Panic responder (#512)

* feat: add panic responder

* refactor: logOut before removing session

* fix(panic): close app after logOut to avoid crash

* build: reset gradle.properties

mastodon/src/main/AndroidManifest.xml

@@ -38,6 +38,22 @@
 				<category android:name="android.intent.category.LAUNCHER"/>
 			</intent-filter>
 		</activity>
+		<activity
+			android:name=".PanicResponderActivity"
+			android:exported="true"
+			android:launchMode="singleInstance"
+			android:noHistory="true"
+			android:theme="@android:style/Theme.NoDisplay">
+			<intent-filter>
+				<action android:name="info.guardianproject.panic.action.TRIGGER" />
+
+				<category android:name="android.intent.category.DEFAULT" />
+			</intent-filter>
+		</activity>
+		<activity
+			android:name=".ExitActivity"
+			android:exported="false"
+			android:theme="@android:style/Theme.NoDisplay" />
 		<activity android:name=".OAuthActivity" android:exported="true" android:configChanges="orientation|screenSize" android:launchMode="singleTask">
 			<intent-filter>
 				<action android:name="android.intent.action.VIEW"/>

mastodon/src/main/java/org/joinmastodon/android/ExitActivity.java

@@ -0,0 +1,24 @@
+package org.joinmastodon.android;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+
+public class ExitActivity extends Activity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        finishAndRemoveTask();
+    }
+
+    public static void exit(Context context) {
+        Intent intent = new Intent(context, ExitActivity.class);
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
+        context.startActivity(intent);
+    }
+
+}

mastodon/src/main/java/org/joinmastodon/android/PanicResponderActivity.java

@@ -0,0 +1,49 @@
+package org.joinmastodon.android;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Bundle;
+
+import org.joinmastodon.android.api.requests.oauth.RevokeOauthToken;
+import org.joinmastodon.android.api.session.AccountSession;
+import org.joinmastodon.android.api.session.AccountSessionManager;
+
+import me.grishka.appkit.api.Callback;
+import me.grishka.appkit.api.ErrorResponse;
+
+
+public class PanicResponderActivity extends Activity {
+    public static final String PANIC_TRIGGER_ACTION = "info.guardianproject.panic.action.TRIGGER";
+
+    @Override
+    protected void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        final Intent intent = getIntent();
+        if (intent != null && PANIC_TRIGGER_ACTION.equals(intent.getAction())) {
+            AccountSessionManager.getInstance().getLoggedInAccounts().forEach(accountSession -> logOut(accountSession.getID()));
+            ExitActivity.exit(this);
+        }
+        finishAndRemoveTask();
+    }
+
+    private void logOut(String accountID){
+        AccountSession session=AccountSessionManager.getInstance().getAccount(accountID);
+        new RevokeOauthToken(session.app.clientId, session.app.clientSecret, session.token.accessToken)
+                .setCallback(new Callback<>(){
+                    @Override
+                    public void onSuccess(Object result){
+                        onLoggedOut(accountID);
+                    }
+
+                    @Override
+                    public void onError(ErrorResponse error){
+                        onLoggedOut(accountID);
+                    }
+                })
+                .exec(accountID);
+    }
+
+    private void onLoggedOut(String accountID){
+        AccountSessionManager.getInstance().removeAccount(accountID);
+    }
+}