Layout looks different in Android emulator compared to real device

Question

I am encountering a problem and I need your help. The thing is that the layout in Android emulator that I created using Android studio looks different on a real device. I have 4 ImageButtons and they are separated in the layout file. This is correctly displayed in the Emualtor. However, on a 4'screen on a real device they are overlapping, which looks quite bad. Here you can see the two layouts. I indicated the gap with an error on the emulator's screenshot.:enter image description here

Here you can see the code of the XML layout file:

<android.support.constraint.ConstraintLayout xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar_mainActivity"
        android:layout_width="432dp"
        android:layout_height="135dp"
        android:background="#435cb53f"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
        app:titleTextColor="@android:color/holo_green_light">

        <TextView
            android:id="@+id/textView_ToolBar_FoodSelectionActivity"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:gravity="center"
            android:layout_gravity="center"
            android:textColor="@android:color/white"
            android:textSize="24sp"
            android:text="Food" />
    </android.support.v7.widget.Toolbar>

    <ScrollView
        app:layout_constraintTop_toBottomOf="@id/toolbar_mainActivity"
        app:layout_constraintBottom_toTopOf="@id/bottom_layout"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        android:layout_width="0dp"
        android:layout_height="0dp">
        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            tools:context=".MainActivity"
            tools:ignore="ExtraText">


            <ImageButton
                android:id="@+id/imageButton_1"
                android:layout_width="0dp"
                android:layout_height="128dp"
                android:layout_marginTop="12dp"
                android:background="#00000000"
                android:scaleType="fitCenter"
                app:layout_constraintEnd_toStartOf="@+id/imageButton_2"
                app:layout_constraintHorizontal_chainStyle="spread"
                app:layout_constraintHorizontal_weight="1"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:srcCompat="@drawable/test_dish_1" />

            <ImageButton
                android:id="@+id/imageButton_2"
                android:layout_width="0dp"
                android:layout_height="128dp"
                android:layout_marginTop="12dp"
                android:background="#00000000"
                android:scaleType="fitCenter"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_weight="1"
                app:layout_constraintStart_toEndOf="@+id/imageButton_1"
                app:layout_constraintTop_toTopOf="parent"
                app:srcCompat="@drawable/test_dish_1" />

            <ImageButton
                android:id="@+id/imageButton_4"
                android:layout_width="0dp"
                android:layout_height="128dp"
                android:layout_marginTop="12dp"
                android:background="#00000000"
                android:scaleType="fitCenter"
                app:layout_constraintEnd_toStartOf="@id/imageButton_3"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@id/imageButton_1"
                app:layout_constraintVertical_chainStyle="packed"
                app:srcCompat="@drawable/test_dish_1" />

            <ImageButton
                android:id="@+id/imageButton_3"
                android:layout_width="0dp"
                android:layout_height="128dp"
                android:layout_marginTop="12dp"
                android:background="#00000000"
                android:scaleType="fitCenter"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toEndOf="@id/imageButton_4"
                app:layout_constraintTop_toBottomOf="@id/imageButton_1"
                app:srcCompat="@drawable/test_dish_1" />






        </android.support.constraint.ConstraintLayout>
    </ScrollView>

    <LinearLayout
        android:background="#FFD600"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        android:id="@+id/bottom_layout"
        android:layout_width="0dp"
        android:layout_height="60dp">

        <Button
            android:id="@+id/button1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_margin="4dp"
            android:layout_weight="1"
            android:background="@drawable/test_dish_1"
            android:text="A" />


        <Button
            android:layout_gravity="center_vertical"
            android:id="@+id/button2"
            android:layout_weight="1"
            android:text="B"
            android:layout_width="0dp"
            android:layout_margin="4dp"
            android:layout_height="wrap_content"/>


        <Button
            android:layout_gravity="center_vertical"
            android:id="@+id/button3"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:text="C"
            android:layout_margin="4dp"
            android:layout_height="wrap_content"/>

        <Button
            android:layout_gravity="center_vertical"
            android:id="@+id/button4"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:text="D"
            android:layout_margin="4dp"
            android:layout_height="wrap_content"/>

    </LinearLayout>
</android.support.constraint.ConstraintLayout>

Does anyone have an idea what the problem might be? For me this is quite strange, as the emulator displays correctly what I specified in the XML layout file while it looks faulty on the real device. I'd appreciate every comment.

Update: I added margins for all ImageButtons by using android:layout_marginStart="10dp" android:layout_marginEnd="10dp" However, while on the emulator things changed a little bit (the margins to the rims are increased) on the real device nothing changed.

