Java – Android: Import DrawerLayout cannot be resolved

After tracking down this problem as well, I found this note in the Android documentation:

http://source.android.com/source/using-eclipse.html

*Note: Eclipse sometimes likes to add an "import android.R" statement at the top of your files that use resources, especially when you ask Eclipse to sort or otherwise manage imports. This will cause your make to break. Look out for these erroneous import statements and delete them.*

While going through the Android sample tutorials, I would often use the Ctrl + Shift + O command to "Organize Imports" and generate any missing import statements. Sometimes this would generate the incorrect import statement which would hide the R.java class that is automatically generated when you build.

If you want the display dimensions in pixels you can use getSize:

Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;

If you're not in an Activity you can get the default Display via WINDOW_SERVICE:

WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();

If you are in a fragment and want to acomplish this just use Activity.WindowManager (in Xamarin.Android) or getActivity().getWindowManager() (in java).

Before getSize was introduced (in API level 13), you could use the getWidth and getHeight methods that are now deprecated:

Display display = getWindowManager().getDefaultDisplay(); 
int width = display.getWidth();  // deprecated
int height = display.getHeight();  // deprecated

For the use case, you're describing, however, a margin/padding in the layout seems more appropriate.

Another way is: DisplayMetrics

A structure describing general information about a display, such as its size, density, and font scaling. To access the DisplayMetrics members, initialize an object like this:

DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);

We can use widthPixels to get information for:

"The absolute width of the display in pixels."

Example:

Log.d("ApplicationTagName", "Display width in px is " + metrics.widthPixels);

API level 30 update

final WindowMetrics metrics = windowManager.getCurrentWindowMetrics();
 // Gets all excluding insets
 final WindowInsets windowInsets = metrics.getWindowInsets();
 Insets insets = windowInsets.getInsetsIgnoreVisibility(WindowInsets.Type.navigationBars()
         | WindowInsets.Type.displayCutout());

 int insetsWidth = insets.right + insets.left;
 int insetsHeight = insets.top + insets.bottom;

 // Legacy size that Display#getSize reports
 final Rect bounds = metrics.getBounds();
 final Size legacySize = new Size(bounds.width() - insetsWidth,
         bounds.height() - insetsHeight);