Develop Reference

Prevent ImageButton from going in background

Here's the Android ImageButton that I am trying to rotate.
It does rotate but as you can see from the screenshot, part of it goes to background/invisible during the rotation. How do I ensure that the ImageButton stays visible completely during the entire rotation?
Here's the Activity code:
public class MainActivity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ImageButton imgbt = (ImageButton)findViewById(R.id.mybutton);
RotateAnimation ra =new RotateAnimation(0, 360);
ra.setFillAfter(true);
ra.setDuration(2000);
imgbt.startAnimation(ra);
}
}
And the XML:
<LinearLayout
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:orientation="vertical" >
<ImageButton
android:id="#+id/mybutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/mybutton" />
</LinearLayout>

In your LinearLayout, change this:
android:layout_height="wrap_content"
to this:
android:layout_height="match_parent"
So, you will ensure that the container is big enough to show the image button completely, even when it's vertical.

Change your LinearLayout height and width to fill_parent as below:
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:gravity="center"
android:orientation="vertical" >

You can use :
imgbt.bringToFront();

Set match_parent to your LinearLayout height.
If you are not using weight then don't need to include it. So change
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >

chnage your width and height parameter of the linear layout to fill_parent cause the use code:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
android:orientation="horizontal" >
<ImageButton
android:layout_gravity="center"
android:id="#+id/mybutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/mybutton"
/>

Linearlayout inside scrollview with even distriburtion

I have a data entry type activity and im using a linear layout to space out evenly the sets of textviews and edittexts. Then I have a scroll view that is supposed to make it so the user can scroll while the softkeyboard is up.
If I use android:fillViewport the linearlayout works properly and fills the screen and spreads each item out evenly but then when the keyboard comes up and stops each item being spread out evenly. If i use android:windowSoftInputMode="stateVisible|adjustPan" then the linearlayout remains spread out but the scroll view doesn't work anymore (from all the unsolved posts on this i don't think you can have a working scroll view with adjustPan)
is there any way to have a linearlayout inside a scrollview, with items spread out evenly and still work while the softkeyboard is up with out changing the linearlayout?
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport
>
<LinearLayout
android:gravity="left"
android:orientation="vertical"
android:id="#id/tab2"
android:paddingLeft="40.0dip"
android:paddingTop="0.0dip"
android:paddingRight="40.0dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1.0">
<TextView
android:id="#id/textViewBrand"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/brand" />
<AutoCompleteTextView
android:id="#id/editTextBrand"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
</AutoCompleteTextView>
</LinearLayout>
...more linearlayouts with textview and edittext to be spaced out evenly

set the property android:fillViewport="true" in your scrollview it will work

Maybe the ScrollView isn't working because your
android:layout_height attribute
is defined to match_parent. You have to put
wrap_content

Follow This Code, I hope it resolves your Problem
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
//Your Main Layout
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:weightSum="100">
// First Sub Layout Under Main Layout
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:layout_weight="10"
android:weightSum="100" >
<TextView
android:id="#+id/textView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="TextView"
android:layout_weight="70" />
<EditText
android:id="#+id/editText1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="30" />
</LinearLayout>// Finishing First Sub layout
// Second Sub Layout Under Main Layout
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:layout_weight="10"
android:weightSum="100" >
<TextView
android:id="#+id/textView2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="TextView"
android:layout_weight="70" />
<EditText
android:id="#+id/editText2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="30" />
</LinearLayout>// Finishing Second Sub layout
similarly for 3rd,4rth,5th sub layouts and so on........
</LinearLayout> // Finishing Main Layout
</ScrollView> // Finishing ScrollView

you can go over the child views of the LinearLayout and set their size to a fixed size yourself in code using a ViewTreeObserver.OnGlobalLayoutListener.
the following code sets the sizes to not change, so you can use the android:fillViewport option with weights, and then essentially remove the weights, but keep the calculated sizes.
I used this code with some modifications to also make sure child views are distributed evenly in a LinearLayout that is inside a ScrollView, where the LinearLayout is too big for the android:fillViewport option to get the weights to actually work. this was done by doing 2 iterations over the children. first getting the max view's height, and then setting all child views to that max height.
private void distributeViewsEvenlyInLinearLayout() {
ViewTreeObserver observer = linearParentView.getViewTreeObserver();
final ViewTreeObserver.OnGlobalLayoutListener globalLayoutListener = new ViewTreeObserver.OnGlobalLayoutListener() {
#SuppressWarnings("deprecation")
public void onGlobalLayout() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
linearParentView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
} else {
linearParentView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
for (int i = 0; i < linearParentView.getChildCount(); i++) {
View child = linearParentView.getChildAt(i);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, child.getHeight());
child.setLayoutParams(layoutParams);
}
}
};
observer.addOnGlobalLayoutListener(globalLayoutListener);
}

