The performance of button.name is kind of slow?

I wrote a reader for ebooks, including the index of the book. I use Labels to show text and Buttons to show index, because I need to switch to the new chapter when user click the button.
So I need to change the Label.text and Button.title when scrolling. But it is strange that looks like the performance of Button.title is not good. It shows white pieces when I scroll the bar.

cvp

@lpl Are you sure you don't want to use button.title?

@cvp changed.

cvp

@lpl and why do you want to change something in the book index?
You could use a TableView for the index and never change something in it, scrolling is foreseen and select a line is like tapping a button.

https://m.youtube.com/watch?v=vqxlf4iJk20&feature=share

@cvp Maybe the book is very big, then the TableView will be very big too? I can only use 13 Labels to display all the contents now.

cvp

@lpl yes, for the labels, but how much indexes?

@cvp 13 Buttons, too. The index may very big, too?

cvp

@lpl I have a TableView with 10000 lines, very quick. Don't forget that display lines is done only when needed

@cvp But there is another thing, I also want to display the manhwa imgs. So I have to use ImagView like Label in ebook reader. … And I can't make it with TableView, right? So I use the same way to display the index, ebook and emanhwa.

cvp

@lpl Not textview but TableView and you can display what you want, like images, in each line.

The covers of my 13000 ePubs

@cvp I remembered the reason why I didn't use TextView. I can't get the position of the scrollbar. So I use the Labels.

@cvp But I need to display the full images on the screen which may have different sizes.

cvp

@lpl ok, but remember, I didn't say textview but TableView which is a scrollview thus you can get the position of the scroll bar

@cvp Sorry. I wrote another word. I understood that, but I'm not a native speaker so sometimes I may wrote the wrong word.

@cvp So, since I use the same strategy in ebook and index. Why there are some white parts when I display the index, and ebook reader looks well?

@cvp The code is open-source. But I have to say, I'm naive and the code is not easy to review, even I kept changing again and again. Maybe you can help me review?

cvp

@lpl Not easy to help without the code

@cvp https://github.com/yjqiang/yj_ebook_reader

Run eimg_reader.py or ebook_reader.py, and be careful, there are some 18+ contents.

@cvp I can use telegram to chat, if you often uses it too.