I am trying to center horizontally a PopUpWindow on the anchored view, but the Gravity.CENTER parameter is being ignored.
This is the method I am using:
popupWindow.showAsDropDown(anchorView, 0, 0, Gravity.CENTER);
No matter what CENTER gravity value I enter (also TOP or BOTTOM don't work), the pop-up always displays at the same place: the anchor's top left corner, unless I use the START or END values.
The documentation and javaDoc does not list any restriction on the values that it accepts, so I assume that it also accepts any of the CENTER, TOP and BOTTOM values: https://developer.android.com/reference/android/widget/PopupWindow#showAsDropDown(android.view.View,%20int,%20int,%20int)
I also tested this with anchor views that are smaller, equal and larger than the pop-up window and the pop-up window is set to not fill the screen width, as intended.
It appears that this method does nothing different from the equivalent method that does not take the gravity parameter
popupWindow.showAsDropDown(anchorView, 0, 0);
Is this a bug or is this not how it is suppose to be used?
For PopupWindow.showAsDropDown(), it seems that is working as intended, tracing through its source, you can eventually see that the gravity parameter is only meant for horizontal values.
Tracking the value of gravity from PopupWindow.showAsDropDown() to PopupWindow.findDropDownPosition(), we can already see the hint @param gravity horizontal gravity specifying popup alignment
Then a step deeper to Gravity.getAbsoluteGravity() also hints at the same thing @param gravity The gravity to convert to absolute (horizontal) values.
But I believe what you are looking to achieve is at Show a PopupWindow centralized, which uses PopupWindow.showAtLocation()
PopupWindow.showAtLocation(View parent, int gravity, int x, int y)