How to center GridView on the screen

How to center GridView on the screen.I have GridView with 4 items as 2 items per row. I try to center the GridView inside the Relative layout using padding in relative layout. But I developed application for multiple screens.So I think hardcoded padding is not good practice. How to center this Grid view on mulitple screens?
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/gridrelativelayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="60dp"
android:paddingBottom="60dp"
android:paddingLeft="150dp"
android:paddingRight="150dp"
tools:context=".MainMenuActivity" >
<GridView
android:id="#+id/gridview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#F9F9F9"
android:gravity="center"
android:horizontalSpacing="50dp"
android:numColumns="2"
android:stretchMode="columnWidth"
android:verticalSpacing="50dp"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" />
</RelativeLayout>
Updated Code:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/gridrelativelayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="150dp"
android:paddingRight="150dp"
tools:context=".MainMenuActivity" >
<GridView
android:id="#+id/gridview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:columnWidth="20dp"
android:background="#FF0000"
android:gravity="center"
android:horizontalSpacing="50dp"
android:numColumns="2"
android:verticalSpacing="50dp"
android:layout_centerInParent = "true"
/>
</RelativeLayout>
This updated code centers gridView on screen properly. But see,I hardcoded padding for left ad Right in Relative layout.As I want to support to multiple scrrens, I want to make this padding as dynamic using following code.But It not works.
RelativeLayout gridrelativelayout = (RelativeLayout)findViewById(R.id.gridrelativelayout);
int pad=gridrelativelayout.getWidth()/3;
gridrelativelayout.setPadding(pad, 0, pad, 0);

Apply RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
and For GridView
android:layout_centerInParent = "true"

Use android:layout_centerInParent = "true" for GridView. This surely works...

If want write best app to multiple screen devices, so you need read this:
Supporting Multiple Screens
and it is very useful to you:
Supporting Different Screens

Use
android:layout_centerHorizontal = "true"
for GridView.

How to scale an Android layout object during runtime?

I want to set the width of a LinearLayout to half of the screen width dynamically in my UI initialization. I have a RelativeLayout wrapped around the LinearLayout, the hierarchy is the following:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<LinearLayout
android:id="#+id/left_linear_layout"
android:layout_alignParentLeft="true"
android:layout_height="fill_parent"
android:layout_width="155dp" <!--want to set this to 1/2 screen width-->
android:orientation="vertical">
...
</LinearLayout>
<LinearLayout
android:id="#+id/right_linear_layout"
android:layout_alignParentRight="true"
android:layout_height="fill_parent"
android:layout_width="385dp"><!--want to set this relative to screen width as well-->
....
</LinearLayout>
</RelativeLayout>
Alternatively, can this problem be solved using View instead of Layout? Any suggestion is appreciated!

You can do this by using layout_weight, but you'll need to add some invisible views for padding. For instance the following would make your top panel half the screen width:
<RelativeLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout
android:id="#+id/left_linear_layout"
android:layout_alignParentLeft="true"
android:layout_height="fill_parent"
android:layout_width="0dp"
android:layout_weight="1"
android:orientation="vertical"
>
...
</LinearLayout>
<!-- need this view to fill the other half of the screen -->
<View
android:id="#+id/spacer"
android:layout_toRightOf="#id/left_linear_layout"
android:layout_height="fill_parent"
android:layout_width="0dp"
android:layout_weight="1"
/>
....
</RelativeLayout>
The amount each view will take up is layout_weight/total_layout_weight. In this case total_layout_weight = 1+1 = 2 and each view has a layout_weight of 1, so each view takes up 1/2 of the screen.

You could simply use a LinearLayout as your top-level layout, and then set the weight of the two child layouts.

Adding view to bottom of layout inside a scrollview

So my layout looks basically like this:
<ScrollView>
<RelativeLayout>
<BunchOfViews/>
<ImageView android:layout_alignParentBottom="true"/>
</RelativeLayout>
</ScrollView>
I have the ScrollView so all of the layout always is visible no matter the height of the screen. The problem is that on a very high screen, I still want my ImageView to be at the bottom. However, a child of a ScrollView don't seem to have a defined bottom. The View is placed at the top of the layout. How can I solve this problem in a neat way?

