PyQt5 QFileDialog closes when filename clicked - python

I am using PyQt5 QFileDialog.getOpenFileName. I am expecting the box to remain open until the "open" button is clicked. However, when I run the code on my Linux system, the dialog box closes immediately when the file name is clicked. On a Windows system, the box behaves as expected and remains open until the 'Open' button is clicked. The results are the same with or without the QFileDialog.DontUseNativeDialog option set.
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton, QFileDialog
import sys
class Main(QMainWindow):
def __init__(self):
super().__init__()
self.setWindowTitle("QFileDialog Test")
button = QPushButton("Click to open file")
button.setCheckable(True)
button.clicked.connect(self.open_file)
# Set the central widget of the Window.
self.setCentralWidget(button)
def open_file(self):
options = QFileDialog.Options()
options |= QFileDialog.DontUseNativeDialog
file_name, _ = QFileDialog.getOpenFileName(None, "Open File",
"", "Python Files (*.py);;Text Files (*.txt)",options=options)
app = QApplication(sys.argv)
window = Main()
window.show()
app.exec_()
Edit:
I logged out of KDE and started an Openbox session instead, then ran the above code. QFileDialog behaved as I was expecting, and waited for me to click the Open button. This verifies the problem exists with KDE / KWin, and that the code, run under other window managers, will likely work fine.
Still isn't a real solution, but I am more informed now than I was earlier.
2nd Edit:
I found that if I change Workspace Behavior -> General Behavior -> Click Behavior from Single click, to Double click, my QFileDialog issue goes away. How to get around this would be a different topic though.
3rd Edit:
Added 'QFileDialog.DontUseNativeDialog' option to sample code.

It seems like Qt tries to respect the way the OS opens files and folders in its file manager, even when using the native dialog. That depends on the SH_ItemView_ActivateItemOnSingleClick style hint, and the only way to bypass it is to apply a proxy style.
While you could apply the style to the QFileDialog's view within its __init__ (as long as you're using the native dialog), you're using static methods, so you can only do this by setting the style to the whole QApplication.
Note that, unlike stylesheets, palette and font, styles are not propagated to children widgets, and they always use the QApplication style (or the style manually set for them).
class SingleClickWorkaroundProxy(QProxyStyle):
def styleHint(self, hint, option, widget, data):
if hint == self.SH_ItemView_ActivateItemOnSingleClick:
return False
return super().styleHint(hint, option, widget, data)
# ...
app = QApplication(sys.argv)
app.setStyle(SingleClickWorkaroundProxy())
window = Main()
window.show()
app.exec_()

