Re: [ve-dev] Read/Write of complex LayoutManager values

[Rich Kulp <richkulp@xxxxxxxxxx>]

Hi,

First question can be answered by looking
at org.eclipse.ve.internal.swt.GridLayoutPolicyHelper.getLayoutContainerDimensions().
What we've done is we've put over on the remote vm a class that does all
of the complicated work to find the information and then we call it to
figure out the info. The info is put into fields in the remote vm helper
class and then the calls:

         
      IFieldProxy getColumnWidthsFieldProxy = gridLayoutHelperType.getDeclaredFieldProxy("widths");
//$NON-NLS-1$
         
      IFieldProxy getRowHeightsFieldProxy = gridLayoutHelperType.getDeclaredFieldProxy("heights");
//$NON-NLS-1$
         
      try
{
         
              //
Get the column widths and row heights from the target VM helper
         
              IArrayBeanProxy
arrayProxyColumnWidths = 
         
               
      (IArrayBeanProxy) getColumnWidthsFieldProxy.get(gridLayoutHelperProxy);
are used to get the fields values (which
arrays) back.


Note that we do something called JavaStandardSWTBeanConstants.invokeSyncExec(...).
This is only needed in SWT because all of these functions need to run in
the SWT display thread on the the remote vm. That probably isn't necessary
for your stuff since it is not SWT.

Second question is no. At this time
you can't generate code that calls a non-setter/getter method. That is
because the codegen and the model work off of properties, and that is not
a property. Since it is not a property it would not be recognized on reparsing
from code. 

Third question is you don't need to
use the inverse maintenance adapter to get the constraints. The Panel's
(the parent container) "components" feature points to an intermidiate
object that contains both the constraint and the child. Take a look at
ContainerProxyAdapter.addComponentWithConstraint() method and where it
was called from. It is called with the intermediate object (called a ConstraintComponent).
The constraint components are the true value of the "components"
setting on the parent. From the constraint component there are two other
settings, one is the constraint and the other is the child control.

The call in addComponentWithConstraint:

         
              if
(constraintComponent.eIsSet(sfConstraintConstraint))
{
         
               
      constraintAttributeValue = (IJavaInstance)
constraintComponent.eGet(sfConstraintConstraint);
         
               
      constraintIsSet = true;
         
              }

is how you retrieve the constraint out
of the constraint component. Do a search on where sfConstraintConstraint
is is set to see how to get it.

PS: sfContainerComponents
is the feature for getting the cooresponding child out of the constraint
component.

Thanks,
Rich

Gerald Rosenberg <gerald@xxxxxxxxxx>
Sent by: ve-dev-bounces@xxxxxxxxxxx

06/03/2006 03:54 PM

Please respond to
Discussions people developing code for the Visual Editor project <ve-dev@xxxxxxxxxxx>

To	ve-dev@xxxxxxxxxxx
cc
Subject	[ve-dev] Read/Write of complex LayoutManager values

Thanks for the excellent help... FormLayoutSwitcher is
essentially done.

Now working on a simple FormLayoutPolicyEdit -- I see how to read/write
simple bean properties to the layoutmanager using INumberBeanProxy and
IStringBeanProxy.  However, I need to be able to access a property
with a more complex type: 
public int[][] getColumnGroups() 
and 
public ColumnSpec getColumnSpec(int columnIndex) 
So the first question is: is there an IObjectBeanProxy
or some equivalent?  If not, how do I extract existing layoutmanager
constructor arguments (which is what defines the form of the layout format)?

FormLayout layout = new FormLayout( 
"right:pref, 6dlu, 50dlu, 4dlu",
 // 4 columns 
"pref, 3dlu, pref, 3dlu, pref");
 // 5 rows 
---------------

Second question is: is there a way to invoke a non-bean (is/get/set) based
method on the layoutmanager?  Not essential, but it would be helpful
to be able to use layoutmanager methods of the form: 
public void insertColumn(int columnIndex, ColumnSpec columnSpec)

and 
public void removeColumn(int columnIndex) 
----------------

The final question involves working with existing constraint objects --
I will need to enumerate the components in the container and then inspect
the fields of the corresponding constraint object to extract the current
constraint values.  Something like:

...
List cclist = ...  // accumulator for constraint values 
while (childs.hasNext()) { //
where childs is an interator over the List of container components 
EObject constraintComponent = InverseMaintenanceAdapter.getIntermediateReference((EObject)

getContainerBean(), sfComponents, sfConstraintComponent,
(EObject) childs.next()); 

// this is the unknown part vvvvvv

CellConstraints constraint = ????(constraintComponent);

cclist.add(constraint.gridX); 
cclist.add(constraint.gridY); 
cclist.add(constraint.gridWidth); 
cclist.add(constraint.gridHeight);

}

Explanations and/or pointers to exemplary source in the project would be
appreciated.

Gerald_______________________________________________
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