Develop Reference

Why cant I see the all 3 ImageButtons on the same row?

I'm trying to create a layout (which I could include in other layouts), which contains 3 Image buttons (back, menu, forward).
Those 3 Image buttons should be on the same line (because later I would include this layout to other layouts in the bottom of each layout)
I don't understand what I'm doing wrong, I can't see the all 3 Buttons, and they are not in the same row (same horizontal line)
<?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="match_parent"
android:orientation="horizontal">
<ImageButton
android:id="#+id/buttomMenuBack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Back"
android:background="#drawable/back_button"
android:onClick="onClickButtomMenu"/>
<ImageButton
android:id="#+id/buttomMenuMenu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Menu"
android:background="#drawable/HomButton"
android:onClick="onClickButtomMenu"/>
<ImageButton
android:id="#+id/buttomMenuForward"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Forward"
android:background="#drawable/forward_button"
android:onClick="onClickButtomMenu"/>
</LinearLayout>

it won't fit because it looks like some of your images are way too big, but we can proportionally weight it so it'll fit.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:weightSum="3">
<ImageButton
android:id="#+id/buttomMenuBack"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Back"
android:background="#drawable/back_button"
android:onClick="onClickButtomMenu"/>
<ImageButton
android:id="#+id/buttomMenuMenu"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Menu"
android:background="#drawable/HomButton"
android:onClick="onClickButtomMenu"/>
<ImageButton
android:id="#+id/buttomMenuForward"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Forward"
android:background="#drawable/forward_button"
android:onClick="onClickButtomMenu"/>
</LinearLayout>
using weightSum and layout_weight, 3 and 1, we ensure they all each take 1/3 of the space in your linearlayout (oh, and layout_width is 0 because layout_weight overrides it)

You can use LinearLayout with orientation as "horizontal". This will make all the views appear in a row. This LinearLayout can reside as a nested layout inside a another layout, like for example RelativeLayout. You can use this layout design by importing it in other XMLlayouts too.
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageButton
android:id="#+id/buttomMenuBack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Back"
android:background="#drawable/back_button"
android:onClick="onClickButtomMenu"/>
<ImageButton
android:id="#+id/buttomMenuMenu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Menu"
android:background="#drawable/HomButton"
android:onClick="onClickButtomMenu"/>
<ImageButton
android:id="#+id/buttomMenuForward"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Forward"
android:background="#drawable/forward_button"
android:onClick="onClickButtomMenu"/>
</LinearLayout>

Looks like different sized images.
Assuming you have these in a horizontal linear layout; Try changing the height to a fixed dp and put the weight to 1 for all three imagebuttons
Example:
<ImageButton
android:id="#+id/buttomMenuBack"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="35dp"
android:text="Back"
android:background="#drawable/back_button"
android:onClick="onClickButtomMenu"/>
If you do this for all three imagebuttons, they will fill the screen and all be the same height, right beside each other.

How do I align the right/left side of a button in android to the center of the screen?

I was thinking it would be something like android:layout_startOf"centerHoriztonal" or something like that but I have searched and couldn't find anything. If it helps I am trying to make a soundboard app where all the buttons can be the same size across multiple device screens.

try this xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/button1"
android:text="Here is button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_centerVertical="true"
/>
<Button
android:id="#+id/button2"
android:text="Here is button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_centerVertical="true"
/>
</RelativeLayout>

You can wrap the button(s) inside a horizontal LinearLayout and use layout_weight to divide the screen in half and then layout_alignParentLeft/layout_alignParentRight to align the buttons inside a RelativeLayout that takes up exactly half the screen width.
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<RelativeLayout
android:layout_width="0px"
android:layout_height="wrap_content"
android:layout_weight="1">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="Button Text"
/>
</RelativeLayout>
<RelativeLayout
android:layout_width="0px"
android:layout_height="wrap_content"
android:layout_weight="1">
</RelativeLayout>
</LinearLayout>
Another way to do it is to create a dummy view object that is centered horizontally in the parent view, and align your buttons to the left or right of it:
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<View
android:id="#+id/dummyview"
android:layout_width="0px"
android:layout_height="0px"
android:layout_centerHorizontal="true"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toLeftOf="#id/dummyview"
android:text="Button Text"/>
</RelativeLayout>

