I'm trying to create a screenshot utility for linux using python. Right now I'm stuck at trying to implement a function that lets the user select a region from a live screen and screenshot it. After much pondering, I reached the conclusion to create a full-screen window on each screen to get the mouse's click and drag coordinates.
How can I have my program create a full-screen window (without the toolbar icon) for each screen connected to the system?
import sys
from PyQt5 import QtWidgets as qtw
from PyQt5 import QtGui as qtg
from PyQt5 import QtCore as qtc
class InvisWindow(qtw.QWidget):
def __init__(self, screens):
super().__init__()
self.setWindowFlags(qtc.Qt.Tool | qtc.Qt.FramelessWindowHint)
self.show()
self.showFullScreen()
self.windowHandle().setScreen(screens[0])
if __name__ == '__main__':
app = qtw.QApplication(sys.argv)
mw = InvisWindow(app.screens())
sys.exit(app.exec_())
I found this code searching for a way to do it, but no matter which screen I pass to setScreen() it always appears on a single screen, i.e. changing the argument doesn't change which screen it appears in.
There are two problems:
as the documentation explains:
If the screen is part of a virtual desktop of multiple screens, the window will not move automatically to newScreen.
on Linux, there's some amount of time and system events between the call to show and when the window is actually mapped on the screen the first time (see Initial Geometry), which can be overridden by the window manager if no geometry is explicitly set;
That said, there should be no need to use the QWindow for this, as using move is usually be enough, you only must do it before any call to show() or related functions:
class InvisWindow(qtw.QWidget):
def __init__(self, screens):
super().__init__()
self.setWindowFlags(qtc.Qt.Tool | qtc.Qt.FramelessWindowHint)
self.move(screens[0].geometry().topLeft())
self.showFullScreen()
Note that there's no use in calling show() before showFullScreen(), since it implicitly calls setVisible(True).
If what you want is to show a single window on top of everything, then you could try the following:
class InvisWindow(qtw.QWidget):
mapped = False
def __init__(self, screens):
super().__init__()
self.setWindowFlags(
qtc.Qt.WindowStaysOnTopHint |
qtc.Qt.Tool |
qtc.Qt.FramelessWindowHint
)
self.show()
def moveEvent(self, event):
if not self.mapped:
geometry = qtc.QRect()
for screen in qtw.QApplication.screens():
geometry |= screen.geometry()
if self.pos() != geometry.topLeft():
self.setGeometry(geometry)
self.mapped = True
Please consider the last lines, as they are very important, because trying to do geometry changes in a geometry change event (moveEvent and resizeEvent) can cause recursion.
Related
A long time ago, I wanted to make a logo appear on top of the text in a QPushButton stacked on top of each other, but I couldn't find anyway
I read some stylesheets (couldn't find a single doc to read it all about all styles I can apply to a button)
tried the setLayoutDirection (RightToLeft and LeftToRight were there, but no UpToDown direction)
In my (I wish) last attempt I tried to inherit a QAbstractButton (I didn't find QAbstractPushButton, so I guess QAbstractButton is the answer) and change its paintEvent/paintEngine to draw an image or maybe add a vbox inside it as a layout to draw to components, but I can't find anything in python (specially PySide) which has an example in any possible way close to that. The best thing I found was the analogue clock example which was not very helpful because it was trying to work a QWidget and not a QAbstractButton and I want to keep the feel of a Native looking button.
I like my final product to be something like this.
source of the implemention of that
Python Enaml toolkit supported this feature out of the box (in one of its widgets), and I know it is QT based, so I really wish to know how it is possible?
p.s.: Also, is there a market for qt widgets? e.g.: a plugin system. Because rewriting an android like switch doesn't seem like the correct thing that I should do! even a good tutorial or doc would be appreicated (excluding official doc)
It is easier than you think, you can use QToolButton() like this:
import sys
from PySide6.QtCore import Qt, QSize
from PySide6.QtWidgets import QApplication, QVBoxLayout,QStyle, QWidget,
QToolButton
class Window(QWidget):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
button = QToolButton()
# here you choose the position of the icon and its text
button.setToolButtonStyle(
Qt.ToolButtonStyle.ToolButtonTextUnderIcon)
# here I just use built-in icon by PySide6 for this example
name = 'SP_DialogSaveButton'
pixmapi = getattr(QStyle, name)
icon = self.style().standardIcon(pixmapi)
# here we set text and icon of size 32x32 to the button
button.setIcon(icon)
button.setText("Sample text")
button.setIconSize(QSize(32, 32))
# finally we add our button to the layout
lay = QVBoxLayout(self)
lay.addWidget(button, alignment=Qt.AlignCenter)
if __name__ == "__main__":
app = QApplication(sys.argv)
win = Window()
win.show()
sys.exit(app.exec())
I have been trying to get a QComboBox in PyQt5 to become populated from a database table. The problem is trying to find a method that recognizes a click event on it.
