Develop Reference

Dynamic Shortcuts to open Fragments in Android

Hi I'm developing an application that has 2 types of user: Admin and normal user; The admin obviously has more actions than the normal user, so I need to use dynamic Shortcuts, depending on the user the Shortcuts are created.
At this point everything is already codified and working. However, at the time of assigning an Intent, even to the MainActivity I receive an error.
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.motusk.Monit", "com.motusk.Monit.activity.MainActivity"));
shortcut.add(new ShortcutInfo.Builder(this, "ub")
.setShortLabel("Location")
.setLongLabel("Location")
.setIcon(Icon.createWithResource(this, R.drawable.bg))
.setIntent(intent)
.build());
I also tried with:
Intent intent = new Intent(this, MainActivity.class);
But, in both I get the error:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.motusk.Monit/com.motusk.Monit.activity.MainActivity}: java.lang.NullPointerException: intent's action must be set
In what I need help with is:
1) How to create a correct Intent to the MainActivity?
2) How to know which shortcut was pressed? (The process of depending on which shortcut was pressed to open a certain Fragment will be performed in the MainActivity, that's why I need to know which Shortcut was pressed).

As per the error message, your Intent must set an action with setAction:
intent.setAction("LOCATION_SHORTCUT");
You can then check the action in your Activity:
String action = getIntent() != null ? getIntent().getAction() : null;
if ("LOCATION_SHORTCUT".equals(action)) {
// Show the correct fragment
}

Android Start Activity for Result returns different resultCode

There are a lot of questions out there on similar topics, but after searching around I haven't found one that matches my issue.
I know about starting intents for result, and overriding onActivityResult() to handle these intents, but for some reason, I'm having issues when I'm coming back from activity b to activity a. So, for example, in the last of 3 activities (AddDirections class) I start in my project, I call this method to return back to the previous activity:
public void finish(View v){
Intent intent = new Intent(getApplicationContext(), AddIngredients.class);
intent.putExtra(Home.RECIPE_INTENT, (Parcelable)recipe);
intent.putExtra(Home.RECIPE_ID_INTENT, recipe.getId());
setResult(RESULT_OK, intent);
finish();
}
In the AddIngredients class, I have this method:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK && requestCode == DIRECTIONS_REQUEST){
Intent intent = new Intent(getApplicationContext(), NameRecipe.class);
Recipe recipe = data.getParcelableExtra(Home.RECIPE_INTENT);
intent.putExtra(Home.RECIPE_INTENT, (Parcelable)recipe);
setResult(RESULT_OK, intent);
finish();
}
}
This should accept the returned result from the AddDirections class, and pass it off to NameRecipe, where I have the exact same method (Except for in the new Intent method it says Home.class). In the Home class, I have basically the same method again to receive the intent as it backs all the way out of the app.
Now, I will say that this works if I go straight through the steps from beginning to end. But if I use the up navigation to go the current activity's parent activity, then it messes everything up. Then when I click finish in the final step it messes up the resultCodes that I set for each intent. I make sure to explicitly set the correct result to RESULT_OK (which equals 1) but then for some reason, sometimes it changes what I've set to be the resultCode to be 0 instead.
Here's what I do in an activity if the user clicks the up navigation:
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
Intent intent = NavUtils.getParentActivityIntent(this);
intent.putExtra(Home.RECIPE_INTENT, (Parcelable)recipe);
setResult(RESULT_OK, intent);
NavUtils.navigateUpTo(this, intent);
finish(); //Have tried with and without this
return true;
}
return super.onOptionsItemSelected(item);
}
Like I said, I've searched for a lot of reasons why the resultCode gets overwritten after using the up navigation, but I haven't found a single reason why.
Any help would be greatly appreciated.

