Adds 'Add to Calendar' integration (#286)

* Calender provider implementation

* Undo Calendar provider. Intent approach with dialog

* Lambdas, undo manifest change

* Settings ListPreference added. Fixes minor bug from #284

* Improving EventFragment diff, cleanup

* Preserve going status of event on going back to fragment

app/src/main/java/app/insti/Constants.java

@@ -6,6 +6,10 @@ public class Constants {
     public static final int RESULT_LOAD_IMAGE = 11;
     public static final int REQUEST_CAMERA_INT_ID = 101;
     public static final String DARK_THEME = "dark_theme";
+    public static final String CALENDAR_DIALOG = "calendar_dialog";
+    public static final String CALENDAR_DIALOG_YES = "Yes";
+    public static final String CALENDAR_DIALOG_NO = "No";
+    public static final String CALENDAR_DIALOG_ALWAYS_ASK = "Always ask";
     public static final String NOTIFICATIONS_RESPONSE_JSON = "notifications_json";
     public static final String EVENT_ID = "event_id";
     public static final String EVENT_LATITUDE = "event_latitude";

app/src/main/java/app/insti/api/model/Event.java

@@ -274,14 +274,20 @@ public class Event implements CardInterface {
 
             subtitle += simpleDateFormatDate.format(Date) + " | " + simpleDateFormatTime.format(Date);
         }
+
+        String eventVenueName = getEventVenueString();
+        if (!eventVenueName.equals(""))
+            subtitle += " | " + eventVenueName;
+
+        return subtitle;
+    }
+
+    public String getEventVenueString() {
         StringBuilder eventVenueName = new StringBuilder();
         for (Venue venue : getEventVenues()) {
             eventVenueName.append(", ").append(venue.getVenueShortName());
         }
-        if (!eventVenueName.toString().equals(""))
-            subtitle += " | " + eventVenueName.toString().substring(2);
-
-        return subtitle;
+        return eventVenueName.toString().equals("") ? "" : eventVenueName.toString().substring(2);
     }
 
     public String getAvatarUrl() {

app/src/main/java/app/insti/fragment/EventFragment.java

@@ -5,12 +5,16 @@ import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
+import android.app.AlertDialog;
+import android.content.Context;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.graphics.Color;
 import android.graphics.Point;
 import android.graphics.Rect;
 import android.net.Uri;
 import android.os.Bundle;
+import android.provider.CalendarContract;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.Spanned;
@@ -24,6 +28,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.view.animation.DecelerateInterpolator;
 import android.widget.Button;
+import android.widget.CheckBox;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.TextView;
@@ -168,12 +173,7 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
         ((CoordinatorLayout.LayoutParams) mAppBarLayout.getLayoutParams()).setBehavior(new AppBarLayout.Behavior());
 
         // Set offset on init
-        mAppBarLayout.post(new Runnable() {
-            @Override
-            public void run() {
-                setAppBarOffset(appBarOffset);
-            }
-        });
+        mAppBarLayout.post(() -> setAppBarOffset(appBarOffset));
 
         // Store offset for next init
         mAppBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@@ -279,15 +279,12 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
             if (event.getEventVenues().get(0).getVenueLatitude() == 0) {
                 navigateButton.setVisibility(View.GONE);
             } else {
-                navigateButton.setOnClickListener(new View.OnClickListener() {
-                    @Override
-                    public void onClick(View v) {
+                navigateButton.setOnClickListener(v -> {
                     Venue primaryVenue = event.getEventVenues().get(0);
                     Uri gmmIntentUri = Uri.parse("google.navigation:q=" + primaryVenue.getVenueLatitude() + "," + primaryVenue.getVenueLongitude() + "(" + primaryVenue.getVenueName() + ")");
                     Intent mapIntent = new Intent(Intent.ACTION_VIEW, gmmIntentUri);
                     mapIntent.setPackage("com.google.android.apps.maps");
                     startActivity(mapIntent);
-                    }
                 });
             }
         } else {
@@ -318,37 +315,26 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
             });
         }
 
