There have been similar questions asked about overriding the QCompleter popup position but i'll still not found a working solution. I simply want to move the popup down around 5px (I have some specific styling requirements)
I've tried subclassing a QListView and using that as my popup using setPopup(). I then override the showEvent and move the popup down in Y. I also do this on the resizeEvent since I believe this is triggered when items are filtered and the popup resizes. However this doesn't work.. I then used a singleshot timer to trigger the move after 1ms. This does kind of work but it seems quite inconsistent - the first time it shows is different to subsequent times or resizing.
Below is my latest attempt (trying to hack it by counting the number of popups..), hopefully someone can show me what i'm doing wrong or a better solution
import sys
import os
from PySide2 import QtCore, QtWidgets, QtGui
class QPopup(QtWidgets.QListView):
def __init__(self, parent=None):
super(QPopup, self).__init__(parent)
self.popups = 0
def offset(self):
y = 3 if self.popups < 2 else 7
print('y: {}'.format(y))
self.move(self.pos().x(), self.pos().y() + y)
self.popups += 1
def showEvent(self, event):
print('show')
# self.offset()
QtCore.QTimer.singleShot(1, self.offset)
def resizeEvent(self, event):
print('resize')
# self.offset()
QtCore.QTimer.singleShot(1, self.offset)
class MyDialog(QtWidgets.QDialog):
def __init__(self, parent=None):
super(MyDialog, self).__init__(parent)
self.create_widgets()
self.create_layout()
self.create_connections()
def create_widgets(self):
self.le = QtWidgets.QLineEdit('')
self.completer = QtWidgets.QCompleter(self)
self.completer.setCaseSensitivity(QtCore.Qt.CaseInsensitive)
self.completer.setCompletionMode(QtWidgets.QCompleter.PopupCompletion)
self.completer.setMaxVisibleItems(10)
self.completer.setFilterMode(QtCore.Qt.MatchContains)
self.completer.setPopup(QPopup())
popup = QPopup(self)
self.completer.setPopup(popup)
self.model = QtCore.QStringListModel()
self.completer.setModel(self.model)
self.le.setCompleter(self.completer)
self.completer.model().setStringList(['one','two','three'])
def create_layout(self):
main_layout = QtWidgets.QVBoxLayout(self)
main_layout.addWidget(self.le)
def create_connections(self):
pass
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
my_dialog = MyDialog()
my_dialog.show() # Show the UI
sys.exit(app.exec_())
One solution could be to make a subclass of QLineEdit and override keyPressEvent to display the popup with an offset:
PySide2.QtWidgets.QCompleter.complete([rect=QRect()])
For PopupCompletion and QCompletion::UnfilteredPopupCompletion modes, calling this function displays the popup displaying the current completions. By default, if rect is not specified, the popup is displayed on the bottom of the widget() . If rect is specified the popup is displayed on the left edge of the rectangle.
see doc.qt.io -> QCompleter.complete.
Complete, self-contained example
The rect is calculated based on the y-position of the cursor rect. The height of the popup window is not changed. The width is adjusted to the width of the ZLineEdit widget.
rect = QtCore.QRect(0,
self.cursorRect().y() + 4,
self.width(),
self.completer().widget().height())
Your code, slightly modified using the points mentioned above, could look like this:
import sys
from PySide2 import QtCore, QtWidgets
from PySide2.QtWidgets import QLineEdit, QDialog, QCompleter
class ZLineEdit(QLineEdit):
def __init__(self, string, parent=None):
super().__init__(string, parent)
def keyPressEvent(self, event):
super().keyPressEvent(event)
if len(self.text()) > 0:
rect = QtCore.QRect(0,
self.cursorRect().y() + 4,
self.width(),
self.completer().widget().height())
self.completer().complete(rect)
class MyDialog(QDialog):
def __init__(self, parent=None):
super().__init__(parent)
self.le = ZLineEdit('')
autoList = ['one', 'two', 'three']
self.completer = QCompleter(autoList, self)
self.setup_widgets()
self.create_layout()
self.create_connections()
def setup_widgets(self):
self.completer.setCaseSensitivity(QtCore.Qt.CaseInsensitive)
self.completer.setCompletionMode(QtWidgets.QCompleter.PopupCompletion)
self.completer.setMaxVisibleItems(10)
self.completer.setFilterMode(QtCore.Qt.MatchContains)
self.le.setCompleter(self.completer)
def create_layout(self):
main_layout = QtWidgets.QVBoxLayout(self)
main_layout.addWidget(self.le)
def create_connections(self):
pass
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
my_dialog = MyDialog()
my_dialog.show()
sys.exit(app.exec_())
Test
On the left side you see the default behavior. On the right side the popup is moved down 4px:
I am trying to find a way to have one of my widgets maintain a width based on its height. I have other widgets working fine reimplementing the heightForWidth method. That was easy because that method is standard. I know there is no included widthForHeight method so I have tried many options the internet has suggested but have not gotten anything to work all the way. What I currently have almost gets me there.
