Questions tagged [android]

Android is Google's software stack for mobile devices. For non-developer questions, see http://android.stackexchange.com

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39
votes
7answers
3k views

Is my code a 'safe' singleton?

I was wondering if my code will produce a true singleton. I am creating an Android app, and all activities should access my API through one instance of the SyncApi ...
32
votes
2answers
32k views

Custom CursorAdapter Design

Here's the code which I use for my Android custom cursor adapter which I use to bind data to my list view. ...
24
votes
3answers
25k views

Reusing StringBuilder or creating a new one? [closed]

Given that it is better to reuse objects than create new ones when developing with Android, is it worth while deleting the contents of a StringBuilder and reusing ...
24
votes
2answers
2k views

Android Flashlight app

This is my first project, a Flashlight application for Android-based devices: ...
15
votes
4answers
22k views

Integer seconds to formated string mm:ss

I have a String like "Time left (XX)" or "You need stay here for (XX)" and int as second. I use those two variables to format ...
15
votes
2answers
3k views

Localizing an enum in Java

I am currently using an enum in my Android application to display time periods: Weekly Bi-Weekly Monthly Quarterly Yearly I created the enum like this, because I wanted to know the description, and (...
13
votes
3answers
99k views

Run different methods in background threads without duplication

In my Android app I have number of methods that should be executed in a background thread. One of the methods looks like this ...
13
votes
5answers
16k views

Remove useless whitespace from styled string

I have a big string resource (basically the "about" text of the application) which contains styles (such as <b>, <a> ...
12
votes
2answers
1k views

Simple LibGDX Pong game

I created my first java game in LibGDX and it's working fine but I'm 100% sure a lot of my code can be written shorter than now. Does anyone have tips how I can make this code better? Like the ...
12
votes
1answer
2k views

Why does the new ADT create a static inner class Fragment by default?

Honestly, I can't help but feel that this is done merely to confuse newcomers. Most of the errors on Stack Overflow by complete Android newbies mostly stem from that they have a static inner class ...
12
votes
1answer
1k views

Small android app that gives a movie based on the chosen genre

Working on my first "big" project using the mighty Xamarin. Likewise my first venture in XAML so I suppose most focus will be going towards these new areas. Performance- and user-experience related ...
12
votes
2answers
2k views

Productivity app for Android

I wrote a productivity app for Android. It lets you switch system settings, like Bluetooth, wife, screen brightness, volumes, ringtones, mobile data, airplane mode, etc. Unfortunately I have ...
11
votes
3answers
789 views

Optimization of aStar in Java

I'm currently looking to optimize my aStar algorithm as my last run through took roughly a minute to generate one path. I've never had to optimize before as I've never run into performance issues, so ...
11
votes
3answers
19k views

Simplified Android Spinner

I have written a simple spinner wrapper, but was wondering if any of you could think of any ways to make it more robust. It only handles strings at the moment. ...
11
votes
3answers
44k views

Using an AsyncTask to populate a ListView in a Fragment From a SQLite table

This is the first time that I have played around with AsyncTask in Android and I wanted to make sure I'm using it correctly. The idea is I'm grabbing all the rows from a table in the database using <...
11
votes
1answer
2k views

Determine differences between two Strings, for use in undo/redo feature

I made a library that adds undo/redo functionality to EditText widgets in Android. It came from problem I had building text-editing apps that deal with large (1,...
10
votes
2answers
1k views

Image handling class

Let me start by saying that I am very happy with this code. I want to share it with other people because I think they will find it helpful, but I want to make sure I did everything in good form ...
10
votes
2answers
2k views

Create albums out of songs

I have made a method which returns a list of all songs on my device. Now I want to get a list of albums out of these songs. What I basically do is go through every song I have in my list, check if ...
10
votes
2answers
391 views

Find index of double number delimiter

I have a String with a double number. Unfortunately, the number is created on backends with different locals, so it could be ...
10
votes
2answers
21k views

Custom grid view with different columns

I am developing a custom grid view with different columns. ViewPossibilities Mockup Here is the full demo. You can directly use it, with Internet uses permission. This works perfectly but I want ...
10
votes
4answers
6k views

Persistent cookie support using Volley and HttpUrlConnection

I need to add support for persistent cookies on an Android app that I'm building for Authentication/Authorization. This app uses Volley for making HTTP requests and its ...
10
votes
2answers
1k views

OpenCV Mat processing time

I'd like to know whether having different variables for the src (source) and dst (destination) of an OpenCV function will have an effect on the processing time. I have two functions below that does ...
10
votes
2answers
4k views

Safely accepting a known SSL certificate with a different host name

My app communicates with a server over an internal network through HTTPS. The SSL certificate on this server is listed for the host as its external host name. I want to accept this certificate, but I ...
10
votes
1answer
543 views

ActivityLifecycleHelper implementation

Description The ActivityLifecycleHelper uses wrap(Context)to create the class and save a global ...
9
votes
4answers
5k views

Sound manager for Android

I created a singleton class for managing sound effects on Android. This class will only be instanced and loaded once at the beginning, and each activity will use the loaded songs. I don't know either ...
9
votes
3answers
879 views