Does someone have an idea what the problem might be. I am still struggeling on this one and I am running out of ideas. I'd appreciate your help.

Update 2: Here is the '@drawable/test_dish_1' picture as lincollincol demanded:

Answer 1

Add android:layout_marginStart or android:layout_marginRight

and

android:layout_marginEnd or android:layout_marginLeft

to your ImageButtons like this:

<ImageButton
    android:id="@+id/imageButton_1"
    android:layout_width="0dp"
    android:layout_height="128dp"
    android:layout_marginTop="12dp"
    android:layout_marginStart="10dp" // <==== Change to your margin
    android:layout_marginEnd="10dp" //  <==== Change to your margin
/>

Your full XML with margins: (Edited)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar_mainActivity"
        android:layout_width="match_parent"
        android:layout_height="135dp"
        android:background="#435cb53f"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
        app:titleTextColor="@android:color/holo_green_light">

        <TextView
            android:id="@+id/textView_ToolBar_FoodSelectionActivity"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:gravity="center"
            android:layout_gravity="center"
            android:textColor="@android:color/white"
            android:textSize="24sp"
            android:text="Food" />
    </android.support.v7.widget.Toolbar>

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_above="@+id/bottom_layout"
        android:layout_below="@+id/toolbar_mainActivity"
        android:layout_marginTop="0dp"
        android:layout_marginBottom="0dp"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fillViewport="true"
            android:orientation="vertical">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="horizontal">

                <View
                    android:id="@+id/imageButton_1"
                    android:layout_width="0dp"
                    android:layout_height="150dp"
                    android:layout_weight="50"
                    android:layout_marginLeft="10dp"
                    android:layout_marginRight="10dp"
                    android:layout_marginBottom="10dp"
                    android:layout_marginTop="10dp"
                    android:background="@drawable/test" />

                <View
                    android:id="@+id/imageButton_2"
                    android:layout_width="0dp"
                    android:layout_height="150dp"
                    android:layout_weight="50"
                    android:layout_marginLeft="10dp"
                    android:layout_marginRight="10dp"
                    android:layout_marginBottom="10dp"
                    android:layout_marginTop="10dp"
                    android:background="@drawable/test" />

            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="horizontal">
                <View
                    android:id="@+id/imageButton_3"
                    android:layout_width="0dp"
                    android:layout_height="150dp"
                    android:layout_weight="50"
                    android:layout_marginLeft="10dp"
                    android:layout_marginRight="10dp"
                    android:layout_marginBottom="10dp"
                    android:layout_marginTop="10dp"
                    android:background="@drawable/test" />

                <View
                    android:id="@+id/imageButton_4"
                    android:layout_width="0dp"
                    android:layout_height="150dp"
                    android:layout_weight="50"
                    android:layout_marginLeft="10dp"
                    android:layout_marginRight="10dp"
                    android:layout_marginBottom="10dp"
                    android:layout_marginTop="10dp"
                    android:background="@drawable/test" />

            </LinearLayout>

        </LinearLayout>

    </ScrollView>

    <LinearLayout
        android:id="@+id/bottom_layout"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:background="#FFD600"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true">

        <Button
            android:id="@+id/button1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_margin="4dp"
            android:layout_weight="1"
            android:background="@drawable/test"
            android:text="A" />


        <Button
            android:layout_gravity="center_vertical"
            android:id="@+id/button2"
            android:layout_weight="1"
            android:text="B"
            android:layout_width="0dp"
            android:layout_margin="4dp"
            android:layout_height="wrap_content"/>


        <Button
            android:layout_gravity="center_vertical"
            android:id="@+id/button3"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:text="C"
            android:layout_margin="4dp"
            android:layout_height="wrap_content"/>

        <Button
            android:layout_gravity="center_vertical"
            android:id="@+id/button4"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:text="D"
            android:layout_margin="4dp"
            android:layout_height="wrap_content"/>

    </LinearLayout>
</RelativeLayout>

Xml for @drawable/test

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <corners android:radius="10dp"/>
    <solid android:color="#ffaa"/>
</shape>

The problem is solved by replacement ConstraintLayout with RelativeLayout and LinearLayout

Answer 2

In android development testing on a real device is better.It assures you that your application will run smoothly on other phones(customer devices). The emulator is just a software that tends to imitate the functionalities of a real device. You are not going to get 100% functionality from your emulator. You are advised to use a real device when testing your apps.