Develop Reference

Android UI: "Smart" centering?

So I have a UI element (a single line of text) that I want horizontally centered with respect to the overall device -- unless/until it collides with other UI elements in the given view group / layout. At that point I'd like it to be either centered in the space remaining or pegged as close to being centered overall as possible without colliding. [When there's finally not enough space, then I want to use ellipses.]
Is there any way to achieve this using just standard Android layouts?
I'm currently achieving this via code that adjusts layout constraints when the view group's width changes, the text changes, or related UI elements become visible/invisible. It works fine, but I can't help thinking that some layout should just do this for me.

You can use a weighted horizontal LinearLayout like this:
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:gravity="center_horizontal"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="i am centered"
android:ellipsize="end"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="another widget"/>
.
.
.
</LinearLayout>
The TextView with width 0dp and weight 1 will use the remaining horizontal space.
You can add additional widgets to the LinearLayout, and the TextView will always take the remaining space.
For example, if you change the Visibility of the Button to GONE, you'll see the TextView will expand to use the whole width. Similarly, if you programmatically add new widgets to the LinearLayout, the available space for the TextView will adjust.
You can further add ellipsize options to control what happens when the text does not fit in the TextView size.

Android buttons are cut off (LinearLayout horizontal)

In my app I am calling API to get list of people with some informations (address, phone numbers etc.). Under every phone number, I am creating programatically 3 buttons (add to contacts, edit and call). Problem is, that last button is cut off (small screen). I am using Linear Layout horizontal.
Is there any way to control size of screen and if needed, put last button to second line? When I rotate screen to landscape, I have enough space, so buttons should stay in one line.
Now, I am using horizontalScrollView with visible scrollbar. It's working, but I am not very satisfied with it.
Thanks for help.

I'm not really sure if you can do that with LinearLayout. But you could do that using FlowLayout. Check this link: https://github.com/ultimate-deej/FlowLayout-for-Android.
This layout moves the buttons to the next line if there is no space for them on the screen.

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:weight="1" />
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:weight="1" />
</LinearLayout>
the weight attribute will automatically adjust your button size
make sure you set width to match parent for all buttons.

Best to create a new variant of the listitem layout for smaller screenshots:
layout-w200dp/listitem.xml : layout with 3 buttons on one line
layout/listitem.xml : layout with buttons on separate lines
Android will then choose the multiline layout when the current available width is smaller than 200dp. (Note that you can still tweak the 200 to a different value)
Alternatively you can also use an alternatieve linearlayout which does the wrapping for you: Flowlayout

This is probably more complicated to achieve that you wan't it to be but the best shot is to use some adapter based solution:
GridView - this is the old solution, better go for the 2nd
RecyclerView with StaggeredLayoutManager setup to your needs
Simple solution is using android:layout_weight="1" and android:layout_width="0dp" as params for each button in your LinearLayout but then they will fit the whole screen and take the same percent of the width, and if the screen is too small buttons might get cut off.

Layout troubles

I am having a spot of bother with a fairly simple layout. Here it is:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="#+id/id1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:ellipsize="end"
android:maxLines="1"/>
<TextView
android:id="#+id/id2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"/>
</LinearLayout>
3 Questions:
How do I center vertical both TextViews (or perhaps better said, the text within those views) within the parent LinearLayout? The left view is vertically centered OK, but the right one (because it has a smaller font) is not. It seems to be centered vertically at the top. I obviously tried playing with layout_gravity of the second view but that makes no difference whatsoever. The only way I can solve it is to wrap the second TextView in a LinearLayout with its layout height parameter set to match_parent (but is this the correct way of doing this?)
Similarly, I want the View on the left horizontally centered on the left, and the View on the right horizontally centered on the right. Currently the right View is placed immediatly next to the left one. The only way I can solve this is by adding something like this inbetween the two text views:
<TextView
android:layout_width="0dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="">
basically acting as a spacer which decreases in size depending on the legth of the text in both TextViews
I want the text in the left View to be truncated if the combined text of the Views does not fit horizontally. No wrapping onto a new line. Currently the text in the left View simply "pushes" the right one out of the parent. No idea how to achieve that (apart from adding android:maxLines="1" to stop the text from wrapping). I have tried android:ellipsize="end" but that does not seem to have any effect.