I ran into the same issue. I never could find a very pleasing solution, but here is how I did it. Maybe someone else has a better way, I hate adding layouts that don't do anything.
My hack was to add a dummy linearlayout at the bottom of the scrollview that has fill_parent to take up all the room and force the scrollview to fill the screen. Then add whatever component I want to that linearlayout.
Here is one of my layouts that does this:
<ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:fillViewport="true" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginTop="15px" >
<!-- bunch of components here -->
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="#+id/spinner"
android:layout_marginTop="5px"
android:gravity="center_horizontal|bottom"
android:paddingTop="2px" >
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="20px"
android:paddingRight="20px"
android:text="Delete" />
</LinearLayout>
</RelativeLayout>
</ScrollView>

I had the same issue and found this page:
http://www.curious-creature.org/2010/08/15/scrollviews-handy-trick/
Basically, you set the ScrollView's android:fillViewport to true, which will allow the child view to expand to the same height as the ScrollView itself, filling out the space. You then just need to have one of the child controls' layout_height set to fill_parent and layout_weight to 1, causing that control to "spring" to fill the empty space.
Note that if the contents of the ScrollView are already tall enough to fill the ScrollView, the android:fillViewport has no effect, so the setting only kicks in when needed.
My final XML looks like similar to this:
<ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fillViewport="true">
<LinearLayout
android:orientation="vertical"
android:layout_height="wrap_content">
<LinearLayout
android:layout_height="fill_parent"
android:layout_weight="1">
<!-- this expands to fill the empty space if needed -->
</LinearLayout>
<!-- this sits at the bottom of the ScrollView,
getting pushed out of view if the ScrollView's
content is tall enough -->
<ImageView
android:layout_height="wrap_content"
android:src="#drawable/footer_image">
</ImageView>
</LinearLayout>
</ScrollView>

it seems that the linearlayout isn't necessary, all that is important is the fillViewPort.
you could just use
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottomParent="true">
now that you have specified the relativelayout to be at least the size of the screen.

its work for me perfectly android:fillViewport="true"

Joel Malone's answer Adding view to bottom of layout inside a scrollview does that trick. My solution is almost the same, except that I use Space widget to do the work of filling the rest height inside the parent layout. Like this:
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
>
<LinearLayout
android:orientation="vertical"
android:layout_height="wrap_content"
>
<android.support.v4.widget.Space
android:layout_height="match_parent"
android:layout_weight="1"
/>
<ImageView
android:layout_height="wrap_content"
android:src="#drawable/footer_image"
/>
</LinearLayout>
</ScrollView>
Attention:
fill_parent in the other answers is noted as deprecated for a long time;
Compare to an empty LinearLayout to fill the rest of parent layout, I think Space is much more appropriate(it's designed to do that job.)
Finally, don't forget that important attribute at the beginning of ScrollView: android:fillViewport="true". They together make this trick.

just put this attribute android:fillViewport="true" to your ScrolView
and you will got what you need

On your view that you want to be at the bottom use android:gravity="bottom"

From: http://code.google.com/p/k9mail/source/browse/k9mail/trunk/res/layout/account_setup_basics.xml?r=1314
This should help you:
<RelativeLayout
android:layout_marginTop="-45dip"
android:padding="0dip"
android:layout_alignParentBottom="true"
android:gravity="bottom|right"
android:background="#android:drawable/bottom_bar"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<Button
android:id="#+id/manual_setup"
android:text="#string/account_setup_basics_manual_setup_action"
android:minWidth="#dimen/button_minWidth"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_marginBottom="-4dip"
android:layout_alignParentLeft="true"
android:layout_centerVertical="false"
/>
<Button
android:id="#+id/next"
android:text="#string/next_action"
android:minWidth="#dimen/button_minWidth"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:drawableRight="#drawable/button_indicator_next"
android:layout_marginBottom="-4dip"
android:layout_alignParentRight="true"
android:layout_centerVertical="false"
/>
</RelativeLayout>

ScrollView view = new ScrollView( this );
ScrollView.LayoutParams lps = new FrameLayout.LayoutParams( FILL_PARENT, FILL_PARENT, Gravity.CENTER );
LinearLayout layout = new LinearLayout( this );
// what ever you want in the Layout
view.addView( layout, lps );

I tried alot to align the Scroll View to bottom of the screen but thats not possible according to this link.
https://newbedev.com/how-do-i-align-views-at-the-bottom-of-the-screen
The way i found was to create a view with 1dp height and aa id (lets say android:id="#+id/bottomView") at the bottom of your XML page.
now just add these attributes to your scroll view..
<ScrollView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fillViewport="true"
android:layout_alignBottom="#+id/bottomView"
>

Here is how you can use a ConstraintLayout to align the image view at the bottom:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/content_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/text_view"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Text 1"
app:layout_constraintBottom_toTopOf="#+id/space_view"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="parent" />
<Space
android:id="#+id/space_view"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/image_view"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/text_view" />
<ImageView
android:id="#+id/image_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="..."
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/space_view" />
</androidx.constraintlayout.widget.ConstraintLayout>
</ScrollView>