Java tutorial
/* * Copyright (C) 2016 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.android.deskclock; import android.annotation.SuppressLint; import android.app.Activity; import android.app.DialogFragment; import android.app.FragmentManager; import android.app.FragmentTransaction; import android.app.LoaderManager; import android.content.AsyncTaskLoader; import android.content.Context; import android.content.DialogInterface; import android.content.Loader; import android.content.pm.PackageManager; import android.database.Cursor; import android.media.AudioManager; import android.media.RingtoneManager; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.support.annotation.NonNull; import android.support.annotation.StringRes; import android.support.v13.app.FragmentCompat; import android.support.v4.content.ContextCompat; import android.support.v7.app.AlertDialog; import android.util.Pair; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ListView; import android.widget.TextView; import java.util.ArrayList; import java.util.List; import static android.Manifest.permission.READ_EXTERNAL_STORAGE; /** * This ringtone picker offers some flexibility over the system ringtone picker. It can be themed * and it allows control of the ringtones that are displayed and their labels. */ public final class RingtonePickerDialogFragment extends DialogFragment implements DialogInterface.OnClickListener, FragmentCompat.OnRequestPermissionsResultCallback, LoaderManager.LoaderCallbacks<RingtoneManager> { private static final String ARGS_KEY_TITLE = "title"; private static final String ARGS_KEY_DEFAULT_RINGTONE_TITLE = "default_ringtone_title"; private static final String ARGS_KEY_DEFAULT_RINGTONE_URI = "default_ringtone_uri"; private static final String ARGS_KEY_EXISTING_RINGTONE_URI = "existing_ringtone_uri"; private static final String STATE_KEY_REQUESTING_PERMISSION = "requesting_permission"; private static final String STATE_KEY_SELECTED_RINGTONE_URI = "selected_ringtone_uri"; private boolean mRequestingPermission; private Uri mSelectedRingtoneUri; private RingtoneAdapter mRingtoneAdapter; private AlertDialog mDialog; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Restore saved instance state. if (savedInstanceState != null) { mRequestingPermission = savedInstanceState.getBoolean(STATE_KEY_REQUESTING_PERMISSION); mSelectedRingtoneUri = savedInstanceState.getParcelable(STATE_KEY_SELECTED_RINGTONE_URI); } else { // Initialize selection to the existing ringtone. mSelectedRingtoneUri = getArguments().getParcelable(ARGS_KEY_EXISTING_RINGTONE_URI); } } @Override public AlertDialog onCreateDialog(Bundle savedInstanceState) { final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity(), R.style.DialogTheme); final Bundle args = getArguments(); mRingtoneAdapter = new RingtoneAdapter(builder.getContext()) .addStaticRingtone(R.string.silent_ringtone_title, Utils.RINGTONE_SILENT) .addStaticRingtone(args.getInt(ARGS_KEY_DEFAULT_RINGTONE_TITLE), (Uri) args.getParcelable(ARGS_KEY_DEFAULT_RINGTONE_URI)); mDialog = builder.setTitle(args.getInt(ARGS_KEY_TITLE)) .setSingleChoiceItems(mRingtoneAdapter, -1, this /* listener */) .setPositiveButton(android.R.string.ok, this /* listener */) .setNegativeButton(android.R.string.cancel, null /* listener */).create(); return mDialog; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); if (savedInstanceState == null && ContextCompat.checkSelfPermission(getActivity(), READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { mRequestingPermission = true; FragmentCompat.requestPermissions(this, new String[] { READ_EXTERNAL_STORAGE }, 0 /* requestCode */); } else if (!mRequestingPermission) { getLoaderManager().initLoader(0 /* id */, null /* args */, this /* callback */); } } @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); for (final String permission : permissions) { if (READ_EXTERNAL_STORAGE.equals(permission)) { mRequestingPermission = false; // Show the dialog now that we've prompted the user for permissions. mDialog.show(); getLoaderManager().initLoader(0 /* id */, null /* args */, this /* callback */); break; } } } @Override public void onStart() { super.onStart(); // Disable the positive button until we have a valid selection (Note: this is the first // point in the fragment's lifecycle that the dialog *should* have all its views). final View positiveButton = mDialog.getButton(DialogInterface.BUTTON_POSITIVE); if (positiveButton != null) { positiveButton.setEnabled(!mRingtoneAdapter.isEmpty() && mSelectedRingtoneUri != null); } // Hide the dialog if we are currently requesting permissions. if (mRequestingPermission) { mDialog.hide(); } } @Override public void onResume() { super.onResume(); // Allow the