I'm trying (in vain) to add margins to my ListView items. I have tried adding margin values to my RelativeLayout below but no matter what I do all I seem to get is a 1px line between each item.
What I really would like is to have rounded corners on each item, a 1px black border and a 3-5px margin left, top, and right but right now I'll settle for just a margin around each item :-)
How do I achieve my goals? Just the margin for now... ;-)
Here's what I have:
UPDATE: I have updated the xml below removing main layout and fragment layout. I have also updated the ListView item layout to what I have now which is closer to what I want but still not perfect. Screenshot added as well
listview item layout xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="#dimen/matchMargin"
android:paddingRight="#dimen/matchMargin"
android:paddingTop="#dimen/matchMargin" >
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#cfcfcfcf" >
<include
android:id="#+id/matchKampstart"
layout="#layout/kampstart_layout" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/matchKampstart"
android:layout_marginTop="#dimen/belowKampstartMargin" >
<ImageView
android:id="#+id/tournamentImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="2dp"
android:adjustViewBounds="true"
android:contentDescription="#string/tournamentImageViewContentDescription"
android:gravity="left"
android:src="#drawable/sofabold_launcher" />
<ImageView
android:id="#+id/homeTeamImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="2dp"
android:adjustViewBounds="true"
android:contentDescription="#string/homeTeamImageViewContentDescription"
android:src="#drawable/sofabold_launcher" />
<TextView
android:id="#+id/homeTeam"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="2dp"
android:text="#string/home"
android:textSize="14sp"
android:textStyle="bold" />
<TextView
android:id="#+id/dash"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="2dp"
android:gravity="center"
android:text="#string/dash"
android:textSize="12sp"
android:textStyle="bold" />
<ImageView
android:id="#+id/awayTeamImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="2dp"
android:adjustViewBounds="true"
android:contentDescription="#string/awayTeamImageViewContentDescription"
android:src="#drawable/sofabold_launcher" />
<TextView
android:id="#+id/awayTeam"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:gravity="center"
android:text="#string/away"
android:textSize="14sp"
android:textStyle="bold" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_below="#id/matchKampstart"
android:layout_marginTop="#dimen/belowKampstartMargin" >
<ImageView
android:id="#+id/tvChannelImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="false"
android:contentDescription="#string/tvChannelImageViewContentDescription"
android:gravity="right"
android:src="#drawable/sofabold_launcher" />
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
This gives me the following where you'll notice a very small line to the right and left for each item. That I would also like to get rid of.
I'm not great with layouts, but I have noticed in the past that ListView rows often ignore LayoutParams. I have no idea where this happens or if it's possible to override, I do know you can easily work around it by adding another layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:background="#990000ff" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginRight="10dp"
android:layout_marginTop="10dp"
android:background="#9900ff00"
android:paddingLeft="10dp" >
<TextView
android:id="#+id/text"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#99ff0000" />
</LinearLayout>
</LinearLayout>
Typically layouts that only have one child can be removed, but as you can see this one serves a purpose:
The outer-most layout is blue, the TextView is red, and the green is the extra layout that allows you to add some extra spacing. Notice the difference between padding (the green on the left) and margin (no green on the right). You have clearly stated that you want to use margins (android:layout_margin) but your code clearly uses padding (android:padding) so I included both.
A little late seeing this, but just add the following lines to your ListView xml element
android:divider="#00000000"
android:dividerHeight="10dp"
See the answer here for why. In short the child asks the parent, and the list view row uses AbsListView.LayoutParams, which doesn't include margins.
Why LinearLayout's margin is being ignored if used as ListView row view
In your adapter, catch your relative layout in getView(), then give a layout params ,
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)view.getLayoutParams();
params.setMargins(80, 0, 0, 0); //substitute parameters for left, top, right, bottom
YourRelativeLayoutInAdapter.setLayoutParams(params);
I suppose you have a ListView defined in an XML file somewhere, if so, you could add some padding to it, so that there will be some space between the edge of the screen and the ListView.
Example:
<ListView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="15dp"/>
Related
I am showing and hiding views on a particular actions using some animation, I used LayoutTransition and it seems to work fine except one thing, while the animation is going, the background of some TextViews changes and reset to the default white background!!
