Really Raw version of hierarchy documentation.

docs/hierarchy.md

@@ -0,0 +1,32 @@
+# Hierarchy
+
+![](../docs/images/hierarchy.png)
+
+### Vision
+
+* function `getProperty(name: Name, inherit: Boolean, includeStyles: Boolean, includeDefaults: Boolean)`. 
+
+It gets properties of element with `name` identification.
+`inherit` — toggles parent node property lookup. Null means inference from descriptor. Default is false.
+`includeStyles` — toggles inclusion of. Null means inference from descriptor. Default is true. 
+`includeDefaults` — default is false.
+
+* function `setProperty(name: Name, item: MetaItem?, notify: Boolean = true)`
+
+Sets the `item` property to the element with the `name` identification. `notify` is a value which toggles the necessity of the change notification. Default is true.
+
+### About properties
+**Properties have to be set in particular order:**
+
+* styles
+* prototypes
+* parent
+* parent's styles
+* defaults
+
+
+## Inheritance
+
+Inheritance is a very useful ability of `children` elements to get the same property in default as his parent does have (to 'inherit' it). 
+
+

docs/uml/Vision.puml

@@ -5,6 +5,7 @@ interface Vision{
     val parent: Vision?
     fun getProperty(name): MetaItem?
     fun setProperty(name, value)
+
 }
 
 class VisionBase{

visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionBase.kt

@@ -17,11 +17,6 @@ import space.kscience.dataforge.values.ValueType
 import space.kscience.visionforge.Vision.Companion.STYLE_KEY
 import kotlin.jvm.Synchronized
 
-internal data class PropertyListener(
-    val owner: Any? = null,
-    val action: (name: Name) -> Unit,
-)
-
 /**
  * A full base implementation for a [Vision]
  * @param properties Object own properties excluding styles and inheritance
@@ -43,7 +38,7 @@ public open class VisionBase(
     }
 
     /**
-     * A fast accessor method to get own property (no inheritance or styles
+     * A fast accessor method to get own property (no inheritance or styles)
      */
     override fun getOwnProperty(name: Name): MetaItem? = if (name == Name.EMPTY) {
         properties?.asMetaItem()