summaryrefslogtreecommitdiff
path: root/oox/README.md
diff options
context:
space:
mode:
Diffstat (limited to 'oox/README.md')
-rw-r--r--oox/README.md185
1 files changed, 185 insertions, 0 deletions
diff --git a/oox/README.md b/oox/README.md
new file mode 100644
index 000000000000..6c459f58c92a
--- /dev/null
+++ b/oox/README.md
@@ -0,0 +1,185 @@
+Support for Office Open XML, the office XML-format designed by Microsoft.
+
+
+== DrawingML Custom shapes and presets ==
+
+Custom shapes are part of DrawingML and are different to binary ppt
+and VML in older formats.
+The import happens in oox/source/drawingml, where they are
+imported as LO's enhanced custom shape's. see
+offapi/com/sun/star/drawing/CustomShape.idl and
+offapi/com/sun/star/drawing/EnhancedCustomShape*.idl
+Check CustomShapeProperties::pushToPropSet() and see
+how custom shape properties are converted.
+
+Preset shapes are custom shapes whose guides and handles
+have been defined in OOXML specification. By specifying
+preset type and the adjustment values, the reset can
+be taken from the shape definition.
+
+example of drawingml preset:
+
+ <a:prstGeom prst="star5">
+ <a:avLst/>
+ </a:prstGeom>
+
+example of drawingml custom shape (equal to star5 preset):
+
+ <avLst xmlns="http://schemas.openxmlformats.org/drawingml/2006/main">
+ <gd name="adj" fmla="val 19098" />
+ <gd name="hf" fmla="val 105146" />
+ <gd name="vf" fmla="val 110557" />
+ </avLst>
+ <gdLst xmlns="http://schemas.openxmlformats.org/drawingml/2006/main">
+ <gd name="a" fmla="pin 0 adj 50000" />
+ <gd name="swd2" fmla="*/ wd2 hf 100000" />
+ <gd name="shd2" fmla="*/ hd2 vf 100000" />
+ <gd name="svc" fmla="*/ vc vf 100000" />
+ <gd name="dx1" fmla="cos swd2 1080000" />
+ <gd name="dx2" fmla="cos swd2 18360000" />
+ <gd name="dy1" fmla="sin shd2 1080000" />
+ <gd name="dy2" fmla="sin shd2 18360000" />
+ <gd name="x1" fmla="+- hc 0 dx1" />
+ <gd name="x2" fmla="+- hc 0 dx2" />
+ <gd name="x3" fmla="+- hc dx2 0" />
+ <gd name="x4" fmla="+- hc dx1 0" />
+ <gd name="y1" fmla="+- svc 0 dy1" />
+ <gd name="y2" fmla="+- svc 0 dy2" />
+ <gd name="iwd2" fmla="*/ swd2 a 50000" />
+ <gd name="ihd2" fmla="*/ shd2 a 50000" />
+ <gd name="sdx1" fmla="cos iwd2 20520000" />
+ <gd name="sdx2" fmla="cos iwd2 3240000" />
+ <gd name="sdy1" fmla="sin ihd2 3240000" />
+ <gd name="sdy2" fmla="sin ihd2 20520000" />
+ <gd name="sx1" fmla="+- hc 0 sdx1" />
+ <gd name="sx2" fmla="+- hc 0 sdx2" />
+ <gd name="sx3" fmla="+- hc sdx2 0" />
+ <gd name="sx4" fmla="+- hc sdx1 0" />
+ <gd name="sy1" fmla="+- svc 0 sdy1" />
+ <gd name="sy2" fmla="+- svc 0 sdy2" />
+ <gd name="sy3" fmla="+- svc ihd2 0" />
+ <gd name="yAdj" fmla="+- svc 0 ihd2" />
+ </gdLst>
+ <ahLst xmlns="http://schemas.openxmlformats.org/drawingml/2006/main">
+ <ahXY gdRefY="adj" minY="0" maxY="50000">
+ <pos x="hc" y="yAdj" />
+ </ahXY>
+ </ahLst>
+ <cxnLst xmlns="http://schemas.openxmlformats.org/drawingml/2006/main">
+ <cxn ang="3cd4">
+ <pos x="hc" y="t" />
+ </cxn>
+ <cxn ang="cd2">
+ <pos x="x1" y="y1" />
+ </cxn>
+ <cxn ang="cd4">
+ <pos x="x2" y="y2" />
+ </cxn>
+ <cxn ang="cd4">
+ <pos x="x3" y="y2" />
+ </cxn>
+ <cxn ang="0">
+ <pos x="x4" y="y1" />
+ </cxn>
+ </cxnLst>
+ <rect l="sx1" t="sy1" r="sx4" b="sy3" xmlns="http://schemas.openxmlformats.org/drawingml/2006/main" />
+ <pathLst xmlns="http://schemas.openxmlformats.org/drawingml/2006/main">
+ <path>
+ <moveTo>
+ <pt x="x1" y="y1" />
+ </moveTo>
+ <lnTo>
+ <pt x="sx2" y="sy1" />
+ </lnTo>
+ <lnTo>
+ <pt x="hc" y="t" />
+ </lnTo>
+ <lnTo>
+ <pt x="sx3" y="sy1" />
+ </lnTo>
+ <lnTo>
+ <pt x="x4" y="y1" />
+ </lnTo>
+ <lnTo>
+ <pt x="sx4" y="sy2" />
