): #CollectionViewer with some modifications
def __init__(self, image_collection, update_on='move', **kwargs):
self.image_collection = image_collection
self.index = 0
self.num_images = len(self.image_collection)
first_image = image_collection[0]
super(SilentViewer, self).__init__(first_image)
slider_kws = dict(value=0, low=0, high=self.num_images - 1)
slider_kws['update_on'] = update_on
slider_kws['callback'] = self.update_index
slider_kws['value_type'] = 'int'
self.slider = Slider('frame', **slider_kws)
self.layout.addWidget(self.slider)
self.installEventFilter(self) #Modification to CollectionViewer №1
def update_index(self, name, index):
index = int(round(index))
if index == self.index:
return
index = max(index, 0)
index = min(index, self.num_images - 1)
self.index = index
self.slider.val = index
self.update_image(self.image_collection[index])
def eventFilter(self,obj,evt): #Modification to CollectionViewer №2
try:
print(evt.type(), evt.key(), evt.text())
if (evt.key() == Qt.Key_Left or
evt.key() == Qt.Key_Right or
evt.key() == Qt.Key_Up or
evt.key() == Qt.Key_Down):
print("Ignored arrow button")
return True
else:
return False
except:
print("Smth went wrong")
return False
#for testing reasons
from skimage import data
from skimage.transform import pyramid_gaussian
img = data.coins()
img_pyr = pyramid_gaussian(img, downscale=2, multichannel=False)
img_collection = tuple(img_pyr)
viewer = SilentViewer(img_collection)
viewer.show()
event filter seems to be working: key presses and other events trigger console output. However, arrow keys trigger image change. If I change to update_on='release' (see init), arrow keys do not trigger the image change, but make slider position change.
Could you please tell how can I make the arrow presses to be full consumed by the filter?
Analyzing the Slider source code, it can be seen that it is a container, that is, a widget that has other widgets (QLabel, QSlider and QLineEdit), so the filter must be installed on the internal QSlider and not on the container.
from skimage.viewer import ImageViewer
from skimage.viewer.qt import QtCore
from skimage.viewer.widgets import Slider
class SilentViewer(ImageViewer): # CollectionViewer with some modifications
def __init__(self, image_collection, update_on="move", **kwargs):
self.image_collection = image_collection
self.index = 0
self.num_images = len(self.image_collection)
print(self.num_images)
first_image = image_collection[0]
super(SilentViewer, self).__init__(first_image)
slider_kws = dict(value=0, low=0, high=self.num_images - 1)
slider_kws["update_on"] = update_on
slider_kws["callback"] = self.update_index
slider_kws["value_type"] = "int"
self.slider = Slider("frame", **slider_kws)
self.layout.addWidget(self.slider)
self.slider.slider.installEventFilter(self)
def update_index(self, name, index):
if index == self.index:
return
index = max(index, 0)
index = min(index, self.num_images - 1)
self.index = index
self.update_image(self.image_collection[index])
def eventFilter(self, obj, evt):
if obj is self.slider.slider and evt.type() == QtCore.QEvent.KeyPress:
if evt.key() in (
QtCore.Qt.Key_Left,
QtCore.Qt.Key_Right,
QtCore.Qt.Key_Up,
QtCore.Qt.Key_Down,
):
return True
return super(SilentViewer, self).eventFilter(obj, evt)
def main():
# for testing reasons
from skimage import data
from skimage.transform import pyramid_gaussian
img = data.coins()
img_pyr = pyramid_gaussian(img, downscale=2, multichannel=False)
img_collection = tuple(img_pyr)
viewer = SilentViewer(img_collection)
viewer.show()
if __name__ == "__main__":
main()