-        eventPicture.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                zoomImageFromThumb(eventPicture);
-            }
-        });
+        eventPicture.setOnClickListener(v -> zoomImageFromThumb(eventPicture));
         mShortAnimationDuration = getResources().getInteger(android.R.integer.config_shortAnimTime);
 
-        final FloatingActionButton fab = (FloatingActionButton) getView().findViewById(R.id.edit_fab);
+        final FloatingActionButton fab = getView().findViewById(R.id.edit_fab);
 
         if (((MainActivity) getActivity()).editEventAccess(event)) {
             fab.show();
-            NestedScrollView nsv = (NestedScrollView) getView().findViewById(R.id.event_scrollview);
-            nsv.setOnScrollChangeListener(new NestedScrollView.OnScrollChangeListener() {
-                @Override
-                public void onScrollChange(NestedScrollView v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
+            NestedScrollView nsv = getView().findViewById(R.id.event_scrollview);
+            nsv.setOnScrollChangeListener((NestedScrollView.OnScrollChangeListener) (v, scrollX, scrollY, oldScrollX, oldScrollY) -> {
                 if (scrollY > oldScrollY) fab.hide();
                 else fab.show();
-                }
             });
         }
 
-        fab.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
+        fab.setOnClickListener(v -> {
             AddEventFragment addEventFragment = new AddEventFragment();
             Bundle bundle = new Bundle();
             bundle.putString("id", event.getEventID());
             addEventFragment.setArguments(bundle);
             ((MainActivity) getActivity()).updateFragment(addEventFragment);
-            }
         });
     }
 
@@ -368,9 +354,7 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
     }
 
     private View.OnClickListener getGoingButtonOnClickListener() {
-        return new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
+        return v -> {
             int currentStatus = event.getEventUserUes();
             final int finalStatus;
 
@@ -393,8 +377,17 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
                     event.setEventUserUes(finalStatus);
                     updateGoingInterestedButtonsAppearance(finalStatus);
 
+                    // Preserve status on going back
+                    if (getArguments() != null) {
+                        getArguments().putString(Constants.EVENT_JSON, Utils.gson.toJson(event));
+                    }
+
                     // Update global memory cache
                     Utils.eventCache.updateCache(event);
+
+                    if (finalStatus == Constants.STATUS_GOING) {
+                        addEventToCalender();
+                    }
                 }
 
                 @Override
@@ -403,14 +396,11 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
                 }
 
             });
-            }
         };
     }
 
-        private View.OnClickListener getInterestedButtonOnClickListener () {
-            return new View.OnClickListener() {
-                @Override
-                public void onClick(View v) {
+    private View.OnClickListener getInterestedButtonOnClickListener() {
+        return v -> {
             int currentStatus = event.getEventUserUes();
             final int finalStatus;
 
@@ -422,7 +412,7 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
                 event.setEventGoingCount(event.getEventGoingCount() - 1);
                 finalStatus = Constants.STATUS_INTERESTED;
             } else {
-                        event.setEventGoingCount(event.getEventInterestedCount() + 1);
+                event.setEventInterestedCount(event.getEventInterestedCount() + 1);
                 finalStatus = Constants.STATUS_INTERESTED;
             }
 
@@ -435,6 +425,10 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
 
                     // Update global memory cache
                     Utils.eventCache.updateCache(event);
+
+                    if (finalStatus == Constants.STATUS_INTERESTED) {
+                        addEventToCalender();
+                    }
                 }
 
                 @Override
@@ -443,12 +437,73 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
                 }
 