In my GUI, my combo-box is initially empty, but upon clicking on it I wish for the click event to activate my method for communicating to the database and populating the drop-down list. It seems so far that there is no built-in event handler for a click-event for the combo-box. I am hoping that I am wrong on this. I hope someone will be able to tell me that there is a way to do this.
The best article I could find on my use-case here is from this link referring to PyQt4 QComboBox:
dropdown event/callback in combo-box in pyqt4
I also found another link that contains a nice image of a QComboBox.
The first element seems to be a label followed by a list:
Catch mouse button pressed signal from QComboBox popup menu
You can override the showPopup method to achieve this, which will work no matter how the drop-down list is opened (i.e. via the mouse, keyboard, or shortcuts):
from PyQt5 import QtCore, QtWidgets
class ComboBox(QtWidgets.QComboBox):
popupAboutToBeShown = QtCore.pyqtSignal()
def showPopup(self):
self.popupAboutToBeShown.emit()
super(ComboBox, self).showPopup()
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.combo = ComboBox(self)
self.combo.popupAboutToBeShown.connect(self.populateConbo)
layout = QtWidgets.QVBoxLayout(self)
layout.addWidget(self.combo)
def populateConbo(self):
if not self.combo.count():
self.combo.addItems('One Two Three Four'.split())
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
However, for your particular use-case, I think a better solution might be to set a QSqlQueryModel on the combo-box, so that the items are updated from the database automatically.
Alternative Solution I :
We can use frame click, the code is to be used in the container of the combo box (windows/dialog/etc.)
def mousePressEvent(self, event):
print("Hello world !")
or
def mousePressEvent():
print("Hello world !")
Alternative Solution II :
We could connect a handler to the pressed signal of the combo's view
self.uiComboBox.view().pressed.connect(self.handleItemPressed)
...
def handleItemPressed(self, index):
item = self.uiComboBox.model().itemFromIndex(index)
print("Do something with the selected item")
Why would you want to populate it when it's activated rather than when the window is loaded?
I am currently developing an application with PySide (another Python binding for the Qt framework), and I populate my comboboxes in the mainwindow class __init__ function, which seems to be the way to go, judging by many examples.
Look at the example code under "QCombobox" over at Zetcode.
I have...
class ToolWindow(QtWidgets.QMainWindow):
"""Generic window to be used as non-modal tool
Usage:
tool_win = ToolWindow()
layout = QtWidgets.QHBoxLayout()
button = QtWidgets.QPushButton('hello')
layout.addWidget(button)
tool_win.setup(layout)
button.released.connect(lambda: print('hello'))
tool_win.show()
"""
def __init__(self):
super(ToolWindow, self).__init__()
def setup(self, layout,
window_title='Untitled', object_name=None, tool=True):
"""Setup tool window"""
if tool:
self.setWindowFlags(QtCore.Qt.Tool)
self.widget = QtWidgets.QWidget()
self.widget.setLayout(layout)
self.setCentralWidget(self.widget)
self.setWindowTitle(window_title)
def closeEvent(self, event):
"""Delete object when closed"""
self.deleteLater()
However, I wish to add the typical maximize and minimize window controls to the window. I've attempted to add the following to the ToolWindow class without success (the tool window still doesn't show the maximize/minimize window controls):
self.setWindowFlags(self.windowFlags() |
QtCore.Qt.WindowSystemMenuHint |
QtCore.Qt.WindowMinMaxButtonsHint)
Is it possible to add these controls to a tool window?
Alternatively, can I create a non-modal window but which always sits atop my parent application and which shows the maximize/minimize window controls?
Please note, I don't want this tool window staying on top of ALL windows on my system. I only want it to always stay on top of my application.
You should be able to just use the QMainWindow class without any flags. As long as the tool window is a child of the primary application window, it will stay on top of it (but not windows from other applications, like it would if you set the "Window Stays On Top" flag).
You'll need to change your __init__ to accept parent arguments
def __init__(self, parent):
super(ToolWindow, self).__init__(parent)
If you have multiple Tool Windows and you want them to stay on top in a specific order, you can call my_tool_window.raise_() to bring it to the top of the z-order.
Qt ships with a window flags example. You may want to check that out to see how the different flags affect the window display and behavior.
I know this has been asked many times before. I read all of those threads, and my case seems different. Everybody else who has this trouble has a few straightforward causes that I think I’ve ruled out, such as:
Starting a timer with no event loop running
Starting/stopping a timer from a thread other than the one that created the timer
Failing to set the parent property of a widget, leading to problems with the order of destruction
Below I have a minimal code sample that demonstrates the problem. Notice that I’ve started no threads or timers. I also have set the parent of every widget. If I remove the graph widgets, the problem goes away, so one is tempted to blame pyQtGraph, however, if I include the plot widgets but exclude all the blank tabs (i.e. every tab except tabCatchaTiger), the problem also goes away, and that seems to vindicate pyQtGraph.
