From ed5640d8b587fbcfed7dd7967f3de04b37a76f26 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 11:06:44 +0200 Subject: Adding upstream version 4:7.4.7. Signed-off-by: Daniel Baumann --- svl/README.md | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 svl/README.md (limited to 'svl/README.md') diff --git a/svl/README.md b/svl/README.md new file mode 100644 index 000000000..984d6ecfe --- /dev/null +++ b/svl/README.md @@ -0,0 +1,51 @@ +# Non-Graphical Helper Code (svtools light) + +Contains non-graphical helper code for office applications. + +Specifically this module does not depend on or use includes from module +vcl. Originally all code in svtools that did not depend on vcl was split +off into this svl ("svtools light") module. + +In particular the `SfxItemSet` is a property-bag like container that +stores arbitrary sets of properties for everything from text run +formats, to Chart regression line properties. + +There are lots of other useful helpers in here for various office +tasks; much of this code was originally moved from `svx/sfx2`. + +## Items, Pools and Sets + +### SfxPoolItem + +A small reference counted piece of data. Many subclasses, each with a +unique integer to identify its type (`WhichId`). Can be compared for equality +(`operator==`), `Clone()`d, and converted to/from `uno::Any` (`QueryValue/PutValue`). + +A pool item may have value semantics ("poolable"), meaning that +there will generally be only one instance that compares equal per item pool, +or not, in which case the item will be `Clone()`d quite a bit. + +### SfxItemPool + +Usually there is one item pool per document, with a range of valid `WhichId`s +that is specific to the type of document. + +The item pool owns all instances of `SfxPoolItem` or its subclasses that have +ever been added to an item set. It also contains a default item for +every WhichId, which will be (depending on parameters) returned from item +sets if the set does not contain an item at this `WhichId`. + +### SfxItemSet + +The item set can be created with a user-supplied range of `WhichId`s; it +will accept `SfxPoolItems` with matching `WhichId`s and ignore attempts to +insert items with non-matching `WhichId`s. + +Items that are successfully inserted into the set will be stored in the +set's `SfxItemPool`, and for poolable items only a single instance that +compares equal under the predicate `operator==` will be stored in the pool, +regardless of how many sets contain it, thus conserving memory. + +There are members `m_pWhichRanges` for the valid ranges (as pairs of `WhichId`s), +`m_nCount` for the number of items contained, and `m_pItems` for the pointers to +the actual items. -- cgit v1.2.3