Develop Reference

Android ListView width keeps changing

Firstly, I am new to android so if I have missed something basic I apologise.
I have a page which has two ListViews side by side, both with varying amounts of content. I also have a TextView above the ListViews and another TextView below the listviews. These text view boxes change based on items selected in either of the two ListViews.
These two ListViews sit side by side, taking up half of the screen each, while a Textview sits directly above and directly below, both centred to the page. An image is shown below.
This is the page looking normal on load.
The problem is when I select an item from either list. I have a feeling I am missing some XML properties, but I am not sure which properties or if this is even the case. When an item is selected, let's say from the ListView on the right, the TextView at the bottom is updated with text taken from an array. The ListView also decides to change the width and I am not sure why this is.... I don't want the ListView to change width. I want it to remain taking up half of the page and half of the page only.
This is the page after an item from the right ListView has been selected.
I would also like to keep things in RelativeLayout. I also believe it is only an XML issue and not to do with the adapter or any other code so I will not include that for now. I can include it if required.
Any help would be great. Thanks in advance.
content_titles.xml my activity xml file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".TitlesActivity">
<ListView
android:id="#+id/unlocked_titles_list"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:longClickable="true"
android:layout_below="#+id/current_title"
android:layout_alignEnd="#+id/requirements"
android:layout_marginEnd="26dp"
android:layout_above="#+id/requirements">
</ListView>
<TextView
android:id="#+id/current_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="65dp"
android:text="Current Title: Novice"
android:textSize="24sp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"/>
<ListView
android:id="#+id/locked_titles_list"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_alignStart="#+id/requirements"
android:layout_marginStart="28dp"
android:layout_above="#+id/requirements"
android:layout_below="#+id/current_title"/>
<TextView
android:id="#+id/requirements"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="34dp"
android:text="temp"
android:textAlignment="center"
android:textSize="24sp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"/>
</RelativeLayout>
activity_listview.xml used as the individual rows of the ListViews
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/label"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dip"
android:textSize="16dip"
android:textStyle="bold" >
</TextView>

The problems with layout could be caused by ScrollView to be the wrapper
I stumbled upon some note in http://developer.android.com/reference/android/widget/ExpandableListView.html
"...Note: You cannot use the value wrap_content for the android:layout_height attribute of a ExpandableListView in XML if the parent's size is also not strictly specified (for example, if the parent were ScrollView you could not specify wrap_content since it also can be any length. However, you can use wrap_content if the ExpandableListView parent has a specific size, such as 100 pixels."
I removed wrapping ScrollView and linear layout started working properly. Now its only to understand how to wrap the stuff to ScrollView. God help me
But anyway this is really weird behavior. I think that fill_parent is not really correct wording. When using heirarchyviewer tool I always see WRAP_CONTENT and MATCH_PARENT values for layout_width and leayout_height. So probably fill_parent is actually means match_parent which puts me in cognitive dissonance.

You have your layout_width properties set to wrap_content. This means that they could change as the data changes. I would recommend putting your ListViews in a LinearLayout with orientation:horizontal and set the amount of space that each element takes up with layout_weight. Here is a relevant SO question What does android:layout_weight mean?

Spinner height doesnot change

I have declared a spinner in my layout file. I have set a custom ArrayAdapter for this. My problem is the spinner height gets unexpectedly larger than defined when the view is rendered.
For example if I declare the spinner like this:
<Spinner
android:id="#+id/categorySpinner"
android:layout_width="match_parent"
android:layout_height="45dip"
android:layout_above="#+id/rewardListView"
android:layout_below="#+id/customerRewardPointsTextView"
android:background="#drawable/btn_dropdown"
android:spinnerMode="dropdown" />
Then its rendered like this:
On the other hand if I declare the spinner like this:
<Spinner
android:id="#+id/categorySpinner"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_above="#+id/rewardListView"
android:layout_below="#+id/customerRewardPointsTextView"
android:background="#drawable/btn_dropdown"
android:spinnerMode="dropdown" />
Then its rendered like this:
So the problem is whether I set the android:layout_height="45dip" or android:layout_height="0dip" the height of the spinner remains the same. How to resolve this issue ?

Although you are defining android:layout_height but it's not actually working because of the restriction you have in your view :
android:layout_above="#+id/rewardListView"
android:layout_below="#+id/customerRewardPointsTextView"
As you can see you placed the view between your two view "rewardListView" and "customerRewardPointsTextView". And those view actually adjusting the height of your "categorySpinner" view, so it doesn't matter whether you give 45dip or 0dip.
Try placing "categorySpinner" in your relatvielayout in a way so other view does not mess up with categorySpinner's height.

