ArrayLinkedVariables (core 1.0.4 API)

java.lang.Object
- androidx.constraintlayout.core.ArrayLinkedVariables

All Implemented Interfaces:

ArrayRow.ArrayRowVariables
```
public class ArrayLinkedVariables
extends java.lang.Object
implements ArrayRow.ArrayRowVariables
```
Store a set of variables and their values in an array-based linked list. The general idea is that we want to store a list of variables that need to be ordered, space efficient, and relatively fast to maintain (add/remove). ArrayBackedVariables implements a sparse array, so is rather space efficient, but maintaining the array sorted is costly, as we spend quite a bit of time recopying parts of the array on element deletion. LinkedVariables implements a standard linked list structure, and is able to be faster than ArrayBackedVariables even though it's more costly to set up (pool of objects...), as the elements removal and maintenance of the structure is a lot more efficient. This ArrayLinkedVariables class takes inspiration from both of the above, and implement a linked list stored in several arrays. This allows us to be a lot more efficient in terms of setup (no need to deal with pool of objects...), resetting the structure, and insertion/deletion of elements.

Field Summary

Fields
Modifier and Type Field and Description

protected Cache mCache

Fields
Modifier and Type	Field and Description
`protected Cache`	`mCache`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(SolverVariable variable, float value, boolean removeFromDefinition)` Add value to an existing variable The code is broadly identical to the put() method, only differing in in-line deletion, and of course doing an add rather than a put
`void`	`clear()` Clear the list of variables
`boolean`	`contains(SolverVariable variable)` Returns true if the variable is contained in the list
`void`	`display()`
`void`	`divideByAmount(float amount)` Divide the values of all the variables in the list by the given amount
`float`	`get(SolverVariable v)` Return the value of a variable, 0 if not found
`int`	`getCurrentSize()`
`int`	`getHead()`
`int`	`getId(int index)`
`int`	`getNextIndice(int index)`
`float`	`getValue(int index)`
`SolverVariable`	`getVariable(int index)` Return a variable from its position in the linked list
`float`	`getVariableValue(int index)` Return the value of a variable from its position in the linked list
`int`	`indexOf(SolverVariable variable)`
`void`	`invert()` Invert the values of all the variables in the list
`void`	`put(SolverVariable variable, float value)` Insert a variable with a given value in the linked list
`float`	`remove(SolverVariable variable, boolean removeFromDefinition)` Remove a variable from the list
`int`	`sizeInBytes()`
`java.lang.String`	`toString()` Returns a string representation of the list
`float`	`use(ArrayRow definition, boolean removeFromDefinition)` Update the current list with a new definition

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - mCache
```
protected final Cache mCache
```
- Method Detail
  - put
```
public final void put(SolverVariable variable,
                      float value)
```
    Insert a variable with a given value in the linked list
    
    Specified by:
    
    put in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    variable - the variable to add in the list
    
    value - the value of the variable
  - add
```
public void add(SolverVariable variable,
                float value,
                boolean removeFromDefinition)
```
    Add value to an existing variable The code is broadly identical to the put() method, only differing in in-line deletion, and of course doing an add rather than a put
    
    Specified by:
    
    add in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    variable - the variable we want to add
    
    value - its value
    
    removeFromDefinition -
  - use
```
public float use(ArrayRow definition,
                 boolean removeFromDefinition)
```
    Update the current list with a new definition
    
    Specified by:
    
    use in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    definition - the row containing the definition
    
    removeFromDefinition -
  - remove
```
public final float remove(SolverVariable variable,
                          boolean removeFromDefinition)
```
    Remove a variable from the list
    
    Specified by:
    
    remove in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    variable - the variable we want to remove
    
    removeFromDefinition -
    
    Returns:
    
    the value of the removed variable
  - clear
```
public final void clear()
```
    Clear the list of variables
    
    Specified by:
    
    clear in interface ArrayRow.ArrayRowVariables
  - contains
```
public boolean contains(SolverVariable variable)
```
    Returns true if the variable is contained in the list
    
    Specified by:
    
    contains in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    variable - the variable we are looking for
    
    Returns:
    
    return true if we found the variable
  - indexOf
```
public int indexOf(SolverVariable variable)
```
    Specified by:
    
    indexOf in interface ArrayRow.ArrayRowVariables
  - invert
```
public void invert()
```
    Invert the values of all the variables in the list
    
    Specified by:
    
    invert in interface ArrayRow.ArrayRowVariables
  - divideByAmount
```
public void divideByAmount(float amount)
```
    Divide the values of all the variables in the list by the given amount
    
    Specified by:
    
    divideByAmount in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    amount - amount to divide by
  - getHead
```
public int getHead()
```
  - getCurrentSize
```
public int getCurrentSize()
```
    Specified by:
    
    getCurrentSize in interface ArrayRow.ArrayRowVariables
  - getId
```
public final int getId(int index)
```
  - getValue
```
public final float getValue(int index)
```
  - getNextIndice
```
public final int getNextIndice(int index)
```
  - getVariable
```
public SolverVariable getVariable(int index)
```
    Return a variable from its position in the linked list
    
    Specified by:
    
    getVariable in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    index - the index of the variable we want to return
    
    Returns:
    
    the variable found, or null
  - getVariableValue
```
public float getVariableValue(int index)
```
    Return the value of a variable from its position in the linked list
    
    Specified by:
    
    getVariableValue in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    index - the index of the variable we want to look up
    
    Returns:
    
    the value of the found variable, or 0 if not found
  - get
```
public final float get(SolverVariable v)
```
    Return the value of a variable, 0 if not found
    
    Specified by:
    
    get in interface ArrayRow.ArrayRowVariables
    
    Parameters:
    
    v - the variable we are looking up
    
    Returns:
    
    the value of the found variable, or 0 if not found
  - sizeInBytes
```
public int sizeInBytes()
```
    Specified by:
    
    sizeInBytes in interface ArrayRow.ArrayRowVariables
  - display
```
public void display()
```
    Specified by:
    
    display in interface ArrayRow.ArrayRowVariables
  - toString
```
public java.lang.String toString()
```
    Returns a string representation of the list
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string containing a representation of the list

Class ArrayLinkedVariables

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

mCache

Method Detail

put

add

use

remove

clear

contains

indexOf

invert

divideByAmount

getHead

getCurrentSize

getId

getValue

getNextIndice

getVariable

getVariableValue

get

sizeInBytes

display

toString