Leak Canary in Phimpme Android

Leak Canary is a memory detection library for Android and Java. A memory leak occurs when you hold an object for too long after its purpose has been served. If some object is holding another object then the Garbage collector will not be able to collect and this is known as Memory Leak. These memory leaks can be minor (in KB’s) or can lead to an app in ANR state with OutOfMemoryError.Hence to recover and capture this memory leak, Leak Canary is used for Android and Java.

For every functioning done in android, the system needs resource such as memory. Hence in Java the Garbage Collector(GC) plays a major role in deallocating the memory. The GC is mainly used to reclaim memory. Now the question arises, why do we need a memory leak detection library when GC is already present. The answer is sometimes the developers makes programming mistakes and that leads to inhibit the GC to collect the objects that are of no use and mark them as useful objects.

The GC starts from one point(root) and marks active to all the objects that holds references from GC root and the objects which are not marked are wiped out of memory.Hence when some unuseful objects is marked active, memory leak occurs.Hence to eliminate these problems  of memory leaks, we have employed the use of Leak Canary in our project.

The Phimpme project and every related project has possible memory leaks, like for instance we have used fragments in settings activity and to catch that memory leak we have added the refwatcher instance. Hence if any memory leaks occur we get the error such as ‘org.fossasia.phimpme’  leaked 40kb.This can also be checked by Leaks App in the android phone, which has features of showing and sharing the heap dump and info.

To add the Leak Canary in your android app, follow these steps:

  • Add the dependencies in build.gradle(app level)

    dependencies {
       debugCompile 'com.squareup.leakcanary:leakcanary-android:1.5.4'
       releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.5.4'
  • Add the following code to your Application class

    public class MyApplication extends Application{
    public void onCreate() {
       if (LeakCanary.isInAnalyzerProcess(this)) {
           // This process is dedicated to LeakCanary for heap analysis.
           // You should not init your app in this process.
  • Leak canary now will automatically detect the memory leaks  from all activities.

For fragment a refwatcher is needed, hence

public class MYFragment extends Fragment {

    public void onDestroy() {

Hence LeakCanary is setup finally, and now the memory leaks will be detected.



Getting Started Developing on Phimpme Android

Phimpme is an Android app for editing photos and sharing them on social media. To participate in project start by learning how people contribute in open source, learning about the version control system Git and other tools like Codacy and Travis.

Firstly, sign up for GitHub. Secondly, find the open source projects that interest you. Now as for me I started with Phimpme. Then follow these steps:

  1. Go through the project ReadMe.md and read all the technologies and tools they are using.
  2. Now fork that repo in your account.
  3. Open the Android Studio/Other applications that are required for that project and import the project through Git.
  4. For Android Studio sync all the Gradle files and other changes and you are all done and ready for the development process.

Install the app and run it on a phone. Now explore each and every bit use this app as a tester, think about the end cases and boundary condition that will make the app ‘ANR’ (App not responding) dialog appear. Congratulations you are ready to create an issue if that is a verified and original and actually is a bug.


  • Navigate to the main repo link, you will see an issues section as follows:
  • Create a new issue and report every detail about the issue (logcat, screenshots) For eg. Refer to Issue-1120
  • Now the next step is to work on that issue
  • On your machine, you don’t have to change the code in the development branch as it’s considered to be as a bad practice. Hence checkout as a new branch.
    For eg., I checked out for the above issue as ‘crashfixed’
git checkout -b "Any branch name you want to keep"
  • Make the necessary changes to that branch and test that the code is compiling and the issue is fixed followed by
git add.
git commit -m "Fix #Issue No -Description "
git push origin branch-name
  • Now navigate to the repo and you will an option to create a Pull Request.
    Mention the Issue number and description and changes you done, include screenshots of the fixed app.For eg. Pull Request 1131.

Hence you have done your first contribution in open source while learning with git. The pull request will initiate some checks like Codacy and Travis build and then if everything works it is reviewed and merged by co-developers.

The usual way how this works is, that it should be reviewed by other co-developers. These co-developers do not need merge or write access to the repository. Any developer can review pull requests. This will also help contributors to learn about the project and make the job of core developers easier.