Versions:
Windows 7
Python 2.7.8
Wing IDE 5.0.9-1
PyQt 4.11.1
PyQwt 5.2.1
PyQtGraph 0.9.8
Test case:
from PyQt4 import Qt, QtGui, QtCore
import PyQt4.Qwt5 as Qwt
import pyqtgraph as pg
pg.functions.USE_WEAVE = False # Lets pyqtgraph plot without gcc
pg.setConfigOption('background', 'w')
pg.setConfigOption('foreground', 'k')
# GUI for visualizing data from database
class crashyGUI(QtGui.QWidget) :
def __init__(self) :
# Make the window
QtGui.QWidget.__init__(self)
self.resize(700, QtGui.QDesktopWidget().screenGeometry(self).height()*.85)
self.setWindowTitle('Data Visualization')
# Create tab interface
tabWidget = QtGui.QTabWidget(self)
# define the tab objects
self.tabEeny = QtGui.QWidget(tabWidget)
self.tabMeeny = QtGui.QWidget(tabWidget)
self.tabMiney = QtGui.QWidget(tabWidget)
self.tabMoe = QtGui.QWidget(tabWidget)
self.tabCatchaTiger = QtGui.QWidget(tabWidget)
self.tabByThe = QtGui.QWidget(tabWidget)
self.tabToe = QtGui.QWidget(tabWidget)
# Initialize the tab objects
self.initTabCatchaTiger()
###########################################
############### Main Layout ###############
###########################################
tabWidget.addTab(self.tabEeny, 'Eeny')
tabWidget.addTab(self.tabMeeny, 'Meeny')
tabWidget.addTab(self.tabMiney, 'Miney')
tabWidget.addTab(self.tabMoe, 'Moe')
tabWidget.addTab(self.tabCatchaTiger, 'Catch a Tiger')
tabWidget.addTab(self.tabByThe, 'By The')
tabWidget.addTab(self.tabToe, 'Toe')
self.mainLayout = QtGui.QVBoxLayout(self)
self.mainLayout.addWidget(tabWidget)
self.setLayout(self.mainLayout)
def initTabCatchaTiger(self):
###########################################
############# ADC Capture Tab #############
###########################################
# define tab layout
grid = QtGui.QGridLayout(self.tabCatchaTiger)
# create copy of adc plot and add to row 3 of the grid
self.catchaTigerPlot1 = pg.PlotWidget(name = 'Catch a Tiger 1', parent = self.tabCatchaTiger)
self.catchaTigerPlot1.setTitle('Catch a Tiger 1')
grid.addWidget(self.catchaTigerPlot1, 2, 0, 1, 8)
self.catchaTigerPlot2 = pg.PlotWidget(name = 'Catch a Tiger 2', parent = self.tabCatchaTiger)
self.catchaTigerPlot2.setTitle('Catch a Tiger 2')
grid.addWidget(self.catchaTigerPlot2, 3, 0, 1, 8)
# set layout for tab
self.tabCatchaTiger.setLayout(grid)
def closeEvent(self, event) :
pass
def main() :
# open a QApplication and dialog() GUI
app = QtGui.QApplication([])
windowCrashy = crashyGUI()
windowCrashy.show()
app.exec_()
main()
There seem to be two closely-related issues in the example.
The first one causes Qt to print the QObject::startTimer: QTimer can only be used with threads started with QThread messages on exit.
The second one (which may not affect all users) causes Qt to print QPixmap: Must construct a QApplication before a QPaintDevice, and then dump core on exit.
Both of these issues are caused by python deleting objects in an unpredicable order when it exits.
In the example, the second issue can be fixed by adding the following line to the __init__ of the top-level window:
self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
Unless QApplication.setQuitOnLastWindowClosed has been changed to False, this will ensure that the application quits at the right time, and that Qt has a chance to automatically delete all the children of the top-level window before the python garbage-collector gets to work.
However, for this to be completely successful, all the relevant objects must be linked together in a parent-child hierarchy. The example code does this where it can, but there seem to be some critical places in the initialization of the PlotWidget class where it is not done.
In particular, there is nothing to ensure that the central item of the PlotWidget has a parent set when it is created. If the relevant part of the code is changed to this:
class PlotWidget(GraphicsView):
...
def __init__(self, parent=None, background='default', **kargs):
GraphicsView.__init__(self, parent, background=background)
...
self.plotItem = PlotItem(**kargs)
# make sure the item gets a parent
self.plotItem.setParent(self)
self.setCentralItem(self.plotItem)
then the first issue with the QTimer messages also goes away.
