[Tips] Problems and solutions in the development of python + kivy

Contents of this article

As a reminder, I will describe the problems and solutions in developing the python application using kivy.

Environment (as of 04/04/2020)

OS:macOS Catalina 10.15.3 Version of python used by kivy: 3.6.5 (included in Kivy3.app) Version of python3 displayed by toolchain.py recipes: 3.7.1 (probably different) version of kivy: 1.10.1

Event: The version of kivy displayed in toolchain.py recipes is incorrect.

Event details

When I run toolchain.py recipes immediately after git clone kivy-ios, the version of kivy is displayed as 18f37ed6e29620ee53c2a7699e0e0894e06a7f91. To.

What's happening

The revision number of kivy ver1.11.1 (although not exactly the revision number) is displayed.

Solution

Since the version is solidly written in kivy-ios / recipes / kivy / __ init__.py, modify it (for example, 1.10.1).

• It may not be necessary to do it in particular (I felt uncomfortable, so I fixed it).

Event: kivy cannot be executed (ʻimport XXX` cannot be executed)

Event details

ModuleNotFoundError: No module named'kivy._clock' is displayed

What's happening

It seems that cython has not been compiled (according to the error message).

Solution

I didn't understand the cause, but once I deleted all Kivy3.app and reinserted it, it didn't occur.

Event: kivy module cannot ʻimport`

Event details

Certain modules (eg kivy.uix.listview) cannot ʻimport`

What's happening

For some reason, the module is not stored in Kivy3.app.

• Is the main line the reason why the module is no longer stored because the use of the module is not recommended?

Solution

Bring it from master. Just git clone`` https://github.com/nuigroup/kivy and copy the necessary files. If you copied Kivy3.app to ʻApplications, the copy destination is under /Applications/Kivy3.app/Contents/Resources/kivy`.

• Since there is a possibility that the use of modules is not recommended, it may be better to modify the source code.

Event: _trigger_reset_populate cannot be used

Event details

I've deleted the error message, but I'm told that there is no _trigger_reset_populate item

What's happening

(Probably) ListView is no longer available.

• The author upgraded the version of kivy in the middle of development.

Solution

Use RecycleView instead of ListView. There is a sample here [https://github.com/kivy/kivy/tree/master/examples/widgets/recycleview). self.rv.data is a list that has a dictionary type as an element, so if there are multiple types of values you want to display, you can store them in a dictionary type item and pass them in the same way as value.

Event: The default position of RecycleView is not at the top.

Event details

If you display RecycleView once, scroll a little, go back, and display RecycleView again, I want it to be displayed at the top, but it displays the scrolled location by default.

What's happening

abridgement.

Solution

Set scroll_y of RecycleView to 1. Now when you display RecycleView, the top is always displayed.

Event: Font settings are not reflected

Event details

Even if you set the default font according to the procedure of here, it is not reflected.

• The default font default is Roboto

What's happening

I don `t really understand.

Solution

I couldn't help it, so I decided to change the settings in the Config file. Example)

myFont = './fonts/ipaexg.ttf'
Config.set('kivy', 'default_font', ['ipaexg', myFont, myFont, myFont])
Config.write()

See here for Config. Note that the default_font is listed in the graphics section, but it should be the kivy section (it is stated at the bottom that it has been moved from version 1.10.0 to the kivy section).

If you don't know the version of kivy, it's quick to check the config file in ~ / .kivy.