It looks like the underlying question is really how do I navigate between multiple activities through the stack using the up navigation that is built in. I am wondering if the project is setup correctly for this type of navigation. From the android developer resources, up navigation from google, you have to setup the navigation buttons with a parent activity. Then the application can traverse between the different activities. From what it looks like this should allow A->B B->C c->D and back to A if needed. I would also add in a button that would allow a direct path back to A if the user so chooses.
If you have more information on what you are trying to accomplish between activities whether it is data passed back and forth or just returning to the previous activity that would be helpful. Hopefully the link will help your issue with this.

your problem seems to be the NavUp, this util class tends to clear everything to navigate to the parent including your resultCode and the instance of the activity, resulting in a Canceled result (if started for result) to a new instance of the parent activity, in order to fix that a quick fix would be to declare android:launchMode="singleTop" in your manifest, but I wouldn't recommend to use that unless you are 100% that you want that, instead I would go into my navigator class, or my method for navigate and overwrite that specific navigation to something like:
Intent parentActivityIntent = NavUtils.getParentActivityIntent(this);
parentActivityIntent.setFlags(
Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP
);
NavUtils.navigateUpTo(this, parentActivityIntent);
Hope this helps!!
Sorry for the late answer :p

if by 'up navigation' you mean back key pressed then you need to override a function
#Override
public void onBackPressed() {
// TODO Auto-generated method stub
super.onBackPressed();
}
if from what it seems to be you are trying to get back when clicking an item from the Options Menu to your parent activity directly then i think you will need to go back step by step as at this moment there is already an activity running and waiting for a result so when you go directly to home activity its already waiting an answer from activity B and not activity C i hope i explained it right :)

How can I add a contact programmatically?

I use the following code to add a contact :
Intent intent = new Intent(Intent.ACTION_INSERT, ContactsContract.Contacts.CONTENT_URI);
activity.startActivityForResult(intent, ATTACH_VCARD_REQUEST_CODE);
But on my Google Nexus the default Android Contact Manager application doesn't return result to my activity
I have the following behaviour:
1. I call contact manager
2. Add field name and click "Done"
After that opens other Activity of default Android Contact Manager, and I can leave this activity only if I press back or up button. After that I can't return to my application activity using back stack (back button). I can open my application with Recent Tasks Manager, but then I get resulCode == 0 and intent == null.

I reviewed source code of standart Contacts application and found Activity which is responsible for creating new contact. There is flag INTENT_KEY_FINISH_ACTIVITY_ON_SAVE_COMPLETED = "finishActivityOnSaveCompleted"; If this flag is true then called setResult(RESULT_OK);
So solution of this problem is
Intent intent = new Intent(ContactsContract.Intents.Insert.ACTION);
intent.setType(ContactsContract.Contacts.CONTENT_TYPE);
intent.putExtra("finishActivityOnSaveCompleted", true);
activity.startActivityForResult(intent, ATTACH_VCARD_REQUEST_CODE);

Selecting and launching shortcuts from a non-launcher app

What I would like to do is the following:
User selects a shortcut from a list of all available shortcuts in the system;
The relevant info is stored;
User performs an action and the selected shortcut is executed, like if it was an icon on the home screen.
So far I am able to populate and present a list with all the shortcuts, using
getPackageManager().queryIntentActivities(new Intent(Intent.ACTION_CREATE_SHORTCUT), 0);. Upon selecting a shortcut, I start the ACTION_CREATE_SHORTCUT intent to customize the shortcut parameters - it presents the proper UI and seems to work. I use this code to start the intent:
ActivityInfo activity = resolveInfo.activityInfo;
ComponentName name = new ComponentName(activity.applicationInfo.packageName, activity.name);
Intent i = new Intent(Intent.ACTION_CREATE_SHORTCUT);
i.addCategory(Intent.CATEGORY_DEFAULT);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
i.setComponent(name);
startActivityForResult(i, 1);
Here is my onActivityResult:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode==1 && resultCode == RESULT_OK) {
try {
startActivity((Intent) data.getExtras().get(Intent.EXTRA_SHORTCUT_INTENT));
} catch (Exception e) {
e.printStackTrace();
}
Toast.makeText(getApplicationContext(), "Success!!", Toast.LENGTH_LONG).show();
finish();
}else{
Toast.makeText(getApplicationContext(), "Fail: "+resultCode+" "+resultCode, Toast.LENGTH_LONG).show();
}
super.onActivityResult(requestCode, resultCode, data);
}
Now, the problem is that the onActivityResult always gets triggered immediately after startActivityForResult with requestCode=0, resultCode=0 and with no data. It does not trigger when the ACTION_CREATE_SHORTCUT activity actually ends. I really don't get it. I think that after the activity ends it should return the requestCode I sent it and the data intent, containing the Intent.EXTRA_SHORTCUT_INTENT which I could then use somehow to actually start the shortcut.
The second part of the question is how do I actually store the necessary information for the shortcut the user selected, preferably in SharedPreferences, so I could later execute this shortcut with the specific parameters. I couldn't find any example of this.
Any help would be much appreciated! Thanks!

