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Diffstat (limited to 'doc/dw-size-request-pos.doc')
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diff --git a/doc/dw-size-request-pos.doc b/doc/dw-size-request-pos.doc deleted file mode 100644 index 08af0eec..00000000 --- a/doc/dw-size-request-pos.doc +++ /dev/null @@ -1,73 +0,0 @@ -/** \page dw-size-request-pos Size requisitions depending on positions - -<div style="border: 2px solid #ffff00; margin: 1em 0; - padding: 0.5em 1em; background-color: #ffffe0">The complex "widget - sizes" is currently divided into three documents: \ref - dw-widget-sizes, \ref dw-grows, and **Size requisitions depending on - positions** (this document). </div> - -Motivation -========== - -As described in \ref dw-out-of-flow (*The sizeRequest/sizeAllocate -problem*), the principle that the size of a widget depends only on the -sizes of its children causes some problems with floats; the current -solution is a frequent correction by calling -dw::core::Widget::queueResize. In this document, an alternative -approach is presented. - - -General Idea -============ - -A widget size may depend on the position relative to an anchestor -widget. If a widget wants to get the size of a child widget, it should - -1. call the new method dw::core::Widget::sizeRequestReference, - which returns NULL, when the child's size does not depend on the - position, or a widget relative to which the child's position must - be calculated; -2. call dw::core::Widget::sizeRequest with the position relative to - this widget. - -The position passed to dw::core::Widget::sizeRequest must be the -position at which this child will be allocated. - -There are situations where the parent widget is unable to determine -this position before the size is known. An example: a textblock widget -cannot determine the position of an inline widget (like an image, or -an inline block) before the line is finished; on the other hand, -finishing the line depends on knowing the sizes of the inline widgets. - -This may result in a conflict, when the size of an inline widgets -depends on the position. Fortunately, this is not the case in dillo: -the only widget whose size depends on the position is dw::Textblock -(the size will depend on the position within its floats container); but -an inline blocks constitute its own floats container, so that there is -no dependance on a position within another widget. - -Generally, this case should be handled by providing a fallback -strategy. (TODO: How does this look like? The widget is forced to -calculate its size independant of the position?) - -Resizing --------- -Currently, the size of a widget has to be recalculated, when - -1. it has called dw::core::Widget::queueResize, or -2. the size of a child widget has to be recalculated. - -Since for this new approach, the size does not only depend on the size -of the children, the second condition must be modified. However, -regarding changes of the position is not sufficient. Consider this -example, where a float size changes as soon as the image is loaded: - -\image html dw-size-request-pos-01.png - -The second paragraph ("A longer paragraph" ...) stays at the same -position, both absolute and relative to the float container, but has -to be rewrapped because of the float. - -(TODO: A detailed design is yet to de developed.) - -*/
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