Touch Target Spacing

Actionable controls should have a minimum dimension of 24 x 24 dp or must be positioned so that if a circle with a diameter of 24 dp is placed on the center of control, the circle will not intersect with another target or with the circle for another target.

Impact

On a touch device, small controls are a usability issue for everyone. Additionally, people experiencing motor limitations have increased difficulty interacting with small targets.

Confirmation

1. Identify the pixel density of your Android device.
2. Utilize the view hierarchy inspector to confirm how big the control is in pixels.
3. One of the following will happen:
   • Accessible: The view will be larger than the minimum requirement and not have overlapping views that cause the available target to be smaller than 24x24.
   • Accessible: The view will be smaller than the 24x24 minimum, but the padding around the view will make the button have enough space to be tapped reliably by users.
   • Accessible: Sliders maintain a space of 24dp along the length of the control.
   • Inaccessible: There is another clickable view that reduces the tappable area of the tested view below the minimum threshold.

How to Fix

• Set the minimum height and width of the view to 24dp.

In XML:

Button button = findViewById(R.id.an_accessible_button_yay)
button.setMinimumHeight(24);
button.setMinimumWidth(24);

<Button
     android:id="@+id/an_accessible_button_yay"
     android:minimumHeight="24dp"
     android:minimumWidth="24dp"
     android:text="@string/batman_likes_accessible_buttons" />

In Compose:

Button(modifier = modifier
  .constrainAs(textButtonBottom) {
      top.linkTo(slider.bottom)
      start.linkTo(parent.start)
      bottom.linkTo(parent.bottom)
  }
  .padding(start = 24.dp, top = 24.dp), onClick = { }) {
  Text(stringResource(id = R.string.button))
}

• Adjust neighboring clickable-views to allow for ample space between clickable components.

• Remove obstructions around sliders.

• Add a margin around clickable views.