How to center a ImageView vertically in its parent? - java

My layout design is a TextView with long text and a ImageView to the right of the TextView. I want to center the ImageView in its parent vertically, so I used android:layout_centerVertical="true", but it turned out that the ImageView was aligned to the bottom of its parent. If I don't use layout_centerVertical property, the ImageView will be aligned to the top of its parent. How can I solve this problem? Thanks.
<?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:background="#000000">
<ImageView android:id="#+id/t3" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:src="#drawable/arrow_right"
android:layout_alignParentRight="true" android:background="#ff0000"
android:layout_centerVertical="true" android:scaleType="centerInside" />
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="This a very very very very very very very very very very very very very very very very long sentence"
android:textColor="#231ACC" android:layout_toLeftOf="#id/t3" />
</RelativeLayout>

Try android:layout_gravity="center_vertical"

Add this xml attribute to the child you wish to center within it's parent:
android:layout_centerInParent="true"
This will center it vertically/horizontally.

change android:layout_height="wrap_content" to android:layout_height="fill_parent" of RelativeLayout and add android:layout_centerVertical="true" to TextView, it will work like charm.

You could use a LinearLayout with layout_width and layout_height set to fill_parent and gravity set to vertical_center.
Something like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_vertical|center_horizontal"
android:orientation="horizontal">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/input_field"
android:gravity="left"
android:layout_weight="1"
android:text="Left Aligned"/>
<EditText
android:id="#+id/input_field"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="right"
android:layout_weight="1"
android:text="Right Aligned"/>
</LinearLayout>
</LinearLayout>

This will put your image to the vertical center of it's parent:
android:layout_gravity="center_vertical"
Demo:
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="64dp"
android:orientation="horizontal">
<ImageView
android:layout_width="48dip"
android:layout_height="48dip"
android:src="#drawable/ic_launcher"
android:contentDescription="Application icon"
android:layout_gravity="center_vertical" />
</LinearLayout>

Simply add this:
android:layout_gravity="center_vertical|center_horizontal"

I found this question while building in Android Studio 4.2.1 and the solution after some tinkering was:
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
this way, constraining to both sides automatically centers the widget and satisfies the need for constraints. The same is true when centering vertically, by using:
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"

Related

how to get a portion of a view outside of its parent?

I tried to create an actionBar like this one, "this is a website template "
so I created a file action_bar.xml which I'll inflate, A RelativeLayout which has a height of wrap_content & a width of match_parent , it has the gear icon and all other details except that I can't get a part of the round picture outside of the RelativeLayout like the picture.
I tried using margins but it doesn't get out of the RelativeLayout, The RelativeLayout gets extended instead. so, More margin in the picture results in more height in RelativeLayout.
Any suggestions?
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageButton android:src="#drawable/roundPicture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_marginTop="30sp"
android:layout_marginLeft="30sp"
android:padding="0sp"/>
<ImageButton
android:id="#+id/gearIcon"
android:layout_alignParentRight="true"
android:background="#drawable/gearICON"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10sp"
/>
</RelativeLayout>
No Libraries please, I'm not making an app, I'm just trying to understand.
quick recap. I want a part of the first ImageButton outside of the RelativeLayout
Check if it is this what you are looking for
EDIT:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#fff">
<ImageButton
android:id="#+id/gearIcon"
android:layout_alignParentRight="true"
android:background="#android:drawable/ic_delete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10sp"
/>
</RelativeLayout>
<ImageButton
android:background="#android:drawable/ic_delete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_marginTop="30sp"
android:layout_marginLeft="30sp"
android:padding="0sp"/>
</FrameLayout>
First, I ran into a problem that my data appears under the ImageView, not behind it
but I fixed it by adding my data which is a listview, after the relativeLayout in the frameLayout, Thanks P.Juni for the idea btw
The XML which runs totally fine is
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/transparent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#000">
<ImageButton
android:id="#+id/gearIcon"
android:layout_alignParentRight="true"
android:background="#drawable/ic_launcher_background"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10sp"
/>
</RelativeLayout>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>
<ImageButton android:id="#+id/imageButton"
android:background="#drawable/ic_launcher_background"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_marginTop="60sp"
android:layout_marginLeft="30sp"
android:padding="0sp"/>
</FrameLayout>

Splitting Android Layout Vertically Adding Gravity To Both Sides To Center Objects

I have an android layout I'd like to split down the middle vertically and then add gravity so I can center items within the left and the right halves of the layout.
Can someone explain or post an example of how this might be accomplished?
Thus far I've created a layout and a horizontal layout. My problem is the horizontal layout needs balance so I'd like to figure out a way to change my current layout (show below) to include a way of centering the objects within the left and right halves of the screen.
SOURCE:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/background"
android:orientation="vertical" >
<ImageView
android:id="#+id/emblem"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginTop="24dp"
android:gravity="center"
android:scaleType="fitStart"
android:src="#drawable/apn_app_logo" />
<Button
android:id="#+id/go_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/emblem"
android:layout_alignParentRight="true"
android:layout_marginBottom="23dp"
android:layout_marginRight="22dp"
android:background="#drawable/apn_app_go_button" />
<TextView
android:id="#+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_below="#+id/go_button"
android:gravity="center"
android:text="#string/start_text2"
android:textColor="#000000"
android:textSize="18sp" />
</RelativeLayout>
First of all android:orientation attribute will not work in Relative Layout.If you want to split the screen half into two equal layout your parent layout will be a linear layout with android:orientation= horizontal. Then inside that have 2 LinearLayout with each android:orientation= vertical. Inside 1st Linear layout you can have the ImageView , Button and TextView with each of their layout_gravity=center.
Hope this helps. If you want to do something in the 2nd half of teh screen , do all teh stuffs in the 2nd LinearLayout.
Happy Coding.
Here's some code which should be self-explanotory:
<LinearLayout 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:orientation="horizontal"
tools:context=".MainActivity" >
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal"
android:background="#00dd00"
android:gravity="center"
>
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal"
android:background="#dd0000"
android:gravity="center_horizontal"
>
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
</LinearLayout>
and here's what you'll achieve:

