Initial import of Dillo

devdoc/dw-out-of-flow-positioned.doc

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+/** \page dw-out-of-flow-positioned Handling Elements Out Of Flow: Positioned Elements
+
+<div style="border: 2px solid #ffff00; margin: 1em 0; padding: 0.5em
+  1em; background-color: #ffffe0">Positioned elements have been
+  deactivated, during the development of \ref dw-size-request-pos, to
+  focus on floats. See dw::core::IMPL_POS in file dw/core.hh.</div>
+
+
+Miscellaneous notes
+===================
+
+General
+-------
+(See also *relative positions* below.)
+
+What about negative positions?
+
+dw::oof::OutOfFlowMgr::tellPosition1 and
+dw::oof::OutOfFlowMgr::tellPosition2 could be combined again, and
+called in the respective circumstance, depending on
+dw::oof::OutOfFlowMgr::mayAffectBordersAtAll.
+
+Relative positions
+------------------
+**General Overview:** At the original position, a space as large as
+the positioned element is left. This is implemented by assigning a
+size to the widget *reference*. For this there are two new methods:
+dw::oof::OutOfFlowMgr::calcWidgetRefSize and
+dw::oof::OOFAwareWidget::widgetRefSizeChanged.
+
+**Bug:** Since the size of a relatively positioned element should be
+calculated as if it was in flow, the available width should be
+delegated to the *generator*; however, since
+dw::oof::OOFPosRelMgr::dealingWithSizeOfChild returns *false* in all
+cases, it is delegated to the *container*. **Idea for fix:**
+dw::oof::OOFPosRelMgr::dealingWithSizeOfChild should return *false* if
+and only if the generator of the child is the container (to prevent an
+endless recursion). In other cases,
+dw::oof::OOFPosRelMgr::getAvailWidthOfChild and
+dw::oof::OOFPosRelMgr::getAvailHeightOfChild should directly call the
+respective methods of the *generator*, which must be made public then.
+
+**Performance:** In many cases, the first call of
+dw::oof::OOFPosRelMgr::sizeAllocateEnd will queue again the resize
+idle, since some elements are not considered in
+dw::oof::OOFPosRelMgr::getSize. One case could be removed: if a
+positioned element has *left* = *top* = 0, and its total size (the
+requisition) is equal to the space left at the original position, the
+size of the widget *reference*
+(dw::oof::OOFAwareWidget::getRequisitionWithoutOOF, see
+dw::oof::OOFPosRelMgr::calcWidgetRefSize).
+
+**Documentation:** Describe why the latter is not covered by
+dw::oof::OOFPositionedMgr::doChildrenExceedContainer. (Is this really
+the case?)
+
+**Open:** Stacking order? Furthermore: a relatively positioned element
+does not always constitute a containing block (see CSS specification).
+
+Fixed positions
+---------------
+Currently, fixedly positioned elements are positioned relative to the
+canvas, not to the viewport. For a complete implementation, see \ref
+dw-fixed-positions.
+
+*/