Java tutorial
/* Copyright 2014 Braden Farmer * * 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.farmerbb.notepad.fragment; import android.annotation.TargetApi; import android.app.Activity; import android.app.ActivityManager; import android.content.ActivityNotFoundException; import android.graphics.Bitmap; import android.graphics.drawable.BitmapDrawable; import android.net.Uri; import android.os.FileUriExposedException; import android.support.v4.app.DialogFragment; 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.util.Base64; import android.view.GestureDetector; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.webkit.WebView; import android.webkit.WebViewClient; import android.widget.LinearLayout; import android.widget.ScrollView; import android.widget.TextView; import android.widget.Toast; import com.farmerbb.notepad.R; import com.farmerbb.notepad.fragment.dialog.FirstViewDialogFragment; import org.apache.commons.lang3.StringUtils; import java.io.File; import java.io.IOException; import us.feras.mdv.MarkdownView; public class NoteViewFragment extends Fragment { private MarkdownView markdownView; String filename = ""; String contentsOnLoad = ""; int firstLoad; boolean showMessage = true; // 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)) { // 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.farmerbb.notepad.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 showDeleteDialog(); String loadNote(String filename) throws IOException; String loadNoteTitle(String filename) throws IOException; void exportNote(String filename); void printNote(String contentToPrint); } // 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) { SharedPreferences pref = getActivity().getSharedPreferences(getActivity().getPackageName() + "_preferences", Context.MODE_PRIVATE); return inflater .inflate(pref.getBoolean("markdown", false) && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? R.layout.fragment_note_view_md : R.layout.fragment_note_view, container, false); } @TargetApi(Build.VERSION_CODES.LOLLIPOP) @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Set values setRetainInstance(true); setHasOptionsMenu(true); // Get filename of saved note filename = getArguments().getString("filename"); // Change window title String title; try { title = listener.loadNoteTitle(filename); } catch (IOException e) { title = getResources().getString(R.string.view_note); } getActivity().setTitle(title); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { Bitmap bitmap = ((BitmapDrawable) ContextCompat.getDrawable(getActivity(), R.drawable.ic_recents_logo)) .getBitmap(); ActivityManager.TaskDescription taskDescription = new ActivityManager.TaskDescription(title, bitmap, ContextCompat.getColor(getActivity(), R.color.primary)); getActivity().setTaskDescription(taskDescription); } // Show the Up button in the action bar. ((AppCompatActivity) getActivity()).getSupportActionBar().setDisplayHomeAsUpEnabled(true); // Animate elevation change if (getActivity().findViewById(R.id.layoutMain).getTag().equals("main-layout-large") && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { LinearLayout noteViewEdit = getActivity().findViewById(R.id.noteViewEdit); LinearLayout noteList = 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 TextView noteContents = getActivity().findViewById(R.id.textView); markdownView = getActivity().findViewById(R.id.markdownView); // Apply theme SharedPreferences pref = getActivity().getSharedPreferences(getActivity().getPackageName() + "_preferences", Context.MODE_PRIVATE); ScrollView scrollView = getActivity().findViewById(R.id.scrollView); String theme = pref.getString("theme", "light-sans"); int textSize = -1; int textColor = -1; String fontFamily = null; if (theme.contains("light")) { if (noteContents != null) { noteContents.setTextColor(ContextCompat.getColor(getActivity(), R.color.text_color_primary)); noteContents.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background)); } if (markdownView != null) { markdownView.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background)); textColor = ContextCompat.getColor(getActivity(), R.color.text_color_primary); } scrollView.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background)); } if (theme.contains("dark")) { if (noteContents != null) { noteContents.setTextColor(ContextCompat.getColor(getActivity(), R.color.text_color_primary_dark)); noteContents .setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background_dark)); } if (markdownView != null) { markdownView .setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background_dark)); textColor = ContextCompat.getColor(getActivity(), R.color.text_color_primary_dark); } scrollView.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.window_background_dark)); } if (theme.contains("sans")) { if (noteContents != null) noteContents.setTypeface(Typeface.SANS_SERIF); if (markdownView != null) fontFamily = "sans-serif"; } if (theme.contains("serif")) { if (noteContents != null) noteContents.setTypeface(Typeface.SERIF); if (markdownView != null) fontFamily = "serif"; } if (theme.contains("monospace")) { if (noteContents != null) noteContents.setTypeface(Typeface.MONOSPACE); if (markdownView != null) fontFamily = "monospace"; } switch (pref.getString("font_size", "normal")) { case "smallest": textSize = 12; break; case "small": textSize = 14; break; case "normal": textSize = 16; break; case "large": textSize = 18; break; case "largest": textSize = 20; break; } if (noteContents != null) noteContents.setTextSize(textSize); String css = ""; if (markdownView != null) { String topBottom = " " + Float.toString(getResources().getDimension(R.dimen.padding_top_bottom) / getResources().getDisplayMetrics().density) + "px"; String leftRight = " " + Float.toString(getResources().getDimension(R.dimen.padding_left_right) / getResources().getDisplayMetrics().density) + "px"; String fontSize = " " + Integer.toString(textSize) + "px"; String fontColor = " #" + StringUtils.remove(Integer.toHexString(textColor), "ff"); String linkColor = " #" + StringUtils.remove( Integer.toHexString(new TextView(getActivity()).getLinkTextColors().getDefaultColor()), "ff"); css = "body { " + "margin:" + topBottom + topBottom + leftRight + leftRight + "; " + "font-family:" + fontFamily + "; " + "font-size:" + fontSize + "; " + "color:" + fontColor + "; " + "}" + "a { " + "color:" + linkColor + "; " + "}"; markdownView.getSettings().setJavaScriptEnabled(false); markdownView.getSettings().setLoadsImagesAutomatically(false); markdownView.setWebViewClient(new WebViewClient() { @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url)); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) try { startActivity(intent); } catch (ActivityNotFoundException | FileUriExposedException e) { /* Gracefully fail */ } else try { startActivity(intent); } catch (ActivityNotFoundException e) { /* Gracefully fail */ } return true; } }); } // Load note contents try { contentsOnLoad = listener.loadNote(filename); } catch (IOException e) { showToast(R.string.error_loading_note); // 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(); } // Set TextView contents if (noteContents != null) noteContents.setText(contentsOnLoad); if (markdownView != null) markdownView.loadMarkdown(contentsOnLoad, "data:text/css;base64," + Base64.encodeToString(css.getBytes(), Base64.DEFAULT)); // Show a toast message if this is the user's first time viewing a note final SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE); firstLoad = sharedPref.getInt("first-load", 0); if (firstLoad == 0) { // Show dialog with info DialogFragment firstLoad = new FirstViewDialogFragment(); firstLoad.show(getFragmentManager(), "firstloadfragment"); // Set first-load preference to 1; we don't need to show the dialog anymore SharedPreferences.Editor editor = sharedPref.edit(); editor.putInt("first-load", 1); editor.apply(); } // Detect single and double-taps using GestureDetector final GestureDetector detector = new GestureDetector(getActivity(), new GestureDetector.OnGestureListener() { @Override public boolean onSingleTapUp(MotionEvent e) { return false; } @Override public void onShowPress(MotionEvent e) { } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { return false; } @Override public void onLongPress(MotionEvent e) { } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { return false; } @Override public boolean onDown(MotionEvent e) { return false; } }); detector.setOnDoubleTapListener(new GestureDetector.OnDoubleTapListener() { @Override public boolean onDoubleTap(MotionEvent e) { if (sharedPref.getBoolean("show_double_tap_message", true)) { SharedPreferences.Editor editor = sharedPref.edit(); editor.putBoolean("show_double_tap_message", false); editor.apply(); } Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment = new NoteEditFragment(); fragment.setArguments(bundle); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteEditFragment") .commit(); return false; } @Override public boolean onDoubleTapEvent(MotionEvent e) { return false; } @Override public boolean onSingleTapConfirmed(MotionEvent e) { if (sharedPref.getBoolean("show_double_tap_message", true) && showMessage) { showToastLong(R.string.double_tap); showMessage = false; } return false; } }); if (noteContents != null) noteContents.setOnTouchListener((v, event) -> { detector.onTouchEvent(event); return false; }); if (markdownView != null) markdownView.setOnTouchListener((v, event) -> { detector.onTouchEvent(event); return false; }); } // Register and unregister DeleteNotesReceiver @Override public void onStart() { super.onStart(); LocalBroadcastManager.getInstance(getActivity()).registerReceiver(receiver, filter); } @Override public void onStop() { super.onStop(); LocalBroadcastManager.getInstance(getActivity()).unregisterReceiver(receiver); } @Override public void onResume() { super.onResume(); if (markdownView != null && markdownView.canGoBack()) markdownView.goBack(); } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.note_view, menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: // Override default Android "up" behavior to instead mimic the back button getActivity().onBackPressed(); return true; // Edit button case R.id.action_edit: Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment = new NoteEditFragment(); fragment.setArguments(bundle); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteEditFragment") .commit(); return true; // Delete button case R.id.action_delete: listener.showDeleteDialog(); return true; // Share menu item case R.id.action_share: // Send a share intent Intent intent = new Intent(); intent.setAction(Intent.ACTION_SEND); intent.putExtra(Intent.EXTRA_TEXT, contentsOnLoad); 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; // Export menu item case R.id.action_export: listener.exportNote(filename); return true; // Print menu item case R.id.action_print: listener.printNote(contentsOnLoad); 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(); } private void showToast(int message) { Toast toast = Toast.makeText(getActivity(), getResources().getString(message), Toast.LENGTH_SHORT); toast.show(); } private void showToastLong(int message) { Toast toast = Toast.makeText(getActivity(), getResources().getString(message), Toast.LENGTH_LONG); toast.show(); } public void onDeleteDialogPositiveClick() { // User touched the dialog's positive button deleteNote(filename); showToast(R.string.note_deleted); if (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.farmerbb.notepad.LIST_NOTES"); LocalBroadcastManager.getInstance(getActivity()).sendBroadcast(listNotesIntent); } // 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(); } // Nested class used to listen for keyboard shortcuts public void dispatchKeyShortcutEvent(int keyCode) { switch (keyCode) { // CTRL+E: Edit case KeyEvent.KEYCODE_E: Bundle bundle = new Bundle(); bundle.putString("filename", filename); Fragment fragment = new NoteEditFragment(); fragment.setArguments(bundle); getFragmentManager().beginTransaction().replace(R.id.noteViewEdit, fragment, "NoteEditFragment") .commit(); break; // CTRL+D: Delete case KeyEvent.KEYCODE_D: // Show delete dialog listener.showDeleteDialog(); break; // CTRL+H: Share case KeyEvent.KEYCODE_H: // Send a share intent Intent shareIntent = new Intent(); shareIntent.setAction(Intent.ACTION_SEND); shareIntent.putExtra(Intent.EXTRA_TEXT, contentsOnLoad); 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; } } public void onBackPressed() { // 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(); } public String getFilename() { return getArguments().getString("filename"); } }