The controller for this menu. Default is internal controller, but an
external one (i.e. from class parameter) can be provided and is set to
this variable in the initState() function.
Calculate the location from (0, 0) of the screen if the menu is located at
the bottom center of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.
Calculate the location from (0, 0) of the screen if the menu is located at
the bottom left of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.
Calculate the location from (0, 0) of the screen if the menu is located at
the bottom right of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.
Given the items and possibly a builder , build the actual menu. Uses a
SingleChildScrollView if performance mode is off, or uses a ListView
for lazy loading if performance mode is on. The builder can be used
to completely customize the menu actually shown.
Calculate the position of the menu. Finds dropdown button size, window size,
and popup menu size. Then finds location of the dropdown button. Finally,
depending on the SDropdownMenuPosition, this function will calculate the
location of the menu (from its top left corner) relative to the screen's
(0, 0) coordinate. Also adjusts the positon of the menu will be out of
screen bounds (thus making it clip off screen)
Calculate the location from (0, 0) of the screen if the menu is located at
the center left of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.
Calculate the location from (0, 0) of the screen if the menu is located at
the center of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown
menu button, calculate location of the menu.
Calculate the location from (0, 0) of the screen if the menu is located at
the center right of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.
Calculate the location from (0, 0) of the screen if the menu is located at
the top center of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.
Calculate the location from (0, 0) of the screen if the menu is located at
the top left of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.
Calculate the location from (0, 0) of the screen if the menu is located at
the top right of the dropdown button. Given the location of the button
(offset), the size of the popup menu, and the size of the dropdown menu
button, calculate location of the menu.