I'm trying to do a recycler view animation on scroll, but im struggling to get it started.
Basically, the animation will happen on scroll and always on the first visible child (and only on this one). When the user scrolls the recycler view, second item should overlap the first, and the first will slowly fade out. reverse animation when sliding down.
In short, when the list scroll top for example, when the first item goes offscreen and want to change that behaviour. Instead of going offscreen, it slowly fades based on scroll dY and stay in the same position.
Any hints would be much appreciated.
I think this answer may can help you. I used code like this in my app and work smootly.
https://stackoverflow.com/a/29714138/2971619
Hope to be usefull for you too!
Related
I want to animate the RecyclerView scrolling. I don't want to animate adding or removal of items but rather animate items which are on screen, i.e visible items. What I want is, item settle down smoothly when scrolling is about to finish. I am not sure what approach should I take or how this can be done. I have tried following till now
Using RecyclerView.OnScrollListener, when I get onScrolled callback, I find visible items & animate them upside or downside based on scroll direction. But this approach is no-where near to perfect & many times when scrolling fast, some visible views are null so animation doesn't apply on them & it looks weird.
Tried to animate visible items when I receive SCROLL_STATE_IDLE. But there's noticeable delay for a fraction of second when scrolling is finished & then items animate. It doesn't look natural
Tried to figure out when RecyclerView scrolling is "about to" finish so I can start animation to mimic continuity of animation with scrolling. But didn't get success in identifying reliably that scrolling is about to finish.
Instead of above a little complex ways that doen't work the way I need, I wonder if there is any other way like creating custom LayoutManagerwhere I can override the each item scrolling so that it settle to it's aimed position smoothly?
Edit: Here's something very close to what I wanted
I am animating views between two RecyclerView. The first one is something like a list of folders showing the first item as cover, clicking it opens a new view showing the folders content animating the cover to the first item. Clicking back animates all visible views back to the folder where they came from (the cover being the top most view). This looks great as long as the opened folder shows the first item. If I scroll down the first item will be offscreen and the back animation does not look that good anymore because the cover view is not animated (I'm only animating all visible views currently).
What I think would work is following: the LayoutManager could position the first item at a position shortly offscreen and keeps it as a special view in it's pool so that u always can access the first view and when I animate back to the folder view I can animate the cover in addition to all other currently visible items ( the cover will be animated from top of the screen).
This means I need following:
the LayoutManager must handle the first item as a special one that is not recycled (I may need it any time for the back animation)
the first item must always be layed out (either at the default position in the list, if it is visible or offscreen directly above the screen), again because I may need it at any time for the back animation
Can someone help me where to start here? I think this is possible with extending the LayoutManager but I don't know where to start...
Have you tried the following?
recView.getRecycledViewPool().setMaxRecycledViews(TYPE_XXXX, 0);
I need a component that works like the picture below but I'm having trouble coming up with some kind of decent solution that works.
I want the list to have a center locked selection but being scrollable with the d-pad. This is for an application running on a TV so no need for touch scroll. So when pressing down on the remote d-pad the list will scroll and a new item will size up and the current selected one will size down and the new selection will still be in the middle.
I've tried doing this using a ListView that I extended and programmatically scrolling when pressing down or up. On scroll finished I called notifyDatasetChanged() on the ListView for re-inflating of the childs and in the ListViews adapters getView() I made the animation of the view located at the current selected position.
This is not optimal since I need to call notifyDatasetChanged(), which re-inflates all visible views, for the animation to apply. The UI becomes laggy when doing this and scrolling fast. It's also not possible to make som kind of compress animation when current selected item goes out of selection. There is also some trouble with the end items (read views) such the first or last in the list when doing animation of them, the may sometimes go out of screen.
I think that his must have been done before and maybe I'm missing it when searching for an answer.
Have anyone done something similar or do you have some suggestions of how this can be achieved? Maybe I'm just starting of with the wrong component here..
Regards,
Kristoffer
In my android app, I have a horizontal scroll bar, and I can scroll all the way to the left and right. Go too far and you can't scroll anymore.
How can I change it that, you can keep scrolling left or right for as long as you want. Basically when u see the last thing in the horizontal scroll, then if you keep scrolling, you see the first item, and it loops like this. Similarly if you scroll to the left after seeing the first item, you see the last item.
Is this possible to do in android?
Thanks
I'm trying to achieve the effect that the Google+ Android app has where there is a View that sits at the bottom of the screen, and when the user scrolls the ListView that sits behind it UP the View animates down, off screen. When the user scrolls the ListView down, even slightly, the View animates back up, on screen.
I've set up a GestureDetector, that is giving me callbacks for the scroll event on my ListView, and the callbacks are constant as I scroll so I know that part is working.
In my callback I'm trying to use the ViewPropertyAnimator to animate my y value as such:
headerView.animate().yBy(distanceY).start();
Nothing happens until I stop scrolling. Is there any way to throw this animation in with the ListView scroll on the UI thread? I get the feeling it's waiting.
I've been fighting this one also. The trick I ended up using was to replace
headerView.animate().yBy(distanceY).start();
with
headerView.setTranslationY(floatValue);
Hope this helps!