I'm trying to use QSplashScreen as a 'simple' notification window. I build the actual notification in a dialog and am then trying to use QPixmap.grabWidget() on that and pass the pixmap to the SplashScreen but its not showing. So I'm wondering if the problem is due to me trying to use it post-start.
Simplified version of what I'm doing.
class NotifyHandler:
def showNotify(self, event):
widget = NotifyWidget.createInstance(event) # Build the QDialog
#Do I need to do widget.show()?
pixmap = QtGui.QPixmap.grabWidget(widget) # Convert to pixmap
splash = QtGui.QSplashScreen(pixmap, QtCore.Qt.WindowStayOnTopHint)
(x,y) = getDisplayLocation(splash) # Get coords to put it in bottom-right corner
splash.setGeometry(splash.width(), splash.height(), x, y)
splash.show()
QtCore.QTimer.singleShot(3000, splash.close)
I try this however nothing shows up. If I try it as a Dialog though:
widget.show()
widget.raise_()
widget.activateWindow()
It works fine. So I figure either I can't do this post-launch or there is something going on when I try to feed it a pixmap of a widget. Any ideas?
It seems my dialog issue and splash screen were having the same sort of issue.
I forgot that if you don't assign the dialog (or Splash screen in this case) to a scope outside the method then the GC will just eat the object after the method returns.
So by simply adding something like:
self.splash = splash
self.splash.show()
QtCore.QTimer.singleShot(3000, self.splash.close)
The splash screen wouldn't be garbage collected and I get my splash screen.
Related
I'm trying to take a screenshot of the current active window in PyQt5. I know the generic method to take an screenshot of any window is QScreen::grabWindow(winID), for which winID is an implementation-specific ID depending on the window system. Since I'm running X and KDE, I plan to eventual use CTypes to call Xlib, but for now, I simply execute "xdotool getactivewindow" to obtain the windowID in a shell.
For a minimum exmaple, I created a QMainWindow with a QTimer. When the timer is fired, I identify the active window ID by executing "xdotool getactivewindow", get its return value, call grabWindow() to capture the active window, and display the screetshot in a QLabel. On startup, I also set my window a fixed 500x500 size for observation, and activate Qt.WindowStaysOnTopHint flag, so that my window is still visible when it's not in focus. To put them together, the implementation is the following code.
from PyQt5 import QtCore, QtGui, QtWidgets
import subprocess
class ScreenCapture(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.setWindowFlags(self.windowFlags() | QtCore.Qt.WindowStaysOnTopHint)
self.setFixedHeight(500)
self.setFixedWidth(500)
self.label = QtWidgets.QLabel(self)
self.timer = QtCore.QTimer(self)
self.timer.setInterval(500)
self.timer.timeout.connect(self.timer_handler)
self.timer.start()
self.screen = QtWidgets.QApplication.primaryScreen()
#QtCore.pyqtSlot()
def timer_handler(self):
window = int(subprocess.check_output(["xdotool", "getactivewindow"]).decode("ascii"))
self.screenshot = self.screen.grabWindow(window)
self.label.setPixmap(self.screenshot)
self.label.setFixedSize(self.screenshot.size())
if __name__ == '__main__':
app = QtWidgets.QApplication([])
window = ScreenCapture()
window.show()
app.exec()
To test the implementation, I started the script and clicked another window. It appears to work without problems if there is no overlap between my application window and the active window. See the following screenshot, when Firefox (right) is selected, my application is able to capture the active window of Firefox and display it in the QLabel.
However, the screenshot doesn't work as expected if there is an overlap between the application window and the active window. The window of the application itself will be captured, and creates a positive feedback.
If there is an overlap between the application window and the active window. The window of the application itself will be captured, and creates a positive feedback.
I've already disabled the 3D composite in KDE's settings, but the problem remains. The examples above are taken with all composite effects disabled.
Question
Why isn't this implementation working correctly when the application window and the active window are overlapped? I suspect it's an issue caused by some forms of unwanted interaction between graphics systems (Qt toolkit, window manager, X, etc), but I'm not sure.
Is it even possible solve this problem? (Note: I know I can hide() before the screenshot and show() it again, but it doesn't really solve this problem, which is taking a screenshot even if an overlap exists.)
As pointed out by #eyllanesc, it appears that it is not possible to do it in Qt, at least not with QScreen::grabWindow, because grabWindow() doesn't actually grab the window itself, but merely the area occupied by the window. The documentation contains the following warning.
The grabWindow() function grabs pixels from the screen, not from the window, i.e. if there is another window partially or entirely over the one you grab, you get pixels from the overlying window, too. The mouse cursor is generally not grabbed.
