I'm using a ListView to show a list of items. These items are in a table format with columns and rows. Is there a table like adapter to make sure all the columns and rows line up? I know this brings in the complexity of how large each column should be, what to do with cut off text, and other things. I'm just curious if there is currently and adapter hiding somewhere for this task. Or maybe even another control?
The point of using ListView is to be able to scale to larger data sets by not having to create and layout views for all of the items up-front. Because of this, your request fundamentally conflicts with how ListView works -- ListView simply doesn't know how all of its items will layout, so there is no way for it to automatically make sure they align in some way.
You can ensure they align yourself just by writing the item layout appropriately. For example, very often in the UI you will have an icon followed by a label. If you ensure the icon is a specific size, then all of the list items will align. If you are dealing with elements that are more dynamic like text, you could do the same thing by enforcing up-front a specific width for those elements.
If you really want to have the UI compute the element sizes dynamically and align all of the rows based on them, that is what TableLayout does. It can do this because it always has all elements there to layout together. If you want to allow scrolling in it, you can wrap that in a ScrollView like another poster suggested. Just be aware that this approach will quickly fall apart as your number of rows increases significantly.
I was able to make TableLayout to behave like ListView (at least visually). Here is my answer.
There is GridView for that, but afaik it doesn't work with columns and rows. Luckily you seem to have been expecting some complexity :)
You can use a ListView or a ListFragment and populate items using each time a single TableRow inside a TableLayout (maybe using android:stretchColumns="0")
you'll have a TableLayout per line, so it's probably inefficient but it does what you are trying to do
Related
I'm looking to create a music app and I'd like to make a GridView similar to what Google Play uses where they inject elements that will span rows and columns like the Soilwork album does in this screenshot:
I've thought about using a ListView and populating rows with custom elements, but I couldn't think of a good way to use that with ViewHolder pattern, or really a way to make that reusable and account for differing number of items in width based on screen size (for example, the grid is only two items wide on phones, and "large" items span both columns and only one row).
I've also thought about using a ScrollView filled with custom ViewGroups, but that seems to run into the same issues I previously mentioned.
I next thought about using GridLayout, but that doesn't accept ListAdapters, and doesn't seem tuned to the kind of usage I'm looking at (nor does it seem to scroll)
I'd greatly appreciate if anyone could give me somewhere to start on this, or could point me to a library that does this. I've already checked out StaggeredGridView but it doesn't seem to accomplish what I'd like. My ideal solution would be a view which lays out items on an even grid like GridView and accepts view from a ListAdapter, also like GridView, but allow for elements to span, using the single cell constraint of GridView as the default behaviour.
Cheers.
EDIT
I have a perfectly functioning GridView as shown below, but I'd like to make items at regular intervals (every nth item) span more than one column and/or row, as shown in the previous screenshot.
Check out Parchment. GridDefinitionView may help you achieve the UI you are looking to build.
I'm trying to implement an irregular gridview for my Android app. I've defined the gridview to show 2 columns but I need to show just 1 column at the first row. Is it possible using a DataAdapter?
I don't think you can accomplish this with a gridview. The adapter simple provides the data, but the view decides how to lay it out. If your requirements allow you to make the number of columns constant, then maybe you can use the gridlayout instead. I'm thinking you could try to do you layout like the google currents app.
Gridview and ListView are super useful if you have 1000's of items since it reuses views as it scrolls. If you have lots a items in your grid, then I would probably try to use the GridView or ListView to accomplish your goal. Maybe you have to get your requirement changed. Another option is to use a ListView, but sub-divide each row into 2 columns.
In my app I download from the net some data I need to arrange in a table way.
I already know dimensions: about 26 rows and 6 columns, anyway data can change across subsequent calls so I have to create this table in a dynamic way.
As it is a table I though using a TableLayout (never used before), on the other hand I could simply use a list view, using for the single item a 6 elements linear layout with horizontal orientation.
ListView intrigues me because it is an adapter view (I think I'll store this data in a sqllite db, later) so populating it is quite simple and straightforward, anyway I don't know if it is the best for my problem.
What is your opinion?TableLayout, ListView or other?