Are you sure you want the same size of buttons in all devices? People try to avoid it and make make view elements flexible.
Anyways if you want to set same size just directly write in layout
android:layout_width = "#dimen/valueForButton"; //some absolute value
For starting at same point, just add all buttons inside LinearLayout and make some operations there, such as
android:layout_gravity = "center_horizontal";
Your layout must be something like this:
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:orientation="vertical" >
<Button
android:id="#+id/button1"
android:layout_width="#dimen/valueForButton"
android:layout_height="wrap_content"
android:text="Button" />
<Button
android:id="#+id/button2"
android:layout_width="#dimen/valueForButton"
android:layout_height="wrap_content"
android:text="Button" />
<Button
android:id="#+id/button3"
android:layout_width="#dimen/valueForButton"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>

Block elements in android development

I am going through the tutorials at developer.android.com and they do not cover something I want to try.
In my XML file (LinearLayout) I have 3 elements, a textblock and 2 buttons.
I would like to have the TextBlock taking up all available width. IN HTML terms I would like it to be block.
Then underneath I would like the 2 buttons to be on the same line. In HTML terms I would like it to be inline.
My XML:
<LinearLayout android:orientation="horizontal">
<TextView
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/app_name" />
<Button
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>

Another option:
Create a linearlayout and add textview and another linearlayout with orientation horizontal within that the 2 buttons.
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/app_name" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>

you can sort of do it in one linear layout, but it's not going to be very flexible. You'd either want to use a relative layout and position the button below the text view or you can use two linear layouts (first is vertical orientation containing the textview and the second linear layout, that one is a horizontal linear layout containing the two buttons)

Simple fixes:
<TextView
android:layout_weight="1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/app_name" />
<Button android:id = "#+id/thisbutton"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="thisbutton"
/>
That's the basic idea.
Look up all the features that are available in the layouts. Because there are a lot, and they are quite flexible.

Make a TextView and a Button the same size

I have a TextView and Button in my program and I cannot get the size of the Button and the TextView to be the same. How can I do this?
<LinearLayout
android:layout_width="match_parent"
android:layout_height="67dp"
android:background="#999999"
android:gravity="center"
>
<Button
android:id="#+id/button1"
android:layout_width="130dp"
android:layout_height="60dp"
android:text="Button" />
<TextView
android:id="#+id/textView1"
android:layout_width="130dp"
android:layout_height="60dp"
android:background="#ffffff" android:textColor="#000000"
android:textSize="24dp" android:textStyle="bold"
android:gravity="center"
android:text="0.0" />
</LinearLayout>

Actually, they both have the same size, but the Button uses an image as a background and it seems it has some margins.
To test this, override the background of button with a color and see they are the same size:
android:background="#0F0"
So, the solution would be to provide a custom background for your button, or adapt the TextView to match the Buttons' width and height, minus the margins of Button, which personnaly I don't think is the best approach.

When I want multiple controls to have the same size what i generally do is put them in a TableLayout.
In your case, i'd put a TableLayout inside the linear layout and put the button and textview inside a TableRow, set the weightsum for the TableRow to 2 and set the weights of the individual controls to 1.
This would make the controls take up the same amount of space on the screen. A sample xml is shown below.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TableLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TableRow
android:id="#+id/tableRow1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:weightSum="2" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="#string/hello_world">
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Button" />
</TableRow>
</TableLayout>
</LinearLayout>

How to make buttons cover full screen width in Android Linear Layout?

I have following three button in a Linear Layout with width fill_parent.
How can I set the width of these buttons to equally cover the whole screen area?
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/btnReplyMessage"
android:gravity="left"
android:text="Reply"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/btnMarkAsUnread"
android:gravity="left"
android:text="Mark as unread"
/>
<ImageButton
android:id="#+id/btnDeleteMessage"
android:src="#drawable/imgsearch"
android:gravity="right"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_alignParentRight="true"
/>

Give all buttons the following properties
android:layout_width="fill_parent"
android:layout_weight="1"
fill_parent tells them to consume as much width as possible, and weight determines how that width shall be distributed, when more than one control are competing for the same space. (Try playing around with different values of weight for each button to see how that works)

You should just specify these attributes for each button:
android:layout_width="fill_parent"
android:layout_weight="1"
So it should be something like that:
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"/>
</LinearLayout>

you can use following code:
<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"/>
You must to do 0dp in width on every button.