SlotMachine game as first Android app

After learning a bit of Android Java I've chosen to make a tiny game so that I can use the learned techniques in a real app. I had the idea of a slot machine simulator: You press a button and it ...
9
votes
2answers
8k views

Two Fragments in Landscape Mode Challenge

I did the following code challenge for a job interview. They apparently didn't care for my solution and I'm not sure why. What could I have done better? Here is the challenge: Create a small app ...
9
votes
2answers
10k views

Random 5-character token generator

I have an Android app that uses randomly generated tokens to log in. They're 5 characters long, are sent to a user's email address, and have a short lifespan, so I don't think I need anything that's ...
9
votes
2answers
228 views

Updating positions of enemies every frame

I am making a game for Android using Java and libGdx. I have an ArrayList of enemies that are updated each frame. The update method for the enemy looks like this: <...
8
votes
4answers
2k views

Selecting an enum for a payment transaction

I'm writing a small Android application that deals with payments and, in my function that handles transactions, I need to translate a number of installments (1-12) and whether or not it has interest (...
8
votes
2answers
32k views

Secure AES encryption and decryption in Android [closed]

Is this implementation of AES for Android safe? Is it 128 bit encryption? How can I strengthen this implementation? Please help me, all suggestions are welcome :) ...
8
votes
2answers
26k views

Simple application for finding local restaurants

I was asked to create a test APK file by a company HR when I applied for an Android developers job, Specification: The goal is to develop a simple application which finds the local restaurants. ...
8
votes
4answers
3k views

Poker game classes

I've built this two classes for a Poker game on Android and I would appreciate some feedback on my code. Have no mercy. The harsher you are, the better. Feel free to add your number of WTFs/minute. ...
8
votes
1answer
716 views

Home screen widget to display random numbers

I have created a small HomeScreen Widget which displays random numbers. Attached is the code. Please let me know if the approach is good. https://github.com/gottp/HomeWidgetTest MainAppClass.java <...
8
votes
2answers
404 views

Can this while loop be made cleaner

Moved to Code Review as per comments received on https://stackoverflow.com/questions/20907502/can-this-while-loop-be-made-cleaner Is there a way to make the following while loop a little more ...
8
votes
2answers
932 views

Strategy Pattern Implementation

I thought I would learn a design pattern today and picked this one. I wrote a simple Android test demo to test the pattern. main.xml ...
8
votes
1answer
26k views

Optimize JSON insertion to SQLite (insert … on duplicate key ignore)

In current task, I'm refactoring the code of converting JSON file into SQLite database on Android device. Code compliant with Java 6. As a benchmark, grabbing the code from remote server takes ...
8
votes
1answer
434 views

Latency problem for keyboard remoting from Android phone

I'm writing a simple remote PC app (mouse-keyboard). Android is client and is connect with WiFi to Java PC Server. I'm using TCP but I see a bit of latency compared to other remote apps. Then I used ...
8
votes
2answers
1k views

Adding a Fish Eye Distortion to a Bitmap

I have the following class that processes a Bitmap to place a fisheye distortion on it. I've run my app through TraceView and found that virtually all the processing time is spent looping through the ...
8
votes
2answers
408 views

Camera intents and file manipulation

I am building an Android application and there are five Activity classes or if you're familiar with the MVC pattern they would usually be the ...
8
votes
1answer
2k views

Handling large images efficiently (to avoid OutOfMemoryError)

After lots of attempts thanks to all the Android enthusiasts, I've found a method to handle large images efficiently in Android Applications in order to get rid of ...
8
votes
1answer
566 views

Displaying NFC card data in Binary, Hex, String, etc

I am working on an Android application for reading NFC cards. I came to a point when I needed to design an abstract class to streamline the process of creating ...
7
votes
4answers
263 views

User search implementation

In my Java code I have these three classes. Basically I have a User class, and also a GUI class that holds TextViews and other things (GUI related) for the ...
7
votes
4answers
2k views

Android Global Variable Setup

I am using the Android library Retrofit for networking in my app. The library calls for creating a RestAdapter for making service calls. I want to use this same instance of the RestAdapter for all of ...
7
votes
2answers
2k views

Android Thread and Runnable

This is my code for running a background thread. I believe it is very poor in naming and code structure. ...
7
votes
2answers
6k views

Using Java to Add the Contents of two EditText views in Android

I have a toy app that contains: editText1 for entering a number. Uses inputType of number. <...
7
votes
5answers
2k views

Anonymous Classes for Listeners

While working with Android GUI my approach to adding Listeners for GUI elements is usually: ...
7
votes
3answers
6k views

Fastest way to change the HSV value of all pixels in a bitmap

I want to change all the pixels in an image to have the same value, in terms of the HSV colour space. At the moment I'm running the following code: ...
7
votes
1answer
879 views

Android “Search” Activity and corresponding XML

Below is an Android Activity and corresponding XML layout. The function of the class is to search an ...
7
votes
1answer
240 views

Random Q&A system

Basically, I made a simple app for my Android, where it picks a random question for you, and picks specific answers. Only 1 of the answers is correct, while other's aren't. Also, after editing the <...