When it comes to performance, I think you should use ListView because ListView support Recycling of view and you can check this and this post for more detail regarding Recycling of view.
Hope it helps :)
A ListView is a collection of layouts that are automatically displayed one below the other. The developer adds new items through a piece of code in the Activity. An example is the address book where you have lots of contacts one after the other.
A TableView on the other hand is defined in the layout file and does not only need to contain elements below or above each other but can also arrange elements on the left or on the right. A TableView is exactly what it says: A table with rows and columns.
here's a similar question that might answer what you want to know
In the Google I/O 2010 talk about ListView they say you might not need to use a ListView with a bounded and reasonable number of rows. They state if you are dealing with a reasonable number of rows it is possible to just lay them out in a ScrollView.
I'm curious what people find "reasonble length" means in practice.
Would a list of 50 items with each row's views just having a few strings be reasonable to layout without using a ListView? How about 12?
I'm used to using UITableViews on iPhone for most UI so I'm inclined to use ListViews on Android but I also want to be aware it might be overkill for some scenarios and I have a really limited understanding of perf on android presently.
ListView is really the best option for anything over 3 items, it is a good option for even 2 or 3 items. If not you'll end up writing a bunch of code that converts indexes to individual variables instead of arrays, database rows, or other data structure.
It's not only about the number of items but also about whether or not your data collection will be dynamically updated. If you know you will never update the list while it's on screen and it doesn't have many items then a LinearLayout will do just fine.
In the Google I/O 2010 talk about ListView they say you might not need to use a ListView with a bounded and reasonable number of rows. They state if you are dealing with a reasonable number of rows it is possible to just lay them out in a ScrollView.
Hmmm, I can understand the logic up to a point but in reality using a ListActivity, for example, as your base class makes things very simple. OK, if you have a static list of only a dozen or so lines of text (one for each list 'item') then using a ScrollView containing TextViews would be an alternative but in reality using the adapter approach to ListViews is a lot more flexible in my opinion.
Would a list of 50 items with each row's views just having a few strings be reasonable to layout without using a ListView? How about 12?
No, if each list item has a few strings to be laid out then custom list item layouts together with a ListView and a custom adapter are basically a must.
I have a RelativeLayout with different elements. I was planning to have two ListViews on it, but I have noticed there are some problems with scrolling. Since each ListView only shows a maximum of 5 rows should I try to make some kind of custom adapter to merge those ListViews? Or is it better to replace the ListView with a LinearLayout/RelativeLayout and add the rows as I get them manually? (like the first answer in here: android listview display all available items without scroll with static header ).
Which should be the proper way on doing this? or is there another way? Also, each row will have an OnClickListener.
There's two solutions if you'd like to keep your list... list-y, without having to prerender all the row Views like the above solution suggests (which can be slow to render, eats RAM and doesn't scale nicely to more than a screen or two of Views, but is a fine quick solution for smaller lists, though I'd just use a bunch of Views in a LinearLayout in a ScrollView rather than a ListView in that case).
Write a custom ListAdapter, overriding getItemViewType, getViewTypeCount and GetView to inflate the proper kind of view and recycle appropriately for your two types of views. You'll also either need to override getItem to contain custom logic for figuring out which set of source data to look in and to map the data accordingly, or mush the data down into one list of Objects (if you're using an arrayadapter) and cast in the getView method (probably a bit slower than handling it in the getItem without casting).
Just use cwac-merge, a view-and-adapter wrapping adapter. You can put two ListAdapters into a MergeAdapter and set that as your single ListView's adapter.
I had problems with scrolling. I never figured out how to have the ListView share vertical space with a different View, and have a single scrollbar for them both.
I worked around it by having everything that needs to scroll on the layout a row in the ListView.
Adding views as rows to a LinearLayout may have problems scaling up, but I think you'll be OK if you only have 10 rows in total. On 1st gen Android devices it'll probably start to get sluggish around 20 items (depends on Layout complexity obviously). ListView scales up by only inflating views as they come on screen.
So in answer to your question either of the two alternatives you suggest will be OK, but the LinearLayout option will be the easiest to code.