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How add restriction to add a new component [message #901832]

Tue, 14 August 2012 13:37

Eclipse User

Hi,
I made a new component extending a SashForm, just to start to work with toolkit and window builder. My component just make a new SashForm, but it always do a HORIZONTAL style in the constructor. The component is working!
Now, I want to do some validations when the user try to add a new component in my "SashForm".
How I do that? When the user is trying to add a new component, in the icon of the mouse stay a green or red icon, how can I intercept this?

[]'s

Re: How add restriction to add a new component [message #901838 is a reply to message #901832]

Tue, 14 August 2012 14:02

Eclipse User

SashForm is done as "flow container".

		<!-- flow container -->
		<parameter name="flowContainer">true</parameter>
		<parameter name="flowContainer.horizontal">isHorizontal()</parameter>
		<parameter name="flowContainer.component">org.eclipse.swt.widgets.Control</parameter>

So, your component description file (*.wbp-component.xml) could provide "component-validator" to check component better than just "component" (which checks just type).

There are examples of this in org.eclipse.wb.rcp plugin.

Re: How add restriction to add a new component [message #901839 is a reply to message #901838]

Tue, 14 August 2012 14:14

Eclipse User

Hi Konstantin,

I do this implementation just to test:

<parameter name="flowContainer.component-validator">false</parameter>

If I understand what you say, it will always return false and I could't add a new component to my "SashForm".
But doesn't work... I don't understand what you say, or I implemented wrong?


<parameters>
<parameter name="layout.has">false</parameter>

<parameter name="shouldDrawBorder">true</parameter>

<parameter name="flowContainer">true</parameter>
<parameter name="flowContainer.horizontal">isHorizontal()</parameter>
<parameter name="flowContainer.component">org.eclipse.swt.widgets.Control</parameter>
<parameter name="flowContainer.component-validator">false</parameter>
</parameters>

Thanks!

Re: How add restriction to add a new component [message #901841 is a reply to message #901839]

Tue, 14 August 2012 14:21

Eclipse User

Where do you place this text?
It should be in same package as component, in the file with the same name, but with extension *.wbp-component.xml instead of Java.

Re: How add restriction to add a new component [message #901843 is a reply to message #901841]

Tue, 14 August 2012 14:26

Eclipse User

Sorry...I make a mistake, and it's working!!

Thank you..

just one more question, there is a way to I do this restriction in the object that I'm adding?

For example, a item menu just can be added in a menu..is the same parameter?

And, there is any place that have a complete documentation about all the parameters that could I use in de *.wbp-component.xml?

Re: How add restriction to add a new component [message #901845 is a reply to message #901843]

Tue, 14 August 2012 14:35

Eclipse User

Konstatin,

How can I call a method of my class to validate this?
<parameter name="flowContainer.component-validator">canAdd()</parameter>

I do that, but this generate this error in console:

[Error: unable to access property (null parent): canAdd]

Re: How add restriction to add a new component [message #901846 is a reply to message #901843]

Tue, 14 August 2012 14:36

Eclipse User

These are advanced topics, they are not covered by any documentation.
There is some internal documentation (also may be not 100% complete, but most things are covered) for *.wbp-component.xml files
http://dev.eclipse.org/svnroot/tools/org.eclipse.windowbuilder/trunk/org.eclipse.wb.core/development_doc/
You need Designer_2.0_descriptions.pdf

See
org.eclipse.wb.core.gef.policy.validator.LayoutRequestValidators.mixWithMandatory(ILayoutRequestValidator)
org.eclipse.wb.core.gef.policy.validator.CompatibleLayoutRequestValidator.areCompatible(EditPart, Object)
org.eclipse.wb.core.gef.policy.validator.CompatibleLayoutRequestValidator.childAgreeToBeDroppedOnParent(Object, Object)

i.e. "GEF.requestValidator.child" is *.wbp-component.xml
For example

		<!-- GEF validators -->
		<parameter name="GEF.requestValidator.child"><![CDATA[
			def existChildrenByType(type) {
			  foreach(child : parent.getChildren()){
			    if(isComponentType(child,type)){
			      return true;
			    }
			  }
			  return false;
			}
			existChildrenByType("org.eclipse.jface.viewers.Viewer")
			]]></parameter>
	</parameters>

[Updated on: Tue, 14 August 2012 14:37] by Moderator

Re: How add restriction to add a new component [message #901848 is a reply to message #901845]

Tue, 14 August 2012 14:39

Eclipse User

You have "parent" and "child" variables in these scripts.
Probably you need "child.canAdd()" in this case.

Arthur Fücher wrote on Tue, 14 August 2012 14:35

Konstatin,

How can I call a method of my class to validate this?
<parameter name="flowContainer.component-validator">canAdd()</parameter>

I do that, but this generate this error in console:

[Error: unable to access property (null parent): canAdd]

Re: How add restriction to add a new component [message #901851 is a reply to message #901848]

Tue, 14 August 2012 14:48

Eclipse User

I used child and return this in the console:
[Error: could not access: child; in class: null]

in my class I do this:
public boolean canAdd(){
return false;
}

This method I need to create in the class or in the Info class?

Re: How add restriction to add a new component [message #901854 is a reply to message #901851]

Tue, 14 August 2012 15:00

Eclipse User

Ah... Yes, this method should be in the Info class.
And at the time of creation infoInstance.getObject() will return null.
So, you can not call method of the class.
But if you create it and you provided *.wbp-component.xml for it, you could set parameters for creation to check if this creation is valid to be added to the container.

