Develop Reference

Android Studio Constraint Layout Preview is different than phone screen

I'm trying to program an activity in android studio that will be, at least, similar in any device. In order to achieve this, I'm already using:
Constraint Layout;
Text size as sp and other sizes as dp;
Same resolution (1920x1080) in my android preview and my physical device.
But, I'm getting a different screen behavior in each screen, as you can see by the pics.
Major differences are:
Text size seems different even using "sp" unit to define it;
Phone have a line break but preview not;
Preview has a much larger blank space when compared to the phone.
What is happening? How could I prevent this behavior and design similar layouts for different phone screens?
xml file
<?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=".MainActivity" >
<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorPrimary" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp" >
<LinearLayout
android:background="#color/colorWhite"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="45dp"
android:layout_marginBottom="45dp">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingLeft="30dp"
android:paddingRight="30dp">
<TextView
android:id="#+id/templatetv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView1"
android:textColor="#color/colorPrimary"
android:textStyle="bold"
android:textSize="25sp"
android:layout_marginTop="30dp" />
<TextView
android:id="#+id/textview1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Name: John Sample"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Document number: XXX.XXX.XXX-XX"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Father name: John Sample"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Mother name: Eva Sample"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Birthdate: 01/01/1901"
android:textSize="18sp"
android:layout_marginTop="10dp" />
</LinearLayout>
</ScrollView>
</LinearLayout>
</LinearLayout>
</RelativeLayout>
Android Studio Screen Preview
Phone Screen

Try to remove this part, I think that can be the margin:
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp" >

You need to define different layouts for different screens. Also, if you follow material design guidelines most of the problems will not arise. checkout the google material design documentation.

Why Emulator renders different result to Android Studio?

I have played around with Android Studio and just wonder why the render result is so different to what i created
Here is the image of my screen, you can see that the 2 screen of Android Studio and Genymotion are completely different
Here is the XML file for the layout, basically i just drag and adjust the margin, width and height.
<?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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="tk.miendatmoi.widgetexperiments.WidgetExperimentsActivity"
tools:showIn="#layout/activity_widget_experiments"
android:visibility="visible">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Left Button"
android:id="#+id/button"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:width="150dp"
android:layout_marginLeft="10dp"
android:layout_marginTop="100dp"
android:layout_marginRight="50dp"
android:layout_marginBottom="50dp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Right"
android:id="#+id/button2"
android:layout_alignBottom="#+id/button"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:width="80dp" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="New Text"
android:id="#+id/textView"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:textSize="65sp"
android:width="150dp"
android:height="150dp"
android:gravity="center"
android:alpha=".5"
android:background="#342a2a"
android:textColor="#fdfdfd"
android:typeface="serif"
android:visibility="visible" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/imageView"
android:layout_below="#+id/textView"
android:layout_centerHorizontal="true"
android:layout_marginTop="45dp"
android:src="#android:mipmap/sym_def_app_icon"
android:contentDescription="incon" />
</RelativeLayout>

This is because you are using two different layouts. It seems like the genymotion layout is using tablet layout which has a different resolution to the one is in android studio which is using the nexus 4 resolution.

The result in the emulator is different from the Android Studio preview because you are displaying your layout inside a widget. The tools in the Android Studio layout preview are unable to display the layout inside a widget, so they instead show you the layout as if it were allowed to take up the entire screen. The layout it is displayed correctly inside the widget when you run the application.

text sizes different Android phones

Since I have a Nexus 5, I'm seeing strange stuff regarding text sizes.
An example: I am creating listview items. I put a bigger text at 22sp, a smaller one at 17sp.
On my HTC One X it looks like this:
So I think "ok, that's nice!"
Then I run it on my Nexus 5:
I do not understand why this is happening? Shouldn't the 'sp' part make sure it will look ok
with the default values? I am not talking about the user increasing the font sizes in the settings, I've left everything to defaults.
Eventhough, if I would (don't hit me) use DP here to disable the font size changes for text, it will give the same result (not tested, but I am fairly certain this is the case from other tests).
What is the problem here? Is it the newer Android version, or is it the 1080p screen vs the 720p ?
Should I use different values for different DP using 'values' folder?
here is de layout:
<?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="80dp"
android:orientation="horizontal">
<LinearLayout
android:id="#+id/background"
android:layout_marginTop="10dp"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<com.android.volley.toolbox.NetworkImageView
android:id="#+id/image"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:adjustViewBounds="true"
android:scaleType="centerCrop" />
<RelativeLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_margin="5dp"
android:layout_weight="2">
<ImageView
android:id="#+id/arrow"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_alignParentRight="true"
android:adjustViewBounds="true" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="3dp"
android:layout_toLeftOf="#id/arrow"
android:gravity="center"
android:orientation="vertical">
<TextView
android:id="#+id/name"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:fontFamily="sans-serif-condensed"
android:textSize="22sp"
android:textStyle="bold" />
<TextView
android:id="#+id/address"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:textSize="17sp" />
</LinearLayout>
</RelativeLayout>
</LinearLayout>
</LinearLayout>

For instance, the default size for same SP value may vary depending on device, just to match its readability designed for the device.
The problem you got is because you have some elements sized to fixed size, post your XML code you use for the row and we can make a deep analyse.
Edit -- After xml
Well, instead of point you the wrongs, I did prefer to rebuild your layout, take a look:
<?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"
android:layout_margin="10dp"
android:orientation="horizontal" >
<com.android.volley.toolbox.NetworkImageView
android:id="#+id/image"
android:layout_width="wrap_content"
android:layout_height="match_parent" />
<TextView
android:id="#+id/name"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/image"
android:layout_toLeftOf="#+id/arrow"
android:fontFamily="sans-serif-condensed"
android:textSize="22sp"
android:textStyle="bold" />
<TextView
android:id="#+id/address"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/image"
android:layout_toLeftOf="#id/arrow"
android:layout_below="#id/name"
android:textSize="17sp" />
<ImageView
android:id="#id/arrow"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_alignParentRight="true" />
</RelativeLayout>
Your layout was too complex to a simple row... now the layout will be as tall as the TextViews needs it to be, and it is not a problem, as the user is already used with his text size.

