Make Settings operation to support _OLD and placeholders

Setting can be a file. The Settings path was hard coded to .dat file,
which made it impossible to move the settings file to a different
location or use some other settings file instead.
This change saves the settings path with placeholder name,
which is resolved before performing settings operation or undo
operation. In case settings path is hard coded to .dat file and the
settings file is relocated, this can be overcome by setting variable
name _OLD to point to the location where the settings file originally
was. Installer uses this _OLD syntax to resolve the new location.

For example in the following example Tools.ini is relocated
from OldLocation to NewLocation. Setting the installer values the
following way will tell installer to use the settings from NewLocation
instead of OldLocation.
installer.setValue("MY_OWN_EXECUTABLE", "C:/Qt/NewLocation/Tools.ini")
installer.setValue("MY_OWN_EXECUTABLE_OLD",
"C:/Qt/OldLocation/Tools.ini")

Task-number: QTIFW-2882
Change-Id: I47dc68dfba8a49f37ab361edc8c64d3e5523e02e
Reviewed-by: Arttu Tarkiainen <arttu.tarkiainen@qt.io>

0 files changed, 0 insertions, 0 deletions