SwipeToDeleteCallbac.java

package io.keinix.protoflow.util;

import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.helper.ItemTouchHelper;
import android.view.View;

import io.keinix.protoflow.R;
import io.keinix.protoflow.tasks.TasksAdapter;

public  class SwipeToDeleteCallback extends ItemTouchHelper.SimpleCallback {

    private TasksAdapter mAdapter;

    private Drawable icon;
    private final ColorDrawable background;


    public SwipeToDeleteCallback(MyAdapter adapter) {
        super(0,ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT);
        mAdapter = adapter;
        icon = ContextCompat.getDrawable(mAdapter.getContext(),
                R.drawable.ic_delete_white_36);
        background = new ColorDrawable(Color.RED);
    }

    @Override
    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        // used for up and down movements
        return false;
    }

    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
        int position = viewHolder.getAdapterPosition();
        mAdapter.deleteTask(position);
    }

    @Override
    public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
        super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);

        View itemView = viewHolder.itemView;
        int backgroundCornerOffset = 20; //so background is behind the rounded corners of itemView

        int iconMargin = (itemView.getHeight() - icon.getIntrinsicHeight()) / 2;
        int iconTop = itemView.getTop() + (itemView.getHeight() - icon.getIntrinsicHeight()) / 2;
        int iconBottom = iconTop + icon.getIntrinsicHeight();

        if (dX > 0) { // Swiping to the right
            int iconLeft = itemView.getLeft() + iconMargin + icon.getIntrinsicWidth();
            int iconRight = itemView.getLeft() + iconMargin;
            icon.setBounds(iconLeft, iconTop, iconRight, iconBottom);

            background.setBounds(itemView.getLeft(), itemView.getTop(),
                    itemView.getLeft() + ((int) dX) + backgroundCornerOffset, itemView.getBottom());
        } else if (dX < 0) { // Swiping to the left
            int iconLeft = itemView.getRight() - iconMargin - icon.getIntrinsicWidth();
            int iconRight = itemView.getRight() - iconMargin;
            icon.setBounds(iconLeft, iconTop, iconRight, iconBottom);

            background.setBounds(itemView.getRight() + ((int) dX) - backgroundCornerOffset,
                    itemView.getTop(), itemView.getRight(), itemView.getBottom());
        } else { // view is unSwiped
            background.setBounds(0, 0, 0, 0);
        }

        background.draw(c);
        icon.draw(c);
    }
}

hello.
first sorry for my bad english
i use your code in my project it is great, but i had to apply this change
this-> if (dX > 0) { // Swiping to the right
int iconLeft = itemView.getLeft() + iconMargin + icon.getIntrinsicWidth();
int iconRight = itemView.getLeft() + iconMargin;

to->
if (dX > 0) { // Swiping to the right
int iconLeft = itemView.getLeft() + iconMargin;
int iconRight = iconLeft+ icon.getIntrinsicWidth();

is there a full working project for this as I've been unable to retrofit into my app (simply not experienced enough at java and android).

what are the last two import statements?

just loading this code into my sample app I get errors with 'getcontext()' in the following icon = ContextCompat.getDrawable(mAdapter.getContext(),
R.drawable.ic_delete_white_36);

and the deletetask() function cannot be resolved.

@millesm:

You can create the asset for R.drawable.ic_delete_white_36. File -> New -> Vector Asset. You can pick your icon from there.

Then create the class MyAdapter with a method named deleteTask then pass an instance of that to the constructor of SwipeToDeleteCallback.

Where I can find a complete project zip for this?

@araxis +1 ! thank you for sharing

Code leaves the bloody trash can in the middle of the row if the user doesn't complete the swipe!

Hi,
there is a bug on this for left to right swipe

line 55 and 56 should be

int iconLeft = itemView.getLeft() + iconMargin;
int iconRight = itemView.getLeft() + iconMargin + icon.getIntrinsicWidth();

Hi,
there is a bug on this for left to right swipe

line 55 and 56 should be

int iconLeft = itemView.getLeft() + iconMargin;
int iconRight = itemView.getLeft() + iconMargin + icon.getIntrinsicWidth();

Thank you! That saved my day :)

My problem was that the icon not disappeared after the user cancelled the swipe.
This solved my problem:

} else {  // view is unSwiped
      icon.setBounds(0, 0, 0, 0);     // ADD THIS LINE
      background.setBounds(0, 0, 0, 0);
   }

Can you provide a link to the TaskAdapter code and coordinator_layout.xml. Thanks

My problem was that the icon not disappeared after the user cancelled the swipe.
This solved my problem:

} else {  // view is unSwiped
      icon.setBounds(0, 0, 0, 0);     // ADD THIS LINE
      background.setBounds(0, 0, 0, 0);
   }

or you just don't draw it

for me, Icon does not show. icon.draw(c) is not working

@ZaccharieBOUVY you're welcome.

thanks man!