Home > Articles > Mobile Application Development & Programming

From the Rough Cut Adapting to Screen Orientation

Adapting to Screen Orientation

As with almost all smartphones, Android supports two screen orientations: portrait and landscape. When the screen orientation of an Android device is changed, the current activity being displayed is destroyed and re-created automatically to redraw its content in the new orientation. In other words, the onCreate() method of the activity is fired whenever there is a change in screen orientation.

Portrait mode is longer in height and smaller in width, whereas landscape mode is wider but smaller in height. Being wider, landscape mode has more empty space on the right side of the screen. At the same time, some of the controls don’t appear because of the smaller height. Thus, controls needs to be laid out differently in the two screen orientations because of the difference in the height and width of the two orientations.

There are two ways to handle changes in screen orientation:

  • Anchoring controls—Set the controls to appear at the places relative to the four edges of the screen. When the screen orientation changes, the controls do not disappear but are rearranged relative to the four edges.
  • Defining layout for each mode—A new layout file is defined for each of the two screen orientations. One has the controls arranged to suit the Portrait mode, and the other has the controls arranged to suit the Landscape mode.

Anchoring Controls

For anchoring controls relative to the four edges of the screen, we use a RelativeLayout container. Let’s examine this method by creating an Android project called ScreenOrientationApp. To lay out the controls at locations relative to the four edges of the screen, write the code in the layout file activity_screen_orientation_app.xml as shown in Listing 3.15.

Listing 3.15 The Layout file activity_screen_orientation_app.xml on Laying Out Controls Relative to the Four Edges of the Screen

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button  
        android:id="@+id/Apple"  
        android:text="Apple"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:layout_marginTop="15dip"  
        android:layout_marginLeft="20dip" />
    <Button  
        android:id="@+id/Mango"  
        android:text="Mango"
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:padding="28dip"
        android:layout_toRightOf="@id/Apple" 
        android:layout_marginLeft="15dip"
        android:layout_marginRight="10dip"
        android:layout_alignParentTop="true" />
    <Button  
        android:id="@+id/Banana"  
        android:text="Banana"
        android:layout_width="200dip" 
        android:layout_height="50dip"    
        android:layout_marginTop="15dip"  
        android:layout_below="@id/Apple" 
        android:layout_alignParentLeft="true" />
    <Button  
        android:id="@+id/Grapes"  
        android:text="Grapes"
        android:layout_width="wrap_content" 
        android:layout_height="match_parent"    
        android:minWidth="100dp"
        android:layout_alignParentRight="true"     
        android:layout_below="@id/Banana" />
    <Button  
        android:id="@+id/Kiwi"  
        android:text="Kiwi"
        android:layout_width="100dip" 
        android:layout_height="wrap_content"    
        android:layout_below="@id/Banana"
        android:paddingTop="15dip"     
        android:paddingLeft="25dip" 
        android:paddingRight="25dip" />
</RelativeLayout>

Listing 3.15 shows five Button controls arranged in a RelativeLayout container. The controls are aligned relative to the edges of the container or in relation to each other. Let’s keep the activity file ScreenOrientationAppActivity.java unchanged with the default code, as shown in Listing 3.16.

Listing 3.16 Default Code in the Java Activity File ScreenOrientationAppActivity.java

package com.androidunleashed.screenorientationapp;
import android.app.Activity;
import android.os.Bundle;

public class ScreenOrientationAppActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_screen_orientation_app);
    }
}

When the application is run while in the default Portrait mode, the controls appear as shown in Figure 3.16 (left). Because the five Button controls are placed in relation to the four edges of the container and in relation to each other, none of the Button controls disappear if the screen is rotated to Landscape mode, as shown in Figure 3.16 (right). To switch between portrait mode and landscape mode on the device emulator, press the Ctrl+F11 keys.

Figure 3.16 (left) Controls in Portrait mode, and (right) the controls in Landscape mode

Now that we understand the concept of adapting to screen orientation through anchoring controls, let’s have a look at another approach.

Defining Layout for Each Mode

In this method, we define two layouts. One arranges the controls in the default portrait mode, and the other arranges the controls in landscape mode. To understand this, let’s write code as shown in Listing 3.17 for laying out the controls for portrait mode in the default layout file activity_screen_orientation_app.xml (found in the res/layout folder).

