When my program start I would like to do some settings before is really starting. Forexample choose the user, check the updates and so on. After these settings I would like to start the main program with the appropriate.
Which is the best way to do this?
You can run an AyncTask, or multiple if you need one for each check, in your onCreate() and show a ProgressDialog while the data is being fetched then cancel it in onPostExecute() and move on to the rest of the MainActivity depending on the data that is downloaded. If you need help getting started with AsyncTask you can see this SO answer on the basic structure.
If you use a ProgressDialog then the app will still start but the users will see something and know that data is loading so they won't feel like it is freezing or taking too long to load (or at least they will know why it isn't loaded right away).
AsyncTask Docs
Edit after comment
For what you said you want in your comment you can do this easily with an Activity that has a Dialog Theme. This will give you the functionality you need (a couple Buttons and store the values) but it will look like a little popup. You can't use an actual Dialog as they need an Activity, the same with any menus, AFAIK. Just create your Activity and make it the launcher and main using the Intent-filters then also add the following line to that Activity's tag in the manifest
android:theme="#android:style/Theme.Dialog"
This approach should give you what you need
There are numerous ways to do that.
First - your app is doing some heavy stuff and this may be freezing user interface. In that version do:
1. Create and activity on what you will override onCreate method and set some content with a spinner - so something will be alive and user will see that something is being done.
2. after you will compute all the things that your app need and may I suggest write it to some global variables override onStart method in what change layout to what suit you and give a user a great UI!
Second - you app is not heavy lifting here just throw everything into override of onStart method.
Handy material here for educating:
Related
When I change the screen size in the multiview / split screen mode, the onCreate function in MainActivity is called again.
Because in onCreate I have a ProcessLifecycleOwner observer:
ProcessLifecycleOwner.get().GetLifecycle().AddObserver(this);
I don't want it to be restarted ... How do I know that onCreate has been called before?
I know you can add:
android:configChanges="screenSize"
in the manifest, but unfortunately needs to "refresh the layout" when resizing.
Android is going to manage the life cycle, and the programmer needs to deal with all eventualities. On this page, there's an abbreviated diagram:
That would indicate that you would need to manage the observer in the onStop().
I have a code that requires two edittexts, this information is used to display direction on a map. How can I submit this data automatically on activity start, without the need of a button.
Side question, is there a way to hide these edittexts? To prevent further manipulation by users.
EditTexts can be either disabled using editText.setEnabled(false); or hidden using editText.setVisibility(View.INVISIBLE);.
If you want to execute code on an activity start just write it into the onCreate(...) method.
I am following the Google tutorial for building your first android application. I got to the point where I needed to implement the actionbar actions with the functions openSearch() and openSettings().
I implemented all of this in the MainActivity.java file.
My question is this:
In the example app you can type a message and then send it and it displays it in a second activity. In the second activity, the top action bar changes and does not display my Search icon or perform the action when the settings button is clicked. In order to have these icons displayed in the action bar for this activity as well, do I need to add those methods and update onOptionsItemSelected method in DisplayMessageActivity.java as well as in MainActivity.java? Is this the only way to carry the action bar icons/actions over? To retype the same methods in each activity that you want them in? Or is there a better way to do it?
My other somewhat related curiosity is this. The method openSettings() is called when I click the 3 vertical dots and then settings. These 3 vertical dots show up on every activity, and settings is always in the list. However clicking settings obviously doesn't perform the call to openSettings() when in the DisplayMessageActivity and not MainActivity. How is it that settings and the vertical dots are carried over?
Second to last, how can I add other selections to the drop down list from the options/vertical dots in the action bar? Settings is always there although it responds differently in each activity which was my first question. But I would like to add certain things to the options menu that are on all activities, and some things that are unique to some activities. I assume there must be a better way than repeating switch statements and methods in every Activity.java file.
And finally, what is the best practice to implement an action bar over multiple activities?
Obviously different activities will often have different icons/actions in the action bar, however some things like the 3 vertical dots(options) and settings within that would obviously be acceptable to have in every Activity, while it would be nice to add other things to the options list I don't see why settings should ever change across activities. Yet as I stated before the method is not called in DisplayMessageActivity unless I repeat the code in DisplayMessageActivity.java that I had added to MainActivity.java. I'm confused as to where I can add these so that they are displayed on all activities without repeating code. And I'm confused as to how the actionbar's options/vertical dots are carried over to all activities while others require the repeating of code in each activities' java file that I want them to show up in.
I know this was a bit of a long winded quesiton, I will clarify if necessary. I'm just a bit confused. I was able to make it through the tutorial fine as I have a decent understanding of java. However google's guide isn't written that well and the Android environment is very confusing to a beginner.
I do understand how things work to a degree, I just want to ensure that I'm actually doing it in a way that when my app grows in complexity it won't be a mess of unnecessarily repeated statements and methods.