Related

QFileDialog opens in new window while adding it to QHBoxLayout

My issue is that when I am adding QFileDialog to QVBoxLayout it opens in new window. Below is the code which produces my problem.
from PyQt5.QtWidgets import QVBoxLayout, QFileDialog, QPushButton, QWidget
class MainWindow(QtWidgets.QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.setWindowTitle("My own MainWindow")
self.fileDialog = QFileDialog()
self.confirmAction = QPushButton("Press me", self)
mainLayout = QVBoxLayout()
mainLayout.addWidget(self.fileDialog)
mainLayout.addWidget(self.confirmAction)
self.setLayout(mainLayout)
According to the docs:
Window flags are a combination of a type (e.g. Qt::Dialog) and zero or
more hints to the window system (e.g. Qt::FramelessWindowHint).
If the widget had type Qt::Widget or Qt::SubWindow and becomes a
window (Qt::Window, Qt::Dialog, etc.), it is put at position (0, 0) on
the desktop. If the widget is a window and becomes a Qt::Widget or
Qt::SubWindow, it is put at position (0, 0) relative to its parent
widget.
So these flags are used to vary the behavior of the widget, for example to convert it into a window, a dialog, a tooltip, and so on.
In the docs gives the following list:
Qt::Widget: This is the default
type for QWidget. Widgets of this type are child widgets if they have
a parent, and independent windows if they have no parent. See also
Qt::Window and Qt::SubWindow.
Qt::Window: Indicates that the
widget is a window, usually with a window system frame and a title
bar, irrespective of whether the widget has a parent or not. Note that
it is not possible to unset this flag if the widget does not have a
parent.
Qt::Dialog :Window Indicates that the widget is a
window that should be decorated as a dialog (i.e., typically no
maximize or minimize buttons in the title bar). This is the default
type for QDialog. If you want to use it as a modal dialog, it should
be launched from another window, or have a parent and used with the
QWidget::windowModality property. If you make it modal, the dialog
will prevent other top-level windows in the application from getting
any input. We refer to a top-level window that has a parent as a
secondary window.
Qt::Sheet: Window Indicates that the
window is a Macintosh sheet. Since using a sheet implies window
modality, the recommended way is to use QWidget::setWindowModality(),
or QDialog::open(), instead.
Qt::Drawer: Window Indicates
that the widget is a Macintosh drawer.
Qt::Popup : Window Indicates that the widget is a pop-up top-level window, i.e.
that it is modal, but has a window system frame appropriate for pop-up
menus.
Qt::Tool: Window Indicates that the widget is a
tool window. A tool window is often a small window with a smaller than
usual title bar and decoration, typically used for collections of tool
buttons. If there is a parent, the tool window will always be kept on
top of it. If there isn't a parent, you may consider using
Qt::WindowStaysOnTopHint as well. If the window system supports it, a
tool window can be decorated with a somewhat lighter frame. It can
also be combined with Qt::FramelessWindowHint.
On Mac OS X, tool windows correspond to the Floating class of windows.
This means that the window lives on a level above normal windows; it
impossible to put a normal window on top of it. By default, tool
windows will disappear when the application is inactive. This can be
controlled by the Qt::WA_MacAlwaysShowToolWindow attribute.
Qt::ToolTip:Window Indicates that the widget is a
tooltip. This is used internally to implement tooltips.
Qt::SplashScreen: Window Indicates that the window is a
splash screen. This is the default type for QSplashScreen.
Qt::Desktop:Window Indicates that this widget is the
desktop. This is the type for QDesktopWidget.
Qt::SubWindow: Indicates that this widget is a sub-window,
such as a QMdiSubWindow widget.
In your case we must change the behavior of Qt::Dialog to Qt::Widget, in the following code I show the code that does it:
class MainWindow(QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.setWindowTitle("My own MainWindow")
self.fileDialog = QFileDialog(self)
self.fileDialog.setOption(QFileDialog.DontUseNativeDialog)
self.fileDialog.setWindowFlags(Qt.Widget)
self.confirmAction = QPushButton("Press me", self)
mainLayout = QVBoxLayout()
mainLayout.addWidget(self.fileDialog)
mainLayout.addWidget(self.confirmAction)
self.setLayout(mainLayout)
Screenshot:
I've been looking into this myself, dissatisfied with the "just use non-native dialogs" bit. I've been hacking around in the KDE platform file dialog implementation and have gotten (stuck) pretty close to what I'd want.
The only point of attach I've found is just before the dialog will actually be shown; before that there seems to be no way to know the actual parent widget. But there we can:
find the parent QWidget (from the parent QWindow)
from that, obtain the (first) (user-side) QFileDialog instance
if the parent QWidget has a layout, replace the found QFileDialog instance with our own dialog
save the original user-side QFileDialog instance
in the dtor, either restore the original QFD in the layout, or call deleteLater() on it (and set it to NULL in case the action causes recursive calling of the dtor).
Glitches:
- dialogs may end up with 2 sets of OK/Cancel/etc. buttons
- if not, these buttons may actually close only the embedded QFD and not the enclosing dialog (seen with the python example linked above)
- resizing works but the saveSize/restoreSize mechanism doesn't
- AFAICT all signals aren't connected properly (the preview in the Scribus open-file dialog doesn't react to selecting a file as it should). File opening does work though.
Full patch here on this BKO ticket:
https://bugs.kde.org/show_bug.cgi?id=404833#c15
Evidently this is only useful for hackers and software that can ship its own platform theme plugin (which is where the KDE platform file dialog comes from). Fortunately those plugins tend to be relatively small.

