Java tutorial
/* Copyright 2016 COMP231 Team 6 - Anjali Macwan * * 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.anjalimacwan.fragment; import android.annotation.TargetApi; import android.app.Activity; import android.app.ActivityManager; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentTransaction; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.content.SharedPreferences; import android.content.res.Configuration; import android.graphics.Typeface; import android.os.Build; import android.os.Bundle; import android.support.v4.content.ContextCompat; import android.support.v4.content.LocalBroadcastManager; import android.support.v7.app.AppCompatActivity; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.view.inputmethod.InputMethodManager; import android.widget.EditText; import android.widget.LinearLayout; import android.widget.ScrollView; import android.widget.Toast; import com.anjalimacwan.MainActivity; import com.anjalimacwan.R; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; public class NoteEditFragment extends Fragment { private EditText noteContents; String filename = String.valueOf(System.currentTimeMillis()); String contentsOnLoad = ""; int length = 0; long draftName; boolean isSavedNote = false; String contents; boolean directEdit = false; // Receiver used to close fragment when a note is deleted public class DeleteNotesReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { String[] filesToDelete = intent.getStringArrayExtra("files"); for (Object file : filesToDelete) { if (filename.equals(file)) { // Hide soft keyboard EditText editText = (EditText) getActivity().findViewById(R.id.editText1); InputMethodManager imm = (InputMethodManager) getActivity() .getSystemService(Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(editText.getWindowToken(), 0); // Add NoteListFragment or WelcomeFragment Fragment fragment; if (getActivity().findViewById(R.id.layoutMain).getTag().equals("main-layout-normal")) fragment = new NoteListFragment(); else fragment = new WelcomeFragment(); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteListFragment") .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN).commit(); } } } } IntentFilter filter = new IntentFilter("com.anjalimacwan.DELETE_NOTES"); DeleteNotesReceiver receiver = new DeleteNotesReceiver(); /* The activity that creates an instance of this fragment must * implement this interface in order to receive event call backs. */ public interface Listener { void showBackButtonDialog(String filename); void showDeleteDialog(); void showSaveButtonDialog(); boolean isShareIntent(); String loadNote(String filename) throws IOException; String loadNoteTitle(String filename) throws IOException; } // Use this instance of the interface to deliver action events Listener listener; // Override the Fragment.onAttach() method to instantiate the Listener @SuppressWarnings("deprecation") @Override public void onAttach(Activity activity) { super.onAttach(activity); // Verify that the host activity implements the callback interface try { // Instantiate the Listener so we can send events to the host listener = (Listener) activity; } catch (ClassCastException e) { // The activity doesn't implement the interface, throw exception throw new ClassCastException(activity.toString() + " must implement Listener"); } } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.fragment_note_edit, container, false); } @TargetApi(Build.VERSION_CODES.LOLLIPOP) @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Set values setRetainInstance(true); setHasOptionsMenu(true); // Show the Up button in the action bar. ((AppCompatActivity) getActivity()).getSupportActionBar().setDisplayHomeAsUpEnabled(true); // Animate elevation change if (getActivity() instanceof MainActivity && getActivity().findViewById(R.id.layoutMain).getTag().equals("main-layout-large") && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { LinearLayout noteViewEdit = (LinearLayout) getActivity().findViewById(R.id.noteViewEdit); LinearLayout noteList = (LinearLayout) getActivity().findViewById(R.id.noteList); noteList.animate().z(0f); if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) noteViewEdit.animate() .z(getResources().getDimensionPixelSize(R.dimen.note_view_edit_elevation_land)); else noteViewEdit.animate().z(getResources().getDimensionPixelSize(R.dimen.note_view_edit_elevation)); } // Set up content view noteContents = (EditText) getActivity().findViewById(R.id.editText1); // Apply theme SharedPreferences pref = getActivity().getSharedPreferences(getActivity().getPackageName() + "_preferences", Context.MODE_PRIVATE); ScrollView scrollView = (ScrollView) getActivity().findViewById(R.id.scrollView1); String theme = pref.getString("theme", "light-sans"); if (theme.contains("light")) { noteContents.setTextColor(ContextCompat.getColor(getActivity(), R.color.text_color_primary)); noteContents.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background)); scrollView.