Listing 3.17 The Layout File activity_screen_orientation_app.xml on Laying Out Controls in Portrait Mode

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button  
        android:id="@+id/Apple"  
        android:text="Apple"
        android:layout_width="300dp" 
        android:layout_height="wrap_content" 
        android:padding="20dip"
        android:layout_marginTop="20dip" />
    <Button  
        android:id="@+id/Mango"  
        android:text="Mango"
        android:layout_width="300dp" 
        android:layout_height="wrap_content" 
        android:padding="20dip"
        android:layout_marginTop="20dip" />
    <Button  
        android:id="@+id/Banana"  
        android:text="Banana"
        android:layout_width="300dip" 
        android:layout_height="wrap_content"   
        android:padding="20dip" 
        android:layout_marginTop="20dip"  />
    <Button  
        android:id="@+id/Grapes"  
        android:text="Grapes"
        android:layout_width="300dip" 
        android:layout_height="wrap_content"    
        android:padding="20dip"
        android:layout_marginTop="20dip"   />
    <Button  
        android:id="@+id/Kiwi"  
        android:text="Kiwi"
        android:layout_width="300dip" 
        android:layout_height="wrap_content"    
        android:padding="20dip"
        android:layout_marginTop="20dip"  />
</LinearLayout>

In Listing 3.17, we can see that five Button controls are vertically arranged in a LinearLayout container, one below the other. This vertical arrangement makes a few of the Button controls disappear when the screen is in Landscape mode.

If we run the application without defining the layout for the Landscape mode, we find the controls arranged in Portrait mode, as shown in Figure 3.17 (left). But when we switch the screen orientation to Landscape, we find the last two Button controls have disappeared, as shown in Figure 3.17 (right).This is because in Landscape mode, the screen becomes wider but shorter in height.

Figure 3.17 (left) Controls in Portrait mode, and (right) some controls disappear in Landscape mode.

To use the blank space on the right side of the screen in Landscape mode, we need to define another layout file, activity_screen_orientation_app.xml, created in the res/layout-land folder. The layout-land folder has to be created manually inside the res folder. Right-click on the res folder in the Package Explorer window and select the New, Folder option. A dialog box opens, asking for the name for the new folder. Assign the name layout-land to the new folder, and click the Finish button. Copy the activity_screen_orientation_app.xml file from the res/layout folder and paste it into res/layout-land folder. Modify the activity_screen_orientation_app.xml file in the res/layout-land folder so as to arrange the controls in Landscape mode. The code in the newly created activity_screen_orientation_app.xml is modified as shown in Listing 3.18.

Listing 3.18 The Layout File activity_screen_orientation_app.xml in the res/layout-land Folder

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button  
        android:id="@+id/Apple"  
        android:text="Apple"
        android:layout_width="250dp" 
        android:layout_height="wrap_content" 
        android:padding="20dip"
        android:layout_marginTop="20dip" />
    <Button  
        android:id="@+id/Mango"  
        android:text="Mango"
        android:layout_width="250dp" 
        android:layout_height="wrap_content" 
        android:padding="20dip"
        android:layout_marginTop="20dip" 
        android:layout_toRightOf="@id/Apple" />
    <Button  
        android:id="@+id/Banana"  
        android:text="Banana"
        android:layout_width="250dip" 
        android:layout_height="wrap_content"   
        android:padding="20dip" 
        android:layout_marginTop="20dip" 
        android:layout_below="@id/Apple" />
    <Button  
        android:id="@+id/Grapes"  
        android:text="Grapes"
        android:layout_width="250dip" 
        android:layout_height="wrap_content"    
        android:padding="20dip"
        android:layout_marginTop="20dip"  
        android:layout_below="@id/Apple"
        android:layout_toRightOf="@id/Banana"  />
    <Button  
        android:id="@+id/Kiwi"  
        android:text="Kiwi"
        android:layout_width="250dip" 
        android:layout_height="wrap_content"    
        android:padding="20dip"
        android:layout_marginTop="20dip" 
        android:layout_below="@id/Banana" />
</RelativeLayout>

In this code block, we can see that, to fill up the blank space on the right side of the screen, the Mango and Grapes button controls are set to appear to the right of the Apple and Banana button controls.

We can also detect the screen orientation via Java code. Let’s modify the activity file ScreenOrientationAppActivity.java to display a toast message when the screen switches between landscape mode and portrait mode. The code written in the Java activity file ScreenOrientationappActivity.java is shown in Listing 3.19.

Listing 3.19 Code Written in the Java Activity File ScreenOrientationappActivity.java

package com.androidunleashed.screenorientationapp;

import android.app.Activity;
import android.os.Bundle;
import android.widget.Toast;

public class ScreenOrientationAppActivity extends Activity {
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_screen_orientation_app);
   if(getResources().getDisplayMetrics().widthPixels>getResources().getDisplayMetrics().
            heightPixels) 
        {  
            Toast.makeText(this,"Screen switched to Landscape mode",Toast.LENGTH_SHORT).show(); 
        } 
        else 
        { 
            Toast.makeText(this,"Screen switched to Portrait mode",Toast.LENGTH_SHORT).show(); 
        }
    }
}

Now, when we run the application, the controls appear in portrait mode as shown in Figure 3.18 (left) and in landscape mode as shown in Figure 3.18 (right). We can see that none of the Button controls are now hidden in landscape mode.

Figure 3.18 (left) Controls in Portrait mode, and (right) all controls are visible in Landscape mode.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020