Here's a better answer:
You are allowing the QApplication to be collected before python exits. This causes two different issues:
The QTimer error messages are caused by pyqtgraph trying to track its ViewBoxes after the QApplication has been destroyed.
The crash appears to be intrinsic to Qt / PyQt. The following crashes in the same way:
from PyQt4 import Qt, QtGui, QtCore
def main() :
app = QtGui.QApplication([])
x = QtGui.QGraphicsView()
s = QtGui.QGraphicsScene()
x.setScene(s)
x.show()
app.exec_()
main()
You can fix it by adding global app to your main function, or by creating the QApplication at the module level.
Try to write this in block of __init__:
self.setAttribute(Qt.WA_DeleteOnClose)
Personally, I don't put any effort into chasing exit crashes anymore--just use pg.exit() and be done with it.
(but if you do happen to find a bug in pyqtgraph, don't hesitate to open an issue on github)
I had this happen as well and in my case it was caused by a call to deleteLater() on the aboutToQuit-Signal of the application, like so:
def closeEvent(self, *args, **kwargs):
self.deleteLater()
if __name__ == "__main__":
application = QtWidgets.QApplication(sys.argv)
window = testApplication()
# Handle application exit
application.aboutToQuit.connect(window.closeEvent)
# System exit
sys.exit(application.exec_())
Getting rid of the deleteLater on the whole window seemed to solve it.
Firstly, I'm new to Python, Qt and PySide so forgive me if this question seems too simple.
What I'm trying to do is to display a bunch of photos in a grid in a GUI constructed using PySide API. Further, when a user clicks on a photo, I want to be able to display the information corresponding to that photo. Additionally, I would like the container/widget used for displaying the photo to allow for the photo to be changed e.g. I should be able to replace any photo in the grid without causing the entire grid of photos to be created from scratch again.
Initially I tried to use QLabel to display a QPixmap but I realized (whether mistakenly or not) that I have no way to detect mouse clicks on the label. After some searching, I got the impression that I should subclass QLabel (or some other relevant class) and somehow override QWidget's(QLabel's parent class) mousePressEvent() to enable mouse click detection. Problem is I'm not sure how to do that or whether there is any alternative widget I can use to contain my photos other than the QLabel without having to go through subclass customization.
Can anyone suggest a more suitable container other than QLabel to display photos while allowing me to detect mouse clicks on the photo or provide some code snippet for subclassing QLabel to enable it to detect mouse clicks?
Thanks in advance for any replies.
I've added an example of how to emit a signal and connect to another slot. Also the docs are very helpful
from PySide.QtCore import *
from PySide.QtGui import *
import sys
class Main(QWidget):
def __init__(self, parent=None):
super(Main, self).__init__(parent)
layout = QHBoxLayout(self)
picture = PictureLabel("pic.png", self)
picture.pictureClicked.connect(self.anotherSlot)
layout.addWidget(picture)
layout.addWidget(QLabel("click on the picture"))
def anotherSlot(self, passed):
print passed
print "now I'm in Main.anotherSlot"
class PictureLabel(QLabel):
pictureClicked = Signal(str) # can be other types (list, dict, object...)
def __init__(self, image, parent=None):
super(PictureLabel, self).__init__(parent)
self.setPixmap(image)
def mousePressEvent(self, event):
print "from PictureLabel.mousePressEvent"
self.pictureClicked.emit("emit the signal")
a = QApplication([])
m = Main()
m.show()
sys.exit(a.exec_())
Even if the question has been answered, i want to provide an other way that can be used in different situations (see below) :
from PySide.QtCore import *
from PySide.QtGui import *
import sys
class Main(QWidget):
def __init__(self, parent=None):
super(Main, self).__init__(parent)
layout = QHBoxLayout(self)
picture = QLabel()
picture.setPixmap("pic.png")
layout.addWidget(picture)
layout.addWidget(QLabel("click on the picture"))
makeClickable(picture)
QObject.connect(picture, SIGNAL("clicked()"), self.anotherSlot)
def anotherSlot(self):
print("AnotherSlot has been called")
def makeClickable(widget):
def SendClickSignal(widget, evnt):
widget.emit(SIGNAL('clicked()'))
widget.mousePressEvent = lambda evnt: SendClickSignal(widget, evnt)
a = QApplication([])
m = Main()
m.show()
sys.exit(a.exec_())
This way doesn't imply subclassing QLabel so it can be used to add logic to a widget made with QtDeigner.
Pros :
Can be used over QTdesigner compiled files
Can be applied to any kind of widget (you might need to include a super call to the overrided function to ensure widget's normal behavior)
The same logic can be used to send other signals
Cons :
You have to use the QObject syntax to connect signals and slots