Following is the code I am using to apply animation after hide/show.
mRightTransitioner = new LayoutTransition();
mRightTransitioner.setDuration(1000);
vg_rightContainer.setLayoutTransition(mRightTransitioner);
Edited: even without animation i tried, same problem, the background resets once view's position changes
Edited: here how i declared the views in the XML
<LinearLayout
android:id="#+id/ll_req_reasonwrapper"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_marginTop="10dp"
android:baselineAligned="false"
android:gravity="right"
android:orientation="horizontal"
android:visibility="gone" >
<EditText
android:id="#+id/et_req_reasons"
android:layout_width="400dp"
android:layout_height="match_parent"
android:background="#drawable/comments_textbox"
android:gravity="right|center_vertical"
android:inputType="text"
android:paddingRight="8dp" />
<TextView
android:layout_width="100dp"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:text="#string/str_req_preasons" />
</LinearLayout>
<LinearLayout
android:id="#+id/ll_req_timewrapper"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_marginBottom="10dp"
android:layout_marginTop="10dp"
android:baselineAligned="false"
android:gravity="right"
android:orientation="horizontal"
android:visibility="gone" >
<LinearLayout
android:id="#+id/ll_req_endtimewrapper"
android:layout_width="wrap_content"
android:layout_height="match_parent" >
<TextView
android:id="#+id/ftv_req_endtime"
android:layout_width="100dp"
android:layout_height="match_parent"
android:background="#drawable/comments_textbox"
android:freezesText="true"
android:gravity="right|center_vertical"
android:inputType="numberDecimal"
android:paddingRight="8dp" />
<TextView
android:layout_width="100dp"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:text="#string/str_req_endtime" />
</LinearLayout>
<LinearLayout
android:id="#+id/ll_req_starttimewrapper"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginLeft="50dp" >
<TextView
android:id="#+id/ftv_req_starttime"
android:layout_width="100dp"
android:layout_height="match_parent"
android:background="#drawable/comments_textbox"
android:freezesText="true"
android:gravity="right|center_vertical"
android:inputType="numberDecimal"
android:paddingRight="8dp" />
<TextView
android:layout_width="100dp"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:text="#string/str_req_starttime" />
</LinearLayout>
</LinearLayout>
for instance: if i hide 'll_req_reasonwrapper', then the LinearLayout 'll_req_timewrapper' moves up, then the backgrounds of the textViews like 'ftv_req_starttime' becomes white!!
Please help.
Edited Answer:
if your are using linear layout then if the child is not being displayed, it is not going to be laid out and not going to be the part of the measurements ( as it looks like ). I recommend to use the RelativeLayout.
You can try
android:background="#null"
for your buttons. if your are using some custom class for button then add
.setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));
for this specific views.
Need more code. The fact that disabling the LayoutTransition does not solve your issue, means that the animation is not the issue.
How do you reinstantiate child views or populate your view. Are you removing views with setVisibility(View.GONE) and then setting them back with setVisibility(View.VISIBLE)
OR
Are you removing childAt(i) and then dynamically adding custom views
I'm sorry I couldnt add a comment since I dont have the reputation for that but I think I am able to answer your question if you post more code.
Having a problem with nested LinearLayouts to use as a custom row in a ListView.
App is a kind of internal corporate phone book and this row will be repeated in the ListView.
The "Details Witheld" on the right looks fine when gravity is set to left for it, but if gravity is set to center then it appears half off the page.
I'd guess my parent LinearLayout is too wide for the screen but it's set as fill_parent so I don't see how.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
Full XML source is below.
Aligned Left looks like this and I'd like Details to be a space in so it's centered above the Witheld.
Aligned Center looks like this
Full XML Source
<?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="wrap_content"
android:orientation="horizontal" >
<!-- Left side name & post / parish -->
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="80"
android:orientation="vertical" >
<TextView
android:id="#+id/txtrowname"
android:layout_marginBottom="2dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Smtih, Mr John"
android:textSize="24sp"
android:textColor="#color/darkblue_text"
android:textStyle="normal" />
<TextView
android:id="#+id/txtrowpost"
android:layout_marginBottom="2dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="12 Some Street, SomeTown. SS11 1SS"
android:textSize="12sp"
android:textColor="#000000"
android:textStyle="normal" />
</LinearLayout>
<!-- Details withheld on right -->
<TextView
android:id="#+id/txtrowwitheld"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:text="Details Witheld"
android:layout_weight="20"
android:textSize="18sp"
android:gravity="center"
android:lines="2"
android:maxLines="2"
android:textColor="#FF0000"
android:layout_marginBottom="2dp"
android:textStyle="normal" />
</LinearLayout>
Image with layout_gravity as suggested by Ramesh
try layout_gravity in place of gravity that will work and dont use line="2". it will automatically fit into 2 lines if width exceeds.
