FAPI.UI.getPageInfo

It invokes the method API_callback, passing it as a parameter data object that contains the field (all values in pixels):

ParameterDescription
clientWidthThe width of the page (not to be confused with a screen resolution, if the value is larger than the screen resolution, a scroll bar appears)
clientHeightThe height of the page (not to be confused with a screen resolution, if the value is larger than the screen resolution, a scroll bar appears)
scrollLeftThe horizontal scroll position
scrollTopThe vertical scroll position
offsetLeftThe distance between the left edge of the page and the left edge iframe application
offsetTopThe distance between the upper edge and the upper edge of the page application iframe
innerHeightThe height of the user’s browser window (window.innerHeigth)
innerWidthThe width of the user’s browser window (window.innerWidth)

Example

function getPageInfo(){
    FAPI.UI.getPageInfo();
}