Android Tabs & Intents - android

I have a auto-complete textbox in which the user makes a selection. From here I want to load a tabbed layout which is based on the user selection. The problem is I cant figure out a clean way to pass that selection to each of the tabs. At the moment I can pass an intent to the 'tabhost' activity and then pass to each child activity explicitly, however this just seems like messy iterative code to me! So basically how can I pass my intent data bundles to the tabs activities cleanly & efficiently! Psuedo code is also very welcome ;)
Cheers guys

Sounds like you need to broadcast some information. You than will be able to set broadcast receivers in any activity/service you would like to get notified.
Read more online about Broadcastreceiver and about send broadcast

You can store the selection as SharedPreference and then just obtain the value from any activity. Second option that comes in mind is saving the selected value on the Application context which is also easily accessible from any activity.

Related

Passing data to other activity without opening it

I'm trying to pass the data from one activity to another activity without opening the activity. I tried it by not writing startActivity(intent) part but it fails.
How do I pass the data from one activity(1) to another activity(2) without opening that activity(2)?
Activities are UI elements so your question makes no sense. If you want perform some action that does not have UI create a service to perform the work and start or otherwise call that service from your first activity.
If you want to make data available to activity 2 when it does start, pick a persistent storage mechanism and write the data there, then read the data when activity 2 opens.
https://developer.android.com/guide/topics/data/data-storage
Alternatively, you can create a custom Application and store the data there and share it between activities.
Just a word of advice. You should describe what you are trying to accomplish not how you want to accomplish it. Activities are not the right tool for this task, but we can't suggest the right tool because we don't know what you want to build.
You can use events for passing around data. Either use the android native LocalBroadcastsSytem and put data as parcelable in the intent, or you can use any event library like EventBus
Pass the data from one activity to another activity without opening the activity try to do with the broadcast receiver or SharePhreferance or make that data public static You can access your data in anywhere of the application.

Two SearchView components with different searchable configuration

Hi I have problem with planning implementation of specific search interface.
I am making navigation application where you can navigate from point to point.
For this I need two seachviews both with different searchable configuration, where I can define different custom intent action to recognize if user enter source or destination and react properly. I have already created suggestion logic because I am using one SearchView in other activity and already have different configuration there.
So my plan is creating an activity for result which will be in same time SearchActivity where I will setup two different SearchViews components where based on user input there will appear suggestions and after clicking them (first later second) the intent will be picked by CUSTOM1/2 ation intent in onNewIntent() as it will be "singleTop" activity and stored properly. Then i will process stored source&destination data and finish with proper response code to the source activity with extras based on processed data.
I don't know if I explained it properly. The main problem for me here is that I need to have two different SeachViews widgets. How to achieve this?
Eventually I can manage both SearchView suggestion results with default ACTION_VIEW and recognize them by sent data but I think the first plan is more clear.
PS I am planning to put them directly to the layout without appbar.

Is it possible to recursively use the same activity using intents?

I am at a point of code where I need to use same activity with different values. Is it possible to use same activity recursively?
Yes, its possible but you have to use the condition inside the activity based on the value pass through intents.
It may possible for the same activity with different values so the value pass from previous activity will decide what data will display..
Yes.you can use the same activity but make sure,you don't go into infinite loop nor you get messed up with different codes for various conditions you call the activity.you can achieve that by maintaining extras in Intent you use to call the activity.
Wouldn't it be more suitable (in terms of readability) to create a new Activity-class with the same layout but other functionality? This way one Activity will have one behaviour instead of two - making your code more simple, readable and maintainable.

Anyway to append to the activity stack without doing a StartActivity?

I'm parsing a huge xml to display a list of titles in a listview in activity A. However the same xml also has details for a list item which needs to be shown in a different view (like list mail subjects/view mail details scenario).
On click event of this list i dont want to load a new activity with a bundle, parse the same xml and show detailed view, while i have the required data in activity A itself.
I figured out a way to hide show layouts in my XML to do this as required, but handling back button is an issue. I can probably do this by capturing back button action, but want to know whether there is a better solution for this.
Like broadcasting an intent to A (from A itself) and somehow managing to add that to the activity stack.
Excuse if there is a duplicate question, couldnt find one when i searched.
BTW, i dont want to do a solution with a database caching.
I would handling the back press. Just use a flag within your activity that tells you in which view you are (so back within the detailed view shows you the overview view).
Another way would be to save the values in your applicationContext. Much easier way to do it than database usage.
Take a look at an answer here: How to declare global variables in Android?
But I would definitely go with handling back presses. I have a solution similar to this where I use the same listview in the layout and instead I use different adapters depending on which detailed view the user is in.
Handling back press is the easiest way to go.
Else you could also pass the information to view as Intent extra to the second activity.
Another possibility is to have a local service running in the background and in charge of loading your XML and offering access to its information in a convenient way.
You can also stuff the XML content in an Application object of your own. However I have had not so great experience with that option in some projects.
I would use a second activity. Pass additional data (like contact list, message details, etc.) to it and display it. How you keep parsed XML in memory is up to you to decide (static member? yuck! but it works).
Now back to original Activity. Does your source XML change a lot? Maybe you can parse it and put all data into a DB so that you could retrieve necessary (and hierarchical) data quicker. This way you do not need to deal with storing lots of data in memory, re-parsing and you could perform search faster.
On click event of this list i dont want to load a new activity with a bundle, parse the same xml and show detailed view, while i have the required data in activity A itself.
Cache the parsed XML in a static data member. Your activities that need the data look at the static data member first, then kick off the parsing if and only if that cache is not there.
IOW, this is not an activity problem, but a data model problem. Do a better job with your data model, and your activities can behave naturally.

When to use more Activities

I have an Activity which is an OpenGL view. I also have an xml layout to use for preferences. Until now, to show the preference menu, I just brought it to front by setContentView(). And the same to get back to the OpenGL view.
But is this a case where I should give the preference menu its own Activity?
I guess this would make a few things much easier. For example, the back button would just work, opposed to now where I have to code it or it will just exits the application.
And if this is a good idea, how do I pass data both ways? I have a class that store all preferences. Can I send it to the Activity and back again? Or is the best way to store the preferences in a sqlite database and then use it for passing data?
I find it easier to segregate menus and such into separate activities (unless you are using dialogs etc..) As far as storing data you can do it a number of ways:
Database
StoredPreferences
Intent extras with putExtra/Bundle
Creating an application subclass and storing preferences there
Each have their merit. 4 is pretty easy as you just have to state the application class name in your manifest then call: MyAppClass app = (MyAppClass)getApplicationContext(); and you can then use any variables in MyAppClass via app. 2 is also straightforward.
You already pointed out the main difference: history management.
You can pass data to Activity via Intents putExtra()/getExtra():
Create an Intend and add custom data via Intent.putExtra(..)
Start the new Activity: startActivityForResult(intent).
Inside new Activity you can get extra data with intent.getXyzExtra() (where xyz is type).
When new Activity is done just call setResult(int, resultIntent). Again you can add extra data as described in 1.
Call finish() to end the activity.
In original Activity method onActivityResult will be called. Again extract data from Intent as described in 3.

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