dagger.internal.codegen

Class ComponentTreeTraverser

java.lang.Object

dagger.internal.codegen.ComponentTreeTraverser

public class ComponentTreeTraverser
extends Object

An object that traverses the entire component hierarchy, starting from the root component.

Subclasses can override visitComponent(BindingGraph) to perform custom logic at each component in the tree, and visitSubcomponentFactoryMethod(BindingGraph, BindingGraph, ExecutableElement) to perform custom logic at each subcomponent factory method.

Subclasses can override bindingGraphTraverser(ComponentTreePath, DependencyRequest) to traverse each entry point within each component in the tree.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ComponentTreeTraverser.BindingGraphTraverser An object that traverses the binding graph starting from an entry point.
static class	ComponentTreeTraverser.ComponentTreePath A path from the root component to a component within the component tree during a traversal.
static class	ComponentTreeTraverser.DependencyTrace An immutable snapshot of a path through the binding graph.

Constructor Summary

Constructors

Constructor and Description
ComponentTreeTraverser(dagger.internal.codegen.BindingGraph rootGraph) Constructs a traverser for a root (component, not subcomponent) binding graph.

Method Summary

Modifier and Type	Method and Description
protected ComponentTreeTraverser.BindingGraphTraverser	bindingGraphTraverser(ComponentTreeTraverser.ComponentTreePath componentPath, dagger.internal.codegen.DependencyRequest entryPoint) Returns an object that traverses the binding graph starting from an entry point.
protected ComponentTreeTraverser.ComponentTreePath	componentTreePath() Returns an immutable snapshot of the path from the root component to the currently visited component.
void	traverseComponents() Calls visitComponent(BindingGraph) for the root component.
protected void	visitComponent(dagger.internal.codegen.BindingGraph graph) Called once for each component in a component hierarchy.
protected void	visitEntryPoint(dagger.internal.codegen.DependencyRequest entryPoint, dagger.internal.codegen.BindingGraph graph) Called once for each entry point in a component.
protected void	visitSubcomponentFactoryMethod(dagger.internal.codegen.BindingGraph graph, dagger.internal.codegen.BindingGraph parent, ExecutableElement factoryMethod) Called if this component was installed in its parent by a subcomponent factory method.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ComponentTreeTraverser

public ComponentTreeTraverser(dagger.internal.codegen.BindingGraph rootGraph)

Constructs a traverser for a root (component, not subcomponent) binding graph.

Method Detail

traverseComponents

public final void traverseComponents()

Calls visitComponent(BindingGraph) for the root component.

Throws:

IllegalStateException - if a traversal is in progress

visitComponent

protected void visitComponent(dagger.internal.codegen.BindingGraph graph)

Called once for each component in a component hierarchy.

Subclasses can override this method to perform whatever logic is required per component. They should call the super implementation if they want to continue the traversal in the standard order.

This implementation does the following:

1. If this component is installed in its parent by a subcomponent factory method, calls visitSubcomponentFactoryMethod(BindingGraph, BindingGraph, ExecutableElement).
2. For each entry point in the component, calls visitEntryPoint(DependencyRequest, BindingGraph).
3. For each child component, calls visitComponent(BindingGraph), updating the traversal state.

Parameters:

graph - the currently visited graph

visitSubcomponentFactoryMethod

protected void visitSubcomponentFactoryMethod(dagger.internal.codegen.BindingGraph graph,
                                              dagger.internal.codegen.BindingGraph parent,
                                              ExecutableElement factoryMethod)

Called if this component was installed in its parent by a subcomponent factory method.

This implementation does nothing.

Parameters:

graph - the currently visited graph

parent - the parent graph

factoryMethod - the factory method in the parent component that declares that the current component is a child

visitEntryPoint

protected void visitEntryPoint(dagger.internal.codegen.DependencyRequest entryPoint,
                               dagger.internal.codegen.BindingGraph graph)

Called once for each entry point in a component.

Subclasses can override this method to perform whatever logic is required per entry point. They should call the super implementation if they want to continue the traversal in the standard order.

This implementation passes the entry point and the current component tree path to bindingGraphTraverser(ComponentTreePath, DependencyRequest), and calls ComponentTreeTraverser.BindingGraphTraverser.traverseDependencies() on the returned object.

Parameters:

graph - the graph for the component that contains the entry point

bindingGraphTraverser

protected ComponentTreeTraverser.BindingGraphTraverser bindingGraphTraverser(ComponentTreeTraverser.ComponentTreePath componentPath,
                                                                             dagger.internal.codegen.DependencyRequest entryPoint)

Returns an object that traverses the binding graph starting from an entry point.

This implementation returns a no-op object that does nothing. Subclasses should override in order to perform custom logic within the binding graph.

Parameters:

componentPath - the path from the root component to the component that includes the entry point

entryPoint - the entry point

componentTreePath

protected final ComponentTreeTraverser.ComponentTreePath componentTreePath()

Returns an immutable snapshot of the path from the root component to the currently visited component.