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--- spec:css3-grid-layout [2011/11/01 08:39] – created mmielke
+++ spec:css3-grid-layout [2012/05/15 13:42] – [Issues for F2F] fantasai
@@ Line 9: / Line 9: @@
 Link to current Editor's draft: [[http://dev.w3.org/csswg/css3-grid-align/]]
+===== Issues for Hamburg F2F =====
+=== Scoping ===
+  - Scoping of Grid Layout and Template Layout specs
+  - Drop named lines from this level of Grid Layout
+  - Adopting column-gap etc., adding row equivalents, to handle gutters
+=== Naming ===
+  - grid-flow: row | column | layer
+  - rename grid-rows --> grid-row-tracks, grid-columns --> grid-column-tracks
+  - auto/fit-content becomes fit-content
+  - grid positioning properties:
+^  //grid-area//  ^  grid-column  ^  grid-row  |
+^  grid-position  |  grid-column-position  |  grid-row-position  |
+^  grid-span  |  grid-column-span  |  grid-row-span  |
+=
+^  //C R ΔC ΔR//  ^  C ΔC  ^  R ΔR  |
+^  C R  |  C  |  R  |
+^  ΔC ΔR  |  ΔC  |  ΔR  |
+=== Default handling of content ===
+  - auto-placement is progressive pack w/ pointer @ start before corner
+  - auto-placement vs. anonymous block
+  - default value of grid-flow?
+  - using "display: grid" vs implied grid lines
+  - default track sizing is an open issue, if you have ideas let us know
 ===== Action Items =====
@@ Line 14: / Line 47: @@
 ===== Issues =====
 ==== Issue 1:  ====
+Grid-layer vs. z-index property for Grid
+== Summary: ==
+Grid-layer is currently used to control the stacking of grid items in a grid element; one example of this that is mentioned in the current Editor's Draft would be using Grid to build a range control where the "thumb" of the control is displayed on top of the underlying track. However, grid-layer is in many ways similar to the existing z-index property. Is a separate property needed, or can z-index replace the grid-layer property?
+We have three primary goals w/r/t stacking Grid Items:
+  - Grid Items draw atomically.  Like positioned elements, Grid has among its primary scenarios the ability to overlap and layer its items (see section 2.4 Grid Layering of Elements).  To avoid a counter-intuitive interleaving of backgrounds, floats, and inline content, Grid Items should form a new stacking context.
+  - Grid Items are in front of the Grid Element, even when the Grid Item is given a negative z-index.  Imagine an author using a tool, right-clicking an item and choosing "send to back" from a context menu.  The tool should set a negative z-index on the Grid Item and not have the Grid Item disappear behind the background of the Grid Element.  Also, if a nested Grid is given a positive z-index, it should not cover its Grid Items.  Therefore we need the Grid Element to serve as a stacking context for its Grid Items.
+  - We want to avoid impacting any positioning scenarios.  It would be unexpected if the author inadvertently changed the containing block or the stacking context for a positioned descendant just by inserting a Grid layout in its ancestry.
+== Proposal: ==
+Z-index should be used to replace the grid-layer property (i.e. z-index applies to statically-positioned Grid Items.) Specifically, in cases where Grid Items overlap, z-index provides control over the drawing order of Grid Items. Both Grid elements and Grid Items generate a stacking context as described for floats (step 5, section 14) in the [[http://www.w3.org/TR/2007/WD-css3-box-20070809/#stacking|CSS3 Box Model]].
+Note also that using z-index in place of grid-layer has been [[http://lists.w3.org/Archives/Public/www-style/2011May/0344.html|previously discussed]] on the www-styling mailing list.
+==== Issue 2:  ====
+Fractional-track sizing algorithm update
+== Summary: ==
+The grid-sizing algorithm introduced in the previous [[http://dev.w3.org/csswg/css3-grid-align|Editor's Draft]] did not define the expected behavior for sizing a fractionally-sized track (e.g. 1fr, 2fr,...) when a Grid Element was shrink-to-fit. This should be addressed so that future implementations of Grid Layout behave predictably across platforms.
+== Proposal: ==
+We propose to modify the existing grid sizing algorithm as follows: if the Grid Element is shrink-to-fit, then we set the size of a fractional track (i.e. determine the size of a '1fr' track) by making sure that 1) the proportions of all fractional tracks are preserved (e.g. a '1fr' track is half the size of a '2fr' track) and 2) fractional tracks are large enough contain all Grid Items that span them. If the Grid Element is not shrink-to-fit, then the algorithm follows its current path. The specific algorithm updates can be found in step 6 of the updated Editor's Draft.