Thanks in advance for any assistance and tips.
In order to have these icons displayed in the action bar for this activity as well, do I need to add those methods and update onOptionsItemSelected method in DisplayMessageActivity.java as well as in MainActivity.java? Is this the only way to carry the action bar icons/actions over? To retype the same methods in each activity that you want them in? Or is there a better way to do it?
That is certainly one solution, but as you obviously know, it's not a very good one. There are at least two alternative solutions:
Create a MenuActivity class which implements all the logic for common menu items and then extend this class from all of your activities, rather than extending the standard Activity class.
Use fragments to implement your UI. Fragments are similar to activities in that they create UI elements from an XML layout. One difference is that they live inside a "host activity". In this particular case, the host activity will provide the common menu functionality and each fragment can customize it further depending on your needs.
How is it that settings and the vertical dots are carried over?
Most likely your DisplayMessageActivity overrides onCreateOptionsMenu() and inflates a menu XML layout which was created by Android Studio (or Eclipse?) when you created the activity class.
Hi and thanks in advance for your time and attention.
I actually have 2 questions i'm not too sure about building an android app. Pretty basic stuff I believe:
1) My app is fully on Horizontal mode, like AngryBirds for example. When it starts the user figures out he should hold the phone like that, if he isn't already. And that is setup in the manifest for all the activities and works fine. but is there a way to prevent the physical device tilting to call onCreate again? can i override it's method or whatever? the reason i'm asking, is because i have a few ButtonViews that after you click on them, change their picture. i am using onRetainNonConfigurationInstance() to save the array of those ImageButtons, and i even mark the ones changed with the ImageButton setTag() and getTag() methods, so when onCreate is called because of the device tilt it gets the saved array from getLastNonConfigurationInstance() , but i've been trying to make it work for quite some time now and I just can't get it right. After the device tilt (I'm actually using the emulator so it's Ctrl+F11 but i believe it will happen with a device as well) all of the ImageButtons loose their pictures.. Long story short - are there better ways of doing this that you can recommend or is preventing the tilt from doing anything is possible or better?
2) What is the best way to know how many seconds the user has been on a screen? I tried to use two longs that i get via SystemClock.currentThreadTimeMillis() as follows: get the starting time onCreate, and the ending time on the method i call to move to the second intent just before i startActivity. but I think because they are called from different threads, the endingpoint - startingpoint is not correct. What is the way to insure both of the methods of SystemClock.currentThreadTimeMillis() are called from the same thread, the main thread of the activity that i'm stopwatching? Is there a better way to go around this?
Thanks again.
You are doing the right to handle orientation change. Please refer to this link http://developer.android.com/guide/topics/resources/runtime-changes.html . This will help you to get it working.
Good way would be to count the time between onResume and onPause. OnCreate is not called all the time if you are resuming activity.
1) You can try adding the property android:configChanges="orientation" to your activity in the manifest file. It worked for me when my dynamic Action Bar tabs got messed up upon rotation of the screen.
You need specify orientation in android manifest for each of your activities, it will not call onCreate then. android:screenOrientation look at http://developer.android.com/guide/topics/manifest/activity-element.html
User see and interact with your activity starting since onResume and ends on onPause. Other time it does not guarantee that user actually see and can click on something in the activity. System.getCurrentMillis() is good enough.
I change Linear Layout background image via this code:
mainlayout.setBackgroundResource(R.drawable.back);
But i want do this on every time that activity starts, In first start and switching between activities. I put this code inside an IF statement in onCreate() but background not change! Of course when i set this code to a button works fine! How and where i have to put my code?
my complete code is:
//check theme id
if(myDbHelper.gettheme()==1)
{
mainlayout.setBackgroundResource(R.drawable.back);
}else if(myDbHelper.gettheme()==2)
{
mainlayout.setBackgroundResource(R.drawable.blueback);
}
You need to put your code into the onResume() method.
Here are details that will explain why
http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle
You may want to refer to the Android activity lifecycle, but I'd recommend the onResume() method.
I'm assuming based off your code snippet you have the image you want as a background as a drawable resource already in project. If so you could just go into the XML and add into the linerayout:
android:background="#drawable/back"
This should just set the background within the XML layout avoiding having to have code set it within one of the activity life-cycle functions.
Though in the case you wanted different themes as I just saw in the original post (seemed to be edited since I was typing this up), you could try storing the constant int of the R.drawable that the user wants as the background or theme, and have your DB Helper's getTheme() return that reference to set the background without the if statements.
Such saying the user changes their preference to R.drawable.black or .blueback store the int within the DB so it get return by gettheme rather than a 1 or 2 enumeration. Not sure if this would be a best practice though.
EDIT: Are you sure theme is either 1 or 2?
If you want to do it everytime, why don't you just define it as mainLayout's background in your layout.xml? Otherwise, use onResume() rather than onCreate().