Re: How add restriction to add a new component [message #901859 is a reply to message #901854]

Tue, 14 August 2012 15:12

Eclipse User

Ok,

To explain what I'm doing: I have 2 classes extends SashForm: HorizontalBox and VertivalBox. To start, I want to allow the user just add a Horizontal in a Vertical, and a Vertical in a Horizontal...
For this I do this implementation:
<parameter name="flowContainer.component-validator"><![CDATA[!isComponentType('com.test.fw.wb.mvc.core.HorizontalBox')]]>

But I want to do more...I want to allow the user just add 2 children for each "Box", to do this I need to access a method...right? Or can I do it otherwise?

Re: How add restriction to add a new component [message #901862 is a reply to message #901859]

Tue, 14 August 2012 15:22

Eclipse User

If you want to limit number of children, this is actually "component-validator", not "GEF.requestValidator.child", because this is parent imposed limitation, not children.
And parent is actually always accessible, both Info and its toolkit Object.
Here is part of Nebula CompositeTable.

<parameter name="flowContainer.component-validator"><![CDATA[ReflectionUtils.getFullyQualifiedName(component.description.componentClass,false) == 'org.eclipse.swt.widgets.Composite' && container.getChildren().size() < 2]]></parameter>

So, something like "container.getChildren().size() < 2" could work.
Only trick is if we move same component inside, we should not include moving component into these "2" components.
But again, if this is creation, then "component.object === null", i.e. we don't have object yet.

Note that for flow containers "container" and "component" variables are available.
Not "parent" and "child".

Also, "ReflectionUtils.getFullyQualifiedName" is not the best way to check type.

[Updated on: Tue, 14 August 2012 15:23] by Moderator

Re: How add restriction to add a new component [message #901870 is a reply to message #901862]

Tue, 14 August 2012 16:50

Eclipse User

I do what you say, and it's is working, but when I'm adding the second component into the Box the component-validator allows because I have only one. But, the validation is called one more time in:
FlowContainerLayoutEditPolicy [line: 58] - decorateChild(EditPart)
(m_container.validateComponent(child.getModel()))

This time, it's not more valid because I have 2 childrens, and they don't install my SelectionEditPolicy.

The parameter in *.wbp-component.xml is like this:
<parameter name="flowContainer.component-validator"><![CDATA[
!isComponentType('com.test.fw.wb.mvc.core.HorizontalBox') && container.getChildren().size() < 2]]>
</parameter>

I'm doing something wrong? Or missing something?

[Updated on: Tue, 14 August 2012 16:51] by Moderator

Re: How add restriction to add a new component [message #901874 is a reply to message #901870]

Tue, 14 August 2012 17:00

Eclipse User

Ah... You could check in "component-validator" if component is already child of container.
This will solve two problems at once - move component inside of container and decorateChild().

Re: How add restriction to add a new component [message #901878 is a reply to message #901874]

Tue, 14 August 2012 17:14

Eclipse User

I try to do this, using component.parent() == container, but it cause this error:
unable to resolve method: org.eclipse.wb.internal.swt.model.widgets.ButtonInfo.parent() [arglength=0]

It's wrong this method? Or it's the problem that the object in the first time we don't have the object?

*I'm trying to add a button!

Re: How add restriction to add a new component [message #901879 is a reply to message #901878]

Tue, 14 August 2012 17:15

Eclipse User

Use property access "component.parent" or method call "component.getParent()", but not combination of them Smile

BTW, "component" and "container" are Info instances, not toolkit objects.
So, they exist always.

[Updated on: Tue, 14 August 2012 17:16] by Moderator

Re: How add restriction to add a new component [message #901976 is a reply to message #901879]

Wed, 15 August 2012 07:38

Eclipse User

Thanks Konstatin for help me!

Now it's working, and I will continue in my project...

[]'s

Re: How add restriction to add a new component [message #902008 is a reply to message #901976]

Wed, 15 August 2012 09:21

Eclipse User

Another question...

When I need to do a restriction in "SashForm" I've used flowContainer.component-validator because as you say 'SashForm is done as "flow container"'.. but if I need to do a restriction in a class that extend for example "Shell", how can I know what I need to use in the place of flow container?

Re: How add restriction to add a new component [message #902032 is a reply to message #902008]

Wed, 15 August 2012 11:06

Eclipse User

Each container has LayoutEditPolicy, which decides which components to accept, how to show feedback and what command to execute to add/move component.
"Flow container" means just special kind of LayoutEditPolicy which is description-driven, uses information specified in *.wbp-component.xml files, so users can easily configure such often cases.
Some LayoutEditPolicy implementations are very specific, for example for GridLayout or BorderLayout.
So, if you have specific Layout manager, you may be will need to create plugin with LayoutEditPolicy.

But may be "GEF.requestValidator.parent" parameter can be used for your task.

Re: How add restriction to add a new component [message #902053 is a reply to message #902032]

Wed, 15 August 2012 12:30

Eclipse User

Hmm...ok!

If I have a Shell with a FillLayout, the restriction need to stay on...?FillLayout or Shell?

I think that is FillLayout, but I can't extend it to do create the "MyFillLayout.wbp-component.xml"...it's right?

Re: How add restriction to add a new component [message #902057 is a reply to message #902053]

Wed, 15 August 2012 12:55

Eclipse User

You can not restrict anything if you are not involved.
I.e. you will need your Shell subclass, FillLayout subclass or component subclass.
Not all listed classes can be subclassed, restrictions apply, etc Smile

Re: How add restriction to add a new component [message #902058 is a reply to message #902057]

Wed, 15 August 2012 12:58

Eclipse User

Ok, but FillLayout is a final class and I can't extend it... So, can I create "MyFillLayout" based on the FillLayout.java ?

Re: How add restriction to add a new component [message #902061 is a reply to message #902058]

Wed, 15 August 2012 13:17

Eclipse User

So, you can not.

Re: How add restriction to add a new component [message #902064 is a reply to message #902061]

Wed, 15 August 2012 13:35

Eclipse User