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Diffstat (limited to 'doc/dw-miscellaneous.doc')
| -rw-r--r-- | doc/dw-miscellaneous.doc | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/doc/dw-miscellaneous.doc b/doc/dw-miscellaneous.doc index a19b1fd6..596f4ce5 100644 --- a/doc/dw-miscellaneous.doc +++ b/doc/dw-miscellaneous.doc @@ -12,10 +12,35 @@ Widget allocation outside of parent allocation A widget allocation outside of the allocation of the parent is allowed, but the part outside is not visible. +Which widgets may be drawn? +------------------- + +All drawing starts with the toplevel widget +(cf. dw::core::Widget::queueDrawArea, dw::core::Layout::queueDraw, and +dw::core::Layout::expose), and a widget has to draw its children, in a +way consistent with their stacking order. + +There are two exceptions: + +1. Direct descendants, which are not children, may be drawn, if the + parent can distinguish them and so omit drawing them a second + time. See dw::core::StackingContextMgr and \ref dw-stacking-context. + Parents should not draw children in flow for which + dw::core::StackingContextMgr::handledByStackingContextMgr returns + true. +2. Interrupted drawing: via dw::core::Widget::drawInterruption; see + \ref dw-interrupted-drawing. + +Similar rules apply to handling mouse events +(dw::core::Widget::getWidgetAtPoint). + Interrupted drawing ------------------- \ref dw-interrupted-drawing. +Similar rules apply to handling mouse events +(dw::core::Widget::getWidgetAtPoint). + Floats ====== |