The conclusion is that it's impossible do to it in pure Qt. It's only possible to implement such a functionality by writing a low-level X program. Since the question asks for a solution "in Qt", any answer that potentially involves deeper, low-level X solutions are out-of-scope. This question can be marked as resolved.
The lesson to learn here: Always check the documentation before using a function or method.
Update: I managed to solve the problem by reading the window directly from X via Xlib. Somewhat ironically, my solution uses GTK to grab the window and sends its result to Qt... Anyway, you can write the same program with Xlib directly if you don't want to use GTK, but I used GTK since the Xlib-related functions in GDK is pretty convenient to demonstrate the basic concept.
To get a screenshot, we first convert our window ID to an GdkWindow suitable for use within GDK, and we call Gdk.pixbuf_get_from_window() to grab the window and store it in a gdk_pixbuf. Finally, we call save_to_bufferv() to convert the raw pixbuf to a suitable image format and store it in a buffer. At this point, the image in the buffer is suitable to use in any program, including Qt.
The documentation contains the following warning:
If the window is off the screen, then there is no image data in the obscured/offscreen regions to be placed in the pixbuf. The contents of portions of the pixbuf corresponding to the offscreen region are undefined.
If the window you’re obtaining data from is partially obscured by other windows, then the contents of the pixbuf areas corresponding to the obscured regions are undefined.
If the window is not mapped (typically because it’s iconified/minimized or not on the current workspace), then NULL will be returned.
If memory can’t be allocated for the return value, NULL will be returned instead.
It also has some remarks about compositing,
gdk_display_supports_composite has been deprecated since version 3.16 and should not be used in newly-written code.
Compositing is an outdated technology that only ever worked on X11.
So basically, it's only possible to grab a partially obscured window under X11 (not possible in Wayland!), with a compositing window manager. I tested it without compositing, and found the window is blacked-out when compositing is disabled. But when composition is enabled, it seems to work without problem. It may or may not work for your application. But I think if you are using compositing under X11, it probably will work.
from PyQt5 import QtCore, QtGui, QtWidgets
import subprocess
class ScreenCapture(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.setWindowFlags(self.windowFlags() | QtCore.Qt.WindowStaysOnTopHint)
self.setFixedHeight(500)
self.setFixedWidth(500)
self.label = QtWidgets.QLabel(self)
self.screen = QtWidgets.QApplication.primaryScreen()
self.timer = QtCore.QTimer(self)
self.timer.setInterval(500)
self.timer.timeout.connect(self.timer_handler)
self.timer.start()
#staticmethod
def grab_screenshot():
from gi.repository import Gdk, GdkX11
window_id = int(subprocess.check_output(["xdotool", "getactivewindow"]).decode("ascii"))
display = GdkX11.X11Display.get_default()
window = GdkX11.X11Window.foreign_new_for_display(display, window_id)
x, y, width, height = window.get_geometry()
pb = Gdk.pixbuf_get_from_window(window, 0, 0, width, height)
if pb:
buf = pb.save_to_bufferv("bmp", (), ())
return buf[1]
else:
return
#QtCore.pyqtSlot()
def timer_handler(self):
screenshot = self.grab_screenshot()
self.pixmap = QtGui.QPixmap()
if not self.pixmap:
return
self.pixmap.loadFromData(screenshot)
self.label.setPixmap(self.pixmap)
self.label.setFixedSize(self.pixmap.size())
if __name__ == '__main__':
app = QtWidgets.QApplication([])
window = ScreenCapture()
window.show()
app.exec()
Now it captures an active window perfectly, even if there are overlapping windows on top of it.
I want to save window position and size when user is closing main window of my application, but i cant get correct window position
myTopLevelWindow.connect('unrealize', self.__onUnrealize)
def __onUnrealize(self, widget):
myTopLevelWindow.get_size() #OK
myTopLevelWindow.get_position() <-- always (0, 0) :P
in what signal handler get_position() will work correctly? I've tried 'destroy' and it's also not good :/
Have you tried "delete-event"? I just tested it in C and gtk gives me the correct position/size in the handler.
I am trying to adjust the context menu in a QTextEdit. I have succeeded in getting access to and then displaying the default menu with the following code:
class LinkTextBrowser(QTextBrowser):
def contextMenuEvent(self, event):
menu = self.createStandardContextMenu(event.pos())
# do stuff to menu here
menu.popup(event.globalPos())
However, this does not work for location-sensitive clicks. The case in question is the "Copy Link Location" item in a QTextBrowser's right click menu, which is only enabled if you right click on a link, for obvious reasons. I can't get it to ever be enabled. I suspect I am passing the wrong position to createStandardContextMenu, but I can't figure out the correct position to feed it.
