[PyQt] Hover Event for a QGraphicsItem
Elvis Stansvik
elvstone at gmail.com
Sun May 8 12:07:17 BST 2016
2016-05-07 23:05 GMT+02:00 sw33tz <nyavuz.nm20 at gmail.com>:
> Thanks for replying...I've updated my code but I still cant get it to work:
I've now had a closer look at your code. There are several problems
with which I point out inline below.
>
> class graphics_Object(QtGui.QGraphicsPixmapItem):
> def __init__(self, parent=None):
> super(switch_Object, self).__init__(parent)
This, as I already mentioned, should be graphics_Object and not
graphics_Object in the call to super(..).
> pixmap = QtGui.QPixmap("item.png")
> self.graphics_pixItem = QtGui.QGraphicsPixmapItem(pixmap.scaled(40,
> 40, QtCore.Qt.KeepAspectRatio))
>
> self.graphics_pixItem.setFlag(QtGui.QGraphicsPixmapItem.ItemIsSelectable)
>
> self.graphics_pixItem.setFlag(QtGui.QGraphicsPixmapItem.ItemIsMovable)
> self.graphics_pixItem.setAcceptHoverEvents(True)
>
>
> def hoverEnterEvent(self, event):
> print 'hello'
Here's your real problem, you are overriding hoverEnterEvent in the
graphics_Object class, but the item that you are later adding to the
scene is self.graphics_pixItem, which is of type
QtGui.QGraphicsPixmapItem.
>
> class graphicsScene(QtGui.QGraphicsScene):
> def __init__(self, parent=None):
> super(graphicsScene, self).__init__(parent)
>
> def mousePressEvent(self, event):
> self.graphics_item = graphics_Object()
> def mouseReleaseEvent(self, event)
There's a missing ':' above.
> self.addItem(self.self.graphics_item.graphics_pixItem)
Apart from "self.self" which makes no sense (it should be just
"self.graphics_item"), here you are adding graphics_pixItem to the
scene, which is of type QtGui.QGraphicsPixmapItem, not of type
graphics_Object.
You seem to have a misunderstanding of how inheritance vs composition works.
> self.graphics_item.self.graphics_pixItem.setPos(event.scenePos())
Here's again a strange use of "self" which will give an error. `self`
is only available from within the class itself, the
"self.graphics_item.self" here should be just "self.graphics_item".
Here's roughly how I would structure the code, given what I've seen in
your example (Python 2, PyQt 4, since I'm guessing that's what you
use):
main.py:
from sys import argv, exit
from PyQt4.QtGui import QApplication
from PyQt4.QtGui import QGraphicsItem
from PyQt4.QtGui import QGraphicsPixmapItem
from PyQt4.QtGui import QGraphicsScene
from PyQt4.QtGui import QMainWindow
from PyQt4.QtGui import QPixmap
from PyQt4.QtCore import Qt
from PyQt4.uic import loadUi
class Item(QGraphicsPixmapItem):
def __init__(self, parent=None):
super(Item, self).__init__(parent)
pixmap = QPixmap('item.png').scaled(40, 40, Qt.KeepAspectRatio)
self.setPixmap(pixmap)
self.setFlag(QGraphicsItem.ItemIsSelectable)
self.setFlag(QGraphicsItem.ItemIsMovable)
self.setAcceptHoverEvents(True)
def hoverEnterEvent(self, event):
print('hover enter') # Do whatever you need to do here
def hoverLeaveEvent(self, event):
print('hover leave') # Do whatever you need to do here
class Scene(QGraphicsScene):
def __init__(self, parent=None):
super(Scene, self).__init__(parent)
def mouseReleaseEvent(self, event):
item = Item()
item.setPos(event.scenePos())
self.addItem(item)
class Window(QMainWindow):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
loadUi('window.ui'), self)
self.scene = Scene(self)
self.view.setScene(self.scene)
app = None
def main():
global app
app = QApplication(argv)
window = Window()
window.show()
exit(app.exec_())
if __name__ == '__main__':
main()
window.ui:
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>Window</class>
<widget class="QMainWindow" name="Window">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>800</width>
<height>600</height>
</rect>
</property>
<property name="windowTitle">
<string>MainWindow</string>
</property>
<widget class="QWidget" name="centralwidget">
<layout class="QVBoxLayout" name="verticalLayout">
<item>
<widget class="QGraphicsView" name="view"/>
</item>
</layout>
</widget>
</widget>
<resources/>
<connections/>
</ui>
Hope you can use that as starting point / inspiration and figure out
things from there.
