Scale Item while Dragging

[lkevin029]

How to make the item bigger when dragging start?
this is my code.

        mRecyclerViewDragDropManager.setOnItemDragEventListener(new RecyclerViewDragDropManager.OnItemDragEventListener() {
        @Override
        public void onItemDragStarted(int position) {
            View v = mRecyclerView.getChildAt(position);
            ScaleAnimation animation = new ScaleAnimation(1, 1.2f, 1, 1.2f, Animation.RELATIVE_TO_SELF, 1, Animation.RELATIVE_TO_SELF, 1);
            v.setAlpha(0.5f);
            animation.setFillAfter(true);
            v.startAnimation(animation);

        }

        @Override
        public void onItemDragPositionChanged(int fromPosition, int toPosition) {

        }

        @Override
        public void onItemDragFinished(int fromPosition, int toPosition, boolean result) {
        }
    });

but its not working because the holder in dragging is different its just a copy of the original one.

I think its better you add holder in onItemDrag events so every one can make any changes in Item while dragging

[h6ah4i]

Hi. Thanks for your suggestion, but that is difficult to implement onItemDrag() like events.

1. views and its holder objects will be recycled, so should not implement callback to holders
2. in generally, item views should be manipulated in onBindViewHolder() method only
3. dragging item is rendered as RecyclerView.ItemDecoration, so ObjectAnimator won't work

However, there is a way to implement scaling animation of the dragging item. You can achieve that by modifying the DraggingItemDecorator class of this library.

https://github.com/h6ah4i/android-advancedrecyclerview/blob/master/library/src/main/java/com/h6ah4i/android/widget/advrecyclerview/draggable/DraggingItemDecorator.java

[lkevin029]

thank you for your reply this was helpful..
I got one more question
I got a gridlayout recyclerview
numbers = span

1 1 2 1 1

I can't drag the 2 in the corner its on purpose or it is a bug ?
lets just say 2 span width is bigger than 1 so i can't drag it in the 1st element of the row and last element...
sorry for my english >,<

[h6ah4i]

@lkevin029 Thanks for pointing it out. I have just fixed the behavior for GridLayoutManager. Try the patched version of the library via jitpack.

build.gradle

repositories {
    maven { url "https://jitpack.io" }
}

dependencies {
    compile 'com.github.h6ah4i:android-advancedrecyclerview:fbb4f3bc883de883d79ec04d03d9cf74f2773322'
}

branch: https://github.com/h6ah4i/android-advancedrecyclerview/tree/feature/issue_193_improve_grid_layout_drag

[h6ah4i]

@lkevin029 The feature/issue_193_improve_grid_layout_drag branch has been merged into master branch now and released as v.0.8.7. Thanks.

[richardjbs]

@h6ah4i I am trying to implement your suggestion to be able to scale the dragged view while dragging. I was trying to customize the DraggingItemDecorator. The issue is that the decorator is being use by the RecyclerViewDragDropManager internally on the startDragging() which is a private method. So extending from RecyclerViewDragDropManager to override startDragging and specify a custom DraggingItemDecorator is not an option. A lot of classes within the library are protected so I cannot use them on my project. I don't want to include all the source code on my project. I was trying to keep using gradle to import it dynamically. Any suggestion on this? How should I proceed to specify the DraggingItemDecorator implementation that I want to use to the RecyclerViewDragDropManager?

Thanks

[h6ah4i]

@richardjbs Hi. Yes, I meant that my suggestion require to fork this project. I admit that forking & modifying DraggingItemDecorator is not the best option. I think creating a new stable classes or API is needed, because DraggingItemDecorator is tightly integrated to RecyclerViewDragDropManager and it will be changed in future.

Also, I will reopen this issue. I closed this issue by mistake, I have fixed the sub-issue in v0.8.7 but the main issue is still not fixed yet.

Thanks

[h6ah4i]

Related #292.

[h6ah4i]

This enhancement has been included in v0.10.0.

[egek92]

setDraggingItemScale(float scale) works perfect but it only draws inside the recyclerView bounds, is it possible to make it get bigger on outside as well?