I first reimplement my widget's sizeHint to get its width to be a ratio of its parent's (QHBoxLayout) height.
The sizeHint makes MyCustomLabel show with the right size at first show but did not update during times the user resized the window. I don't know if this the best way but to fix that I am reimplementing resizeEvent and calling adjustSize to force the sizeHint recalculation.
With those two reimplemented methods MyCustomLabel shows with the right size. I placed this custom widget in a QHBoxLayout with a few other standard widgets. The problem is the other widgets in the layout don't respect the new size of my MyCustomLabel when the user resizes the window. What I end up with is the other widgets in the layout either overlapping or being placed too far from MyCustomLabel. I kind of get it, I am brute forcing my widget to a size and not letting the layout do the work. However I thought updating the sizeHint would inform the layout of MyCustomLabel's new size and adjust everything accordingly. How do I fix this layout problem or am I going about this widthForHeight problem all the wrong way?
Edit:
I tried #AlexanderVX suggestion of setting the SizePolicy to Minimum and while it does prevent the other widgets from overlapping it also locked MyCustomLabel to a fixed size. I need the widget to expand and shrink with the layout. I also tried Preferred, Expanding, MinimumExpanding policies just to see if they would do anything but with no luck.
from __future__ import division
from PySide import QtCore
from PySide import QtGui
import sys
class MyCustomLabel(QtGui.QLabel):
clicked = QtCore.Signal(int)
dblClicked = QtCore.Signal(int)
def __init__(self, leadSide='height', parent=None):
super(MyCustomLabel, self).__init__()
self.leadSide = leadSide
# sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Preferred,
# QtGui.QSizePolicy.Preferred)
# sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Expanding,
# QtGui.QSizePolicy.Expanding)
# sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.MinimumExpanding,
# QtGui.QSizePolicy.MinimumExpanding)
# sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Minimum,
# QtGui.QSizePolicy.Minimum)
# self.setSizePolicy(sizePolicy)
def resizeEvent(self, event):
super(MyCustomLabel, self).resizeEvent(event)
self.adjustSize()
def sizeHint(self):
super(MyCustomLabel, self).sizeHint()
parentSize = self.parent().size().toTuple()
if self.leadSide.lower() == 'height':
new_size = QtCore.QSize(parentSize[1] * (16 / 9), parentSize[1]) * .9
if self.leadSide.lower() == 'width':
new_size = QtCore.QSize(parentSize[0], parentSize[0] / (16 / 9)) * .9
return new_size
class __Test__(QtGui.QWidget):
def __init__(self):
super(__Test__, self).__init__()
self.initUI()
def initUI(self):
customLabel = MyCustomLabel(leadSide='height')
# customLabel.setScaledContents(True)
customLabel.setStyleSheet('background-color: blue;'
'border:2px solid red;')
btn01 = QtGui.QPushButton('button')
btn01.setFixedHeight(80)
textEdit = QtGui.QTextEdit()
textEdit.setFixedSize(150, 150)
layout01 = QtGui.QHBoxLayout()
layout01.setContentsMargins(0,0,0,0)
layout01.setSpacing(0)
layout01.addWidget(customLabel)
layout01.addWidget(btn01)
layout01.addWidget(textEdit)
self.setLayout(layout01)
self.setGeometry(300, 300, 600, 300)
self.setWindowTitle('Testing')
self.show()
def main():
app = QtGui.QApplication(sys.argv)
ex = __Test__()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
I'm working on an opensource markdown supported minimal note taking application for Windows/Linux. I'm trying to remove the title bar and add my own buttons. I want something like, a title bar with only two custom buttons as shown in the figure
Currently I have this:
I've tried modifying the window flags:
With not window flags, the window is both re-sizable and movable. But no custom buttons.
Using self.setWindowFlags(QtCore.Qt.FramelessWindowHint), the window has no borders, but cant move or resize the window
Using self.setWindowFlags(QtCore.Qt.CustomizeWindowHint), the window is resizable but cannot move and also cant get rid of the white part at the top of the window.