volume rocker to control the alarm stream volume while the picker is showing. mDialog.setVolumeControlStream(AudioManager.STREAM_ALARM); } @Override public void onSaveInstanceState(@NonNull Bundle outState) { super.onSaveInstanceState(outState); outState.putBoolean(STATE_KEY_REQUESTING_PERMISSION, mRequestingPermission); outState.putParcelable(STATE_KEY_SELECTED_RINGTONE_URI, mSelectedRingtoneUri); } @Override public void onStop() { super.onStop(); // Stop playing the preview unless we are currently undergoing a configuration change // (e.g. orientation). final Activity activity = getActivity(); if (activity != null && !activity.isChangingConfigurations()) { RingtonePreviewKlaxon.stop(activity); } } @Override public Loader<RingtoneManager> onCreateLoader(int id, Bundle args) { return new RingtoneManagerLoader(getActivity()); } @Override public void onLoadFinished(Loader<RingtoneManager> loader, RingtoneManager ringtoneManager) { // Swap in the new ringtone manager. mRingtoneAdapter.setRingtoneManager(ringtoneManager); // Preserve the selected ringtone. final ListView listView = mDialog.getListView(); final int checkedPosition = mRingtoneAdapter.getRingtonePosition(mSelectedRingtoneUri); if (checkedPosition != ListView.INVALID_POSITION) { listView.setItemChecked(checkedPosition, true); // Also scroll the list to the selected ringtone (this method is poorly named). listView.setSelection(checkedPosition); } else { // Can't find the selected ringtone, clear the current selection. mSelectedRingtoneUri = null; listView.clearChoices(); } // Enable the positive button if we have a valid selection (Note: the positive button may // be null if this callback returns before onStart). final View positiveButton = mDialog.getButton(DialogInterface.BUTTON_POSITIVE); if (positiveButton != null) { positiveButton.setEnabled(mSelectedRingtoneUri != null); } // On M devices the checked view's drawable state isn't updated properly when it is first // bound, so we must use a blunt approach to force it to refresh correctly. if (Build.VERSION.SDK_INT == Build.VERSION_CODES.M) { listView.post(new Runnable() { @Override public void run() { for (int i = listView.getChildCount() - 1; i >= 0; --i) { listView.getChildAt(i).refreshDrawableState(); } } }); } } @Override public void onLoaderReset(Loader<RingtoneManager> loader) { mRingtoneAdapter.setRingtoneManager(null); } @Override public void onClick(DialogInterface dialog, int which) { if (which == DialogInterface.BUTTON_POSITIVE) { if (mSelectedRingtoneUri != null) { OnRingtoneSelectedListener listener = null; if (getParentFragment() instanceof OnRingtoneSelectedListener) { listener = (OnRingtoneSelectedListener) getParentFragment(); } else if (getActivity() instanceof OnRingtoneSelectedListener) { listener = (OnRingtoneSelectedListener) getActivity(); } if (listener != null) { listener.onRingtoneSelected(getTag(), mSelectedRingtoneUri); } } } else if (which >= 0) { // Update the selected ringtone, enabling the positive button if valid. mSelectedRingtoneUri = mRingtoneAdapter.getItem(which); // Enable the positive button if we have a valid selection. final View positiveButton = mDialog.getButton(DialogInterface.BUTTON_POSITIVE); positiveButton.setEnabled(mSelectedRingtoneUri != null); // Play the preview for the clicked ringtone. if (mSelectedRingtoneUri == null || mSelectedRingtoneUri.equals(Utils.RINGTONE_SILENT)) { RingtonePreviewKlaxon.stop(getActivity()); } else { RingtonePreviewKlaxon.start(getActivity(), mSelectedRingtoneUri); } } } /** * Callback interface for when a ringtone is selected via a picker. Typically implemented by * the activity or fragment which launches the ringtone picker. */ public interface OnRingtoneSelectedListener { /** * Called when the ringtone picker dialog is confirmed and dismissed. * * @param tag the tag of the ringtone picker dialog fragment * @param ringtoneUri the uri of the ringtone that was picked */ void onRingtoneSelected(String tag, Uri ringtoneUri); } public static final class Builder { private final Bundle mArgs = new Bundle(); public Builder setTitle(@StringRes int titleId) { mArgs.putInt(ARGS_KEY_TITLE, titleId); return this; } public Builder setDefaultRingtoneTitle(@StringRes int titleId) { mArgs.putInt(ARGS_KEY_DEFAULT_RINGTONE_TITLE, titleId); return this; } public Builder setDefaultRingtoneUri(Uri ringtoneUri) { mArgs.putParcelable(ARGS_KEY_DEFAULT_RINGTONE_URI, ringtoneUri); return this; } public Builder setExistingRingtoneUri(Uri ringtoneUri) { mArgs.putParcelable(ARGS_KEY_EXISTING_RINGTONE_URI, ringtoneUri); return this; } public void show(FragmentManager fragmentManager, String tag) { final DialogFragment fragment = new