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Set empty cell in the middle of android GridView layout

I working on my project with gridview layout, and the whole code is pretty identical to Android Developers example (I can't post links because of my low reputation, sorry).
Its works fantastic, when I need to fill screen with 3*3 or 4*4 (and etc) grids, but now I have to design my gridview with only 8 imageviews and I want to set the empty cell in the middle of GridView, just like that (click for images):
That is my current position:
This is what I need to do:
I have googled that a lot, but I can't find some example that shows how to implement that.
Have you any idea how can I solve that issue?
Set it to invisible -
imageView.setVisibility(View.INVISIBLE);
not works for me, because then I "lost" one of my imageViews.
Thanks a lot!

Let's consider you will always have an (x*x) number of items in your GridView, where x is an odd number bigger than 1, like 3 or 5. The index of the item that you want to hide is items.size()/2. Note that in Android, 9/2 = 4 and 25/2 = 12. So, we already know the index of the item that should be hidden.
Following, in the code, you just have to make your item View stay invisible when that your adapter.getView() method is called for that index. Here is that getView() portion of the code:
#Override
public View getView(final int position, View convertView, ViewGroup parent)
{
ViewHolder viewHolder;
LayoutInflater inflater = yourContext.getLayoutInflater();
if(convertView==null)
{
viewHolder = new ViewHolder();
convertView = inflater.inflate(R.layout.your_grid_item_layout, null);
convertView.setTag(viewHolder);
}
else
{
viewHolder = (ViewHolder) convertView.getTag();
}
if(position == yourItemsList.size()/2){
convertView.setVisibility(View.INVISIBLE);
}
else{
convertView.setVisibility(View.VISIBLE);
}
return convertView;
}
This will make your middle View invisible. The effect that you wanted.
Also note that your GridView number of lines has to be equal to the number of rows for this method to work.
You can always change the number of rows dynamically, according to the number of items that you have. In your Activity code, before gridView.setAdapter(), like this:
gridView.setNumColumns((int) Math.sqrt(myItemsList.size()));
Again I warn you that this code only works for GridView configurations of 3*3, 5*5, 7*7, and so on.

How to make an empty space between Expandable ListView groups [duplicate]

This question already has answers here:
android expandablelistview how to set space between groups items
(6 answers)
Closed 8 years ago.
Can somebody tell me how to make an empty space between the groups of Expandable ListView. I tried many solutions but whenever I give height to divider it always increase the height of child divider too. I tried separately android:divider="#drawable/group_separator" and android:childDivider="#drawable/child_separator" and also tried to set the height programmatically separately in getChildView and in getGroupView but the same result. It always increase the space between child divider too but i just want to make space only between the groups even if there no item between them. Like to give the space of 40dp even if there is no item just like in the below image. Any help will be highly appreciated. Thanks in advance.
and after I applied the divider height it become like

Answering to my own question so that anybody else may happen this problem so here is a solution after trying to much.I have done it through a single condition by just checking that if the group has no child then it should set the white layout that will be shown as a white blank space and no other things like padding, dividers or margin needed. just like in the below code in getGroupView() and you don't have to do anything else. The layout (blank_white_layout) I use is just a relativelayout having white background and you can give it height according to your needs.
if (getChildrenCount(groupPosition) == 0) {
view = inflater.inflate(R.layout.blank_white_layout, null);
}
and below is the complete getGroupView code in my adapter class
public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
ViewGroup parent) {
if (groupPosition == 0 ) {
convertView = inflater.inflate(R.layout.group_layout1, null);
}
if (getChildrenCount(groupPosition) == 0) {
convertView = inflater.inflate(R.layout.blank_white_layout, null);
}else{
convertView = inflater.inflate(R.layout.group_layout2, null);
}
TextView text1 = (TextView) convertView.findViewById(android.R.id.text1);
return convertView;
}

From your getView() method detect the rows that you want to separate( by position and type)
and just add to them padding or margin, very simple.
Just make sure to remove that padding or margin when the listview recycles that view.

Create separate xml layout for group and child views. Set padding to the group layout xml file.

Simply add this tag in the group2 xml view.
android:layout_marginTop="40dp"

listview recycling strange empty space

I have a similar problem to the one in this question: ListView and rows recycling problem
Above is solved. but same solution does not work for me.
I have a listview consisting of textviews. Each textview can contain variable number of images. I am getting images with html.imagegetter and I am using recycling in getview method of list adapter.
If there is one or more images in a textview, it will have a height to be able to fit its content. When this textview is recycled and new content does not fill the height defined before, then empty space will appear.
The problem is that I can't restore the textview height in getview because I dont know what height the next list item will have.
this is my getview:
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
View rowView = convertView;
if (rowView == null) {
LayoutInflater inflater = context.getLayoutInflater();
rowView = inflater.inflate(resource, parent, false);
holder = new ViewHolder();
holder.imgAvatar = (ImageView) rowView.findViewById(R.id.imgAvatar);
holder.textDetails = (TextView) rowView.findViewById(R.id.textDetails);
holder.textPostTime = (TextView) rowView.findViewById(R.id.textPostTime);
holder.textPost = (TextView) rowView.findViewById(R.id.textPost);
rowView.setTag(holder);
} else {
holder = (ViewHolder) rowView.getTag();
}
holder.textDetails.setText(details.toString());
holder.textPostTime.setText(x.postTime);
holder.textPost.setText(Html.fromHtml(x.postBody, new URLImageGetter(holder.textPost, context), null, context));
return rowView;
}
this is row layout:
<TextView
android:ellipsize="none"
android:autoLink="web"
android:textColor="#000000"
android:id="#+id/textPost"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
THE PROBLEM: The listview recycling mechanism can't calculate the new height for used views according to its new contents.
Without recycling, it is too slow.

