Android get window height

Kotlin Android – Get screen Width and Height Programmatically

Android – Get Screen Width and Height

In Android, WindowManager is available to every Activity. Through WindowManager, we can get the metrics of default display in which the activity is being shown.

In this tutorial, we will learn how to get width and height of the screen, on which the application is running, with the help of example Android Application.

Steps to Get Width and Height of Screen

To get Android screen width and height programmatically, follow these steps.

1. Create a DispalyMetrics() object.
2. Pass the displayMetrics object to getMetrics() method of Display class. WindowManager.defaultDisplay() returns the Display object.
3. Screen Width could be obtained using displayMetrics.widthPixels
4. Screen Height could be obtained using displayMetrics.heightPixels

In the following screenshot, width and height of the Android device screen is obtained programmatically and displayed using TextView.

Code – Get Width and Height

A quick snippet of the code to obtain screen dimensions programmatically is provided below

Example – Kotlin Android – Get Screen Dimensions Programmatically

In the following example, we shall obtain screen width and height, display it in the Activity with the help of TextView.

activity_main.xml

MainActivity.kt

Conclusion

In this Kotlin Android Tutorial – Get Screen Dimensions Programmatically, we have learnt to get screen width and height programmatically using DisplayMetrics.

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Tek Eye

For efficient bitmap handling or dynamic View creation in an app, the area that a screen item or layout is using needs to be known. If no fixed sizes are allocated at design time the size of a View may not be known until an app is executed. This is because of the wide range of display sizes that Android supports. Just look on GSMArena to see the huge range of Android devices produced over the years, and to see the wide variation in screen sizes and pixel densities. The example code in this article shows how to read the screen size and the size of Views as the app runs.

(Note: All Android screen items are derived from Views. A screen component, e.g. a TextView , is derived from the View class. Such screen components are also known as widgets. Layouts are ViewGroups and are also derived from Views.)

Determining the Size of an Android View or Screen at Run Time

To run the example code in this article first create a new Android project. Those new to Android programming can read the article Your First Android Hello World Java Program to see how. For this article the app is called View Size.

Use a simple layout for activity_main.xml (the layout file may have another name). Add a TextView with id labXY and set the Text attribute to X,Y. Next to it add another TextView called textXY with Text set to ? (actually \? to make it valid in the XML). Here is the layout used for this example:

Add this code to the bottom of the onCreate method in MainActivity.java (or whatever the class was called). Add the required an imports for TextView and DisplayMetrics when prompted with the Alt-Enter:

This is the code running on an Android Virtual Device (AVD) with a 320×480 screen:

Finding the Size of an Android View in Code

Drop an ImageView onto the layout, here using the ic_launcher.png icon file, or other images can be used. The size of a View can be retrieved using the getWidth and getHeight methods. Change the code in the onCreate to set the TextView to the ImageView’s width and height (an import for View is required, again usually prompted for and added with Alt-Enter):

Mmmmm! The code is showing 0,0 for the ImageView size, even though we can see that it is not 0,0:

This is because in onCreate the screen has not yet been laid out so the size of the ImageView has not been determined hence the getWidth() and getHeight() methods are returning zero. In fact they will likely return zero in onStart() and onResume(). What is needed is to override onWindowFocusChanged() to get the ImageView sizes:

Finding the Size of an Android Layout in Code

The same code can be used to get the size of the View (the layout, i.e. ViewGroup) in which the screen components sit. Notice that in the screen XML the RelativeLayout was given an id (@+id/screen), which means the base View’s width and height can be grabbed (change R.id.imageView to R.id.screen in the code):

Notice that the layout height is less than the screen height because of the notification bar.

Finding the Size of an Android View During Screen Construction

To get the the size of a View as soon as it is known (rather than waiting for the onWindowFocusChanged event) attach a listener to its ViewTreeObserver . Do this by writing a class that implements ViewTreeObserver.OnGlobalLayoutListener in the Activity’s class. This new class will have an onGlobalLayout method that gets the View dimensions that can then be stored for later use (here they are displayed as before). Here is the example source code for the entire MainActivity.java file to show this way of getting the ImageView’s width and height:

Download some example code in view-size.zip from this article, ready for importing into Android Studio. See the instructions in the zip file, alternatively the code can also be accessed via the Android Example Projects page.

See Also

• Using Immersive Full-Screen Mode on Android Developers
• See the Android Example Projects page for lots of Android sample projects with source code.
• For a full list of all the articles in Tek Eye see the full site alphabetical Index.

Archived Comments

Kestrel on December 15, 2014 at 4:20 am said: Hey fantastic article, can you also talk about the fitSystemWindows and how things are affected when its set or not set by default. Thanks in advance.

Author: Daniel S. Fowler Published: 2013-06-19 Updated: 2017-12-17

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