material-dialogs/library/src/main/java/com/afollestad/materialdialogs/MaterialDialogAdapter.java

package com.afollestad.materialdialogs;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.content.res.Configuration;
import android.os.Build;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CompoundButton;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.afollestad.materialdialogs.internal.MDCheckBox;
import com.afollestad.materialdialogs.internal.MDRadioButton;

class MaterialDialogAdapter extends ArrayAdapter<CharSequence> {

    private final MaterialDialog dialog;
    private final GravityEnum itemGravity;

    public MaterialDialogAdapter(MaterialDialog dialog, int resource, int textViewResourceId, CharSequence[] objects) {
        super(dialog.mBuilder.context, resource, textViewResourceId, objects);
        this.dialog = dialog;
        this.itemGravity = dialog.mBuilder.itemsGravity;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @SuppressLint("WrongViewCast")
    @Override
    public View getView(final int index, View convertView, ViewGroup parent) {
        final View view = super.getView(index, convertView, parent);
        TextView tv = (TextView) view.findViewById(R.id.title);
        switch (dialog.listType) {
            case SINGLE: {
                @SuppressLint("CutPasteId")
                MDRadioButton radio = (MDRadioButton) view.findViewById(R.id.control);
                boolean selected = dialog.mBuilder.selectedIndex == index;
                radio.setColorFilter(dialog.mBuilder.widgetColor);
                radio.setChecked(selected);
                break;
            }
            case MULTI: {
                @SuppressLint("CutPasteId")
                MDCheckBox checkbox = (MDCheckBox) view.findViewById(R.id.control);
                boolean selected = dialog.selectedIndicesList.contains(index);
                checkbox.setColorFilter(dialog.mBuilder.widgetColor);
                checkbox.setChecked(selected);
                break;
            }
        }
        tv.setText(dialog.mBuilder.items[index]);
        tv.setTextColor(dialog.mBuilder.itemColor);
        dialog.setTypeface(tv, dialog.mBuilder.regularFont);
        view.setTag(index + ":" + dialog.mBuilder.items[index]);
        setupGravity((ViewGroup) view);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            ViewGroup group = (ViewGroup) view;
            if (group.getChildCount() == 2) {
                // Remove circular selector from check boxes and radio buttons on Lollipop
                if (group.getChildAt(0) instanceof CompoundButton)
                    group.getChildAt(0).setBackground(null);
                else if (group.getChildAt(1) instanceof CompoundButton)
                    group.getChildAt(1).setBackground(null);
            }
        }

        return view;
    }

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
    private void setupGravity(ViewGroup view) {
        final LinearLayout itemRoot = (LinearLayout) view;
        final int gravityInt = itemGravity.getGravityInt();
        itemRoot.setGravity(gravityInt | Gravity.CENTER_VERTICAL);

        if (view.getChildCount() == 2) {
            if (itemGravity == GravityEnum.END && !isRTL() && view.getChildAt(0) instanceof CompoundButton) {
                CompoundButton first = (CompoundButton) view.getChildAt(0);
                view.removeView(first);

                TextView second = (TextView) view.getChildAt(0);
                view.removeView(second);
                second.setPadding(second.getPaddingRight(), second.getPaddingTop(),
                        second.getPaddingLeft(), second.getPaddingBottom());

                view.addView(second);
                view.addView(first);
            } else if (itemGravity == GravityEnum.START && isRTL() && view.getChildAt(1) instanceof CompoundButton) {
                CompoundButton first = (CompoundButton) view.getChildAt(1);
                view.removeView(first);

                TextView second = (TextView) view.getChildAt(0);
                view.removeView(second);
                second.setPadding(second.getPaddingRight(), second.getPaddingTop(),
                        second.getPaddingRight(), second.getPaddingBottom());

                view.addView(first);
                view.addView(second);
            }
        }
    }

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
    private boolean isRTL() {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1)
            return false;
        Configuration config = getContext().getResources().getConfiguration();
        return config.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL;
    }
}