+ Re-implement fixed positioning using the absolute positioning code.
+ Add reftests for absolute positioning and fixed positioning.
+ Refactor assign_widths in BlockFlow to isolate the calculation of
widths and margins.
+ Pass down details of the Containing Block for absolute and fixed flows
during layout. Use it to calculate the static position of absolute flows.
+ Defer calculation of absolute flow dimensions till we build the
display list.
This implements https://github.com/mozilla/servo/issues/1537 and https://github.com/mozilla/servo/issues/787
This only traverses absolute flows, nothing else.
+ Also, a separate mini-traversal for store overflow.
+ Store descendants with position 'absolute' and 'fixed' in BaseFlow.
+ Bubble up links to absolute and fixed descendants during Flow Construction.
+ Set Rawlink to the CB in absolute descendants.
+ store_overflow() now uses absolute descendants' overflows too.
+ Add reftests for 'absolute' and 'fixed' static y position.
+ Add reftests for overflow (they all fail now).
+ Put absolute flow display items under their CB's ClipDisplayItem.
+ Paint borders in Box_ before the actual box stuff (minor fix in lieu of paint-order).
+ Re-implement fixed positioning using the absolute positioning code.
+ Add reftests for absolute positioning and fixed positioning.
+ Refactor assign_widths in BlockFlow to isolate the calculation of
widths and margins.
+ Pass down details of the Containing Block for absolute and fixed flows
during layout. Use it to calculate the static position of absolute flows.
+ Defer calculation of absolute flow dimensions till we build the
display list.
After applying this patch, on Linux you will need to
../configure
make clean-rust-azure clean-fontconfig clean-rust-fontconfig
Fixes#1752.
Expect Fontconfig warnings and possibly worse breakage, but for me this makes it possible to use parallel layout at all.