More then 2 years later, here is the answer to my question:
The proper functioning of the startActivityForResult/onActivityResult system obviously depends on both the calling and the called Activities being part of the same Task. Therefore any action which would cause the two activities to be launched in separate Tasks would break this functionality. Such actions include setting any exclusive launchMode for any of the Activities in the AndroidManifest.xml or using flags such as Intent.FLAG_ACTIVITY_NEW_TASK when launching any of the two Activities.
Upvoted the answer of user2427931 for the Intent.parseUri() solution.

I had the same behavior when my calling activity had launchMode="singleInstance". Do you have that defined as well?
Regarding saving the Intents. You could turn the intent into an URI and save it as a string in SharedPreferences. You could then use Intent.pareseUri() once you have retrieved it.
//Erty

Refresh activity and re-open

This is my first post, so please be nice :)
I have a question and no one gave the answer in the post I've seen.
My app has a list and a button to open an activity, this activity creates a new item to show in the list of the previous activity when pressing the button Create.
How can I do this?
This is the code I made for the first button:
intent = new Intent(this.getBaseContext(), NewTestActivity.class);
this.finish();
startActivity(intent);
and this is the code to go back an refresh:
Intent intent = new Intent(getBaseContext(), TestListActivity.class);
startActivity(intent);
But the code to goback is useful, because the activity don't refresh.
I have to call the new activity in a diferent way? Or go back to previus activity in a diferent way? Or go back normally and refresh the activity when I'm back in the previus activity?
Well...this is all.
Sorry for my bad english and, if this question has been answered in another thread, give me the link to read, because I can't find it :)
PS: I started with android in December.
Thanks for your help.

When you are going to start new activity you shouldn't close a current one until you actually need this behaviour. (remove this.finish(); row from your code)
Also you shouldn't close an active activity manually until you actually need it. When the user presses the "back" button on the device Android pops the previous activity from the "back stack". Read once more Activity documentation.
According to your description you have a list of elements. So in order to refresh the list you need to update your dataset and notify the list about it by ListView.notifyDataSetChanged() method call.

Before getting to a real answer, I'd like to show some improvements to your code.
First, when creating an Intent (or when you need a context in general) from an Activity there is no need to call getBaseContext(), you can just use this:
intent = new Intent(this, NewTestActivity.class);
Second, android is good at handling Activities, you do not have to close your first activity manually with finish(). Android will automatically pause or stop your first activity and bring it back when you return to it.
Third, in your case you might want to use startActivityForResult() instead of startActivity() for reasons I will explain below.
This will make your code look like the following:
private static final int MY_REQUEST_CODE = 33487689; //put this at the top of your Activity-class, with any unique value.
intent = new Intent(this, NewTestActivity.class);
startActivityForResult(intent, MY_REQUEST_CODE);
Now, the startActivityForResult() starts an activity and waits for a result from that new Activity. When you call finsih() in the new Activity you will end up in the first Activitys onActivityResult()-method, with data supplied from the new Activty that is now closed:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode != MY_REQUEST_CODE) return; //We got a result from another request, so for this example we can return.
if(resultCode != RESULT_OK) return; //The user aborted the action, so we won't get any data.
//After the above if-statements we know that the activity that gives us a result was requested with the correct request code, and it's action was successful, we can begin extracting the data, which is in the data-intent:
Item item = (Item) data.getSerializableExtra("customData"); //casts the data object to the custom Item-class. This can be any class, as long as it is serializable. There are many other kinds of data that can be put into an intent, but for this example a serializable was used.
itemList.add(item); //This is the list that was specified in onCreate()
//If you use an Adapter, this is the place to call notifyDataSetChanged();
}
For this all to work, we need to do some things in the second Activity:
When the item has been created, we must set a result:
//We begin by packing our item in an Intent (the Item class is an example that is expected to implement Serializable)
Item theCreatedItem; //This is what was created in the activity
Intent data = new Intent();
data.putSerializable(theCreatedItem);
setResult(RESULT_OK, data);
finish();
This should return to the first Activitys onActivityResult()-method with the item, as explained above.