             });
-                }
         };
     }
     
+    private void addEventToCalender() {
+        SharedPreferences sharedPref = getContext().getSharedPreferences(Constants.PREF_NAME, Context.MODE_PRIVATE);
+        String savedOption = sharedPref.getString(Constants.CALENDAR_DIALOG, Constants.CALENDAR_DIALOG_ALWAYS_ASK);
+        if (savedOption.equals(Constants.CALENDAR_DIALOG_YES)) {
+            createAddToCalendarIntent();
+        } else if (savedOption.equals(Constants.CALENDAR_DIALOG_ALWAYS_ASK)) {
+            showAddEventToCalendarDialog();
+        }
+    }
+
+    private void saveCalendarDialogPreference(boolean dontAskAgain, boolean yes) {
+        SharedPreferences sharedPref = getActivity().getSharedPreferences(Constants.PREF_NAME, Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = sharedPref.edit();
+        if (!dontAskAgain) {
+            editor.putString(Constants.CALENDAR_DIALOG, Constants.CALENDAR_DIALOG_ALWAYS_ASK);
+            editor.commit();
+        } else {
+            if (yes) {
+                editor.putString(Constants.CALENDAR_DIALOG, Constants.CALENDAR_DIALOG_YES);
+                editor.commit();
+            } else {
+                editor.putString(Constants.CALENDAR_DIALOG, Constants.CALENDAR_DIALOG_NO);
+                editor.commit();
+            }
+        }
+    }
+
+    private void showAddEventToCalendarDialog() {
+        AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(getContext());
+        LayoutInflater layoutInflater = LayoutInflater.from(getContext());
+        View layout = layoutInflater.inflate(R.layout.calendar_dialog_checkbox, null);
+        dialogBuilder.setView(layout);
+        CheckBox dontShowAgain = layout.findViewById(R.id.skip);
+
+        dialogBuilder.setTitle("Add to Calendar")
+                .setMessage("You will be notified about this event by InstiApp. Do you also want to add this event to your calendar?")
+                .setPositiveButton("Yes", (dialog, which) -> {
+                    createAddToCalendarIntent();
+                    saveCalendarDialogPreference(dontShowAgain.isChecked(), true);
+                })
+                .setNegativeButton("No", (dialog, which) -> {
+                    dialog.cancel();
+                    saveCalendarDialogPreference(dontShowAgain.isChecked(), false);
+                })
+                .create()
+                .show();
+    }
+
+    private void createAddToCalendarIntent() {
+        Intent intent = new Intent(Intent.ACTION_INSERT);
+        intent.setType("vnd.android.cursor.item/event");
 
-        private void zoomImageFromThumb ( final ImageView thumbView){
+        intent.putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, event.getEventStartTime().getTime());
+        intent.putExtra(CalendarContract.EXTRA_EVENT_END_TIME, event.getEventEndTime().getTime());
+        intent.putExtra(CalendarContract.EXTRA_EVENT_ALL_DAY, event.isAllDayEvent());
+
+        intent.putExtra(CalendarContract.Events.TITLE, event.getTitle());
+        intent.putExtra(CalendarContract.Events.DESCRIPTION, event.getEventDescription());
+        intent.putExtra(CalendarContract.Events.EVENT_LOCATION, event.getEventVenueString());
+
+        startActivity(intent);
+    }
+
+    private void zoomImageFromThumb(final ImageView thumbView) {
         // If there's an animation in progress, cancel it
         // immediately and proceed with this one.
         if (mCurrentAnimator != null) {
@@ -456,7 +511,7 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
         }
 
         // Load the high-resolution "zoomed-in" image.
-            expandedImageView = (ImageView) getActivity().findViewById(
+        expandedImageView = getActivity().findViewById(
                 R.id.expanded_image_event);
         expandedImageView.setImageDrawable(thumbView.getDrawable());
 
@@ -544,8 +599,8 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
         zoomMode = true;
     }
 