you have to Create two different layout folder and see the result

How to make my layout fit in all screens

I have gone through many relative answers on stockoverflow and link's such as Supporting Different Screens or Screen Compatibility Mode
I have created the following relative layout and I am trying to make it look alike in all android screens.
My images fit perfect for 4.8 inch phones but when I try to use a 2.8 inch display or something like like that, some buttons go on top of others, and they do not shrink.
Does anyone have any suggestion how to improve that?
And preferably without increasing the size of my app.
Thanks in advance!
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:mm="http://millennialmedia.com/android/schema"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#drawable/background"
tools:context=".MainActivity" >
<ImageButton
android:id="#+id/Switch_off"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:onClick="someMethod"
android:background="#drawable/switch_off"/>
<ImageView
android:id="#+id/warning_shot"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:background="#drawable/more"
android:onClick="someMethod" />
<ImageView
android:id="#+id/imageViewBatteryState"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_below="#+id/Switch_off"
/>
<ImageView
android:id="#+id/sh"
android:layout_width="147dp"
android:layout_height="54dp"
android:layout_below="#+id/Switch_off"
android:layout_centerHorizontal="true"
android:background="#drawable/me"/>
<ImageView
android:id="#+id/sit"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_below="#+id/Switch_off"
android:layout_centerHorizontal="true"
/>
<TextView
android:id="#+id/textViewBatteryInfo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffff"
android:textSize="12sp"
android:textStyle="bold"
android:typeface="monospace"
android:layout_alignBottom="#+id/sit"
android:layout_centerHorizontal="true"/>
</RelativeLayout>

I will suggest you to use LinearLayout instead of Relativelayout specially for the issue :
My images fit perfect for 4.8 inch phones but when I try to use a 2.8
inch display or something like like that, some buttons go on top of
others, and they do not shrink.
Because When you give orientation to Linearlayout then Its child will never get on top of each other for any resolution or screen size.
And If you give them Weight then Views will be in fix position for Each and Every device.
For example Put below Xml in your project and Check this out in Any resolution, It will give the same Result.
XML:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:mm="http://millennialmedia.com/android/schema"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
tools:context=".MainActivity" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<Button
android:id="#+id/button1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Button 1" />
<Button
android:id="#+id/button2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Button 2" />
<Button
android:id="#+id/button3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Button 3" />
</LinearLayout>
</LinearLayout>

How to change layout so that it fits a tablet size screen?

I have tested this app on mobile devices and the layout looks fine but when tested it on a 7 inch tablet the main activity is missing textViews and images,the rest of the activities are fine though.
Could someone show me how to fix this situation as I'm sure its a fairly simple fix.The layout for the activity is shown below.
<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fillViewport="true"
android:scrollbars="none"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
tools:context=".MainActivity"
>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
>
<LinearLayout
android:id="#+id/llayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<ImageView
android:id="#+id/imageView1"
android:layout_width="271dp"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_weight="0.68"
android:src="#drawable/mark3" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:text="#string/depth_"
android:textColor="#90f030"
android:textSize="30sp" />
<EditText
android:id="#+id/ductDepth"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="20dp"
android:ems="10"
android:hint="#string/enter_duct_depth_mm"
android:inputType="numberDecimal"
android:singleLine="true" >
<requestFocus />
</EditText>
<TextView
android:id="#+id/textView3"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:text="Duct Depth:"
android:textColor="#90f030"
android:textSize="30sp" />
<EditText
android:id="#+id/offDepth"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="14dp"
android:ems="10"
android:hint="#string/enter_offset_depth_mm"
android:inputType="numberDecimal"
android:singleLine="true" />
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="50dp"
android:text="Length:"
android:textColor="#90f030"
android:textSize="30sp" />
<EditText
android:id="#+id/offLength"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="20dp"
android:ems="10"
android:hint="#string/enter_offset_length_mm"
android:inputType="numberDecimal"
android:singleLine="true" />
</LinearLayout>
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
<!--
This title strip will display the currently visible page title, as well as the page
titles for adjacent pages.
-->
<android.support.v4.view.PagerTitleStrip
android:id="#+id/pager_title_strip"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:background="#33b5e5"
android:paddingBottom="4dp"
android:paddingTop="4dp"
android:textColor="#fff" />
</android.support.v4.view.ViewPager>
<ImageButton
android:id="#+id/calc"
android:layout_width="200dp"
android:layout_height="70dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_below="#+id/llayout"
android:background="#drawable/calcbttrans" />
</RelativeLayout>
</ScrollView>

what exactly is the problem? the stretched image at the bottom?
if so, it's probably because you've set it to an exact size without allowing it the freedom to keep its aspect ratio. a possible solution is using 9-patch image or an xml drawable, or just keep the aspect ratio of the current image.
btw, the action bar doesn't look well. have you considered using the support library or actionBarSherlock? google already has guidelines about native look and feel (for example here: http://developer.android.com/design/patterns/pure-android.html )
EDIT: it seems the problem is on the layouts .
looks like the viewPager is on top of all the layouts, while the imageButton is beneath the linearLayout, when you scroll all the way to the bottom (not a native android UX, btw).
just check the UI designer and the outline . it clearly shows the problem (i had to replace all images since i don't have them, but this isn't the important thing) :