Develop Reference

Button Margin Changes with Button text content

Let's start with the fun part, here's the graphic of the trouble. Horizontally, everything is beautiful.
The middle button, I'd like to to be aligned with the other three. Here are the basics:
overall, it's a relativelayout
inside this relativelayout, it's a horizontal linear layout, containing the three buttons
the "sinking" of the middle button is 100% correlated with it being a dual line of text, if I change it to a single line, it aligns properly
the specified height of the buttons has nothing to do with the sinking, even at more than double their current size (from current 70 to 170) the exact same behavior (and size of behavior) is displayed
The "custom_button" background has no effect, if I change them all to no background, stock looking buttons, the same positioning occurs
And here's the XML (of just the linearlayout within the relativelayout):
<LinearLayout
android:id="#+id/wideButtons"
android:layout_below="#+id/buttonClockFinish"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_marginLeft="30dp"
android:layout_marginRight="30dp"
android:orientation="horizontal">
<Button
android:id="#+id/buttonLog"
android:layout_weight="1"
android:layout_height="70dp"
android:padding="0dp"
android:layout_marginRight="3dp"
android:layout_width="fill_parent"
android:background="#drawable/custom_button"
android:text="View Log" />
<Button
android:id="#+id/buttonLocation"
android:layout_weight="1"
android:layout_height="70dp"
android:padding="0dp"
android:layout_marginLeft="3dp"
android:layout_marginRight="3dp"
android:layout_width="fill_parent"
android:background="#drawable/custom_button"
android:text="Location\nD1-RS" />
<Button
android:id="#+id/buttonHelp"
android:layout_weight="1"
android:layout_height="70dp"
android:padding="0dp"
android:layout_marginLeft="3dp"
android:layout_width="fill_parent"
android:background="#drawable/custom_button"
android:text="Help" />
</LinearLayout>
So why on earth is it not aligning?

I was just about to post this question, and did one final experiment. I added a THIRD line of text to the button. This pushed it down even further. But what I realized it had in common was that the text of the top line of the middle button remained perfectly aligned with the text of the two buttons to either side of it.
So it wasn't that it was having trouble with an interior margin, unable to squish the text against the top border. The alignment was of the TEXT, not the button graphic. All along I had thought that there was some mystery :padding that I was not nulling out, but with three lines of button text it was quite happy to have just about 1dp or so of padding.
The solution was to add
android:layout_gravity="center_vertical"
to that button. I added it to the rest of them too, just for consistency.
Lesson: When you think things aren't aligning, perhaps they actually are, but maybe you're looking at the wrong thing.

Right-align button with dynamic text

In my user interface, I have a fragment with a RelativeLayout. At the bottom of this RelativeLayout, I have two buttons: one should be on the left, the other on the right, with empty space between them. The left one has static text (but because the app will be translated, I don't know what width it will be). The text in the right one can change arbitrarily.
Since I already have a RelativeLayout, I started out trying to lay them out inside the RelativeLayout like this:
<Button
android:id="#+id/button_left"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:text="#string/left" />
<Button
android:id="#+id/button_right"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:text="#string/right" />
But this has the problem that if the text in the right-hand button is too long, it will overlap the left-hand button.
I next tried to constrain the left-hand edge of the right-hand button by adding android:layout_toRightOf="#+id/button_left", but with this, the right-hand button would always fill the available width. When the text in the right-hand button is short, I want it to shrink to leave a gap between it and the left-hand button.
I next tried to use a LinearLayout, so I could set layout_gravity on the buttons, like this:
<LinearLayout
android:id="#+id/buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true" >
<Button
android:id="#+id/button_left"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/left" />
<Button
android:id="#+id/button_right"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:drawableLeft="#drawable/pass"
android:text="#string/right" />
</LinearLayout>
Still no joy. I expected this to work, but the right-hand button stays just to the right of the left-hand button, instead of sticking to the right edge of the screen. I can see in the layout editor that the LinearLayout correctly fills the width of the screen, but the button stubbornly stays next to its friend.
I tried adding android:layout_weight="1" to the right-hand button too, but again, that made it always expand to fill the available space.
Next, I tried to add an empty View between the buttons, to expand and force the right button to the right, like this:
<LinearLayout
android:id="#+id/buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true" >
<Button
android:id="#+id/button_right"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/left" />
<View
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="1" />
<Button
android:id="#+id/button_left"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:text="#string/right" />
</LinearLayout>
This works fine when the text is short, just like my original RelativeLayout did, but now when the text on the right-hand button is long, its width is limited by the width of the screen, not the available space, so it extends off the right-hand edge of the screen. Again, I can see in the layout editor that the LinearLayout has the correct width, but the button is extending ourside its parent's bounds. This happens even if the button has android:layout_width="match_parent". Oddly enough, increasing the layout_gravity on the right-hand button makes it smaller until it fits inside the available space, but of course that also makes it fill the space when the text is small.
I can't believe it's this hard to get this right. I've seen half a dozen similar questions on SO, but they all have easy workarounds. If the button text is fixed, you can set the margin to a fixed width by hand. If the expanding widget is a TextView instead of a Button, you can just let it expand and use android:gravity to move the text inside the widget, but you can't do that with a button because the background and borders are visible on the screen.