Best way is to use Relative layout , but still if you want to do the same thing in Linear layout than do some changes in your xml file
-First is set Linear layout hight as match parent :
<LinearLayout android:layout_width="fill_parent"
android:layout_height="match_parent"
android:orientation="horizonatal">
-Second for making the views visible at centre vertical do
android:layout_gravity="center_vertical"
same property android:layout_gravity = "center_horizontal" , you have to add in second text view also.
It will make your both text view appear at centre vertical but one next to other.
To make the second view appear on right I think you can add
android:layout_marginLeft="xx dp"
put some value in place of xx.
For your third question about truncating your text, you should give some size to your TextView not wrap content..Like android:layout_width ="25dp"
and then use android:ellipsize="end".
I guess you will get that..Actually I am in hurry,time to leave the office.

Android horizontal LinearLayout with wrapped text in TextView

I've observed a behavior with layout_weight that I can't explain. The following is a trivial example:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:text="This is a very very very very very very very very very very very very very very very long string."
android:layout_weight="1"
/>
<View
android:layout_width="32dp"
android:layout_height="32dp"
android:layout_gravity="center_vertical"
android:background="#ffffffff"
/>
</LinearLayout>
In a QVGA display, the TextView wraps the text. The white square is displayed to the right of the text.
However, if I remove android:layout_weight="1" from the TextView, the TextView now takes up the entire display width. The white square is no longer displayed.
Why would layout_weight in the TextView affect whether or not the white square is displayed? Shouldn't the View with the white background always be assigned 32dpx32dp first? (It makes no difference if the view were any other types - ImageView or TextView).
The problem I was working on is that I want the white square to always be displayed to the right of the TextView (whether or not the text is wrapped), but I don't want any empty space between the TextView and the white square. (If I add android:layout_weight="1" to the TextView, then there is a gap if the text is not wrapped.)
Any help would be appreciated!

To answer my question #1: One thing I learned by looking at the source for LinearLayout: Not only does layout_weight assign unused space to a child, it also shrinks a child with layout_weight if the child extends beyond the bounds of the LinearLayout. That explains why a TextView with wrapped text is shrunk in my layout.
As for the answer to my question #2, I think you meant android:toRigthOf instead of android:layout_alignRight. Using a RelativeLayout instead of a LinearLayout doesn't change the layout behavior. The tricky part is placing a view immediately to the right of a TextView, without gaps, whether or not the text is wrapped. Setting a maxWidth would limit the TextView's width, but that solution doesn't scale across portrait/landscape and different display dimensions.
Solution - Looks like Dyarish's solution is the best available. My layout problem exists regardless of the layout you use. The key is to set a maxWidth for the TextView so that it doesn't take up the all of the horizontal space in the layout. Because hardcoding a android:maxWidth value in the TextView doesn't scale across different displays, setting the maxWidth at runtime, as Dyarish suggested, is a good solution.

Hopefully this is what you are looking for.
First off, here is a great resource I found for Creating UI's.
layout_weight - Specifies how much of the extra space in the layout to be allocated to the View.
If you want to ensure that the white square is always to the right of the textview, you can use a Relative View, and add the parameter to the view. android:layout_alignRight="+id#yourTextViewID". This should always make the box appear right beside the textView area. You should probably also add something like android:maxWidth="250px" This will ensure that you don't push the white box completely out of the screen.
Here is a code sample:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<TextView
android:layout_width="wrap_content"
android:maxWidth="250px"
android:id="#+id/TextForWhiteBox"
android:layout_height="wrap_content"
android:layout_gravity="center|left"
android:text="This is a very very very very very very very very very very very very very very very long string."
/>
<View android:background="#ffffffff" android:layout_width="32dp" android:layout_height="32dp" android:id="#+id/view1" android:layout_toRightOf="#+id/TextForWhiteBox"></View>
</RelativeLayout>
You could also add to the View:
android:layout_alignTop="#+id/TextForWhiteBox" android:layout_alignBottom="#+id/TextForWhiteBox"
to make the white box the same size as the TextView.

