Телеграмм чат группы proalgorithms страница 3752

Firstly, how do you want to scroll the content? By dragging the content or by scrolling the wheel/dragging a scrollbar?

14:17пожаловаться #1

VA

Matthew Good

Like, scrolling the scroll bar should scroll the content proportionally right?

For example

If the bar is at the top, the content is at the top

If the bar is in the middle, the content is in the middle

If the bar is at the bottom, the content is at the bottom

OK. I understand

14:17пожаловаться #2

MG

Matthew Good in pro.algorithms

Vadim Averin

Firstly, how do you want to scroll the content? By dragging the content or by scrolling the wheel/dragging a scrollbar?

Dragging a scroll bar

14:17пожаловаться #3

VA

The JScrollPane is the solution

14:17пожаловаться #4

VA

It will handle all scrolling logic

14:17пожаловаться #5

MG

Matthew Good in pro.algorithms

Yes but I want to implement the logic myself

14:18пожаловаться #6

VA

🤦‍♂️

14:18пожаловаться #7

AM

Matthew Good

Like, scrolling the scroll bar should scroll the content proportionally right?

For example

If the bar is at the top, the content is at the top

If the bar is in the middle, the content is in the middle

If the bar is at the bottom, the content is at the bottom

Oh, well, you divide the current position of the bar by the total height of it (minus the height of the draggable bar itself) to get a value between 0 and 1, you can then multiply it by the page height in pixels or something to get the desired offset

14:18пожаловаться #8

AM

Smth like curBarY / (totalScrollHeight - barHeight) * pageHeight

14:20пожаловаться #9

VA

Azure Mynn

Oh, well, you divide the current position of the bar by the total height of it (minus the height of the draggable bar itself) to get a value between 0 and 1, you can then multiply it by the page height in pixels or something to get the desired offset

It wouldn't work if the scrollbar's thumb isn't just a dot/a circle.

14:20пожаловаться #10

VA

Azure Mynn

Smth like curBarY / (totalScrollHeight - barHeight) * pageHeight

Well, but it would

14:21пожаловаться #11

AM

Vadim Averin

It wouldn't work if the scrollbar's thumb isn't just a dot/a circle.

It would, because we subtract the height of it :)

14:21пожаловаться #12

VA

@smallville7123 Hey, are you inventing a graphic engine or something?

14:22пожаловаться #13

MG

Matthew Good in pro.algorithms

Azure Mynn

Oh, well, you divide the current position of the bar by the total height of it (minus the height of the draggable bar itself) to get a value between 0 and 1, you can then multiply it by the page height in pixels or something to get the desired offset

Hmm, so as an example

If the window is 30 pixels

The content is 60 pixels

The scroll bar (excuding buttons) is 30 pixels

And the bar itself is 15 pixels

If the bar is offset by 15 pixels (at the bottom)

Then...

Val = 15 / (30-15)

Offset = Val * 60

Something like that?

14:22пожаловаться #14

AM

And as for the height itself, it can be the height of the container divided by the real height of the contents

14:22пожаловаться #15

AM

Matthew Good

Hmm, so as an example

If the window is 30 pixels

The content is 60 pixels

The scroll bar (excuding buttons) is 30 pixels

And the bar itself is 15 pixels

If the bar is offset by 15 pixels (at the bottom)

Then...

Val = 15 / (30-15)

Offset = Val * 60

Something like that?

Yep, something like that

14:23пожаловаться #16

AM

Oh, actually you might also want to subtract 30 from 60

14:24пожаловаться #17

AM

Because the offset probably should leave a certain amount of height after it