It turns out that adding the LinearLayout was the wrong approach. Using android:layout_toRightOf="#+id/button_left" android:layout_alignParentRight="true" works fine with a TextView, because that can soak up the available space without changing its appearance. Instead of trying to change the layout, I just need to use something that can expand to fill the available space and contain the Button: a FrameLayout. Here's the working code, which still goes inside my root RelativeLayout:
<Button
android:id="#+id/button_left"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:text="#string/left" />
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_toRightOf="#+id/button_left" >
<Button
android:id="#+id/Turn_button_pass"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:text="#string/right" />
</FrameLayout>
Now, the FrameLayout always takes up all the space to the right of the left-hand button, and lays out the right-hand button inside that space using android:layout_gravity="right".
This answer only adds one extra layout, but if someone has a way to do it only using the existing RelativeLayout, to minimise the number of ViewGroups in the layout, I'll accept that as a solution.

IF you can live with the constraint, that the right button only can take up to up half of the available space, this could be a solution for you:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_weight="1" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="A short text" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="A very long text which is limited to one half of the available space" />
</RelativeLayout>
</LinearLayout>

You could just use a TextView and make it look like a button. Create a dummy button, extract the background and set that background to the textfield programmatically.
(Not tested but should give it the apperance of a button)
Drawable d = button1.getBackground();
textView1.setBackground(d);
then you just set the onClickListener and that should yield what you're looking for. The TextView would take the place of the "button_right" in your first layout.
**Edit
Your xml would look something like this
<Button
android:id="#+id/button_left"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:text="#string/left" />
<TextView
android:id="#+id/button_right"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:maxEms="10"
android:text="TextView" />

Why are my "centered" objects slightly off-center in my RelativeLayout?

I wanted to make two equally-sized radio buttons with a custom background, text, and an image to the right of the text. Because of how different these are from a standard "Button", I made them using a clickable "RelativeLayout".
The text and the image are of different heights, but I want each one to be centered vertically in the button. I also want the combination of the text+image to be centered horizontally in the button. This second part is what I'm having trouble with; it's off-center, close to the left side. In the image below, the left side is what I want, but the right side is what's happening. The image on one of the buttons (the one with the longer text) is resized to be smaller, too... Though there is still plenty of space on the right side of the button.
Here is my code:
<LinearLayout
android:baselineAligned="false"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<RelativeLayout
android:id="#+id/my_button"
android:background="#drawable/radio_button"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:gravity="center_horizontal">
<TextView
android:id="#+id/button_textview"
android:text="#string/button_label"
android:textAppearance="?android:attr/textAppearanceButton"
android:layout_centerVertical="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></TextView>
<ImageView
android:contentDescription="#string/image_description"
android:id="#+id/button_imageview"
android:layout_centerVertical="true"
android:src="#drawable/my_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/button_textview">
</ImageView>
</RelativeLayout>
<RelativeLayout
... same thing for the second button ...
</RelativeLayout>
</LinearLayout>
What am I doing wrong?

Use this as your button:
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_gravity="center_horizontal"
>
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:text="MyButton"/>
<ImageView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:src="#drawable/my_image"/>
</LinearLayout>
Now, you can place it in other parent views. To apply layout attributes to above button, place those attributes in the outer <LinearLayout> tag of above button.
Alternative:
You can set custom images to be drawn on sides(Left,Right,Top,Bottom) of a TextView using attributes like:
android:drawableLeft="#drawable/my_image"

Turns out the solution was adding
android:paddingRight="0dip"
strangely enough, even though I didn't put any padding there in the first place.

