The reason why Embedded Wizard Studio does not allow to drag and drop certain templates to the Composer is, because not all templates fit to the currently selected Composer page.
First of all you need to understand the three main navigation levels in the Composer.
1. Project level
Only one project page can be opened in the Composer of an Embedded Wizard project. The members of a project view can have only four types of bricks – units and three types of variant identifiers:
2. Unit level
If the Composer shows the members of a unit, only the following bricks can be added to this composer page:
- Resources (fonts or bitmaps)
- Auto Objects
- Inline Code
3. Class level
A class Composer page can cover the following types of members:
- Views (visible objects like Rectangles, Texts, Images, etc.)
- Objects (instances of predefined or customized classes)
- Methods (normal methods, slot methods, OnGet- and OnSet-methods)
Some special templates can only be used in the dedicated type. These are:
- EnumItem can only be part of an "Enum" or "Set" Composer page
- Macros can only be added to a "Profile" Composer page
All other drag and drop action beside above listed will be refused from Embedded Wizard.