softwarehomework/testing/RecyclerItemTouchHelper.java

package com.example.doitnow;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Typeface;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.view.Gravity;
import android.view.View;
import android.widget.TextView;

import androidx.core.content.ContextCompat;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.RecyclerView;

import com.example.doitnow.Adapter.ToDoAdapter;

public class RecyclerItemTouchHelper extends ItemTouchHelper.SimpleCallback {
    private ToDoAdapter adapter;

    public RecyclerItemTouchHelper(ToDoAdapter adapter) {
        super(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT);
        this.adapter = adapter;
    }

    @Override
    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        return false;
    }

    @Override
    public void onSwiped(final RecyclerView.ViewHolder viewHolder, int direction) {
        final int position = viewHolder.getAdapterPosition();
        if (direction == ItemTouchHelper.LEFT) {
            AlertDialog.Builder builder = new AlertDialog.Builder(adapter.getContext());
            builder.setTitle("Delete Task");
            builder.setMessage("Are you sure you want to delete this Task?");
            builder.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    adapter.deleteItem(position);
                }
            });
            builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int i) {
                    adapter.notifyItemChanged(viewHolder.getAdapterPosition());
                }
            });
            AlertDialog dialog = builder.create();
            dialog.show();

            TextView messageText = dialog.findViewById(android.R.id.message);
            if (messageText != null) {
                messageText.setTextColor(Color.parseColor("#8E7DBE")); // 紫色
                messageText.setTextSize(16); // 如果你想微調大小
                messageText.setGravity(Gravity.CENTER);
                messageText.setTypeface(null, Typeface.BOLD);
            }
            TextView titleText = dialog.findViewById(
                    dialog.getContext().getResources().getIdentifier("alertTitle", "id", "android"));
            if (titleText != null) {
                titleText.setTextColor(Color.parseColor("#8E7DBE"));
                titleText.setTextSize(18);
                titleText.setTypeface(null, Typeface.BOLD);
            }
            dialog.getButton(AlertDialog.BUTTON_POSITIVE).setTextColor(Color.parseColor("#8E7DBE"));
            dialog.getButton(AlertDialog.BUTTON_NEGATIVE).setTextColor(Color.parseColor("#A0A0A0"));
        } else {
            adapter.editItem(position);
        }
    }

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

        Drawable icon;
        ColorDrawable background;

        View itemView = viewHolder.itemView;
        int backgroundCornerOffset = 20;

        if (dX > 0) {
            icon = ContextCompat.getDrawable(adapter.getContext(), R.drawable.baseline_edit);
            background = new ColorDrawable(ContextCompat.getColor(adapter.getContext(), R.color.colorPrimaryDark));
        } else {
            icon = ContextCompat.getDrawable(adapter.getContext(), R.drawable.baseline_delete);
            background = new ColorDrawable(Color.RED);
        }

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

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

            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, iconButtom);

            background.setBounds(itemView.getRight() + ((int) dX) - backgroundCornerOffset, itemView.getTop(),
                    itemView.getRight(), itemView.getBottom());
        } else {
            background.setBounds(0, 0, 0, 0);
        }
        background.draw(c);
        icon.draw(c);
    }
}