Any help appreciated. You can find the project on GitHub here.
Thanks..
This is my python code:
from PyQt5 import QtCore, QtWidgets, QtWebEngineWidgets, uic
import sys
import os
import markdown2 # https://github.com/trentm/python-markdown2
from PyQt5.QtCore import QRect
from PyQt5.QtGui import QFont
simpleUiForm = uic.loadUiType("Simple.ui")[0]
class SimpleWindow(QtWidgets.QMainWindow, simpleUiForm):
def __init__(self, parent=None):
QtWidgets.QMainWindow.__init__(self, parent)
self.setupUi(self)
self.markdown = markdown2.Markdown()
self.css = open(os.path.join("css", "default.css")).read()
self.editNote.setPlainText("")
#self.noteView = QtWebEngineWidgets.QWebEngineView(self)
self.installEventFilter(self)
self.displayNote.setContextMenuPolicy(QtCore.Qt.NoContextMenu)
#self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
def eventFilter(self, object, event):
if event.type() == QtCore.QEvent.WindowActivate:
print("widget window has gained focus")
self.editNote.show()
self.displayNote.hide()
elif event.type() == QtCore.QEvent.WindowDeactivate:
print("widget window has lost focus")
note = self.editNote.toPlainText()
htmlNote = self.getStyledPage(note)
# print(note)
self.editNote.hide()
self.displayNote.show()
# print(htmlNote)
self.displayNote.setHtml(htmlNote)
elif event.type() == QtCore.QEvent.FocusIn:
print("widget has gained keyboard focus")
elif event.type() == QtCore.QEvent.FocusOut:
print("widget has lost keyboard focus")
return False
The UI file is created in the following hierarchy
Here are the steps you just gotta follow:
Have your MainWindow, be it a QMainWindow, or QWidget, or whatever [widget] you want to inherit.
Set its flag, self.setWindowFlags(Qt.FramelessWindowHint)
Implement your own moving around.
Implement your own buttons (close, max, min)
Implement your own resize.
Here is a small example with move around, and buttons implemented. You should still have to implement the resize using the same logic.
import sys
from PyQt5.QtCore import QPoint
from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QApplication
from PyQt5.QtWidgets import QHBoxLayout
from PyQt5.QtWidgets import QLabel
from PyQt5.QtWidgets import QPushButton
from PyQt5.QtWidgets import QVBoxLayout
from PyQt5.QtWidgets import QWidget
class MainWindow(QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.layout = QVBoxLayout()
self.layout.addWidget(MyBar(self))
self.setLayout(self.layout)
self.layout.setContentsMargins(0,0,0,0)
self.layout.addStretch(-1)
self.setMinimumSize(800,400)
self.setWindowFlags(Qt.FramelessWindowHint)
self.pressing = False
class MyBar(QWidget):
def __init__(self, parent):
super(MyBar, self).__init__()
self.parent = parent
print(self.parent.width())
self.layout = QHBoxLayout()
self.layout.setContentsMargins(0,0,0,0)
self.title = QLabel("My Own Bar")
btn_size = 35
self.btn_close = QPushButton("x")
self.btn_close.clicked.connect(self.btn_close_clicked)
self.btn_close.setFixedSize(btn_size,btn_size)
self.btn_close.setStyleSheet("background-color: red;")
self.btn_min = QPushButton("-")
self.btn_min.clicked.connect(self.btn_min_clicked)
self.btn_min.setFixedSize(btn_size, btn_size)
self.btn_min.setStyleSheet("background-color: gray;")
self.btn_max = QPushButton("+")
self.btn_max.clicked.connect(self.btn_max_clicked)
self.btn_max.setFixedSize(btn_size, btn_size)
self.btn_max.setStyleSheet("background-color: gray;")
self.title.setFixedHeight(35)
self.title.setAlignment(Qt.AlignCenter)
self.layout.addWidget(self.title)
self.layout.addWidget(self.btn_min)
self.layout.addWidget(self.btn_max)
self.layout.addWidget(self.btn_close)
self.title.setStyleSheet("""
background-color: black;
color: white;
""")
self.setLayout(self.layout)
self.start = QPoint(0, 0)
self.pressing = False
def resizeEvent(self, QResizeEvent):
super(MyBar, self).resizeEvent(QResizeEvent)
self.title.setFixedWidth(self.parent.width())
def mousePressEvent(self, event):
self.start = self.mapToGlobal(event.pos())
self.pressing = True
def mouseMoveEvent(self, event):
if self.pressing:
self.end = self.mapToGlobal(event.pos())
self.movement = self.end-self.start
self.parent.setGeometry(self.mapToGlobal(self.movement).x(),
self.mapToGlobal(self.movement).y(),
self.parent.width(),
self.parent.height())
self.start = self.end
def mouseReleaseEvent(self, QMouseEvent):
self.pressing = False
def btn_close_clicked(self):
self.parent.close()
def btn_max_clicked(self):
self.parent.showMaximized()
def btn_min_clicked(self):
self.parent.showMinimized()
if __name__ == "__main__":
app = QApplication(sys.argv)
mw = MainWindow()
mw.show()
sys.exit(app.exec_())
Here are some tips:
Option 1:
Have a QGridLayout with widget in each corner and side(e.g. left, top-left, menubar, top-right, right, bottom-right, bottom and bottom left)
With the approach (1) you would know when you are clicking in each border, you just got to define each one size and add each one on their place.
