note description: "Memory device context compatible with a given % %device context or the application's current screen." legal: "See notice at end of class." status: "See notice at end of class." date: "$Date$" revision: "$Revision$" class WEL_MEMORY_DC inherit WEL_DC redefine destroy_item end create make, make_by_dc, make_by_pointer feature {NONE} -- Initialization make -- Make a memory dc compatible with the application's -- current screen. local a_default_pointer: POINTER do item := cwin_create_compatible_dc (a_default_pointer) end make_by_dc (a_dc: WEL_DC) -- Make a memory dc compatible with `a_dc'. require a_dc_not: a_dc /= Void a_dc_exists: a_dc.exists do item := cwin_create_compatible_dc (a_dc.item) end feature -- Basic operations get -- Get the device context do end release -- Release the device context do end feature {NONE} -- Removal destroy_item -- Delete the current device context. local p: POINTER -- Default_pointer do -- Protect the call to DeleteDC, because `destroy_item' can -- be called by the GC so without assertions. if item /= p then unselect_all cwin_delete_dc (item) end item := p end feature {NONE} -- Externals cwin_create_compatible_dc (hdc: POINTER): POINTER -- SDK CreateCompatibleDC external "C [macro ] (HDC): EIF_POINTER" alias "CreateCompatibleDC" end note copyright: "Copyright (c) 1984-2006, Eiffel Software and others" license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)" source: "[ Eiffel Software 356 Storke Road, Goleta, CA 93117 USA Telephone 805-685-1006, Fax 805-685-6869 Website http://www.eiffel.com Customer support http://support.eiffel.com ]" end -- class WEL_MEMORY_DC