- Extending Qt Creator Manual
- TaskingSolution
- TaskAdapter
- Extending Qt Creator Manual 13.0.0

# TaskAdapter Class

template <typename Task, typename Deleter> class Tasking::TaskAdapter

A class template for implementing custom task adapters. More...

Header: | #include <solutions/tasking/tasktree.h>
Inherits: | Tasking::TaskInterface

- List of all members, including inherited members

Note: All functions in this class are reentrant.

## Protected Functions

| TaskAdapter()
Task * | task()
const Task * | task() const

## Detailed Description

The TaskAdapter class template is responsible for creating a task of the `Task` type, starting it, and reporting success or an error when the task is finished. It also associates the adapter with a given `Task` type.

Reimplement this class with the actual `Task` type to adapt the task's interface into the general TaskTree's interface for managing the `Task` instances.

Each subclass needs to provide a public default constructor, implement the start() method, and emit the done() signal when the task is finished. Use task() to access the associated `Task` instance.

To use your task adapter inside the task tree, create an alias to the Tasking::CustomTask template passing your task adapter as a template parameter:

     // Defines actual worker
     class Worker {...};

     // Adapts Worker's interface to work with task tree
     class WorkerTaskAdapter : public TaskAdapter<Worker> {...};

     // Defines WorkerTask as a new custom task type to be placed inside Group items
     using WorkerTask = CustomTask<WorkerTaskAdapter>;

Optionally, you may pass a custom `Deleter` for the associated `Task` as a second template parameter of your `TaskAdapter` subclass. When the `Deleter` parameter is omitted, the `std::default_delete<Task>` is used by default. The custom `Deleter` is useful when the destructor of the running `Task` may potentially block the caller thread. Instead of blocking, the custom deleter may move the running task into a separate thread and implement the blocking destruction there. In this way, the fast destruction (seen from the caller thread) of the running task with a blocking destructor may be achieved.

For more information on implementing the custom task adapters, refer to Task Adapters.

See also start(), done(), and task().

## Member Function Documentation

### `[protected]` TaskAdapter::TaskAdapter()

Creates a task adapter for the given `Task` type.

Internally, it creates an instance of `Task`, which is accessible via the task() method. The optionally provided `Deleter` is used instead of the `Task` destructor. When `Deleter` is omitted, the `std::default_delete<Task>` is used by default.

See also task().

### `[protected]` Task *TaskAdapter::task()

Returns the pointer to the associated `Task` instance.

### `[protected]` const Task *TaskAdapter::task() const

This is an overloaded function.

Returns the `const` pointer to the associated `Task` instance.