I ended up just making do without it being centered.
Here's the layout (below). I'm trying to reposition the location of the checkbox; move it to the right of the view. android:gravity and android:layout_gravity seem to have no effect. Any explanation? This LinearLayout is a child of a Relative Layout.
<LinearLayout
android:id="#+id/deviceLinear"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_below="#id/view1" >
<ImageView
android:contentDescription="#string/devices_icon"
android:id="#+id/devices_img"
android:layout_width="0dip"
android:layout_height="match_parent"
android:layout_weight="0.15"
android:layout_gravity="center"
android:src="#drawable/hardware_phone" />
<TextView
android:id="#+id/devices"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="0.43"
android:text="#string/devices"
android:textSize="20sp" />
<CheckBox
android:id="#+id/check_devices"
android:button="#drawable/custom_checkbox"
android:layout_width="0dip"
android:layout_height="fill_parent"
android:layout_weight="0.42"
android:onClick="onCheckboxClicked" />
</LinearLayout>
I assume that you want the CheckBox to be on the right side of the LinearLayout. Since you have given it a layout_weight it will always take up some fixed percentage of the width regardless of its size as you can see by that blue bounding box.
Try wrapping the checkbox in another LinearLayout that has android:orientation='horizontal'. Give the 0.42 weight to the wrapping LinearLayout and then set the LinearLayout's android:gravity to be right. That should keep your spacing while moving the checkbox to the far right.
Something like this:
<LinearLayout
android:orientation="horizontal"
android:layout_width="0dp"
android:layout_weight="0.42"
android:layout_height="wrap_content"
android:gravity="right" />
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
You might also want to consider a RelativeLayout which enables you to position Views based on where other views are.
You are giving layout_weight="0.42" to your checkbox, that means that it will be measured with a width based on the LinearLayout's width. By this approach you will never manage to put it on the right.
The best way to achieve your goal is to use a RelativeLayout. Here is my list item layout with a checkbox on the right. Sorry about the merge tag but it is merged inside a RelativeLayout with
android:layout_width="match_parent"
android:layout_height="wrap_content"
attributes
<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android">
<ImageView android:id="#+id/imgChannelIcon"
android:layout_alignParentLeft="true"
style="?muListItemImage60x60" />
<CheckBox android:id="#+id/chkIsChecked"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_alignTop="#+id/imgChannelIcon"
android:layout_alignParentRight="true"
android:layout_alignBottom="#+id/imgChannelIcon"
android:layout_marginLeft="#dimen/list_item_checkbox_margin_left"
android:layout_marginRight="#dimen/list_item_checkbox_margin_right"
android:layout_marginTop="#dimen/list_item_checkbox_margin_top"
android:layout_marginBottom="#dimen/list_item_checkbox_margin_bottom"
android:focusable="false"
android:focusableInTouchMode="false" />
<TextView android:id="#+id/lblChannelTitle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_toRightOf="#+id/imgChannelIcon"
android:layout_alignTop="#+id/imgChannelIcon"
android:layout_toLeftOf="#+id/chkIsChecked"
android:layout_alignWithParentIfMissing="true"
android:includeFontPadding="false"
android:textStyle="bold"
android:text="#string/channel_item_dummy_title"
style="?muListItemTextBig" />
<TextView android:id="#+id/lblChannelSubtitle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_toRightOf="#+id/imgChannelIcon"
android:layout_below="#+id/lblChannelTitle"
android:layout_toLeftOf="#+id/chkIsChecked"
android:layout_alignWithParentIfMissing="true"
android:includeFontPadding="false"
android:textStyle="normal"
android:text="#string/channel_item_dummy_subtitle"
style="?muListItemTextNormal" />
<TextView android:id="#+id/lblChannelCategory"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_toRightOf="#+id/imgChannelIcon"
android:layout_below="#+id/lblChannelSubtitle"
android:layout_alignBottom="#+id/imgChannelIcon"
android:layout_toLeftOf="#+id/chkIsChecked"
android:layout_alignWithParentIfMissing="true"
android:includeFontPadding="false"
android:paddingLeft="3dp"
android:gravity="center_vertical|left"
android:textStyle="italic"
android:text="#string/channel_item_dummy_category"
style="?muListItemTextNormal_Inverse" />
<TextView android:id="#+id/lblChannelUpdate"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_below="#+id/imgChannelIcon"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:includeFontPadding="false"
android:paddingTop="3dp"
android:paddingBottom="3dp"
android:textStyle="italic"
android:text="#string/channel_item_dummy_update"
style="?muListItemTextTiny" />
</merge>
As you can see I first place an image with layout_alignParentLeft="true" then the checkbox with layout_alignParentRight="true" and finally I arrange the other components based on those two. From your image I can see that you can use your devices_img as the left component (but you will have to give it a fixed height and maybe some margins in order to became the Layout's height) and your check box as your right.