Elvis
>
> class Form(QtGui.QMainWindow):
> def __init__(self):
> super(Form, self).__init__()
> self.ui = uic.loadUi('form.ui')
>
> self.scene = graphicsScene()
> self.ui.view.setScene(self.scene)
>
> self.setMouseTracking(True)
>
>
> On Sat, May 7, 2016 at 10:55 PM, Elvis Stansvik [via Python] <[hidden
> email]> wrote:
>>
>> Hi Nesibe,
>>
>> 2016-05-07 19:46 GMT+02:00 sw33tz <[hidden email]>:
>> > I want some small text to pop up when I have my curser over a
>> > QGraphicsItem
>> > in my QGraphicsScene. I have a class that inherits from QGraphicsItem,
>> > and
>> > this represents my graphical items in the scene.
>> >
>> > I tried using the QGraphicsItem.hoverEnterEvent and I also set the
>> > setAcceptHoverEvents(True), but I still can't enable that hover event. I
>> > also came across an event filter method but I'm not sure where to
>> > implement
>> > it.
>>
>> This seems to work here:
>>
>>
>> test.py:
>>
>> from sys import argv, exit
>>
>> from PyQt5.QtCore import Qt
>> from PyQt5.QtWidgets import QApplication
>> from PyQt5.QtWidgets import QGraphicsEllipseItem
>> from PyQt5.QtWidgets import QGraphicsScene
>> from PyQt5.QtWidgets import QGraphicsView
>> from PyQt5.QtWidgets import QMainWindow
>>
>>
>> class MyItem(QGraphicsEllipseItem):
>>
>> def __init__(self, parent=None):
>> super(MyItem, self).__init__(parent)
>>
>> self.setRect(50, 50, 50, 50)
>> self.setBrush(Qt.red)
>> self.setAcceptHoverEvents(True)
>>
>> def hoverEnterEvent(self, event):
>> print('hover enter')
>>
>> def hoverLeaveEvent(self, event):
>> print('hover leave')
>>
>>
>> app = None
>>
>>
>> def main():
>> global app
>>
>> app = QApplication(argv)
>>
>> scene = QGraphicsScene()
>> scene.addItem(MyItem())
>>
>> view = QGraphicsView()
>> view.setScene(scene)
>>
>> window = QMainWindow()
>> window.setCentralWidget(view)
>> window.show()
>>
>> exit(app.exec_())
>>
>>
>> if __name__ == '__main__':
>> main()
>>
>>
>> Hope that helps.
>>
>> Best regards,
>> Elvis
>>
>> >
>> > Should I install the event filter in the QGraphicsItem class, or the
>> > scene?
>> > I tried both and I'm still not getting the desired result. I want to be
>> > able
>> > to hover over all the items in the scene.
>> >
>> >
>> > class HoverEventFilter(QtCore.QObject):
>> > def eventFilter(self, receiver, event):
>> > if (event.type() == QtCore.QEvent.HoverEnter):
>> > # this is for test purposes
>> > print 'hover event'
>> > return True
>> > else:
>> > # Call Base Class Method to Continue Normal Event Processing
>> > return super(HoverEventFilter, self).eventFilter(receiver,
>> > event)
>> >
>> >
>> >
>> > --
>> > View this message in context:
>> > http://python.6.x6.nabble.com/Hover-Event-for-a-QGraphicsItem-tp5190283.html
>> > Sent from the PyQt mailing list archive at Nabble.com.
>> > _______________________________________________
>> > PyQt mailing list [hidden email]
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>
>
>
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>
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