-        private void zoomOut ( final ImageView expandedImageView, Rect startBounds,
-        float startScaleFinal, final View thumbView){
+    private void zoomOut(final ImageView expandedImageView, Rect startBounds,
+                         float startScaleFinal, final View thumbView) {
         expandedImageView.setBackgroundColor(0x00000000);
         if (mCurrentAnimator != null) {
             mCurrentAnimator.cancel();
@@ -585,4 +640,4 @@ public class EventFragment extends BackHandledFragment implements TransitionTarg
         set.start();
         mCurrentAnimator = set;
     }
-    }
+}

app/src/main/java/app/insti/fragment/SettingsFragment.java

@@ -5,6 +5,8 @@ import android.content.Intent;
 import android.content.SharedPreferences;
 import android.net.Uri;
 import android.os.Bundle;
+
+import androidx.preference.ListPreference;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceFragmentCompat;
 import androidx.preference.SwitchPreferenceCompat;
@@ -37,64 +39,54 @@ public class SettingsFragment extends PreferenceFragmentCompat {
 
         // Show contact number
         showContactPref = (SwitchPreferenceCompat) findPreference("show_contact");
-        showContactPref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-            @Override
-            public boolean onPreferenceChange(Preference preference, Object o) {
-                toggleShowContact((SwitchPreferenceCompat) preference, o);
+        showContactPref.setOnPreferenceChangeListener((preference, option) -> {
+            toggleShowContact((SwitchPreferenceCompat) preference, option);
             return false;
-            }
         });
         showContactPref.setEnabled(false);
 
         // Dark Theme
         SwitchPreferenceCompat darkThemePref = (SwitchPreferenceCompat) findPreference("dark_theme");
-        darkThemePref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-            @Override
-            public boolean onPreferenceChange(Preference preference, Object o) {
-                toggleDarkTheme((SwitchPreferenceCompat) preference, o);
+        darkThemePref.setOnPreferenceChangeListener((preference, option) -> {
+            toggleDarkTheme((boolean) option);
             return true;
-            }
         });
         darkThemePref.setChecked(sharedPref.getBoolean(Constants.DARK_THEME, false));
 
+        // Add to Calendar
+        ListPreference calendarPref = (ListPreference) findPreference("add_to_calendar");
+        calendarPref.setOnPreferenceChangeListener((preference, option) -> {
+            toggleCalendarDialog((String) option);
+            return true;
+        });
+        calendarPref.setValue(sharedPref.getString(Constants.CALENDAR_DIALOG, Constants.CALENDAR_DIALOG_ALWAYS_ASK));
+
         // Update Profile
         Preference profilePref = findPreference("profile");
-        profilePref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
-            @Override
-            public boolean onPreferenceClick(Preference preference) {
+        profilePref.setOnPreferenceClickListener(preference -> {
             openWebURL("https://gymkhana.iitb.ac.in/sso/user");
             return false;
-            }
         });
 
         // Feedback
         Preference feedbackPref = findPreference("feedback");
-        feedbackPref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
-            @Override
-            public boolean onPreferenceClick(Preference preference) {
+        feedbackPref.setOnPreferenceClickListener(preference -> {
             openWebURL("https://insti.app/feedback");
             return false;
-            }
         });
 
         // About
         Preference aboutPref = findPreference("about");
-        aboutPref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
-            @Override
-            public boolean onPreferenceClick(Preference preference) {
+        aboutPref.setOnPreferenceClickListener(preference -> {
             openAbout();
             return false;
-            }
         });
 
         // Logout
         Preference logoutPref = findPreference("logout");
-        logoutPref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
-            @Override
-            public boolean onPreferenceClick(Preference preference) {
+        logoutPref.setOnPreferenceClickListener(preference -> {
             logout();
             return false;
-            }
         });
 
         // Disable buttons if not logged in
@@ -139,8 +131,8 @@ public class SettingsFragment extends PreferenceFragmentCompat {
         }
     }
 
-    public void toggleShowContact(final SwitchPreferenceCompat showContactPref, Object o) {
-        final boolean isChecked = (boolean) o;
+    private void toggleShowContact(final SwitchPreferenceCompat showContactPref, Object option) {
+        final boolean isChecked = (boolean) option;
         showContactPref.setEnabled(false);
         RetrofitInterface retrofitInterface = Utils.getRetrofitInterface();
         retrofitInterface.patchUserMe(Utils.getSessionIDHeader(), new UserShowContactPatchRequest(isChecked)).enqueue(new Callback<User>() {
@@ -166,17 +158,29 @@ public class SettingsFragment extends PreferenceFragmentCompat {
         });
     }
 