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background)); } if (theme.contains("dark")) { noteContents.setTextColor(ContextCompat.getColor(getActivity(), R.color.text_color_primary_dark)); noteContents.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background_dark)); scrollView.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background_dark)); } if (theme.contains("sans")) noteContents.setTypeface(Typeface.SANS_SERIF); if (theme.contains("serif")) noteContents.setTypeface(Typeface.SERIF); if (theme.contains("monospace")) noteContents.setTypeface(Typeface.MONOSPACE); switch (pref.getString("font_size", "normal")) { case "smallest": noteContents.setTextSize(12); break; case "small": noteContents.setTextSize(14); break; case "normal": noteContents.setTextSize(16); break; case "large": noteContents.setTextSize(18); break; case "largest": noteContents.setTextSize(20); break; } // Get filename try { if (!getArguments().getString("filename").equals("new")) { filename = getArguments().getString("filename"); if (!filename.equals("draft")) isSavedNote = true; } } catch (NullPointerException e) { filename = "new"; } // Load note from existing file if (isSavedNote) { try { contentsOnLoad = listener.loadNote(filename); } catch (IOException e) { showToast(R.string.error_loading_note); finish(null); } // Set TextView contents length = contentsOnLoad.length(); noteContents.setText(contentsOnLoad); if (!pref.getBoolean("direct_edit", false)) noteContents.setSelection(length, length); } else if (filename.equals("draft")) { SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE); String draftContents = sharedPref.getString("draft-contents", null); length = draftContents.length(); noteContents.setText(draftContents); if (!pref.getBoolean("direct_edit", false)) noteContents.setSelection(length, length); } // Show soft keyboard InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE); imm.showSoftInput(noteContents, InputMethodManager.SHOW_IMPLICIT); } @Override public void onPause() { super.onPause(); // Disable saving drafts if user launched Notepad through a share intent if (!listener.isShareIntent() && !isRemoving()) { // Set current note contents to a String noteContents = (EditText) getActivity().findViewById(R.id.editText1); contents = noteContents.getText().toString(); if (!contents.equals("")) { SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE); // Save filename to draft-name preference SharedPreferences.Editor editor = sharedPref.edit(); editor.putLong("draft-name", Long.parseLong(filename)); editor.putBoolean("is-saved-note", isSavedNote); // Write draft to SharedPreferences editor.putString("draft-contents", contents); editor.apply(); // Show toast notification showToast(R.string.draft_saved); } } } @Override public void onResume() { super.onResume(); SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE); // Disable restoring drafts if user launched Notepad through a share intent if (!listener.isShareIntent()) { if (filename.equals("draft")) { // Restore draft preferences draftName = sharedPref.getLong("draft-name", 0); isSavedNote = sharedPref.getBoolean("is-saved-note", false); // Restore filename of draft filename = Long.toString(draftName); // Reload old file into memory, so that correct contentsOnLoad is set if (isSavedNote) { try { contentsOnLoad = listener.loadNote(filename); } catch (IOException e) { showToast(R.string.error_loading_note); finish(null); } } else contentsOnLoad = ""; // Notify the user that a draft has been restored showToast(R.string.draft_restored); } // Clear draft preferences SharedPreferences.Editor editor = sharedPref.edit(); editor.remove("draft-name"); editor.remove("is-saved-note"); editor.remove("draft-contents"); editor.apply(); } // Change window title String title; if (isSavedNote) try { title = listener.loadNoteTitle(filename); } catch (IOException e) { title = getResources().getString(R.string.edit_note); } else title = getResources().getString(R.string.action_new); getActivity().setTitle(title); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { ActivityManager.TaskDescription taskDescription = new ActivityManager.TaskDescription(title, null, ContextCompat.getColor(getActivity(), R.color.primary)); getActivity().setTaskDescription(taskDescription); } SharedPreferences pref = getActivity().getSharedPreferences(getActivity().getPackageName() + "_preferences", Context.MODE_PRIVATE); directEdit = pref.getBoolean("direct_edit", false); } // Register and unregister DeleteNotesReceiver @Override public void onStart() { super.onStart(); if (!listener.isShareIntent()) LocalBroadcastManager.getInstance(getActivity()).registerReceiver(receiver, filter); } @Override public void onStop() { super.onStop(); if (!listener.isShareIntent()) LocalBroadcastManager.getInstance(getActivity()).unregisterReceiver(receiver); } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.note_edit, menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { // Hide soft