Adding bottom margin to ListView last element

I need to add to add ListView with complicated items background: different for even/odd and rounded corners at the top and bottom. It looks like this:
I have implemented all this stuff via level-list, but there is one more thing I want to do.
Now the bottom item is near the bottom of the screen. It is better to add some space.
I don't want to add bottom margin to ListView, I need margin only for last item.
The ways I see to do this:
Footer
A kind of hack – add footer with empty TextView to ListView. But footers are quite unstable things, they usually disappear after notifyDataSetChanged and there is no way to get them back
Image with transparent pixels
I asked designer to add transparent pixels to bottom background resource. Unfortunately, in this case vertical centering is completely broken.
For example, there is 9patch like this:
And layout like this:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<!-- View with background with transparent pixels on bottom -->
<LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"
android:id="#+id/item"
android:background="#drawable/some_bgr"
android:padding="10dp"
>
<TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"
android:text="Title"
android:layout_gravity="center"
android:textSize="18sp"
/>
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content"
android:text="Detail"
android:layout_gravity="center"
android:textSize="18sp"
/>
</LinearLayout>
<!-- Just for marking place took by view -->
<FrameLayout android:layout_width="match_parent" android:layout_height="match_parent"
android:layout_below="#id/item"
android:background="#88ff55"
/>
</RelativeLayout>
The result:
As you see, centering is not working. Unfortunately.
(BTW, if specify this 9patch as background for TextView, centering works good. If you know any article, explaining this, please let me know.)
Add bottom margin to last item in Adapter implementation
That should work, but for unknown reason I still can't get it work.
I don't like this way, because I don't like to modify dimensions in code.
So
There is already imaginary way – construct some XML drawable with particular bitmap and margin. According to drawables concept it should be possible, but I can't find implementation. May be somebody knows?
Any other ideas?

In your ListView, set a paddingBottom and clipToPadding="false".
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="8dp"
android:clipToPadding="false"
android:scrollbarStyle="outsideOverlay"/>
This also works for RecyclerView.
Only use android:scrollbarStyle="outsideOverlay" if you want the scroll bar to not overflow into the padded area.

add an empty footer in your list like this:
TextView empty = new TextView(this);
empty.setHeight(150);
listview.addFooterView(empty);

you can also do it from code if you want, for example here I react to
to EditText different situations:
if(s.toString().length()>0)
{
contacts_lv.setClipToPadding(false);
contacts_lv.setPadding(0,0,0,270*screenDensity);
}
else
{
contacts_lv.setClipToPadding(true);
contacts_lv.setPadding(0,0,0,0);
}

Clocksmith's answer is the best and pretty clever. You can also create an empty footer view.

Add these two lines in your listView XML code:
android:transcriptMode="alwaysScroll"
android:stackFromBottom="true"

Another solution might be that you make a mock view with certain height.
In your adapter in getViewCount return 2.
In getCount return yourData.size+1.
In getViewType check if the element is last element return 2;
Use this type in getView to populate the mockview.

I guess you want to add margin only to last item:
So you can do in this manner, in your getview method the index of the list item and check if its the last item, then progrmatically add margin to the view.

Android - RelativeLayout w/TextView .. text in tTextView not centering

I been round and round on this, and I can not seem to get the text in the ListView to center.
The ListView itself centers good, but text inside is not.. I hate to ask seems so basic..
Here is Code I have:
<ListView
android:id="#+id/lvVoiceReturn"
android:layout_width="200dp"
android:layout_height="48dp"
android:layout_above="#+id/mute"
android:layout_toLeftOf="#+id/mute"
android:gravity="center" >
</ListView>
Im sure its an easy line of code but i have not located it, urgh.. =/
Thank you.
Droidster

It is because you have used android:gravity="center"
This doesn't center the textview, but centers the text inside of the text view.
What you want to use is
android:layout_centerInParent="true"
If you were using a linear layout, then you could use
android:layout_gravity="center"
This is where you got confused, in a relative layout you can't use this because it will give you a syntax error.

If you are using a custom adapter with a custom element layout file then please post the xml here. setting gravity attribute to center for list view does not ensure that your list items are gonna center align.

Overlap views in android?

I have a linearlayout which have a textbox(multiline, nearly 5 lines) and image view. Is it possible to draw a image on textview(overlapping)?
Note: I have to specify the coordinates of the image, which are not static, and may be anywhere above text.
Something like this mockup:

I think it can be achieved using RelativeLayout.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<TextView
android:id="#+id/Textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:text="#string/Text2display"
android:textColor="#EEDCAA" />
<ImageView
android:id="#+id/choose_img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="-46dp"
android:adjustViewBounds="true"
android:contentDescription="#string/description_logo"
android:src="#drawable/user2" />
</RelativeLayout>
By placing the TextView block above the ImageView, it ensures that the image view overlaps the TextView. Now, based on your requirements and position, use the following commands from the link :-
http://developer.android.com/reference/android/widget/RelativeLayout.LayoutParams.html
You can align left right, top and bottom. Use negative values to navigate the ImageView, if ur using align bottom and stuff.. This will make it to overlap. Please let me know if this was helpful
Is there any specific reason for Linear Layout?

You can do this easily using RelativeLayout . You can have an ImageView overlapping TextView Unless there is a specific reason for using LinearLayout .

If you really (really) need to use LinearLayout, you can subclass TextView and override onDraw to draw your image.

In all your xml files, should define the background color for it, it will solve the problem :
Add this android:background="#android:color/black" in to the View tag you defined.