So, essentially your problem is with recycling the views. When your views get inflated from XML they look at the images and decide how tall to be. This works fine because the inflater can cause the height to be "wrap_content" aka however tall the tallest child component is - this is dynamic.
However, when your getview recycles the old views it (for some reason) isn't updating the height of the rows, and neither are you (which you never had to do before because the inflater handles it automatically from "wrap_content"). It would appear from what you described that you just get a row with whatever the height of the view happened to be set at previously (this previous value was set by the inflater automatically).
Your two solutions are:
Don't recycle the views - just inflate a new one every time. You will see a performance hit which will probably only be noticeable at lists with ~50 elements or more. If it is a small list this may be the easiest (code-wise) option, although there it will still operate slightly slower.
Keep recycling the views - if you pick this you will have to set the height of the row (or text view, whatever is determining it) yourself based on the image heights. This is doable but will require more work. I'd suggest
secret option 3 - normalize the image heights - If you would a.) like to continue recycling views but b.) don't want to write the code to set the row heights manually and c.) resizing the images wouldn't kill your app, you could use the setMaxHeight(int) method to make sure all of your images are the same height (or use a method like this to resize the images to a predetermined size)
Note: I am pretty sure (almost certain) that, normally, if height is set to "wrap_content" it would wrap to the new content size (since it normally updates the size when the content is updated). I couldn't say why this is not happening for you - it may be that something inside the "wrap_content" has its size set to a concrete value and thus isn't resizing, so the "wrap_content" isn't changing even though there is empty space.

Try using requestLayout on your image and textviews. It will help the listview recompute the height of recycled views.

How to overlay rows of Android Listview

I am trying to implement the below Android ListView. The each yellow box represents one row of ListView. If you see the rows, each row is over lapped by previous and next row. I have searched Google, but I could not find any proper solutions. If anyone has clues, please let me know.
Thanks in advance.

Think outside the box. Imagine this list not having the rows overlap, but just having diagonal lines on it. In your code, set the Listview's divider height to 0:
ListView listView = (ListView)findViewById(R.id.your_listview);
listView.setDivider(null);
listView.setDividerHeight(0);
Then create two drawables for the rows- one for odd rows, another for even rows:
and
(don't use these two images, as they are not properly/evenly sized, but create the ones for your specific list).
Then create an adapter for your list view - and in its getView method, set the corresponding background to your element:
#override
public void getView(int position, View convertView, ViewGroup parent) {
MyView row;
if(convertView == null) {
row = (MyView)convertView;
}
else {
row = ... //create your view - inflate or create in code
}
row.setBackgroundResource(position%2==1 ? R.drawable.row_odd : R.drawable.row_even);
... //populate the rest of the row with whatever you need
return row;
}
And voila! You get what the effect you need (note, on this schematic the black lines represent the boundaries between rows - these are for schematic purposes only - in your final result you will not have them):
Finally, please note that if you want highlight on your "rows" when an item is selected, you'll have to implement custom state change listeners, which would change the background of the cell that's being selected and also the ones above and below it as to create the proper visual effect.

I got the same issue but I managed to find a solution
In the ListView in the xml you can set a negative dividerHeight, it works for me.
<ListView
...
android:dividerHeight="-5dp" />
I hope it can help someone :)

Android HorizontalScrolling laggy

I have a HorzontalScrollView with a LinearLayout inside. During Runtime I can add more LinearLayouts to the LinearLayout.
Now I have the problem that the Scrollview only scrolls a little bit and not smooth with one finger slide!
Does anyone have a solution for this problem?

HorizontalScrollView doesn't use an adapter that manages the list's memory, therefore it can't handle heavy (images, custom views, etc) lists.
You can use this Horizontal ListView http://www.dev-smart.com/archives/34 but make sure you don't write the on list item click method inside the getView, it will make the list scroll slow. Other than that, that's a great resource for a smooth horizontal list view.
You can also explore the Android view pager, which is also supported on lower Android versions using the compatibility pack: http://developer.android.com/sdk/compatibility-library.html
Edit - something like that in the adapter that inflates the XML you want (the linearLayout) and then populates every view with the relevant data.
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.chat_friends_list_item, null);
}
ImageView status = (ImageView)convertView.findViewById(R.id.status);
ImageView image = (ImageView)convertView.findViewById(R.id.image);
ImageView imageBorder = (ImageView)convertView.findViewById(R.id.image_border);
TextView title = (TextView)convertView.findViewById(R.id.title);
}

The problem was my parent Viewflow because it has stolen the swipe event! The HorizontalListView is too buggy for me! (Problems with size attributes)
However,thank you for your answer! ;)