When you click on each one treat them in their respective ways, for example, if you click in the left one and drag to the left, you gotta resize it larger and at the same time move it to the left so it will appear to be stopped at the right place and grow width.
Apply this reasoning to each edge, each one behaving in the way it has to.
Option 2:
Instead of having a QGridLayout you can detect in which place you are clicking by the click pos.
Verify if the x of the click is smaller than the x of the moving pos to know if it's moving left or right and where it's being clicked.
The calculation is made in the same way of the Option1
Option 3:
Probably there are other ways, but those are the ones I just thought of. For example using the CustomizeWindowHint you said you are able to resize, so you just would have to implement what I gave you as example. BEAUTIFUL!
Tips:
Be careful with the localPos(inside own widget), globalPos(related to your screen). For example: If you click in the very left of your left widget its 'x' will be zero, if you click in the very left of the middle(content)it will be also zero, although if you mapToGlobal you will having different values according to the pos of the screen.
Pay attention when resizing, or moving, when you have to add width or subtract, or just move, or both, I'd recommend you to draw on a paper and figure out how the logic of resizing works before implementing it out of blue.
GOOD LUCK :D
While the accepted answer can be considered valid, it has some issues.
using setGeometry() is not appropriate (and the reason for using it was wrong) since it doesn't consider possible frame margins set by the style;
the position computation is unnecessarily complex;
resizing the title bar to the total width is wrong, since it doesn't consider the buttons and can also cause recursion problems in certain situations (like not setting the minimum size of the main window); also, if the title is too big, it makes impossible to resize the main window;
buttons should not accept focus;
setting a layout creates a restraint for the "main widget" or layout, so the title should not be added, but the contents margins of the widget should be used instead;
I revised the code to provide a better base for the main window, simplify the moving code, and add other features like the Qt windowTitle() property support, standard QStyle icons for buttons (instead of text), and proper maximize/normal button icons. Note that the title label is not added to the layout.
class MainWindow(QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.setWindowFlags(self.windowFlags() | Qt.FramelessWindowHint)
self.titleBar = MyBar(self)
self.setContentsMargins(0, self.titleBar.height(), 0, 0)
self.resize(640, self.titleBar.height() + 480)
def changeEvent(self, event):
if event.type() == event.WindowStateChange:
self.titleBar.windowStateChanged(self.windowState())
def resizeEvent(self, event):
self.titleBar.resize(self.width(), self.titleBar.height())
class MyBar(QWidget):
clickPos = None
def __init__(self, parent):
super(MyBar, self).__init__(parent)
self.setAutoFillBackground(True)
self.setBackgroundRole(QPalette.Shadow)
# alternatively:
# palette = self.palette()
# palette.setColor(palette.Window, Qt.black)
# palette.setColor(palette.WindowText, Qt.white)
# self.setPalette(palette)
layout = QHBoxLayout(self)
layout.setContentsMargins(1, 1, 1, 1)
layout.addStretch()
self.title = QLabel("My Own Bar", self, alignment=Qt.AlignCenter)
# if setPalette() was used above, this is not required
self.title.setForegroundRole(QPalette.Light)
style = self.style()
ref_size = self.fontMetrics().height()
ref_size += style.pixelMetric(style.PM_ButtonMargin) * 2
self.setMaximumHeight(ref_size + 2)
btn_size = QSize(ref_size, ref_size)
for target in ('min', 'normal', 'max', 'close'):
btn = QToolButton(self, focusPolicy=Qt.NoFocus)
layout.addWidget(btn)
btn.setFixedSize(btn_size)
iconType = getattr(style,
'SP_TitleBar{}Button'.format(target.capitalize()))
btn.setIcon(style.standardIcon(iconType))
if target == 'close':
colorNormal = 'red'
colorHover = 'orangered'
else:
colorNormal = 'palette(mid)'
colorHover = 'palette(light)'
btn.setStyleSheet('''
QToolButton {{
background-color: {};
}}
QToolButton:hover {{
