There are a few different cases where a shape gets to be created.
| a) | When the user creates a shape from the toolbox, a template-based shape is created. It has no private styles but holds a reference to a template that defines the look of the shape. |
| b) | When loading a diagram from a repository, empty shapes are created that do not possess any references and are not workable until the loading is finished. |
| c) | When copying a shape, we need a clone, which is obtained by first creating an empty shape and then taking over the properties from the source shape. |
| d) | When creating a template shape or another self-contained shape not needing a template, the its required styles must be fetched from a style set provider. |
In order to realize these different cases, the Shape class supports the following methods:
| a) | A standard constructor used to create an empty shape. Empty shapes are not functional and must be initialized through one of the initialization functions. |
| b) | A constructor with a style set provider parameter used to create self-contained shapes. |
| c) | Initialization functions for loading a shape from a repository: LoadFields, LoadInnerObjects and additional properties and methods to set required references. |
| d) | An initialization function for copying called CopyFrom. |
| e) | An initialization function for self-contained shapes called: InitializeToDefault. |
However, the application will rarely use these functions directly. Referring to the above cases, it usually will
| a) | Use the ShapeType.CreateInstance method with the template parameter to create a templated shape. The collection of available shape types is provided by the Project instance. |
| b) | Use the repository functions (for example GetDiagram) to create and load shapes. |
| d) | Use the ShapeType.CreateInstance method without parameter to create a self-contained shape. Alternatively the application might also use the corresponding constructor. |
Scenarios
The user always creates shapes from templates by dragging the template onto a diagram. Internally the shape creation process goes like this:
| 1. | The framework uses the CreateInstance method of the template shape's shape type to create a new shape of the same class. The template parameter of the CreateInstance method is set to the selected template. |
| 2. | The framework calls the CopyFrom method of the new shape to copy all properties of the template shape to the new shape. |
| 3. | The framework continues inserting the new shape. |
