libpdfviewer/app/src/main/java/org/grapheneos/pdfviewer/fragment/JumpToPageFragment.java

package org.grapheneos.pdfviewer.fragment;

import android.app.Dialog;
import android.os.Bundle;
import android.view.Gravity;
import android.widget.FrameLayout;
import android.widget.NumberPicker;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.fragment.app.DialogFragment;

import org.grapheneos.pdfviewer.PdfViewer;

public class JumpToPageFragment extends DialogFragment {
    public static final String TAG = "JumpToPageFragment";

    private final static String STATE_PICKER_CUR = "picker_cur";
    private final static String STATE_PICKER_MIN = "picker_min";
    private final static String STATE_PICKER_MAX = "picker_max";

    private NumberPicker mPicker;
    PdfViewer pdfViewer;

    public static JumpToPageFragment newInstance(PdfViewer pdfViewer) {
        JumpToPageFragment f = new JumpToPageFragment();
        f.pdfViewer = pdfViewer;
        return f;
    }

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        mPicker = new NumberPicker(getActivity());
        mPicker.setMinValue(1);
        mPicker.setMaxValue(pdfViewer.mNumPages);
        mPicker.setValue(pdfViewer.mPage);

        final FrameLayout layout = new FrameLayout(getActivity());
        layout.addView(mPicker, new FrameLayout.LayoutParams(
                FrameLayout.LayoutParams.WRAP_CONTENT,
                FrameLayout.LayoutParams.WRAP_CONTENT,
                Gravity.CENTER));

        return new AlertDialog.Builder(requireActivity())
                .setView(layout)
                .setPositiveButton(android.R.string.ok, (dialogInterface, i) -> {
                    mPicker.clearFocus();
                    pdfViewer.onJumpToPageInDocument(mPicker.getValue());
                })
                .setNegativeButton(android.R.string.cancel, null)
                .create();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        outState.putInt(STATE_PICKER_MIN, mPicker.getMinValue());
        outState.putInt(STATE_PICKER_MAX, mPicker.getMaxValue());
        outState.putInt(STATE_PICKER_CUR, mPicker.getValue());
    }
}