I am currently making an embedded multi-touch software using Kivy.
However, our hardware spec is little tight, so I am trying to optimize GUI for better performance.
Then I've found that Kivy Popup is slow when first pops up then gets faster after that. So now I am guessing that Kivy is doing some caching.
So, I want widgets, especially popups and screens since they are very slow, to act like they were opened once before.
I've tried to open and dismiss every popup widgets and go through all the screens when initializing the program. It seems quite effective except that I could not figure out how to hide the screen changing yet, but I am looking for some better approach.
I've looked for kivy document about kivy.cache here
But it is not clear whether this is what I am looking for or not. In addition, it is hard to understand what do I have to do and what to expect as a result. (Seems it does not work in a way that I want anyway)
It would probably be best to find what takes most time during the first startup, to make sure to cache that, instead of preloading every possible widget. One possibility is that it's just loading the default style texture, which you can load by setting the source of any image widget to images/defaulttheme-0.png, the first widget that needs it (that includes popup) will not to load it itself if you do. If you find that even after displaying a Button, the first Popup is still slow to load, then that's certainly something else, maybe running kivy at trace log_level will help seeing what happens last before the slowdown.
python -c kivy:log_level:trace main.py
Related
I built a small GUI using Tkinter. The GUI features, among some other elements, three buttons. These buttons serve to open a dystem dialog and select certain data-files etc. One of the three buttons is a 'Go' button that runs the underlying data-processing.
When running the .py script the GUI works fine. However, after creating a developer app in alias mode using Py2App the buttons have become invisible! They're still there and usable, but invisible until interacted with.
How can I prevent this from happening?
I was stuck in your exact situation for quite some time. When I ran my tkinter script, it worked perfectly and all the buttons showed up, but once I packaged it, the buttons stopped showing up (They were still there but you couldn't see them). After a long time of trying random things, I found out how to make the buttons and their text show up again. Simply resize the window. Even a difference of 1 or 2 pixels does the trick. I have not yet found a way to PREVENT this issue, but at least this makes the app look right.
Please reply if you figure out a solution to prevent this!
Good Luck!
I am trying to code a message box that just pops up and says something and has a single button to close it however as I only have a small amount of text in the box the icon/image to the left of it is huge and looks bad. I want to know how to remove it. I am also having trouble making custom message boxes. Tutorials say that this is how you make a custom message box:
box = QMessageBox()
box.setText('text')
box.addButton(QPushButton('Close', self))
box.exec_()
However this just closes my program and returns a 1. My current code uses the about method of QMessageBox():
box = QMessageBox().about(self, 'About', 'This is a test Program')
However this has that large icon in the text window and I can't seem to do anything else to the box as it just stops the program and returns 1 again
I am in desperate need of some decent PyQt documentation. I can't seem to find documentation on much at all unless it is in C++. For instance I cannot seem to find any information of options other than question and about for QmessageBox. So if someone could also show me where some proper documentation lives it would prevent me asking too many questions here
Rather than PyQt documentation, it is better to directly use Qt documentation. You only need to switch your language mindset from Python to C++, there and back. It is not that difficult. :) See e.g. http://doc.qt.io/qt-4.8/qmessagebox.html#addButton or http://doc.qt.io/qt-4.8/qmessagebox.html#about I think this is very detailed documentation, unrivaled by most other frameworks.
Note that there are three overrides of addButton(). From the documentation it seems that you either need to pass two arguments to box.addButton(QPushButton('Close', self), QMessageBox.RejectRole) (you forgot the role!) or better, you use the override which uses standard buttons, then you only pass one argument: box.addButton(QMessageBox.Close).
And one more tip for you: I also find it easier to debug my program with PySide than PyQt because unlike PyQt, PySide catches the exception, prints that to console and keeps running. While PyQt usually just silently crashes leaving you clueless. Most of the time, I am using shims Qt.py https://pypi.python.org/pypi/Qt.py/0.6.9 or qtpy https://pypi.python.org/pypi/QtPy to be able to switch from PyQt to PySide on the fly. It also allows switching between Qt4 and Qt5 bindings easily.
