diff options
| -rw-r--r-- | doc/dw-out-of-flow.doc | 137 | ||||
| -rw-r--r-- | doc/dw-widget-sizes.doc | 6 |
2 files changed, 77 insertions, 66 deletions
diff --git a/doc/dw-out-of-flow.doc b/doc/dw-out-of-flow.doc index 88dd4d72..9a43a178 100644 --- a/doc/dw-out-of-flow.doc +++ b/doc/dw-out-of-flow.doc @@ -50,6 +50,71 @@ Both in this text and the code, generating and containing block are abbreviated with **GB** and **CB**, respectively. +Implementation overview +======================= + +Widget level +------------ +The terms *generating block* and *containing block* have been raised +to a higher level, the one of dw::core::Widget, and are here called +*generating widget* and *containing widget*. To represent the +distinction, the type of dw::core::Content has been split into three +parts: + +- If a widget is out of flow, the generating widget keeps a reference + with the type dw::core::Content::WIDGET_OOF_REF, while the + containing block refers to it as dw::core::Content::WIDGET_OOF_CONT. +- For widgets within flow, dw::core::Content::WIDGET_IN_FLOW is used. + +Notice that in the first case, there are two pieces of content +referring to the same widget. + +An application of this distinction is iterators. [TODO: more. And +still missing: DeepIterator may need the generating parent widget in +some cases.] + + +Textblock level +--------------- +Both dw::Textblock::notifySetAsTopLevel and +dw::Textblock::notifySetParent set the member +dw::Textblock::containingBlock appropriately, (according to rules +which should be defined in this document). + +Handling widgets out of flow is partly the task of the new class +dw::OutOfFlowMgr, which is stored by dw::Textblock::outOfFlowMgr, but +only for containing blocks. Generating blocks should refer to +*containingBlock->outOfFlowMgr*. (Perhaps dw::OutOfFlowMgr may become +independent of dw::Textblock.) + +dw::Textblock::addWidget is extended, so that floats and absolutely +positioned elements can be added. Notice that not *this* widget, but +the containing block becomes the parent of the newly added child, if +it is out of flow. dw::Textblock::addWidget decides this by calling +dw::OutOfFlowMgr::isOutOfFlow. (See new content types above.) + +dw::core::Widget::parentRef has become a new representation. Before, +it represented the line numer. Now (least signifant bit left): + + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + | line number | 0 | + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + | left float index | 0 | 0 | 1 | + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + | right float index | 1 | 0 | 1 | + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + | absolutely positioned index | 1 | 1 | + +---+ - - - +---+---+- - - - - -+---+---+---+---+ + +Details are hidden by static inline methods of dw::OutOfFlowMgr. + + The sizeRequest/sizeAllocate problem ======================================== @@ -120,73 +185,13 @@ vague idea, perhaps not even feasible, and for which there are no concrete plans, certainly not in \ref dw-grows.) -Implementation overview -======================= - -<div style="border: 2px solid #ff4040; margin-bottom: 0.5em; -padding: 0.5em 1em; background-color: #fff0f0"><b>Warning:</b> -This complete section must be reviewed. Also, integrate \ref -dw-out-of-flow (most probably into this section).</div> - -Widget level ------------- -The terms _generating block_ and _containing block_ have been raised -to a higher level, the one of dw::core::Widget, and are here called -_generating widget_ and _containing widget_. To represent the -distinction, the type of dw::core::Content has been split into three -parts: - -- If a widget is out of flow, the generating widget keeps a reference - with the type dw::core::Content::WIDGET_OOF_REF, while the - containing block refers to it as dw::core::Content::WIDGET_OOF_CONT. - -- For widgets within flow, dw::core::Content::WIDGET_IN_FLOW is used. - -Notice that in the first case, there are two pieces of content -referring to the same widget. - -An application of this distinction is iterators. TODO: more. And still -missing: DeepIterator may need the generating parent widget in some -cases. - - -Textblock level ---------------- -Both dw::Textblock::notifySetAsTopLevel and -dw::Textblock::notifySetParent set the member -dw::Textblock::containingBlock appropriately, (according to rules -which should be defined in this document). - -Handling widgets out of flow is partly the task of the new class -dw::OutOfFlowMgr, which is stored by dw::Textblock::outOfFlowMgr, but -only for containing blocks. Generating blocks should refer to -_containingBlock->outOfFlowMgr_. (Perhaps dw::OutOfFlowMgr may become -independent of dw::Textblock.) - -dw::Textblock::addWidget is extended, so that floats and absolutely -positioned elements can be added. Notice that not this widget, but the -containing block becomes the parent of the newly added child, if it is -out of flow. dw::Textblock::addWidget decides this by calling -dw::OutOfFlowMgr::isOutOfFlow. (See new content types above.) - -dw::core::Widget::parentRef has become a new representation. Before, -it represented the line numer. Now (least signifant bit left): - - +---+---+- - - - - - - - - - -+---+ - | line number | 0 | - +---+---+- - - - - - - - - - -+---+ - - +---+---+- - - - - - - - -+---+---+ - | number of left float | 0 | 1 | - +---+---+- - - - - - - - -+---+---+ - - +---+---+- - - - - - - - -+---+---+ - | number of right float | 1 | 1 | - +---+---+- - - - - - - - -+---+---+ +Implementation details +====================== -The latter two must be changed, as soom as absolute positions are -introduced. Details are hidden by static inline methods of -dw::OutOfFlowMgr. +- CB and GB lists (general pattern) (see previous section) +- binary search; different search criteria, how they accord +- lastLeftTBIndex, lastRightTBIndex etc. +- limitiation of search; extIndex etc. How *hasRelationChanged* works diff --git a/doc/dw-widget-sizes.doc b/doc/dw-widget-sizes.doc index dcc74bfc..a9b6b00c 100644 --- a/doc/dw-widget-sizes.doc +++ b/doc/dw-widget-sizes.doc @@ -278,4 +278,10 @@ This could be done furthermore: - Is it possible to define exacter rules, along with a proof that no problems (like endless recursion) can occur? + +See also +======== + +- \ref dw-grows + */ |