i got the following "problem".
I want to have an activity thats shows me the standings of some teams at a specific gameday.
therefor i would add a spinner and a TableLayout. At the first Start the activity should show the standings of the actual gameday but then you can choose any other gaymeday and the standing should get updated.
Whats the best way to create this activity?
assemble the whole TableLayout with all TableRows and TextViews, give them ids and update those views via id during runtime. Problem: huge unflexible hardcoded layout.xml
assemble the layout during runtime, add ids, update via ids
assemble the layout during runtime. on update remove old views and create new ones
assemble the layout during runtime. on update restart the activity
just whant to know which one is the best. or is there any other way to achieve that
thx Cheetah
If I were you, I'd actually use a GridView with an Adapter. This will abstract away all the handling of layout changes. You just have to worry about mapping your data to appropriate views. This example maps ImageViews to a GridView, but there's no reason you couldn't map to TextViews containing your data in a GridView. Also, because you're using an adapter, you can take advantage of all the Loader classes and they're asynchronous loading capabilities.
In addition, using the approach will allow you program to easily adapt as your dataset changes. You may want to add more data to the table in the future and this approach will allow you to easily do that without having to constantly change your xml layouts.
Does the number of views change? If no. Best way is to use the already existent views and update their values. Try to avoid recreating/reinflating views since that's an expensive task.
Related
So I have a few arrays of data I would like to display in an activity without having like 15 text views with unique ids. Is there a code efficient way to make a Table layout or something like it where I could feed in data and it would automatically place it in there respective text views? Thanks!
I think you can achieve that by using RecyclerView (with a GridLayoutManager). Have a look at this answer.
If there are only TextViews and you don't want a specific layout you can use SimpleAdapter, if you want to modify the layout you have to extend RecycleView.Adapter (there is an example in the answer above).
You can add/remove items into/from a List and use DiffUtil that
can calculate the difference between two lists and output a list of update operations that converts the first list into the second one.
There are a lot of tutorials about using this class. Have a look here or here.
Or you can use the notifyItemChanged() method:
If the list needs an update, call a notification method on the
RecyclerView.Adapter object, such as notifyItemChanged(). The layout
manager then rebinds any affected view holders, allowing their data to
be updated.
LE: There are some libraries available. Here is a list:
https://github.com/evrencoskun/TableView
https://github.com/HYY-yu/TableRecyclerView
https://github.com/Cleveroad/AdaptiveTableLayout
https://github.com/celerysoft/TableFixHeaders
I am trying to create a fragment and inside that i want to create multiple textviews whoose text is set from the data retreived from the database(mysql).
And also i want to have the feature "refresh" by which the textviews are updated with recent data from the database.Iam trying to do that but iam not getting enough idea how to do it as iam new to android programming.
Please help me with this. thank you in advance and any suggestions are acceptable.
i.e
I have database of a person and i want to get his name and address from that,then in my activity i want to create a fragment that displays a name and address in separate textboxes and if address or name exceeds some length then i can press "more" to see left information
Consider using a ListView to populate data from the database, and a SwiperRefreshLayout to refresh it. Check these links for more info :
SwipeRefreshLayout
ListViews
The answer depends on what your app will do.
If you have a fixed number of TextViews, and the number won't change in the future or depending on the answer to the database query, you could simply stick to normal TextViews; if the number changes, I suggest using ListViews or ExpandableListViews.
Regarding the layout, you can create a normal layout using AndroidStudio's layout designer, and then inflate it to your view.
For the refresh, you can add a button that calls the method in which you fill the textviews/listviews.
Actually your question is too broad: if you want a more specific answer, you should edit it asking what you really need.
I am new to android programming am trying to learn it.
So basically there are two ways of creating whatever is going to be visible on the screen :-
We create views and view group objects inside layout.xml files. And then as the need be we access those views that are already existing
in the layout through our java programs by accessing their ids ( as
r.java….). So basically when we start a particular activity, we
set the content to be displayed corresponding to that activity using
setContentView method, to which we pass the layout.xml file, inside
which we have defined the different views and view groups to be
displayed on the screen.
The second way is we create these views dynamically though our java programs and then set them as the content on the screen using
setContentView again.
Now the above is my basic understanding. Please let me know if the above needs correction.
Now what I want to understand here is :-
Is there a way that using the first method itself, we can do the
vice-versa, as in say instead of fetching the the views through their
ids from the layout.xml files, can we already have a predefined
layout.xml file with different views having ids, and now through our
java programs can we just access those views though their ids and set
their values, something like say (in javascript) :-
document.getElementById(“someTextBoxId”).value= “some calculated
value from java code here”
Thanks.
If you have a layout that has a bunch of views that won't be changed during runtime, for example a TextView used as a label, is it proper to remove the ID from it, or to label it like a view that you would use?
What about layouts? If I have a bunch or table rows in a table, should each have a unique ID or should I clear the field?
It seems to me like it removes a lot of clutter if I clear the IDs if views that I won't be changing but I don't want to do that if it's bad practice.
Thanks.
You only need to define an id for an UI component if you want to reference this component later from your program code (e.g. findViewById(R.id.my_textview) ).
Because you said the views won't change during runtime you don't have to define an id for every view.
It can even help you if you don't define an id, because it keeps the auto complete function of your IDE clean. If you have a lot of layouts (which contain lots of ui elements) and you define an id for each component then you will have a nearly endless list of component ids at the end.
#matt: if your are using canvas to draw the views and set layouts then id is not necessary from my knowledge and I never used id fro and I think its not bad practise.
I ran into the situation that I need a way to edit the data of list-view item from another activity. I can handle the click event on each item, then edit it on the fly. However, I still prefer to handle all the editing in a separate activity. My listview item is customized from BaseAdapter.
Here is my main page,
Each item within the ListView, contains two other TextView. When the I hit the menu setting, it will go to another activity where I can edit and update the information:
I'm currently having two solutions in mind. Either retrieving data from the previous activity and update the whole ListView (which I think it's kinda expensive in the case user just edit one item). Or I can just get rid of the ListView and create a bunch TextView in the xml, by doing this I can just reference to each TextView by their id. So my question is, which way is preferred in this case? Any suggestion would be greatly appreciated.
Your ListView is displaying Email, Name, Headline, etc? That should be a fixed XML layout with TextView entries, I think. ListView is for variable numbers of elements. You CAN implement it with a ListView, but I wouldn't.
However, your concern about updating the whole list being overkill, I wouldn't worry about that either. You're talking about 7-10 fields. The amount of time Android needs to run through its lifecycle and display everything will dwarf you updating a few fields.
You can use SharedPreferences for this. You can create a wrapper class through which you can access the preferences.Thats the usual way to go about solving these kind of problems. You can check this for details.
You can have it as a variable in your application class, so that you can access that in a global context.
Use text views instead. List View code has been optimized for large amounts of data only and not recommended for small data.