fix #1064 by adding timestamp of document in cache key
so that when document is modified the persistent cache will
be invalidated automatically because the cache key will not
be matched. There is no perfermance overhead here at all. We
even don't need to check the modification time of the cache item
on disk, because the name of the on disk cache is a md5sum of the
cacheitem key, now the filename of the cache files contains the
modification time information.
If the document is modified since one rendered page is cached to disk,
the cache key won't match the cache file. And the cache file will
be discarded without the need to open the cache file or to check
the modification time of the cache file itself.
persistent cache item now need an explicit persistent flag
move screenshot settings to submenu of Screenshot entry in readermenu
And also fix a touchmenu bug that prevent some menu entries
(always at the bottom of the menu) from showing submenus. The reason is
that the onTapSelect method of TouchMenuItem doesn't return true, so that
the tap gesture will propagate to the parent widget and be captured by
touchmenu itself. But at this time the dimen of touchmenu is changed to
the submenu of the tapped menuitem. If the submenu is short enough the
tap will be outside of touchmenu which will cause a TapCloseAllMenus
event and the submenu will never be shown.
add modal widget type that will stay on the top of window stack
ConfirmBox and InfoMessage are default to be modal.
Now returning to filamanager after highlighting a PDF page
the confirmbox asking users to save the document will not be hidden by
the filamanager window.
And it's tested on Kindle that #791 is already been solved probably by
out refacorting of MuPDF backend.