How to change current color group for QPalette

I'm trying to change the current color group fora QPalette, but it seems that the setCurrentColorGroup method of QPalette simply does not work.
I'm running this code:
app = QtGui.QApplication(sys.argv)
button = QPushButton()
svgWidget = QSvgWidget(resources_paths.getPathToIconFile("_playableLabels/42-labelPlay-disabled-c.svg"))
button.setLayout(QHBoxLayout())
button.layout().addWidget(svgWidget)
button.setFixedSize(QSize(300, 300))
print button.palette().currentColorGroup()
button.setEnabled(False)
print button.palette().currentColorGroup()
button.palette().setCurrentColorGroup(QPalette.ColorGroup.Normal)
print button.palette().currentColorGroup()
button.show()
print button.palette().currentColorGroup()
app.exec_()
This is the output I get:
PySide.QtGui.QPalette.ColorGroup.Normal
PySide.QtGui.QPalette.ColorGroup.Disabled
PySide.QtGui.QPalette.ColorGroup.Disabled
PySide.QtGui.QPalette.ColorGroup.Disabled
Process finished with exit code -1
So... It seems that setCurrentColorGroup does exactly nothing. Any ideas on how could I change the current color group?
Thanks in advance!
(BTW, I'm running PySide 1.2.4 with Qt 4.8 on a Windows 7 system)
It seems that you are trying to change the way icons are rendered, rather than the way widgets are painted, so the palette is not the right API to use. Instead, you should use a QIcon, which allows different images to be used for various modes and states.
To use the same image for both Normal and Disabled modes, you would use code like this:
icon = QtGui.QIcon()
icon.addPixmap(QtGui.QPixmap('image.svg'), QtGui.QIcon.Normal)
icon.addPixmap(QtGui.QPixmap('image.svg'), QtGui.QIcon.Disabled)
button = QtGui.QPushButton()
button.setIcon(icon)
However, you should take careful note of this warning from the Qt docs:
Custom icon engines are free to ignore additionally added pixmaps.
So there is no guarantee that this will work with all widget styles on all platforms.
UPDATE:
If the above method doesn't work, it probably means the widget style is controlling how disabled icons are rendered. The relevant QStyle API is generatedIconPixmap, which returns a copy of the pixmap modified according to the icon mode and style options. It seems that this method may sometimes also take the palette into account (somewhat contrary to what I stated above) - but when I tested this, it did not have any affect. I reset the palette like this:
palette = self.button.palette()
palette.setCurrentColorGroup(QtGui.QPalette.Normal)
palette.setColorGroup(QtGui.QPalette.Disabled,
palette.windowText(), palette.button(),
palette.light(), palette.dark(), palette.mid(),
palette.text(), palette.brightText(),
palette.base(), palette.window(),
)
button.setPalette(palette)
which made the colours look normal when the button was disabled - but the icon was still greyed out. Still, you might want to try it in case things work differently on your platform (don't be surprised if they don't).
It seems that the correct way to control the disabling of icons is to create a QProxyStyle and override the generatedIconPixmap method. Unfortunately, this class is not available in PyQt4, but I have tested it in PyQt5, and it works. So the only working solution I have at the moment is to upgrade to PyQt5, and use QProxyStyle. Here is a demo script that shows how to implement it:
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class ProxyStyle(QtWidgets.QProxyStyle):
def generatedIconPixmap(self, mode, pixmap, option):
if mode == QtGui.QIcon.Disabled:
mode = QtGui.QIcon.Normal
return super(ProxyStyle, self).generatedIconPixmap(
mode, pixmap, option)
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.button = QtWidgets.QPushButton(self)
self.button.setIcon(QtGui.QIcon('image.svg'))
self.button2 = QtWidgets.QPushButton('Test', self)
self.button2.setCheckable(True)
self.button2.clicked.connect(self.button.setDisabled)
layout = QtWidgets.QVBoxLayout(self)
layout.addWidget(self.button)
layout.addWidget(self.button2)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
app.setStyle(ProxyStyle())
window = Window()
window.setGeometry(600, 100, 300, 200)
window.show()
sys.exit(app.exec_())

How to automatically focus QDialog with a Qt.Popup flag set?