-    public void toggleDarkTheme(final SwitchPreferenceCompat showContactPref, Object o) {
-        editor.putBoolean(Constants.DARK_THEME, (boolean) o);
+    private void toggleDarkTheme(boolean option) {
+        editor.putBoolean(Constants.DARK_THEME, option);
+        editor.commit();
+        Utils.changeTheme(this, option);
+    }
+
+    private void toggleCalendarDialog(String option) {
+        // Using strings.xml values for populating ListPreference. `option` comes from strings.xml
+        // Using Constants for updating SharedPrefs. `choice` comes from Constants.
+        String choice = Constants.CALENDAR_DIALOG_ALWAYS_ASK;
+
+        if (option.equals(getString(R.string.calendar_yes))) choice = Constants.CALENDAR_DIALOG_YES;
+        else if (option.equals(getString(R.string.calendar_no))) choice = Constants.CALENDAR_DIALOG_NO;
+
+        editor.putString(Constants.CALENDAR_DIALOG, choice);
         editor.commit();
-        Utils.changeTheme(this, (boolean) o);
     }
 
-    public void openAbout() {
+    private void openAbout() {
         Utils.updateFragment(new AboutFragment(), getActivity());
     }
 
-    public void logout() {
+    private void logout() {
         final SessionManager sessionManager = new SessionManager(getContext());
         RetrofitInterface retrofitInterface = Utils.getRetrofitInterface();
         retrofitInterface.logout(Utils.getSessionIDHeader()).enqueue(new EmptyCallback<Void>() {

app/src/main/res/drawable/ic_event_gray_36dp.xml

+<vector android:height="36dp" android:tint="#767676"
+    android:viewportHeight="24.0" android:viewportWidth="24.0"
+    android:width="36dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="#FF000000" android:pathData="M17,12h-5v5h5v-5zM16,1v2L8,3L8,1L6,1v2L5,3c-1.11,0 -1.99,0.9 -1.99,2L3,19c0,1.1 0.89,2 2,2h14c1.1,0 2,-0.9 2,-2L21,5c0,-1.1 -0.9,-2 -2,-2h-1L18,1h-2zM19,19L5,19L5,8h14v11z"/>
+</vector>

app/src/main/res/layout/calendar_dialog_checkbox.xml

+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/layout_root"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:orientation="horizontal"
+    android:padding="20dp" >
+    <CheckBox
+        xmlns:android="http://schemas.android.com/apk/res/android"
+        android:id="@+id/skip"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Remember my choice and don't ask me again" >
+    </CheckBox>
+</LinearLayout>
\ No newline at end of file

app/src/main/res/values/strings.xml

@@ -27,6 +27,17 @@
         <item>QIP</item>
     </string-array>
 
+    <string-array name="add_to_calendar_options">
+        <item>@string/calendar_yes</item>
+        <item>@string/calendar_no</item>
+        <item>@string/calendar_always_ask</item>
+    </string-array>
+
+    <!-- Add to Calendar Preference options -->
+    <string name="calendar_yes">Yes</string>
+    <string name="calendar_no">No</string>
+    <string name="calendar_always_ask">Always ask</string>
+
     <string name="default_notification_channel_id">INSTIAPP_NOTIFS</string>
 
     <!--NSS side-->

app/src/main/res/xml/preferences.xml

@@ -15,6 +15,14 @@
         app:summary="Note: this feature is in beta"
         android:icon="@drawable/ic_color_lens_gray_36dp"/>
 
+    <ListPreference
+        app:key="add_to_calendar"
+        app:title="Add to Calendar"
+        app:summary="Add to calendar on Going/Interested press"
+        app:entries="@array/add_to_calendar_options"
+        app:entryValues="@array/add_to_calendar_options"
+        android:icon="@drawable/ic_event_gray_36dp"/>
+
     <Preference
         app:key="profile"
         app:title="Update Profile"