#227 Boundaries can be styled via tags

[kirchsth]

implementation of #227

With following calls is it possible to update existing boundary styles or add new boundary tags, which can then be used in combination with the boundaries. (There was already a tag support but now it has a better legend support and it has its own tag namespace that elements and boundaries can have different style for the same tag name)

• AddBoundaryTag(tagStereo, ?bgColor, ?fontColor, ?borderColor, ?shadowing, ?shape, ?type, ?legendText):
  Introduces a new Boundary tag. The styles of the tagged boundaries are updated and the tag is displayed in the calculated legend.
• UpdateBoundaryStyle(?elementName, ?bgColor, ?fontColor, ?borderColor, ?shadowing, ?shape, ?type, ?legendText):
  This call updates the default style of the existing boundaries and creates no additional legend entry.
  If the element name is "" then it updates generic, enterprise, system and container boundary style in on call.

Boundary specific tag definitions

Like the element specific tag definitions exist boundary specific calls with their default colors and type:

• UpdateContainerBoundaryStyle(?bgColor, ?fontColor, ?borderColor, ?shadowing, ?shape, ?type, ?legendText)
• UpdateSystemBoundaryStyle(?bgColor, ?fontColor, ?borderColor, ?shadowing, ?shape, ?type, ?legendText)
• UpdateEnterpriseBoundaryStyle(?bgColor, ?fontColor, ?borderColor, ?shadowing, ?shape, ?type, ?legendText)

The calls can be used like

Sample with different boundary tag combinations

@startuml
!include https://raw.githubusercontent.com/kirchsth/C4-PlantUML/extended/C4_Component.puml

' Update the generic boundary style and the "system", "enterprise", "container" boundaries styles too
UpdateBoundaryStyle($bgColor="gold", $fontColor="brown", $borderColor="brown")
' (Re-)Updates the system boundary styles; re-set $bgColor avoids '(no back color)' in legend too
UpdateSystemBoundaryStyle($bgColor="gold", $fontColor="white", $borderColor="white")

Boundary(b, "A Boundary") {
}

Container_Boundary(cb, "A Container Boundary") {
}

System_Boundary(sb, "A System Boundary") {
}

' defines a new border style incl. new border type
AddBoundaryTag("repository", $bgColor="green", $fontColor="white", $borderColor="white", $shadowing="true", $shape = RoundedBoxShape(), $type="GitHub repository")

Boundary(c4Respository, "plantuml-stdlib/C4-PlantUML", $tags="repository") {
  Component(readMe, "README.md", "Markdown")
}

' boundary tags are internally extended with '_boundary' that it uses a different name space
' this enables different element and boundary styles for the same tag name
AddBoundaryTag("v1", $bgColor="lightgreen", $fontColor="green", $borderColor="green")
AddElementTag("v1", $bgColor="lightred", $fontColor="red", $borderColor="red")

Boundary(anotherBoundary, "Another Boundary", $type="BOUNDARY TYPE", $tags="v1") {
  Component(anotherComponent, "Another Component", $techn="COMPONENT TYPE", $tags="v1", $descr="Component and boundary use different tag name spaces that both v1 tags can use different styles")
}

Lay_R(b, cb)
Lay_R(cb, sb)

Lay_D(b, c4Respository)

Lay_R(c4Respository, anotherBoundary)

SHOW_LEGEND()
@enduml

It can be tested with my extended branch

BR Helmut