Consider the following code snippet using Python 3 and PyQt 5.5:
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import sys
if __name__ == '__main__':
app = QApplication(sys.argv)
w = QWidget()
d = QDialog()
l = QLineEdit(d)
w.show()
# Comment the following line to gain focus.
d.setWindowFlags(Qt.Popup)
d.show()
app.exec_()
After d.show() is invoked, the dialog is shown but the QLineEdit inside it doesn't have focus. No amount of raise_(), activateWindow() or setFocus() seems to be working. How can I make the dialog automatically gain focus when it's shown? I would like to keep the dialog as Qt.Popup, because I need it to close when I click outside of it.
There is
QWidget::raise();
QWidget::activateWindow();
From the docs:
Sets the top-level widget containing this widget to be the active window.
An active window is a visible top-level window that has the keyboard input focus.
This function performs the same operation as clicking the mouse on the title bar of a top-level window. On X11, the result depends on the Window Manager. If you want to ensure that the window is stacked on top as well you should also call raise(). Note that the window must be visible, otherwise activateWindow() has no effect.
On Windows, if you are calling this when the application is not currently the active one then it will not make it the active window. It will change the color of the taskbar entry to indicate that the window has changed in some way. This is because Microsoft does not allow an application to interrupt what the user is currently doing in another application.
It seems that you need to set focus on the line-edit after the dialog is shown:
l = QLineEdit(d)
w.show()
d.setWindowFlags(Qt.Popup)
d.show()
l.setFocus()
app.exec_()
If that doesn't work, try it with a timer:
QTimer.singleShot(1, l.setFocus)

PyQt:Why a popup dialog prevents execution of other code?

I am having a little problem with a pop up dialog.I have a combobox,which when the option changes it pops up a dialog with a textedit widget,do some stuff and insert some text in the textedit widget.
This is what i use for the popup:
def function_1(self):
dialog = QDialog()
dialog.ui = Ui_Dialog_popup()
dialog.ui.setupUi(dialog)
dialog.setAttribute(QtCore.Qt.WA_DeleteOnClose)
dialog.exec_()
I have the pop up gui code made in QtDesignere in a separate py file.
The popup dialog appears,but if the dialog is not closed,nothing else can be executed.Do you know how can I deal with this ? Thanks.
That's exactly what the exec method of QDialog is designed for: modal dialogs. Read the "Modal" and "Modeless dialog" sections.
If you don't the dialog to block your main UI, call show() instead of exec() (and check the modal property documentation).
Elaborating on what Mat said: The show() function immediately returns, and as dialog is local to this function, the object gets deleted as soon as "function_1" returns. You might want to make the dialog a member or global (whichever suits your requirement) so that the object stays in memory.
HTH
Since you're setting the WA_DeleteOnClose window attribute, I'm assuming you want to create a new dialog every time the function_1 method is called (which is probably a good idea).
If so, the simplest way to solve your issue (based on the code you've given), is to give your dialog a parent (so it is kept alive), and then display it modelessly using show():
def function_1(self):
dialog = QDialog(self)
dialog.ui = Ui_Dialog_popup()
dialog.ui.setupUi(dialog)
dialog.setAttribute(QtCore.Qt.WA_DeleteOnClose)
dialog.show()

Block and hide QDialog: Alternative to exec_()?

In my Qt-based application (built using PyQt 4.8.6), I have a class that is a subclass of QtGui.QDialog:
class ModelDialog(QtGui.QDialog):
...
When I run the application's user interface, I can display the QDialog like so:
def main():
app = QtGui.QApplication(sys.argv)
dialog = ModelDialog()
dialog.exec_()
According to the Qt docs and the PyQt docs, exec_() is a blocking function for this QDialog, which defaults to a modal window (which by definition prevents the user from interacting with any other windows within the application). This is exactly what happens under normal circumstances.
Recently, however, I've been working on a way to call through the entire QApplication using defaults for all input values, and not asking the user for any input. The application behaves as expected except for one single aspect: calling dialog.exec_() causes the modal dialog to be shown.
The only workaround I've been able to find has been to catch the showEvent function and to promptly hide the window, but this still allows the QDialog object to be shown for a split second:
class ModelDialog(QtGui.QDialog):
...
def showEvent(self, data=None):
self.hide()
Is there a way to prevent the modal window from being shown altogether, while continuing to block the main event loop? I'd love for there to be something like:
def main():
app = QtGui.QApplication(sys.argv)
dialog = ModelDialog()
dialog.setHideNoMatterWhat(True)
dialog.exec_()
(to that end, I tried using QWidget.setVisible(False), but dialog.exec_() sets the dialog to be visible anyways, which is expected according to the Qt docs)
Use app.exec_() instead of dialog.exec_().

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