Develop Reference

Creating a complex View in Android

I am new to Android, and still learning it. I understood the difference between View and ViewGroup, and also found that a ViewGroup can contain multiple views, but a View cannot contain more Views inside it.
What I want to achieve is something like this:
And what I have right now is just a black box in the background. The XML for the black-box is as follows:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="400dp"
android:layout_height="200dp"
android:gravity="center"
android:layout_gravity="center_horizontal"
android:orientation="vertical"
>
<TextView
android:id="#+id/simpleTextView"
android:layout_width="400dp"
android:layout_height="200dp"
android:background="#drawable/box"
android:text="Sample"
android:textSize="20sp"
android:gravity="center_horizontal"/>
</LinearLayout>
Where I have defined box in a seperate XML.
I just wanted to ask, can anyone please help me in achieving the Final Image above? Especially, what kind of layout should I be using?

You should make your layouts as flat as possible, I mean you should avoid nesting, for that in most cases use ConstraintLayout. You can read about it here: https://developer.android.com/reference/androidx/constraintlayout/widget/ConstraintLayout and there are tons of tutorials about that.

It not difficute but we recommend ConstraintLayout
<LinearLayout>//Horizontal
<LinearLayout>//Vertical
<TextView/>
<Button/>
</LinearLayout>
<LinearLayout>//Vertical and add Margin
<Button/>// add Margin
</LinearLayout>
</LinearLayout>

How to control the drawing order of overlapping elements android activity?

I think I have tried and researched enough, if not everything, yet I just can't get the two icons on the right get displayed in android emulator.
The strange thing is, that they are perfectly visible in design window.
Moreover, with similar/same GUI design, other activities display all my elements just fine.
I already know well, that how views overlap on screen depends on order of elements as I place them in the 'Component Tree' of Android Studio IDE.
Correctly looking design in Android Studio:
Missing icons on the right in emulator:
Moreover, the app in missing the title, which could be caused by an inappropriate parent activity class (its Activity which I changed from AppCompatActivity as I spent quite some time with the AS Designing tool).
How else can I control the order of elements when they overlap?
Or what weird Android concept am I still missing?
Or what has changed since all worked fine for me?
Below is the code XML for app design:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.sbm.bc.smartbooksmobile.ActivityTeacherHwkCheckByTask">
<ImageView
android:id="#+id/Problems"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_gravity="right"
android:layout_marginTop="57dp"
android:elevation="24dp"
android:visibility="visible"
app:srcCompat="#drawable/ic_problems" />
<ImageView
android:id="#+id/Talar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_gravity="right"
android:layout_marginRight="42dp"
android:layout_marginTop="57dp"
android:elevation="24dp"
android:visibility="visible"
app:srcCompat="#drawable/ic_menu_talar" />
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/holo_blue_dark"
android:fitsSystemWindows="true">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<TableRow
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="45dp"
android:background="#android:color/holo_blue_bright">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="40dp"
android:visibility="visible">
<LinearLayout
android:id="#+id/ListOfTaskRows"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:elevation="24dp"
android:orientation="vertical"
android:visibility="visible">
</LinearLayout>
</ScrollView>
</TableRow>
<TextView
android:id="#+id/Description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="63dp"
android:allowUndo="false"
android:elevation="20dp"
android:ems="10"
android:text="Úloha"
android:textAlignment="center"
android:textSize="18sp"
android:visibility="visible" />
</RelativeLayout>

I think you are missing the fact that the RelativeLayout children are drawn in front of each other if they overlap. In your case you have a TableRow whose width is match_parent - it fills the parent's width but as it's added after the image views it's drawn in front of them.
You could constrain the table's width so that it leaves room for the images by setting it's layout_alignEnd attribute to the id of your left-most image, so that the table would end where the image begins.

Well, believe it or not the reason for missing icons was, that I decided to derive my app from plain Activity and not AppCompatActivity as I had it before.
So I have restored my activity to extends AppCompatActivity again and lo and behold.. It works.
This of course also enabled the Activity title again.
As its a pure nonsence (another one) and my time wasted counts already in days (not only this issue, but many other crappy designs and apparent bugs in ADT), I've just decided to abbandon native Android development in the near future and switch back to Xamarin/C# instead. (I've started my Android development from C# Xamarin 4 years ago and only left because of insufficient HW access support at that time).
Howhg !

For user of "Material Design":
Another simple workaround is using "elevation" property of any GUI element.
By increasing this value, one can force to draw this element on foreground over those with lower elevation.
As a bonus (or drawback), you get shading around your elevated GUI element according to how much you have elevated.
I wonder how much this feature prolongs rendering time
Another question is min supported API version. (Did not find it right away..)