I want to make a heads-up display that pops up it's frame, taking focus from the previous application and then gives focus back to that application when it's done.
wxPython frames have Hide and Show methods that work but don't focus the application. Also, there's SetFocus which you'd think would do it but doesn't.
Update
I found a nasty hack that works. Rather than hide and show the frame, you save the app state and close the app instead of hiding. Then when you want to show again you spark a new one in a new multiprocessing.Process. Hardly ideal though. I hope someone has something better.
Clarification
To clarify, I'm trying to get the keyboard focus, not just to get the frame on top of the stack.
This issue might be specific to OS X.
You might be able to steal focus by calling Raise on the frame. There is the wx.STAY_ON_TOP style flag that could also be applied. Then you might be able to just use the frame's Show and Hide methods to make it work.
Depending on what exactly you want to do, you might take a look at the ToasterBox widget. I can't recall if it actually steals focus, but it just pop up and go away on its own, which is handy in some cases.
I am writing an app in kivy which does cpu-heavy calculations at launch. I want the app to display what it's doing at the moment along with the progress, however, since the main loop is not reached yet, it just displays empty white screen until it finishes working. Can I force kivy to update the interface?
Basically I'm looking for kivy's equivalent of Tkinter's root.update()
I could create a workaround by defining a series of functions with each calling the next one through Clock.schedule_once(nextFunction, 1), but that would be very sloppy.
Thanks in advance.
Leaving aside the question of whether you should be using threading or something instead (which possibly you should), the answer is just that you should move your cpu calculations to somewhere else. Display something simple initially (i.e. returning a simple widget from your build method), then do the calculations after that, such as by clock scheduling them.
Your calculations will still block the gui in this case. You can work around this by doing them in a thread or by manually breaking them up into small pieces that can be sequentially scheduled.
It might be possible to update the gui by manually calling something like Clock.tick(), but I'm not sure if this will work right, and even if so it won't be able to display graphics before they have been initialised.
Beginner python learner here. I have a question that I have tried to Google but I just can't come up with the proper way to ask in just a few words (partly because I don't know the right terminology.)
How do I get python to detect other widgets? For example, if I wanted a script to check and see when I click my mouse if that click put focus on an entry widget on a (for example) website. I've been trying to get it to work in Tkinter and I can't figure out even where to begin.
I've seen this:
focus_displayof(self)
Return the widget which has currently the focus on the
display where this widget is located.
But the return value for that function seems to be some ambiguous long number I can't decipher, plus it only works in its own application.
Any direction would be much appreciated. :)
Do you mean inside your own GUI code, or some other application's/website's?
Sounds like you're looking for a GUI driver, or GUI test/automation driver. There are tons of these, some great, some awful, many abandoned. If you tell us more about what you want that will help narrow down the choices.
Is this for testing, or automation, or are you going to drive the mouse and button yourself and just want something to observe what is going on under the hood in the GUI?
>How do I get Python to detect other widgets?
On a machine, or in a browser? If in a machine, which platform: Linux/Windows (which)/Mac?
If in a browser, which browser (and major version)?
> But the return value for that function seems to be some ambiguous long number I can't decipher
Using longs as resource handles is par for the course, although good GUI drivers also work with string/regex matching on window and button names.
> plus it only works in its own application.
What do you mean, and what are you expecting it to return you? You should be able to look up that GUI object and access its title. Look for a GUI driver that works with window and button names.
Here is one list, read it through and see what sounds useful. I have used AutoIt under Win32, it's great, widely-used and actively-maintained; it can be called from Python (via subprocess).
Here are comparisons by the author of PyWinAuto on his and similar tools. Give a read to his criticisms of its structure from 2010. If none of these is what you want, at least you now have the vocabulary to tell us what would be...