Differentiating between an Activity launch from home screen or from another activity from App

Question

I need to know a generic way to distinguish between a call of activity from launcher and a call from another activity from inside my app, or a BACK on the activity stack

Answer 1

Based on advantej's answer, here is a full example that also hides the UP button if the activity was launched from a launcher icon:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sell);

    /**
     * If this activity was started from launcher icon, then don't show the Up button in the action bar.
     */
    ActionBar actionBar = getSupportActionBar();
    if (actionBar != null) {
        Intent intent = getIntent();
        Set intentCategories = intent.getCategories();
        boolean wasActivityStartedFromLauncherIcon = Intent.ACTION_MAIN.equals(intent.getAction()) && intentCategories != null && intentCategories.contains(Intent.CATEGORY_LAUNCHER);
        boolean showUpButton = !wasActivityStartedFromLauncherIcon;
        actionBar.setDisplayHomeAsUpEnabled(showUpButton);
    }

}