Android Layout xml "buttons stacking" (newbie )

I just started with android development. I just need a screen with some buttons on it that can contact a webserver, to trigger an action there, but i have not even gotten that far.
When i add buttons to the layout, even if they are nicely sided by side, they end up ontop of each other, with the button created last ontop.
And furtermore i have changed the color, but it does not seem to be moved end up in the simulator.
This is a fresh design (2nd try) and i dont understand what is going on. I dont really know what files to include :)
I realize this is something simple, but im just overwhelmed
thank you
Lasse
Phone and design view

You're probably using a FrameLayout, which just stacks things on top of each other and only supports gravity.
For your use case, you can use a LinearLayout, a RelativeLayout or a ConstraintLayout. Here's an example using LinearLayout:
<?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">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp"
android:text="Select releases since last candy fix" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="96dp"
android:layout_height="wrap_content"
android:layout_marginRight="16dp"
android:text="Button 1" />
<Button
android:layout_width="96dp"
android:layout_height="wrap_content"
android:layout_marginRight="16dp"
android:text="Button 2" />
</LinearLayout>
</LinearLayout>
Have a look at the different layouts to see which one better fits your needs, ConstraintLayout would allow you to flatten your layout, which is good for performance.

How to get rid of a TextView's margin?

This layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="90sp"
android:text="5000"
android:id="#+id/textView"
android:layout_gravity="center"
/>
</LinearLayout>
produces the following:
I want to get rid of the top and bottom margin. Where are they coming from in the first place? Maybe for certain letters in certain fonts/languages.
There is already a thread for this question, but none of the answers really work in all situations or the solutions are hacks. There has to be a simple way.
First idea from the thread: android:includeFontPadding="true" (does not change anyting)
Second idea from the thread: android:height="90sp" (removes at least bottom margin)
So, I changed my layout regarding the ideas:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="90sp"
android:text="5000"
android:id="#+id/textView"
android:layout_gravity="center"
android:includeFontPadding="true" <!-- idea 1 -->
android:height="90sp" <!-- idea 2 -->
/>
</LinearLayout>
Still it procudes a top margin:
Third idea from the thread: android:layout_marginTop="-12sp"
If add this property it looks at least as desired. But -12sp seems so arbitrary to me. I just adjusted this value via trial and error and I don't like that.
This does not seem like a clean solution to me. This is such a simple thing, I just cannot believe how Android can make it so hard, that you have to use hacks.
Is there a clean solution out there?

Use the below syntax to set text size programmatically and set the required size in dimes file.
textView.setTextSize(getResources().getDimension(R.dimen.textsize));
To set padding use below code based on your needs
yourTextView.setPadding(0, 10, 0, 0);

Set Linearlayout and TextView padding and margins to 0dp. Should work.
Add those to both views:
android:padding="0dp"
android:layout_margin="0dp"

Adding padding on android AutoCompleteTextView popup

For the last two hour and a half i had been trying to do something really simple: change the padding in the Android's AutoCompleteTextView's popup (the one that shows the auto complete options).
i'm trying to do this because the item in my app has the height of the text (i'm not sure why), so i want to make it easier to click on. But every think i could find didn't work at all.
So i really would be glad if anyone could spot a light in this problem or give an alternative solution.
And just for the record, i'm using android studio, and i had removed the support API (since my min API is 16), so my app is using 100% native resorts only.

I just found a way to make it, i had to make a custom view layout with an textview already including the item's padding. Than i created a custom adapter with uses this layout.
The layout goes like this
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:singleLine="true"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ellipsize="marquee"
android:layout_margin="0dp"
android:paddingLeft="#dimen/thin_margin"
android:paddingRight="#dimen/thin_margin"
android:paddingTop="#dimen/list_1line_item_padding"
android:paddingBottom="#dimen/list_1line_item_padding"/>
And in the custom adapter just used it in the getView method
itemView = LayoutInflater.from(ctx).inflate(R.layout.list_1line_item, null);

<?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="fill_parent"
android:layout_marginTop="20dp"
>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingTop="#dimen/dp_15"
android:paddingBottom="#dimen/dp_15"
android:id="#+id/parentid">
<AutoCompleteTextView
android:id="#+id/address_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/light_gray_bg"
android:drawableRight="#drawable/icon_search_smaller"
android:gravity="center_vertical"
android:hint="Start typing location"
android:inputType="textCapWords"
android:popupBackground="#drawable/auto_location_popup_bg"
android:textColor="#color/black"
android:textColorHint="#color/dark_grey"
android:textSize="16sp"
android:visibility="visible"
android:dropDownWidth="wrap_content"
android:dropDownAnchor="#+id/parentid">/>
<requestFocus />
</RelativeLayout>
</RelativeLayout>

define another relative layout wrapping only the autocomplete textview and the button. look at this link
Android layout padding is ignored by dropdown