Android button layout - get two buttons side-by-side across entire screen

I have two buttons which I would like to appear side-by-side horizontally, but together they fill the horizontal length of the phone. The height is wrap content, that's fine. My issue right now is that only one button is showing up (stretching across the screen).
Here is my XML code:
<LinearLayout
android:id="#+id/page_buttons"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
>
<Button
android:id="#+id/prevButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Previous"
/>
<Button
android:id="#+id/nextButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Next"
/>

Change your Buttons XML to include the layout_weight attribute:
<Button android:id="#+id/nextButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Next"/>

Since nobody is explaining why their solutions work, I will give it a go.
The problem lies in the layout of the buttons. The two concerned attributes are layout_width and layout_weight.
In other layout systems, when you indicate that each element of a layout has to fill the parent (layout_width="fill_parent"), they do so by distributing equally the space of the parent between them. So, each of them would have the same size.
Instead, in Android's layout system, if both elements have
layout_width="fill_parent" the first element (in your case, the
Previews button) will be stretched to fill the parent and the second
(or third, or etc.) will not have any space left to distribute, so it
will not be visible.
Now, to make it understand that you want both buttons to show, you set the layout_weight for each button. To make the buttons have the same size, set the same layout weight to both of them.
The layout_weight defines how many "parts" (or segments) of the parent each of the buttons occupy. The parent will be cut into a number of segments equal to the sum of the children's segments. If you want to make one button three times bigger then the other, you have to assign it the number of parts equal to the number of parts of the first button, multiplied by three.
So if you want your Next button to be two times bigger then the
Previews button, you can do this:
for Previews button: layout_weight=1
for Next button: layout_weight=2
In consequence, the parent will be cut in 3 parts, 2 of which will be allocated to the Next button and 1 to the Previews button.
The example taken here is for buttons and horizontal layout, but this will work just fine for any type of object and also for vertical layout parent.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:id="#+id/button01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/entry"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="#+id/space"/>
<TextView
android:id="#+id/space"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"/>
<Button
android:id="#+id/button02"
android:layout_toRightOf="#id/button01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#id/entry"
android:layout_alignParentRight="true"/>
</RelativeLayout>
Seems like you want two equal buttons, not wrapped content. I created a centered spacer using TextView, and relatively aligned to that. Left button to parent left and spacer, Right button to Left Button and parent right.

Parent of your Button is Linear-Layout, and you are setting Button's width as fill parent and hence it is taking the whole space. You hav two options to Implement this...
Give the fixed width for your button(eg 50dip).
Give the width as 0dp and insert one more attribute in both button "weight" and give 0.5dip for each...

The two buttons should be on a linearlayout. The linear layout should be horizontal and each button has a weight of 1. This should give you two buttons with equal size along the screen width. A sample is here
Horizontal orientation: check the 2 Buttons at the end of this xml layout

Your Requirement is
<LinearLayout
android:id="#+id/page_buttons"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<Button
android:id="#+id/prevButton"
android:layout_width="0dp"
android:weight="0.5"
android:layout_height="wrap_content"
android:text="Previous"
/>
<Button
android:id="#+id/nextButton"
android:layout_width="0dp"
android:weight="0.5"
android:layout_height="wrap_content"
android:text="Next"
/>

<?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:layout_centerHorizontal="true">
<TextView
android:text="#+id/SomeText"
android:id="#+id/TextView01"
android:layout_width="wrap_content" android:layout_height="wrap_content" />
<LinearLayout
android:orientation="horizontal"
android:background="#android:drawable/bottom_bar"
android:paddingLeft="4.0dip"
android:paddingTop="5.0dip"
android:paddingRight="4.0dip"
android:paddingBottom="1.0dip"
android:layout_width="fill_parent" android:layout_height="wrap_content"
android:layout_below="#+id/TextView01">
<Button
android:id="#+id/allow"
android:layout_width="0.0dip" android:layout_height="fill_parent"
android:text="Allow"
android:layout_weight="1.0" />
<Button
android:id="#+id/deny"
android:layout_width="0.0dip" android:layout_height="fill_parent"
android:text="Deny"
android:layout_weight="1.0" />
</LinearLayout>
</RelativeLayout>

I found the leading issue for people who still seems to not get what they want.
when using buttons with their conventional (out-of-the-box/default) background, it has a built in margin.
If you try changing the background manually with a single color, you can tell easily that you just need to set a separate background.
other than that when you have the weights put in, it will work.

View disappear while using relativelayout's "toLeftof"

I'm using Android's relativelayout, trying to make two buttons align side by side.
But, when I use layout_toLeftOf, my button02 suddenly disappear.
It's fine if I use layout_toRightof. Anyone knows why?
<Button
android:id="#+id/Button01"
android:layout_alignParentLeft="true"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="#+id/Button01">
</Button>
<Button
android:id="#+id/Button02"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="#+id/Button02"
android:layout_toLeftOf="#+id/Button01"
android:layout_alignTop="#+id/Button01"
android:layout_alignBottom="#+id/Button01"
>
</Button>

That's because the first one is aligned to the left; if you put the second button to the left of the first one, it will be outside the screen.
So, what if you change
android:layout_alignParentLeft="true"
to
android:layout_alignParentRight="true"
in the first button?

If you want Button2 to be left of Button1, why are you placing alignTop and alignBottom properties? Please remove that and see. Also remove alignParentLeft for Button1, if you want Button1 to be placed at the right side.