+ </lnTo>
+ <lnTo>
+ <pt x="x3" y="y2" />
+ </lnTo>
+ <lnTo>
+ <pt x="hc" y="sy3" />
+ </lnTo>
+ <lnTo>
+ <pt x="x2" y="y2" />
+ </lnTo>
+ <lnTo>
+ <pt x="sx1" y="sy2" />
+ </lnTo>
+ <close />
+ </path>
+ </pathLst>
+
+we needed to extend our custom shapes for missing features and so 5
+new segment commands were added. G command for arcto drawingml record
+and H I J K commands for darken, darkenless, lighten, lightenless
+records. the commands are save into ODF in special namespace drawooo,
+which is extension not yet in the standard. Thorsten suggested to put
+it in such a namespace and keep original (incomplete) geometry for
+backward compatibility, before we can extend the ODF. that's why you
+will see 2 of them in cases where some of the new commands was
+needed.
+
+In order to convert preset shapes to LO's enhanced custom shape,
+we need to load shape definition of preset shapes. The procedure
+to convert the definition from OOXML spec for LO is documented
+( also a script ) in oox/source/drawingml/customshapes/README.
+The scripts in oox/source/drawingml/customshapes/ also generate pptx
+files for single presets and also for all presets
+cshape-all.pptx. The cshape-all.pptx file is then loaded into Impress
+build with debug enabled in oox and the command line output contains
+information. The generated definition is oox-drawingml-cs-presets.
+
+Check CustomShapeProperties::initializePresetDataMap() to see how
+generated presets data are loaded into LO.
+While importing presets, we prefix the name with "ooxml-" so
+that we can detect it on export as save it again as preset.
+
+The generated pptx files
+can be used when debugging bugs in custom shapes import/export. also
+the cshape-all.pptx can be used to test the round trips. there's small
+problem with these pptx as they cannot be imported into powerpoint,
+but that can be fixed quickly. when fixed, we can use it to
+test powerpoint odp export and see how complete it is regarding
+custom shapes. OpenXML SDK tools might help when fixing
+cshape-all.pptx
+http://www.microsoft.com/en-us/download/details.aspx?id=30425
+
+== Export ==
+Here is how LO's enhanced custom shapes are exported:
+* Shape name is ooxml-* - they are imported from ooxml, export as is.
+* Denylist - ODF presets that has OOXML equivalent.
+ We convert adjustment values case by case. Microsoft Office
+ is rather strict about adjustment values, either none of them
+ are provided so that default values are taken, or the exact set
+ of handles have to be provided. In some cases we are converting
+ from the preset with less handles to the one with more handles
+ so that default values suitable for the odf one need to be
+ provided.
+* Allowlist - ODF presets that has OOXML equivalent but looks a bit
+different, export them as PolyPolygon.
+
+Check Andras Timar's presentation[1] and ShapeExport::WriteCustomShape()
+for further detail.
+
+FUTURE WORK: because we have to make sure that all the roundtrips
+like PPTX --> ODP --> PPTX work correctly and doesn't lose data.
+the only problematic part is probably saving custom shapes (ie. not
+presets) to PPTX. that part of code predates work on custom shapes
+and is unable to export general custom shapes yet. It will need a bit
+of work as LO has more complex equations than DrawingML. other parts
+should work OK, PPTX --> ODP should work and don't lose any
+data. presets should already survive PPTX --> ODP --> PPTX roundtrip
+
+[1]https://archive.fosdem.org/2016/schedule/event/drawingml/attachments/
+slides/1184/export/events/attachments/drawingml/slides/1184/
+andras_timar_fosdem_2016.pdf