keyboard InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(getActivity().findViewById(R.id.editText1).getWindowToken(), 0); switch (item.getItemId()) { case android.R.id.home: // Override default Android "up" behavior to instead mimic the back button getActivity().onBackPressed(); return true; // Save button case R.id.action_save: // Get current note contents from EditText noteContents = (EditText) getActivity().findViewById(R.id.editText1); contents = noteContents.getText().toString(); // If EditText is empty, show toast informing user to enter some text if (contents.equals("")) showToast(R.string.empty_note); else if (directEdit) getActivity().onBackPressed(); else { // If no changes were made since last save, switch back to NoteViewFragment if (contentsOnLoad.equals(noteContents.getText().toString())) { Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment = new NoteViewFragment(); fragment.setArguments(bundle); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteViewFragment") .commit(); } else { SharedPreferences pref = getActivity().getSharedPreferences( getActivity().getPackageName() + "_preferences", Context.MODE_PRIVATE); if (pref.getBoolean("show_dialogs", true)) { // Show save button dialog listener.showSaveButtonDialog(); } else { try { saveNote(); if (listener.isShareIntent()) getActivity().finish(); else { Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment = new NoteViewFragment(); fragment.setArguments(bundle); getFragmentManager().beginTransaction() .replace(R.id.noteViewEdit, fragment, "NoteViewFragment").commit(); } } catch (IOException e) { // Show error message as toast if file fails to save showToast(R.string.failed_to_save); } } } } return true; // Delete button case R.id.action_delete: listener.showDeleteDialog(); return true; // Share menu item /*case R.id.action_share: // Set current note contents to a String contents = noteContents.getText().toString(); // If EditText is empty, show toast informing user to enter some text if(contents.equals("")) showToast(R.string.empty_note); else { // Send a share intent Intent intent = new Intent(); intent.setAction(Intent.ACTION_SEND); intent.putExtra(Intent.EXTRA_TEXT, contents); intent.setType("text/plain"); // Verify that the intent will resolve to an activity, and send if(intent.resolveActivity(getActivity().getPackageManager()) != null) startActivity(Intent.createChooser(intent, getResources().getText(R.string.send_to))); } return true;*/ default: return super.onOptionsItemSelected(item); } } private void deleteNote(String filename) { // Build the pathname to delete file, then perform delete operation File fileToDelete = new File(getActivity().getFilesDir() + File.separator + filename); fileToDelete.delete(); } // Saves notes to /data/data/com.anjalimacwan/files private void saveNote() throws IOException { // Set current note contents to a String noteContents = (EditText) getActivity().findViewById(R.id.editText1); contents = noteContents.getText().toString(); // Write the String to a new file with filename of current milliseconds of Unix time if (contents.equals("") && filename.equals("draft")) finish(null); else { // Set a new filename if this is not a draft String newFilename; if (filename.equals("draft")) newFilename = filename; else newFilename = String.valueOf(System.currentTimeMillis()); // Write note to disk FileOutputStream output = getActivity().openFileOutput(newFilename, Context.MODE_PRIVATE); output.write(contents.getBytes()); output.close(); // Delete old file if (!filename.equals("draft")) deleteNote(filename); // Show toast notification if (filename.equals("draft")) showToast(R.string.draft_saved); else showToast(R.string.note_saved); // Old file is no more if (!filename.equals("draft")) { filename = newFilename; contentsOnLoad = contents; length = contentsOnLoad.length(); } // Send broadcast to MainActivity to refresh list of notes Intent listNotesIntent = new Intent(); listNotesIntent.setAction("com.anjalimacwan.LIST_NOTES"); LocalBroadcastManager.getInstance(getActivity()).sendBroadcast(listNotesIntent); } } // Method used to generate toast notifications private void showToast(int message) { Toast toast = Toast.makeText(getActivity(), getResources().getString(message), Toast.LENGTH_SHORT); toast.show(); } public void onBackDialogNegativeClick(String filename) { // User touched the dialog's negative button showToast(R.string.changes_discarded); finish(filename); } public void onBackDialogPositiveClick(String filename) { // User touched the dialog's positive button try { saveNote(); finish(filename); } catch (IOException e) { // Show error message as toast if file fails to save showToast(R.string.failed_to_save); } } public void onDeleteDialogPositiveClick() { // User touched the dialog's positive button deleteNote(filename); showToast(R.string.note_deleted); if (getActivity().getComponentName().getClassName().equals("com.anjalimacwan.MainActivity") && getActivity().findViewById(R.id.layoutMain).getTag().equals("main-layout-large")) { // Send