background-color: {}
}}
'''.format(colorNormal, colorHover))
signal = getattr(self, target + 'Clicked')
btn.clicked.connect(signal)
setattr(self, target + 'Button', btn)
self.normalButton.hide()
self.updateTitle(parent.windowTitle())
parent.windowTitleChanged.connect(self.updateTitle)
def updateTitle(self, title=None):
if title is None:
title = self.window().windowTitle()
width = self.title.width()
width -= self.style().pixelMetric(QStyle.PM_LayoutHorizontalSpacing) * 2
self.title.setText(self.fontMetrics().elidedText(
title, Qt.ElideRight, width))
def windowStateChanged(self, state):
self.normalButton.setVisible(state == Qt.WindowMaximized)
self.maxButton.setVisible(state != Qt.WindowMaximized)
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.clickPos = event.windowPos().toPoint()
def mouseMoveEvent(self, event):
if self.clickPos is not None:
self.window().move(event.globalPos() - self.clickPos)
def mouseReleaseEvent(self, QMouseEvent):
self.clickPos = None
def closeClicked(self):
self.window().close()
def maxClicked(self):
self.window().showMaximized()
def normalClicked(self):
self.window().showNormal()
def minClicked(self):
self.window().showMinimized()
def resizeEvent(self, event):
self.title.resize(self.minButton.x(), self.height())
self.updateTitle()
if __name__ == "__main__":
app = QApplication(sys.argv)
mw = MainWindow()
layout = QVBoxLayout(mw)
widget = QTextEdit()
layout.addWidget(widget)
mw.show()
mw.setWindowTitle('My custom window with a very, very long title')
sys.exit(app.exec_())
This is for the people who are going to implement custom title bar in PyQt6 or PySide6
The below changes should be done in the answer given by #musicamante
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
# self.clickPos = event.windowPos().toPoint()
self.clickPos = event.scenePosition().toPoint()
def mouseMoveEvent(self, event):
if self.clickPos is not None:
# self.window().move(event.globalPos() - self.clickPos)
self.window().move(event.globalPosition().toPoint() - self.clickPos)
if __name__ == "__main__":
app = QApplication(sys.argv)
mw = MainWindow()
mw.show()
# sys.exit(app.exec_())
sys.exit(app.exec())
References:
QMouseEvent.globalPosition(),
QMouseEvent.scenePosition()
This method of moving Windows with Custom Widget doesn't work with WAYLAND. If anybody has a solution for that please post it here for future reference
Working functions for WAYLAND and PyQT6/PySide6 :
def mousePressEvent(self, event):
if event.button() == Qt.MouseButton.LeftButton:
self._move()
return super().mousePressEvent(event)
def _move(self):
window = self.window().windowHandle()
window.startSystemMove()
Please check.
I am trying to put a QLabel widget on top of (ie before) a QLineEdit widget edit.
But it keeps appearing after the QLineEdit widget. My code,
class CentralWidget(QtGui.QWidget):
def __init__(self, parent=None):
super(CentralWidget, self).__init__(parent)
# set layouts
self.layout = QtGui.QVBoxLayout(self)
# Flags
self.randFlag = False
self.sphereFlag = False
self.waterFlag = False
# Poly names
self.pNames = QtGui.QLabel("Import file name", self) # label concerned
self.polyNameInput = QtGui.QLineEdit(self) # line edit concerned
# Polytype selection
self.polyTypeName = QtGui.QLabel("Particle type", self)
polyType = QtGui.QComboBox(self)
polyType.addItem("")
polyType.addItem("Random polyhedra")
polyType.addItem("Spheres")
polyType.addItem("Waterman polyhedra")
polyType.activated[str].connect(self.onActivated)
self.layout.addWidget(self.pNames)
self.layout.addWidget(self.polyNameInput)
self.layout.addWidget(self.pNames)
self.layout.addWidget(self.polyTypeName)
self.layout.addWidget(polyType)
self.layout.addStretch()
def onActivated(self, text):
# Do loads of clever stuff that I'm not at liberty to share with you
class Polyhedra(QtGui.QMainWindow):
def __init__(self):
super(Polyhedra, self).__init__()
self.central_widget = CentralWidget(self)
self.setCentralWidget(self.central_widget)
# Set up window
self.setGeometry(500, 500, 300, 300)
self.setWindowTitle('Pyticle')
self.show()
# Combo box
def onActivated(self, text):
self.central_widget.onActivated(text)
def main():
app = QtGui.QApplication(sys.argv)
poly = Polyhedra()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
The window I get is below.