Keep in mind that in a RelativeLayout with wrap_content as height you cannot use the AlignParentBottom attribute.
Hope this helps...
In a layout resource XML, I have 3 RelativeLayout(s) which are inside a main RelativeLayout. The view will be shown vertically. These 3 RelativeLayout() are set next to each other, and I want them to fill the whole screen, doesnt matter what will be the screen size. My, layout view:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/backg"
>
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginTop="#dimen/top_mr_image"
android:src="#drawable/temp" />
<RelativeLayout
android:id="#+id/r1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_below="#+id/imageView1"
android:layout_marginLeft="10dp"
android:background="#drawable/r1bg"
android:layout_weight="1"
>
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_marginLeft="#dimen/txt_mr_right"
android:layout_marginRight="#dimen/txt_mr_right"
android:layout_marginTop="39dp"
android:text="S"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#id/textView1"
android:layout_marginLeft="#dimen/txt_mr_right"
android:layout_marginRight="#dimen/txt_mr_right"
android:text="T"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/r2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignTop="#+id/r1"
android:layout_toRightOf="#+id/r1"
android:layout_weight="1" >
</RelativeLayout>
<RelativeLayout
android:id="#+id/r3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignTop="#+id/r2"
android:layout_toRightOf="#+id/r2"
android:layout_weight="1" >
</RelativeLayout>
I set weight=1 and layout_width=0dp for each relativeLayout and this technique works with buttons, I thought the same will be with relativeLayout, seems my thoughts were wrong. Any idea?
UPD1: I have added an image of what I would like to have
RelativeLayout does not pay attention to android:layout_weight. (That's a property of LinearLayout.LayoutParams, but not of RelativeLayout.LayoutParams.)
You should be able to get the layout you want with a much simpler view hierarchy. It's not clear what you are trying to do, since the last two RelativeLayouts are empty. If you need a purely vertical organization, I'd suggest using LinearLayout instead of RelativeLayout.
EDIT Based on your edit, it looks like you want a horizontal layout of three compound views, each one clickable. I think something like the following will work:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<!-- First column -->
<LinearLayout
android:id="#+id/firstColumn"
android:orientation="vertical"
android:gravity="center_horizontal"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="..." />
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="text 1"
. . . />
</LinearLayout>
<!-- Second column -->
<LinearLayout . . . >
. . .
</LinearLayout>
</LinearLayout>
If the contents of the buttons aren't correct, you can replace the second-level LinearLayout views with RelativeLayout if that helps organize the layout better.
RelativeLayouts do not support weight. You need to use a LinearLayout as a parent container if you want to use weights.
Solution is very simple. I have been looking for weight distribution in relative layout.
It's a small trick for all these kind situations.
Use LinearLayout with android:orientation="horizontal"
You can use Horizontally oriented LinearLayout Manager in the Recycler View, and place each RelativeLayout in each item, of its Adapter.
The Link: How to build a Horizontal ListView with RecyclerView?
If your RelativeLayouts are set to a fixed width and height, that is to the size of the Screen, that you can get from DisplayMatrics, that will be OK.