I have tried both event.globalPos() and event.pos(), neither of which work. I also looked at the source code for QTextEdit, but didn't get anywhere. What position is it expecting?
Edit: Update: It appears the problem is the scrolling in the TextBrowser; if I scroll to the top of the window and use event.pos() it behaves. I don't have working code yet, but correcting for the scroll is the solution.
(Specifically, I want to disconnect the signal emitted by the Copy Link Location action and connect it to my own function so I can adjust the URL before copying it to the clipboard, allowing me to make links absolute and so forth before copying, and I have no particular desire to re-write the working bits.)
Here is the working transform of the coordinates:
class LinkTextBrowser(QTextBrowser):
def contextMenuEvent(self, event):
self.link_pos = event.pos()
# correct for scrolling
self.link_pos.setX(self.link_pos.x() + self.horizontalScrollBar().value())
self.link_pos.setY(self.link_pos.y() + self.verticalScrollBar().value())
menu = self.createStandardContextMenu(self.link_pos)
# do stuff to menu
menu.popup(event.globalPos())
Try self.mapToGlobal(event.pos()), it should take into account scroll position.
Maybe you can try something like:
QMenu *menu = new QMenu();
menu->addAction(...);
menu->exec(textEdit->mapToGlobal(pos));
It's C++ but I'm sure that you can easy convert it to python.
To display a wxPython window in full screen mode you use:
ShowFullScreen(True)
How do you get out of full screen though? I've tried the obvious way:
ShowFullScreen(True)
sleep(5)
ShowFullScreen(False)
This doesn't work though. When I run the script, nothing appears. After 5 seconds a window roughly 200x250 appears in the top-left corner of the screen, without anything inside of it. It doesn't appear to have any borders either.
If I change this to
showFullScreen(True)
then I get stuck with a full screen window that I have to use Alt + F2 -> xkill to get out of.
It looks like you need to Show() the window first. (According to the documentation, you shouldn't have to. Maybe this is a bug.) I tested on Mac OS X and Windows - they both exhibit issues if you don't call Show() first.
Also note that you shouldn't sleep in the main GUI thread. You'll hang the UI. Using CallLater is one potential solution, as shown in my example.
Working example:
import wx
def main():
app = wx.PySimpleApp()
frame = wx.Frame(None, -1, 'Full Screen Test')
frame.Show()
frame.ShowFullScreen(True)
wx.CallLater(5000, frame.ShowFullScreen, False)
app.MainLoop()
if __name__ == '__main__':
main()
The documentation for ShowFullScreen reads:
ShowFullScreen(show, style=wx.FULLSCREEN_ALL)
Depending on the value of show parameter the window is either shown full screen or restored to its normal state.
Parameters:
show (bool)
style (long): is a bit list containing some or all of the following values, which indicate what elements of the window to hide in full-screen mode:
wx.FULLSCREEN_NOMENUBAR
wx.FULLSCREEN_NOTOOLBAR
wx.FULLSCREEN_NOSTATUSBAR
wx.FULLSCREEN_NOBORDER
wx.FULLSCREEN_NOCAPTION
wx.FULLSCREEN_ALL (all of the above)
So put your Full Screen toggle event/s in a Menu and start full screen mode with:
self.window.ShowFullScreen(True, style=(wx.FULLSCREEN_NOTOOLBAR | wx.FULLSCREEN_NOSTATUSBAR |wx.FULLSCREEN_NOBORDER |wx.FULLSCREEN_NOCAPTION))
Note that I omitted wx.FULLSCREEN_NOMENUBAR, in this way you will still be able to access the menu to turn full screen mode off again.
I am very new to PyS60. I was testing how to set an application to full screen mode but unfortunately, it doesn't work as expected. I tested the script on Nokia 6120 Classic. Here is what I did:
appuifw.app.screen = 'full'
What I get is a half screen of my application with a plain white colour below. What am I doing wrong? Thanks in advance.
Make sure you define own functions for screen redraw and screen rotate callbacks. When you rotate the device, you have to manually rescale everything to fit the new screen size. Otherwise you might get that "half of screen" effect.
canvas = img = None
def cb_redraw(aRect=(0,0,0,0)):
''' Overwrite default screen redraw event handler '''
if img:
canvas.blit(img)
def cb_resize(aSize=(0,0,0,0)):
''' Overwrite default screen resize event handler '''
global img
img = graphics.Image.new(canvas.size)
appuifw.app.screen = 'full'
canvas = appuifw.Canvas(
resize_callback = cb_resize,
redraw_callback = cb_redraw)
appuifw.app.body = canvas
If you haven't already, I would advise using the latest version of PyS60 from https://garage.maemo.org/frs/?group_id=854 and trying again.
Do the other two screen modes work as they are supposed to?