get Visible Pdf Rect
Sets targetRect to contain the visible PDF rect of the given pageIndex. If the pageIndex is not visible on the screen, targetRect won't be modified and the method will return false.
Return
true if the page visible and its visible rect was written to
targetRect, or false if the page is not visible and targetRect was not modified.
Parameters
target Rect
RectF instance which will be set to the visible PDF rect.
page Index
Target page number. 0-based index.