Develop Reference

Positioning Widgets in a Specific Arrangment

I'm quite new with Android programming in general, but I would like to know if there is a way to arrange my widgets in a particular way. Basically, I'm looking for the iOS equivalent of constraints, which will allow me to place to widgets centered horizontally and a specified distance from the bottom:
--------------------
| |
| |
| | <- android device
| |
| |
| | <- x is a button
| x x |
| |
--------------------

You can use a RelativeLayout with alignParentBottom="true"
Then you can add a padding in your relativelayout or a margin in your buttons a bit like this.
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation:"horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="10dp">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
</RelativeLayout>

Android: Placing button relative to ImageView

I want to make a part of a bitmap clickable and my layout looks like this:
________________________________
| ##### |
| ##### |
| ___________________ |
| | | |
| | | |
| | image | |
| | | |
| | | |
| ___________________ |
________________________________
I thought the easiest way to this would be to place a button over the image with a relative layout:
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/ImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
</ImageView>
<Button
android:id="#+id/Button"
android:layout_width="200dip"
android:layout_height="150dip"/>
</RelativeLayout>
But I haven't figured out how to get the button to align with the upper left corner of the image (instead of the upper left corner of the relative layout, as it does now). Is this possible with a relative layout?
Suggestions for other approaches are also welcome, I considered this:
http://blahti.wordpress.com/2012/06/26/images-with-clickable-areas/
But it seems a bit of an overkill for my simple rectangle area.

Try this:
<ImageView
android:id="#+id/ImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
</ImageView>
<Button
android:id="#+id/Button"
android:layout_alignLeft="#id/ImageView"
android:layout_alignTop = "#id/ImageView"
android:layout_width="200dip"
android:layout_height="150dip"/>
</RelativeLayout>

You can also use
<Button
android:id="#+id/image"
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="#drawable/image1"
android:drawableLeft="#drawable/image2t"
android:drawableRight="#drawable/image3"
android:drawableTop="#drawable/image4"
android:drawableTop="#drawable/image4"
android:textColor="#ffffff"
/>

Okay, my google-fu improved and thanks to asenovm I figured it out! The imageview has a android:adjustViewBounds property, which is by default set to false. Setting it to true adjusts the imageviews bounds to the image, so that alignLeft and alignTop work correctly for the button.
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ImageView
android:id="#+id/ImageView"
android:layout_centerInParent="true"
android:adjustViewBounds="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
</ImageView>
<Button
android:id="#+id/Button"
android:layout_alignLeft="#id/ImageView"
android:layout_alignTop = "#id/ImageView"
android:layout_width="200dip"
android:layout_height="150dip"/>
</RelativeLayout>

Positioning of textview for Android

Is there a way to position a textview to be slightly above a centerd android button? I don't want to hardcode values for a particular screen obviously, but something that will dynamically scale. The button will always be centered, however...
Thanks in advance!

Yes if your parent layout is a RelativeLayout you can position Views in relation to each other or to the parent here is a simple example (Warning didn't type this into IDE, may contain typo):
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:id="#+id/mBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="I am a Button!"
android:layout_centerInParent="true" />
<TextView
android:id="#+id/mTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:text"Some Text"
android:layout_above="#+id/mBtn" />
</RelativeLayout>
That will make your layout look roughly like this:
________________________
| |
| |
| Some Text |
| [I am a Button!] |
| |
| |
|______________________|

Spacing LinearLayouts equally by the maximum height

I have a table row defined in XML file.
It contains 3 `LinearLayout' one on top of the other:
I would like to get this look:
|-------------------------------|
| |
| a |
| |
| |
|-------------------------------|
| |
| b |
|-------------------------------|
| |
| c |
|-------------------------------|
The "problem" is that the LinearLayout "a" might expand and be at different heights while "b" and "c" are always in the same height.
I would to find the maximum height of the LinearLayout's and to enforce this height to be the height of all the other LinearLayout's too, so I will get this look for each row:
|-------------------------------|
| |
| a |
| |
| |
|-------------------------------|
| |
| b |
| |
| |
|-------------------------------|
| |
| c |
| |
| |
|-------------------------------|
I tried using android:layout_weight with no success...
Any ideas?

I tried to implement this in one example.
Here is what I did :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#ff0000"
>
<TextView
android:layout_width="30dip"
android:layout_height="wrap_content"
android:text="hjadsh haksj hasjk haksj hjkas hkjas hjkas hkjas "
android:textColor="#000000"
/>
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#00ff00"
></LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#0000ff"
></LinearLayout>
</LinearLayout>
I used the textview in the first layout to show that it works as what you need.
You can also fixed the height of the layout b & c to make them of fixed height and vary layout a by setting layout_height:wrap_content
You can now customized it according to your need.

try this
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="#00ffff"
></LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
></LinearLayout>
</LinearLayout>

Android AppWidget layout troubles with ellipsize

I'm writing an app-widget that displays some numbers, each with label in front of it.
The layout looks like this:
.-----------------------------.
| Label1 | AAAAAAAAAAA |
| LongerLabelLabel2 | BBBBBBB |
| LongLabel3 | CCCCCCCCCC |
'-----------------------------'
There is one outer (vertical) LinearLayout, and each row is a horizontal LinearLayout with two TextViews.
The problem is that the numbers get ellipsized if the width of the label and the number is too wide for the widget. I want the labels to get ellipsized.
The above situation for instance, would end up like this:
.-----------------------------.
| Label1 | AAAAAAAAAAA |
| LongerLabelLabel2 | BBBB... |
| LongLabel3 | CCCCCCCCCC |
'-----------------------------'
instead of the desired
.---------------------------.
| Label1 | AAAAAAAAAAA |
| LongerLabelL... | BBBBBBB |
| LongLabel3 | CCCCCCCCCC |
'---------------------------'
I can't for my life figure out how to solve this. Any help is appreciated.
My current layout is the following:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/widget"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="0dip"
android:orientation="vertical"
style="#style/WidgetBackground">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/ROW1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="7dip"
android:paddingBottom="0dip"
android:paddingRight="10dip"
android:paddingLeft="10dip"
android:orientation="horizontal">
<TextView android:id="#+id/NAME1" android:singleLine="true" android:layout_width="wrap_content" android:layout_height="wrap_content" android:ellipsize="end" style="#style/Text.account" />
<TextView android:id="#+id/BAL1" android:singleLine="true" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="right" style="#style/Text.balance" />
</LinearLayout>
... (more similar rows in the outer layout)
</LinearLayout>

I suspect your problem, in part, is that you have android:layout_width="wrap_content" for your label. I would not expect it to ellipsize at all, since there is enough room to show it.
I would switch away from LinearLayout to RelativeLayout. Define your number "column" as android:layout_alignParentRight="true" and android:layout_width="wrap_content". Define your label "column" as android:layout_alignParentLeft="true", android:layout_toLeftOf="..." (where ... is your number column), and android:ellpsize="end". That should give the number all the space it needs and constrain the label, forcing it to ellipsize.