Firstly I've tested the code from my other answer and it does exactly what you've described you've wanted. (unless I'm misunderstanding what you are asking for). You definitely do not want to use the android:layout_alignRight which is not what is in the code sample. That would simply keep the box on the right hand of the screen and not be affected by the textview at all. This sample uses android:layout_toRightOf="#+id/TextForWhiteBox" which is possible due to it being a relative layout. Since the Relative Layout allows you to place objects in relation to others. That line will always place the box just to the right of the textview with no gaps.
As for the screen orientation changes:
When the orientation changes it creates a new instance of the view.
Here is a simple solution.
//Add to oncreate in your Activity
private TextView textStatus;
textStatus = (TextView) findViewById(R.id.TextForWhiteBox);
// This get's the width of your display.
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int width = displaymetrics.widthPixels;
// Now you know the screen orientation, and it's width. So just set the maxwidth of the text view to match the display width - the pixels of your white box.
textStatus.setMaxWidth(width - 32); // 32 is here because you already know the size of the white box. More logic is needed to dynamically get this value, because you would need to wait for the activity to be fully created.
}
Here is the main.xml I used:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<TextView
android:layout_width="wrap_content"
android:id="#+id/TextForWhiteBox"
android:layout_height="wrap_content"
android:layout_gravity="center|left"
android:text="This is a very very very very very very very very very very very very very very very very very very very long string."
/>
<View android:background="#ffffffff" android:layout_width="32px" android:layout_height="32px" android:id="#+id/view1" android:layout_toRightOf="#+id/TextForWhiteBox"></View>
</RelativeLayout>
You might need some additional logic to keep screen values.
This code has been tested, you should be able to literally copy and paste this to work as you asked.
Also depending on your logic you could use something like this to return the screen orientation.
int orient = getResources().getConfiguration().orientation;
Hope this helps!
If this helped you, please click the accepted button. =) Cheers!

Snapping elements / conditional layouts

Sorry for the extremely bad title, I have no other idea what to call this question. What I'm trying to do is this: have a RelativeLayout which has two children:
one with layout_centerInParent="true"
one with layout_alignParentBottom="true"
However, when the device is in landscape mode, element (1) appears slightly over or under element (2). But, element (1) has enough space above it to appear above element (2). How could I make the layout so that if the screen is too small to center element (1) and make both elements not overlap, then align element (1) above (as in layout_above) element (2)?

This should work to give you a layout where the text1 item fills the available space above text2, and is centered vertically and horizontally in that space; and text2 is on the bottom, centered horizontally.
<LinearLayout
android:orientation="vertical"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<TextView
android:id="#android:id/text1"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:text="Centered"
android:gravity="center_vertical|center_horizontal"
/>
<TextView
android:id="#android:id/text2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Bottom"
android:gravity="center_horizontal"
/>
</LinearLayout>
The important parts are android:layout_weight, combined with android:gravity.

Alright here's a leftfield suggestion that might work if your element (1) isn't too resource intensive.
Have two versions of element (1), the first with layout_centerInParent="true" and the second with layout_above="#id\element2". Default them both to android:visibility="invisible". In your onCreate Post a Runnable that inspects the Y dimension of both elements, and sets View.VISIBLE on the element with the smallest value.

New idea:
This is another idea that's sort of a workaround in that it's not very elegant, but it's very simple. Put element (1) in its own < LinearLayout > configured like so:
<LinearLayout android:layout_width="fill_parent"
android:layout_height="fill_parent" // More on this line below
android:layout_alignParentTop="true"
android:layout_above="#id/element2"
android:gravity="center">
That linear layout will always span from the top of screen to just above element (2), and since its gravity is "center", element (1) will always be in the middle of whatever space is available for it. Note: The line android:layout_height="..." is required, but doesn't seem to actually do anything. Whether it's fill_parent or wrap_content, its height is overridden by the lines anchoring its top to the ParentTop and its bottom to element(2). However, not having the line makes it crash with a Runtime exception.
Original, not very good idea:
Another less-than-ideal solution is to use two layout files. Put the portrait layout xml in your layout folder and the landscape layout in a new folder called layout-land. Android then automatically selects the right one based on the orientation of the phone. I think you could use layout-port, but putting the portrait one in just layout makes sure it knows which one to use by default.