broadcast to NoteListFragment to refresh list of notes Intent listNotesIntent = new Intent(); listNotesIntent.setAction("com.anjalimacwan.LIST_NOTES"); LocalBroadcastManager.getInstance(getActivity()).sendBroadcast(listNotesIntent); } finish(null); } public void onSaveDialogNegativeClick() { // User touched the dialog's negative button if (isSavedNote) { showToast(R.string.changes_discarded); Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment = new NoteViewFragment(); fragment.setArguments(bundle); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteViewFragment") .commit(); } else { showToast(R.string.changes_discarded); finish(null); } } public void onSaveDialogPositiveClick() { // User touched the dialog's positive button try { saveNote(); if (listener.isShareIntent()) finish(null); else { Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment = new NoteViewFragment(); fragment.setArguments(bundle); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteViewFragment") .commit(); } } catch (IOException e) { // Show error message as toast if file fails to save showToast(R.string.failed_to_save); } } public void onBackPressed(String filename) { // Pop back stack if no changes were made since last save if (contentsOnLoad.equals(noteContents.getText().toString())) { finish(filename); } else { // Finish if EditText is empty if (noteContents.getText().toString().isEmpty()) finish(filename); else { SharedPreferences pref = getActivity().getSharedPreferences( getActivity().getPackageName() + "_preferences", Context.MODE_PRIVATE); if (pref.getBoolean("show_dialogs", true)) { // Show back button dialog listener.showBackButtonDialog(filename); } else { try { saveNote(); finish(filename); } catch (IOException e) { // Show error message as toast if file fails to save showToast(R.string.failed_to_save); } } } } } public void dispatchKeyShortcutEvent(int keyCode) { switch (keyCode) { // CTRL+S: Save case KeyEvent.KEYCODE_S: // Set current note contents to a String contents = noteContents.getText().toString(); // If EditText is empty, show toast informing user to enter some text if (contents.equals("")) showToast(R.string.empty_note); else { try { // Keyboard shortcut just saves the note; no dialog shown saveNote(); isSavedNote = true; // Change window title String title; try { title = listener.loadNoteTitle(filename); } catch (IOException e) { title = getResources().getString(R.string.edit_note); } getActivity().setTitle(title); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { ActivityManager.TaskDescription taskDescription = new ActivityManager.TaskDescription(title, null, ContextCompat.getColor(getActivity(), R.color.primary)); getActivity().setTaskDescription(taskDescription); } } catch (IOException e) { // Show error message as toast if file fails to save showToast(R.string.failed_to_save); } } break; // CTRL+D: Delete case KeyEvent.KEYCODE_D: listener.showDeleteDialog(); break; // CTRL+H: Share case KeyEvent.KEYCODE_H: // Set current note contents to a String contents = noteContents.getText().toString(); // If EditText is empty, show toast informing user to enter some text if (contents.equals("")) showToast(R.string.empty_note); else { // Send a share intent Intent shareIntent = new Intent(); shareIntent.setAction(Intent.ACTION_SEND); shareIntent.putExtra(Intent.EXTRA_TEXT, contents); shareIntent.setType("text/plain"); // Verify that the intent will resolve to an activity, and send if (shareIntent.resolveActivity(getActivity().getPackageManager()) != null) startActivity(Intent.createChooser(shareIntent, getResources().getText(R.string.send_to))); } break; } } private void finish(String filename) { if (listener.isShareIntent()) getActivity().finish(); else if (filename == null) { // Add NoteListFragment or WelcomeFragment Fragment fragment; if (getActivity().findViewById(R.id.layoutMain).getTag().equals("main-layout-normal")) fragment = new NoteListFragment(); else fragment = new WelcomeFragment(); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteListFragment") .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN).commit(); } else { Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment; String tag; if (directEdit) { fragment = new NoteEditFragment(); tag = "NoteEditFragment"; } else { fragment = new NoteViewFragment(); tag = "NoteViewFragment"; } fragment.setArguments(bundle); // Add NoteViewFragment or NoteEditFragment getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, tag) .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_CLOSE).commit(); } } public void switchNotes(String filename) { // Hide soft keyboard EditText editText = (EditText) getActivity().findViewById(R.id.editText1); InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE); imm.hideSoftInputFromWindow(editText.getWindowToken(), 0); // Act as if the back button was pressed onBackPressed(filename); } public String getFilename() { return filename; } }