What am I missing? I thought QVbox allowed to stack things vertically in the order that you add the items to the main widget. (Are these sub-widget objects called widgets?)
The problem is because you are adding self.pNames label to layout twice.
#portion of your code
...
self.layout.addWidget(self.pNames) # here
self.layout.addWidget(self.polyNameInput)
self.layout.addWidget(self.pNames) # and here
self.layout.addWidget(self.polyTypeName)
self.layout.addWidget(polyType)
self.layout.addStretch()
...
The first time you add the QLabel, it gets added before the LineEdit and when you add it second time, it just moves to the bottom of LineEdit. This happens because there is only one object of QLabel which is self.pNames. It can be added to only one location. If you want to use two labels, consider creating two separate objects of QLabel
I'd like to tag items by drawing polygons over an image in Python using PyQt4. I was able to implement the image viewer with QGraphicsScene but I don't understand the concept behind painting/updating objects.
What I'd like to do is a Polygon class, what supports adding and editing. What confuses me is the QGraphicsScene.addItem and the different paint or update methods. What I'd like to implement is to
draw a polygon as lines while not complete
draw it as a filled polygon once complete
The algorithm part is OK, what I don't understand is that how do I implement the paint or update functions.
Here is my confusion
In the original example file: graphicsview/collidingmice there is a special function def paint(self, painter, option, widget): what does the painting. There is no function calling the paint function, thus I'd think it's a special name called by QGraphicsView, but I don't understand what is a painter and what should a paint function implement.
On the other hand in numerous online tutorials I find def paintEvent(self, event): functions, what seems to follow a totally different concept compared to the graphicsview / paint.
Maybe to explain it better: for me the way OpenGL does the scene-update is clear, where you always clean everything and re-draw elements one by one. There you just take care of what items do you want to draw and draw the appropriate ones. There is no update method, because you are drawing always the most up-to-date state. This Qt GUI way is new to me. Can you tell me what happens with an item after I've added it to the scene? How do I edit something what has been added to the scene, where is the always updating 'loop'?
Here is my source in the smallest possible form, it creates the first polygon and starts printing it's points. I've arrived so far that the paint method is called once (why only once?) and there is this error NotImplementedError: QGraphicsItem.boundingRect() is abstract and must be overridden. (just copy any jpg file as big.jpg)
from __future__ import division
import sys
from PyQt4 import QtCore, QtGui
class Polygon( QtGui.QGraphicsItem ):
def __init__(self):
super(Polygon, self).__init__()
self.points = []
self.closed = False
def addpoint( self, point ):
self.points.append( point )
print self.points
def paint(self, painter, option, widget):
print "paint"
class MainWidget(QtGui.QWidget):
poly_drawing = False
def __init__(self):
super(MainWidget, self).__init__()
self.initUI()
def initUI(self):
self.scene = QtGui.QGraphicsScene()
self.img = QtGui.QPixmap( 'big.jpg' )
self.view = QtGui.QGraphicsView( self.scene )
self.view.setRenderHint(QtGui.QPainter.Antialiasing)
self.view.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.view.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.pixmap_item = QtGui.QGraphicsPixmapItem( self.img, None, self.scene)
self.pixmap_item.mousePressEvent = self.pixelSelect
self.mypoly = Polygon()
layout = QtGui.QVBoxLayout()
layout.addWidget( self.view )
self.setLayout( layout )
self.resize( 900, 600 )
self.show()
def resizeEvent(self, event):
w_scale = ( self.view.width() ) / self.img.width()
h_scale = ( self.view.height() ) / self.img.height()
self.scale = min( w_scale, h_scale)
self.view.resetMatrix()
self.view.scale( self.scale, self.scale )
def pixelSelect(self, event):
if not self.poly_drawing:
self.poly_drawing = True
self.mypoly = Polygon()
self.scene.addItem( self.mypoly )
point = event.pos()
self.mypoly.addpoint( point )
def main():
app = QtGui.QApplication(sys.argv)
ex = MainWidget()
sys.exit(app.exec_())
if __name__ == '__main__':
main()