19.3.1.45 spTree

This element specifies all shape-based objects, either grouped or not, that can be referenced on a given slide. As most objects within a slide are shapes, this represents the majority of content within a slide. Text and effects are attached to shapes that are contained within the spTree element.

[Example: Consider the following PresentationML slide

<p:sld>
  <p:cSld>
    <p:spTree>
      <p:nvGrpSpPr>
        …
      </p:nvGrpSpPr>
      <p:grpSpPr>
        …
      </p:grpSpPr>
      <p:sp>
        …
      </p:sp>
    </p:spTree>
  </p:cSld>
  …
</p:sld>

In the above example the shape tree specifies all the shape properties for this slide. end example]

Each shape-based object within the shape tree, whether grouped or not, shall represent one unique level of z- ordering on the slide. The z-order for each shape-based object shall be determined by the lexical ordering of each shape-based object within the shape tree: the first shape-based object shall have the lowest z-order, while the last shape-based object shall have the highest z-order.

The z-ordering of shape-based objects within the shape tree shall also determine the navigation (tab) order of the shape-based objects: the shape-based object with the lowest z-order (the first shape in lexical order) shall be first in navigation order, with objects being navigated in ascending z-order.

[Example: Consider the following PresentationML slide with two shapes

<p:sld>
  <p:cSld>
    <p:spTree>
      …
      <p:sp>
        <p:nvSpPr>
          <p:cNvPr id="5" name="Oval 4" />
          …
        </p:nvSpPr>
        …
      </p:sp>
      <p:sp>
        <p:nvSpPr>
          <p:cNvPr id="4" name="Isosceles Triangle 3" />
          …
        </p:nvSpPr>
        …
      </p:sp>
    </p:spTree>
  </p:cSld>
  …
</p:sld>

In the above example the shape with name Oval 4 has the lowest z-order value since that shape is the first shape in the shape tree. Oval 4 is also the first shape in navigation order. The shape with name Isosceles Triangle 3 has the highest z positioning value since that shape is the last shape in the shape tree. Isosceles Triangle 3 is also the last shape in navigation order. end example]

[Note: The W3C XML Schema definition of this element’s content model (CT_GroupShape) is located in A.3. end note]