Allow for editing of read-only documents

When e.g. viewing mail attachments (that have been stored r/o to some download
directory by the mail application), it would be nice if the user could easily
temporarily modify them (say, play around with a spreadsheet, changing some
numbers and triggering recalculation of formulas) by clicking the "Edit File"
button and not being asked to create a copy for editing.

This patch tries to make editability of a view independent of the r/o status of
the medium:

* SID_EDITDOC (the "Edit File" button) now only toggles the r/o status of the
view.  It no longer asks to create a copy for editing if the underlying medium
is r/o.

* When a modified document is toggled to r/o via SID_EDITDOC, LO still asks the
user to save or discard the changes.  However, if the underlying medium is
physically r/o (see next), saving the document opens the "Save As" dialog,
instead of just doing a "Save" operation (which would fail on the r/o file).

* A new state of "IsOriginallyReadOnly" needed to be added to the medium, to
keep track whether the medium was originally opened r/o (and is thus assumed
to be physically r/o), as toggling SID_EDITDOC in the view also changes the
open mode of the underlying medium.  Instead of trying to fully understand and
disentangle that horrible mess, I just added yet another state to the mess...

* The title of the document window now contains "(read-only)" if and only if
either the view is r/o or the medium is originally r/o (or both).

Change-Id: I89d9c6adf0baab411e737a5f4e6f4e770e7a70be

0 files changed, 0 insertions, 0 deletions