[news.eclipse.modeling.gmf] Layout issue with Polygon in Composite Figur

[Christian Muth <c.muth@xxxxxx>]

Hi all,



my goal (one of many actually) with GMF is to create the following
figure:


                 |
                 |   Root connection going into the decision figure.
                 |
                 |
                 V
+------------------------------------+
|                /\                  | The outer Rectangle is
|               /  \                 | fill=false, outline=false
|       _______/    \_______         |
|      |       \    /       |        | The Rhomb shall be placed
|      |        \  /        |        | centered, top inside the outer
|      |         \/         |        | rectangle. So it looks like
|      |                    |        | the root connection above
|      |                    |        | connects to it although it
|      |                    |        | connects to the outer rectangle
+------|--------------------|--------+ instead.
|      |                    |        |
|      |                    |        | This is a non-collapsible
|      V                    V        | compartment, the rectangles
| +---------+          +---------+   | are seperate nodes which in
| | Label   |          |         |   | turn contain a label and
| |---------|          |         |   | collapsible compartments
| |         |          |         |   | hosting other nodes as well
| | Compart-|          |         |   | (sort of activity modelling)
| |  ment   |          |         |   |
| +---------+          +---------+   |
|      |                    |        |
+------|--------------------|--------+
       |                    |
       V                    V
    ============================       This is kind of sync line from
                  |                    activity diagramming.
                  |
                  V
                 END



But I am already stuck at the very beginning:
I tried to adapt the procedure in: 
http://wiki.eclipse.org/GMF_Tutorial_Part_3#Composite_Figures
and also followed the hint working around: 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=142010
(setting myUseLocalCoordinates=true in generated
...edit.parts.ResourceEditPart$ResourceFigure class)

But the generated diagram editor doesn't center a polygon inside the 
outer rectangle while it does center an ellipse or rectangle.

If i create a .gmfgraph containing the following figure descriptor:

    <descriptors
        name="ResourceFigure">
      <actualFigure
          xsi:type="gmfgraph:Rectangle"
          name="ResourceFigure"
          outline="false"
          fill="false">
        <layout
            xsi:type="gmfgraph:StackLayout"/>
        <children
            xsi:type="gmfgraph:Rectangle"
            name="Inner"
            outline="false"
            fill="false">
          <layout
              xsi:type="gmfgraph:GridLayout"
              equalWidth="false"/>
          <children
              xsi:type="gmfgraph:Ellipse"
              name="DecisionRhomb">
            <layoutData
                xsi:type="gmfgraph:GridLayoutData"
                verticalAlignment="BEGINNING"/>
            <backgroundColor
                xsi:type="gmfgraph:ConstantColor"
                value="gray"/>
            <size
                x="25"
                y="25"/>
          </children>
          <children
              xsi:type="gmfgraph:Rectangle"
              name="Body">
            <layoutData
                xsi:type="gmfgraph:GridLayoutData"
                grabExcessHorizontalSpace="true"
                grabExcessVerticalSpace="true"
                verticalAlignment="FILL"
                horizontalAlignment="FILL"/>
            <backgroundColor
                xsi:type="gmfgraph:ConstantColor"
                value="gray"/>
            <size
                x="120"
                y="200"/>
          </children>
        </children>
      </actualFigure>
    </descriptors>

It looks exactly like it should, the ellipse "DecisionRhomb" placed 
centered above the "Body" rectangle which expands to its parent's 
horizontal and vertical dimensions.

But if i chance the ellipse to a polygon in .gmfgraph:

    <descriptors
        name="ResourceFigure">
      <actualFigure
          xsi:type="gmfgraph:Rectangle"
          name="ResourceFigure"
          outline="false"
          fill="false">
        <layout
            xsi:type="gmfgraph:StackLayout"/>
        <children
            xsi:type="gmfgraph:Rectangle"
            name="Inner"
            outline="false"
            fill="false">
          <layout
              xsi:type="gmfgraph:GridLayout"
              equalWidth="false"/>
          <foregroundColor
              xsi:type="gmfgraph:ConstantColor"
              value="gray"/>
          <children
              xsi:type="gmfgraph:Polygon"
              name="DecisionRhomb">
            <layoutData
                xsi:type="gmfgraph:GridLayoutData"
                verticalAlignment="BEGINNING"/>
	        <template
	            x="20"/>
	        <template
	            x="40"
	            y="20"/>
	        <template
	            x="20"
	            y="40"/>
	        <template
	            y="20"/>
          </children>
          <children
              xsi:type="gmfgraph:Rectangle"
              name="Body">
            <layoutData
                xsi:type="gmfgraph:GridLayoutData"
                grabExcessHorizontalSpace="true"
                grabExcessVerticalSpace="true"
                verticalAlignment="FILL"
                horizontalAlignment="FILL"/>
            <backgroundColor
                xsi:type="gmfgraph:ConstantColor"
                value="gray"/>
            <size
                x="120"
                y="200"/>
          </children>
        </children>
      </actualFigure>
    </descriptors>


I either don't see the rhomb at all (myUseLocalCoordinates=false) or
top left with myUseLocalCoordinates=true.

How can the rhomb be aligned like the ellipse? Do i have to make a 
custom rhomb shape?



Thanks a lot in advance,

Christian