The Link: Get Screen width and height
If the contents of your RelativeLayouts are different, then you can use getItemViewType() method.
Please see: How to create RecyclerView with multiple view type?
Happy Coding :-)
I have a RelativeLayout containing a pair of side-by-side buttons, which I want to be centered within the layout. I could just put the buttons in a LinearLayout and center that in the RelativeLayout, but I want to keep my xml as clean as possible.
Here's what I tried, this just puts the "apply" button in the center and the "undo" button to the left of it:
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="15sp">
<TextView
android:id="#+id/instructions"
android:text="#string/instructions"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="15sp"
android:layout_centerHorizontal="true"
/>
<Button
android:id="#+id/apply"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="#string/apply"
android:textSize="20sp"
android:layout_below="#id/instructions"
/>
<Button
android:id="#+id/undo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="#string/undo"
android:textSize="20sp"
android:layout_toLeftOf="#id/apply"
android:layout_below="#id/instructions"
/>
</RelativeLayout>
android:gravity will align the content inside the view or layout it is used on.
android:layout_gravity will align the view or layout inside of his parent.
So adding
android:gravity="center"
to your RelativeLayout should do the trick...
Like this:
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_marginTop="15sp">
</RelativeLayout>
Here is an extension of BrainCrash's answer. It is a non nested option that groups and centers all three horizontally and vertically. In addition, it takes the top TextView and centers it horizontally across both buttons. If desired, you can then center the text within the TextView with android:gravity="center". I also removed the margins, added color, and set the RelativeLayout height to fill_parent to highlight the layout. Tested on API 11.
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
android:background="#android:color/black"
>
<TextView
android:id="#+id/instructions"
android:text="TEST"
android:textSize="20sp"
android:background="#android:color/darker_gray"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_alignLeft="#+id/undo"
android:layout_alignRight="#+id/apply"
android:gravity="center"
/>
<Button
android:id="#+id/apply"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="APPLY"
android:textSize="20sp"
android:layout_below="#id/instructions"
/>
<Button
android:id="#+id/undo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="UNDO"
android:textSize="20sp"
android:layout_toLeftOf="#id/apply"
android:layout_below="#id/instructions"
/>
</RelativeLayout>
android:layout_gravity="center"
will almost give what you're looking for.
Here is a combination of the above answer's that solved my specific situation:
Centering two separate labels within a layout that also includes a button in the left most position of the same layout (button, label, label, from left to right, where the labels are centered relative to the layout containing all three views - that is, the button doesn't push the labels off center).
I solved this by nesting two RelativeLayout's, where the outer most layout included the
Button and an Inner-RelativeLayout.
The Inner-RelativeLayout contained the two text labels (TextView's).
Here is a snippet that provides the details of how the centering and other layout stuff was done:
see: RelativeLayout Gravity not applied? and
Gravity and layout_gravity on Android
for the difference's between gravity and layout_gravity.
Tweak the paddingLeft on the btn_button1 Button to see that the TextView's do not move.
(My apologies to havexz for the downvotes. I was too hasty in thinking that just b/c your suggestions didn't solve the exact question being ask, that they do help to solve very similar situations (the answer here solves a very specific situation, and only the combination of all these answer's solved my problem. I tried upvoting, but it won't let me unless I edit the answer's, which I don't want to do.)
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/rl_outer"
android:layout_width="fill_parent"
android:layout_height="50dip"
android:background="#FF0000FF">
<Button
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/btn_button1"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:background="#FF00FF00"
android:text="<"
android:textSize="20sp"
android:paddingLeft="40dip"/>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/rl_inner"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:background="#FFFF00FF"
android:layout_centerInParent="true"
android:gravity="center">
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/tv_text1"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:background="#FF505050"
android:textSize="20sp"
android:textColor="#FFFFFFFF"
android:text="Complaint #"
android:gravity="center"/>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/tv_text2"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:background="#FF505050"
android:textSize="20sp"
android:textColor="#FFFFFFFF"
android:layout_toRightOf="#id/tv_text1"
android:gravity="center"/>
</RelativeLayout>
</RelativeLayout>
LinearLayout is a good option. Other than that there are options like create an invisible view and center that and then align left button to the left it and right on the right of it. BUT those are just work arounds.