Layout Change Visibility

I'm trying to develop an Augmented Reality aplication for Android using Metaio. But actually I've a problem.
I want to make a little menu appear when the aplication recongize a marker.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageButton
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:background="#android:color/transparent"
android:onClick="onButtonClick"
android:contentDescription="#null"
android:src="#drawable/cancel" />
<LinearLayout
android:id="#+id/buttonBar123"
style="#android:style/ButtonBar"
android:layout_width="300dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="10dp"
android:visibility="invisible"
android:orientation="horizontal"
android:gravity="center">
<Button
android:id="#+id/TextoButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:onClick="onTextoButtonClick"
android:text="Texto" />
<Button
android:id="#+id/ImageButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:onClick="onImagemButtonClick"
android:text="Imagem" />
</LinearLayout>
</RelativeLayout>
My layout is on a View and I don't know how to change the ButtonBar123 to visible in Java code. Can you help me? Thanks
You just need to get a reference to your Layout
LinearLayout buttonBar = (LinearLayout) findViewById(R.id.buttonBar123);
then set the visibility
buttonBar.setVisibility(View.VISIBLE);
Visibility
LinearLayout buttonBar = (LinearLayout)findViewById(R.id.buttonBar123);
buttonBar.setVisibility(View.VISIBLE);

How to layout a VideoView next to TextView with scrolling list underneath

I'm trying to have a VideoView fixed on the upper left with a TextView immediately to the right of it. Below both of those I want a scrollable list of checkboxes, and below that two buttons "prev" and "next". The VideoView and TextView should not scroll, just the checkboxes and buttons. I can't seem to make this work with Linear layouts so i tried RelativeLayout but it seem kinda clunky because I'm hard coding all the relative stuff. What's the best way of laying out this type of thing?
thanks,
Justin
Here is a basic layout that fits your description:
<?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="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<VideoView
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
<ScrollView
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<CheckBox android:id="#+id/chk1"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<CheckBox
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#id/chk1"/>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="horizontal" >
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</RelativeLayout>
</ScrollView>
</LinearLayout>
If the VideoView is to big maybe you'll want to limit the space available to it by using the 0dp value and layout_weight attribute on the enclosing LinearLayout.

android: image in icon not showing

I'm trying to place a banner at the top of a listview, one that stays there when the list scrolls down. The layout I currently have actually show what I want in the preview but when I run it in the emulator the only thing that appears is the list.
The XML is:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView android:src="#drawable/edinburghcrest"
android:layout_height="wrap_content" android:layout_width="wrap_content"
android:id="#+id/EdUniCrest" android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"></ImageView>
<TextView android:layout_height="wrap_content" android:id="#+id/banner"
android:text="Hotels Nearby" android:textColor="#FFFFFF"
android:gravity="center" android:textSize="20dp" android:layout_width="wrap_content"
android:layout_alignParentTop="true" android:layout_toRightOf="#+id/EdUniCrest"
android:layout_alignParentRight="true" android:layout_alignBottom="#+id/EdUniCrest"
android:background="#25476C"></TextView>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="fill_parent"
android:background="#color/listcolor" android:orientation="vertical" android:layout_marginTop="50dp">
<ListView android:id="#android:id/list" android:layout_width="wrap_content"
android:layout_height="wrap_content">
</ListView>
<TextView android:id="#android:id/empty" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="#string/no_lunchs" />
</LinearLayout>
Anyway, I can't see why it isn't working. Does anyone have any idea what it might be?
Thanks.
The RelativeLayout here just makes it confusing. You can achieve this simply with a couple of LinearLayouts. Wrap your banner in a horizontal layout with a height=wrap_content and set you ListView to height=fill_parent. The list will then fill all available space. The List will scroll independently of the rest of the page.
Something like below should work:
<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:orientation="horizontal" android:id="#+id/bannerBar"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<ImageView android:src="#drawable/edinburghcrest"
android:layout_height="wrap_content" android:layout_width="wrap_content"
android:id="#+id/EdUniCrest"/>
<TextView android:layout_height="wrap_content" android:id="#+id/banner"
android:text="Hotels Nearby" android:textColor="#FFFFFF"
android:gravity="center" android:textSize="20dp" android:layout_width="wrap_content"
android:background="#25476C"/>
</LinearLayout>
<ListView android:id="#android:id/list" android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<TextView android:id="#android:id/empty" android:layout_width="fill_parent"
android:layout_height="fill_parent" android:text="#string/no_lunchs" />
</LinearLayout>
What if you wrapped your RelativeLayout in a ScrollView, and since a ScrollView can only have one child, put the banner above it?

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