RingtonePickerDialogFragment(); fragment.setArguments(mArgs); fragment.show(fragmentManager, tag); } public void show(FragmentTransaction fragmentTransaction, String tag) { final DialogFragment fragment = new RingtonePickerDialogFragment(); fragment.setArguments(mArgs); fragment.show(fragmentTransaction, tag); } } private static class RingtoneManagerLoader extends AsyncTaskLoader<RingtoneManager> { private RingtoneManager mRingtoneManager; private Cursor mRingtoneCursor; public RingtoneManagerLoader(Context context) { super(context); } @Override public RingtoneManager loadInBackground() { final RingtoneManager ringtoneManager = new RingtoneManager(getContext()); ringtoneManager.setType(AudioManager.STREAM_ALARM); // Force the ringtone manager to load its ringtones. The cursor will be cached // internally by the ringtone manager. ringtoneManager.getCursor(); return ringtoneManager; } @Override public void deliverResult(RingtoneManager ringtoneManager) { if (mRingtoneManager != ringtoneManager) { if (mRingtoneCursor != null && !mRingtoneCursor.isClosed()) { mRingtoneCursor.close(); } mRingtoneManager = ringtoneManager; mRingtoneCursor = mRingtoneManager.getCursor(); } super.deliverResult(ringtoneManager); } @Override protected void onReset() { super.onReset(); if (mRingtoneCursor != null && !mRingtoneCursor.isClosed()) { mRingtoneCursor.close(); mRingtoneCursor = null; } mRingtoneManager = null; } @Override protected void onStartLoading() { super.onStartLoading(); if (mRingtoneManager != null) { deliverResult(mRingtoneManager); } else { forceLoad(); } } } private static class RingtoneAdapter extends BaseAdapter { private final List<Pair<Integer, Uri>> mStaticRingtones; private final LayoutInflater mLayoutInflater; private RingtoneManager mRingtoneManager; private Cursor mRingtoneCursor; public RingtoneAdapter(Context context) { mStaticRingtones = new ArrayList<>(2 /* magic */); mLayoutInflater = LayoutInflater.from(context); } /** * Add a static ringtone item to display before the system ones. * * @param title the title to display for the ringtone * @param ringtoneUri the {@link Uri} for the ringtone * @return this object so method calls may be chained */ public RingtoneAdapter addStaticRingtone(@StringRes int title, Uri ringtoneUri) { if (title != 0 && ringtoneUri != null) { mStaticRingtones.add(Pair.create(title, ringtoneUri)); notifyDataSetChanged(); } return this; } /** * Set the {@link RingtoneManager} to query for system ringtones. * * @param ringtoneManager the {@link RingtoneManager} to query for system ringtones * @return this object so method calls may be chained */ public RingtoneAdapter setRingtoneManager(RingtoneManager ringtoneManager) { mRingtoneManager = ringtoneManager; mRingtoneCursor = ringtoneManager == null ? null : ringtoneManager.getCursor(); notifyDataSetChanged(); return this; } /** * Returns the position of the given ringtone uri. * * @param ringtoneUri the {@link Uri} to retrieve the position of * @return the ringtones position in the adapter */ public int getRingtonePosition(Uri ringtoneUri) { if (ringtoneUri == null) { return ListView.INVALID_POSITION; } final int staticRingtoneCount = mStaticRingtones.size(); for (int position = 0; position < staticRingtoneCount; ++position) { if (ringtoneUri.equals(mStaticRingtones.get(position).second)) { return position; } } final int position = mRingtoneManager.getRingtonePosition(ringtoneUri); if (position != -1) { return position + staticRingtoneCount; } return ListView.INVALID_POSITION; } @Override public int getCount() { if (mRingtoneCursor == null) { return 0; } return mStaticRingtones.size() + mRingtoneCursor.getCount(); } @Override public Uri getItem(int position) { final int staticRingtoneCount = mStaticRingtones.size(); if (position < staticRingtoneCount) { return mStaticRingtones.get(position).second; } return mRingtoneManager.getRingtoneUri(position - staticRingtoneCount); } @Override public long getItemId(int position) { return position; } @Override @SuppressLint("PrivateResource") public View getView(int position, View view, ViewGroup parent) { if (view == null) { // Use AlertDialog's singleChoiceItemLayout directly here, if this breaks in the // future just copy the layout to DeskClock's res/. view = mLayoutInflater.inflate(R.layout.select_dialog_singlechoice_material, parent, false /* attachToRoot */); } final TextView textView = (TextView) view.findViewById(android.R.id.text1); final int staticRingtoneCount = mStaticRingtones.size(); if (position < staticRingtoneCount) { textView.setText(mStaticRingtones.get(position).first); } else { mRingtoneCursor.moveToPosition(position - staticRingtoneCount); textView.setText(mRingtoneCursor.getString(RingtoneManager.TITLE_COLUMN_INDEX)); } return view; } } }