Forms Container

OpenOffice.org Developer's Guide

Forms

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• Models and Views

• The Model-View Paradigm
• Models and Views for Form Controls
• Model-View Interaction
• Form Layer Views

• Form Elements in the Document Model

• A Hierarchy of Models

• FormComponent Service
• FormComponents Service
• Logical Forms
• Forms Container
• Form Control Models

• Control Models and Shapes

• Form Components

• Control Models
• Forms
• HTML Forms

• Data Awareness

• Forms

• Forms as Row Sets
• Loadable Forms
• Sub Forms
• Filtering and Sorting
• Parameters

• Data Aware Controls

• Control Models as Bound Components
• Committing Controls

• External Value Suppliers

• Value Bindings

• Form Controls accepting Value Bindings

• External List Sources

• Validation

• Validation in OpenOffice.org
• Validation and Bindings

• Scripting and Events
• Common Tasks

• Initializing Bound Controls
• Automatic Key Generation
• Data Validation
• Programmatic Assignment of Scripts to Events

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In our model hierarchy, we have inner nodes called the logical forms, and the basic element called the form component. As in every tree, our hierarchy has a root, that is, an instance of the com.sun.star.form.Forms service. This is nothing more than an instance of com.sun.star.form.FormComponents. In fact, the differentiation exists for a non-ambiguous runtime instantiation of a root.

Note that the com.sun.star.form.Forms service does not state that components implementing it are a com.sun.star.form.FormComponent. This means this service acts as a tree root only, as opposed to a com.sun.star.form.Forms that is a container, as well as an element, thus it can be placed anywhere in the tree.

Actually, it is not necessary for external components to instantiate a service directly. Every document has at least one instance of it. A root forms container is tied to a draw page, which is an element of the document model, as well. Refer to com.sun.star.drawing.DrawPage. A page optionally supports the interface com.sun.star.form.XFormsSupplier giving access to the collection. In the current Apache OpenOffice implementation, Writer and Calc documents fully support draw pages supplying forms.

The following example shows how to obtain a root forms collection, if the document model is known which is denoted with s_aDocument.

  /** gets the <type scope="com.sun.star.drawing">DrawPage</type> of our sample document
   */
  public static XDrawPage getDocumentDrawPage() throws java.lang.Exception {
      XDrawPage xReturn;
 
      // in case of a Writer document, this is rather easy: simply ask the XDrawPageSupplier
      XDrawPageSupplier xSuppPage = (XDrawPageSupplier)UnoRuntime.queryInterface(
          XDrawPageSupplier.class, s_aDocument);
      xReturn = xSuppPage.getDrawPage();
      if (null == xReturn) {
          // the model itself is no draw page supplier - then it may be an Impress or Calc
          // (or any other multi-page) document
          XDrawPagesSupplier xSuppPages = (XDrawPagesSupplier)UnoRuntime.queryInterface(
              XDrawPagesSupplier.class, s_aDocument);
          XDrawPages xPages = xSuppPages.getDrawPages();
 
          xReturn = (XdrawPage)UnoRuntime.queryInterface(XDrawPage.class, xPages.getByIndex(0));
 
          // Note that this is not really error-proof code: If the document model does not support the
          // XDrawPagesSupplier interface, or if the pages collection returned is empty, this will break.
      }
 
      return xReturn;
  }
 
  /** retrieves the root of the hierarchy of form components
   */
  public static XNameContainer getFormComponentTreeRoot() throws java.lang.Exception {
      XFormsSupplier xSuppForms = (XFormsSupplier)UnoRuntime.queryInterface(
          XFormsSupplier.class, getDocumentDrawPage());
 
      XNameContainer xFormsCollection = null;
      if (null != xSuppForms) {
          xFormsCollection = xSuppForms.getForms();
      }
      return xFormsCollection;
  }

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