diff options
Diffstat (limited to 'src/main/python/utils/graphics.py')
| -rw-r--r-- | src/main/python/utils/graphics.py | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/src/main/python/utils/graphics.py b/src/main/python/utils/graphics.py index 8c87b96..4d754b5 100644 --- a/src/main/python/utils/graphics.py +++ b/src/main/python/utils/graphics.py @@ -2,9 +2,11 @@ from PyQt5.QtCore import Qt from PyQt5.QtWidgets import QGraphicsView class customView(QGraphicsView): - + """ + Defines custom QGraphicsView with zoom features, overriding wheel event + """ def __init__(self, scene = None, parent=None): - if scene is not None: + if scene is not None: #overloaded constructor super(customView, self).__init__(scene, parent) else: super(customView, self).__init__(parent) @@ -12,23 +14,28 @@ class customView(QGraphicsView): self.setDragMode(True) def wheelEvent(self, QWheelEvent): - if Qt.ControlModifier: - if QWheelEvent.source() == Qt.MouseEventNotSynthesized: - if self.zoom + QWheelEvent.angleDelta().y()/2880 > 0.1: + #overload wheelevent, to zoom if control is pressed, else scroll normally + if Qt.ControlModifier: #check if control is pressed + if QWheelEvent.source() == Qt.MouseEventNotSynthesized: #check if precision mouse(mac) + # angle delta is 1/8th of a degree per scroll unit + if self.zoom + QWheelEvent.angleDelta().y()/2880 > 0.1: # hit and trial value (2880) self.zoom += QWheelEvent.angleDelta().y()/2880 else: + # precision delta is exactly equal to amount to scroll if self.zoom + QWheelEvent.pixelDelta().y() > 0.1: self.zoom += QWheelEvent.angleDelta().y() - QWheelEvent.accept() + QWheelEvent.accept() # accept event so that scrolling doesnt happen simultaneously else: - return super().wheelEvent(self, QWheelEvent) + return super().wheelEvent(self, QWheelEvent) # scroll if ctrl not pressed @property def zoom(self): + # property for zoom return self._zoom @zoom.setter def zoom(self, value): + # set scale according to zoom value being set temp = self.zoom self._zoom = value self.scale(self.zoom / temp, self.zoom / temp)
\ No newline at end of file |