Android: Add cells to GridView dynamically? - android

I am want to add cells to GridView dynamically when the user reach the last row of cells its like the show more?

Check out CommonsWare EndlessAdapter. Very straight-forward Adapter implementation.
You could also manually use an OnScrollListener on the GridView. Use the onScrollStateChanged() callback to figure out when the grid is OnScrollListener.SCROLL_STATE_IDLE, then determine if the last grid item is visible. If so, get more items for your Adapter, and call notifyDataSetChanged().

Related

View for a list of items that don't scroll, and handle on item click events by the item position

Just like a ListView but instead it doesn't scroll. Its content is added programatically via an ArrayAdapter. Is there any view that can be used for this purpose?
PS: Not LinearLayout, since it doesn't get its content from an adapter (I want the observer pattern)
Edit: Let me explain a little bit more. Suppose you need a list of items, but the list itself is not scrollable, what is scrollable is the screen.
That being said, the list of items should show ALL items, not a limited amount based on a fixed height. The way to go is LinearLayout as it is both non-scrollable and shows all items within itself.
But there is a third requierement. You don't want to add(View) directly, but instead, you want something similar to an ArrayAdapter so that you have a control of the items and their position, so you can handle on item click events based on their position. As far as I know, this can't be done using a LinearLayout. So my question is, does any view exist for this purpose?
You could try using a ListView, but disable scrolling, as described here
Put your layout inside a ScrollView and yes you have to use a Linearlayout. You need to set tag for each of your view that you add dynamically and whenever your view is clicked you can get it's position by view.getTag() and perform the required operation.
Note : Adding views at run time may affect performance.

Android listview with horizontal lines when empty

I have a Listview in my Android app, and I want there to be some horizontal lines when the list is empty to indicate to the user that this is a List. I know that there is the setEmptyView method on ListView, but I'm not sure what to put in that view if I want there to be list rows with horizontal lines. How would I accomplish this?
Having a bunch of horizontal lines for an empty list is an iOS convention. If you want your app to fit in with Android better you should set something else. Perhaps notify the user there was an error or that there are no items in the list. You can add this right to your layout.xml file if you're using a ListActivity. All you need to do is create a view and give it the id #android:id/empty.
put the listView in a FrameLayout and add another view in that Frame.
if you having any item in the list hide its (visiblity="gone") and show the other view.
OR
change your adapter to return multi ViewType
in your adapter if you have no item return other type of view

Android: How do I remove an item from a gridview, having the remaing items shuffle into place

BACKGROUND:
I have a grid of 36 buttons, lets say a 6 rows & 6 columns numbered 1 to 36, displayed 2 rows at a time via a GridView and custom Adapter
The grid displays fine, and all of the scrolling works properly.
QUESTION:
I want to be able to click on an item, have it removed from the grid and the remain items shuffle up into place. Currently I am able to disable the item disabled, set its visibility to INVISIBLE or GONE, but none of these will actually remove it from the display.
Suggestions?
Specifically, you need to remove the corresponding object from the data set of the underlying adapter and then call adapter.notifyDataSetChanged(). This isn't going to provide you with an animation, though, if that was part of this question.
It may be interesting to try a tween animation for the item in question and then finally remove it from your adapter at the end. I'm not well-versed in animation, so I'm not sure how well this will work in an AdapterView.
You should be able to update the adapter, and then call notifyDataSetChanged to force the grid view to be updated.

How to reference first list item inside ListView?

I would like to add Top Margin on the first item in the ListView. Is that possible?
Or, how can I reference first list item in the List View?
I tried
lv = (ListView)getListView();
View myRowItem = lv.getChildAt(0);
Probably, it doesn't work, because at the moment I executed it, list items didn't exist yet. I assume I should try above code in something like onPostRender event. Is there something like that in Java Android?
You would have to create your own adapter, and put that condition in the getView method. However, I'd like to know why you would want to add top margin just to the first item... wouldn't it behaves the same if you put that top margin to the ListView itself?
In order to get the items, write your code wherever you set the list adapter.
By the way, in order to set the margin, just set android:PaddingTop of the ListView on the layout file (XML file).
The best place to customize ListItems is its Adapter. Create a customized adapter for your ListView and use the getView method to decide what to do with every ListItem. See an example here: How to repaint listview items when changing orientation

ListView and propagating click events from children views in the items

I have a ListView with custom items - 3 ImageViews and a TextView. I have a call to setItemsCanFocus(true), so I can make the ImageViews clickable. I'm currently using SimpleAdapter to populate the View.
I'd like to trigger the AdapterView's onItemClick event when one of those subviews is clicked. The onItemClickListener receives a view as the second argument and that can be used to identify which subview was clicked. Frankly, I was expecting this to be the default behaviour but it isn't, unfortunately.
Is there any way to implement this behaviour without bluntly breaking encapsulation (i.e. creating an Adapter that holds a reference to its View)?
What is the accepted way of dealing with events from views in list items? How do you keep the Adapter from knowing too much about the ListView?
Unfortunately you have to choose between using onItemClick() or onClick() on individual children. One way to do it however is to make the top-level view of each item clickable.
Setting android:addStatesFromChildren="true" on the listview in your xml will send clicks on the child elements to the onItemClick method in the onItemClickListener connected to your listview.

Categories

Resources