ToolTipView

ToolTipView.java

/*
 * +info: https://gist.github.com/romannurik/3982005
 */

public class ToolTipView {
  public static final int LENGTH_SHORT = Toast.LENGTH_SHORT;
  public static final int LENGTH_LONG = Toast.LENGTH_LONG;

  @Retention(RetentionPolicy.CLASS) @IntDef({ LENGTH_SHORT, LENGTH_LONG }) public @interface Duration {
  }

  private static final int ESTIMATED_TOAST_HEIGHT_DIPS = 48;

  public static void show(@NonNull View view, @NonNull CharSequence text, @Duration int duration) {
    if (view == null || TextUtils.isEmpty(text)) {
      return;
    }

    final int[] screenPos = new int[2];
    final Rect displayFrame = new Rect();
    view.getLocationOnScreen(screenPos);
    view.getWindowVisibleDisplayFrame(displayFrame);

    final Context context = view.getContext();
    final int viewWidth = view.getWidth();
    final int viewHeight = view.getHeight();
    final int viewCenterX = screenPos[0] + viewWidth / 2;
    final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
    final int estimatedToastHeight = (int) (ESTIMATED_TOAST_HEIGHT_DIPS * context.getResources().getDisplayMetrics().density);

    Toast toast = Toast.makeText(context, text, duration);
    boolean showBelow = screenPos[1] < estimatedToastHeight;
    if (showBelow) {
      toast.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL, viewCenterX - screenWidth / 2,
          screenPos[1] - displayFrame.top + viewHeight);
    } else {
      toast.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL, viewCenterX - screenWidth / 2,
          screenPos[1] - displayFrame.top - estimatedToastHeight);
    }
    toast.show();
  }
}