- Extending Qt Creator Manual
- TaskTree
- QSequentialTaskTreeRunner
- Extending Qt Creator Manual 20.0.0-beta1

# QSequentialTaskTreeRunner Class

A sequential task tree execution controller. More...

Header: | `#include <qtasktreerunner.h>`
Inherits: | QAbstractTaskTreeRunner

- List of all members, including inherited members

## Public Functions

| QSequentialTaskTreeRunner(QObject *parent = nullptr)
virtual | ~QSequentialTaskTreeRunner()
void | cancelCurrent()
void | enqueue(const QtTaskTree::Group &recipe, SetupHandler &&setupHandler = {}, DoneHandler &&doneHandler = {}, QtTaskTree::CallDoneFlags callDone = QtTaskTree::CallDone::Always)
void | resetCurrent()

## Reimplemented Public Functions

virtual void | cancel() override
virtual bool | isRunning() const override
virtual void | reset() override

## Detailed Description

Manages sequential task tree execution. Use the enqueue() method to schedule the execution of a given recipe. It's guaranteed that at most one task tree is executing at any given time.

## Member Function Documentation

### QSequentialTaskTreeRunner::QSequentialTaskTreeRunner(QObject *parent = nullptr)

Constructs a sequential task tree runner for the given parent.

### `[virtual noexcept]` QSequentialTaskTreeRunner::~QSequentialTaskTreeRunner()

Destroys the sequential task tree runner. A possibly running task tree is deleted and enqueued tasks are removed. No task tree's done handler is called nor done() signal is emitted.

See also ~QTaskTree().

### `[override virtual]` void QSequentialTaskTreeRunner::cancel()

Reimplements: QAbstractTaskTreeRunner::cancel().

Cancels the running task tree. Calls task tree' done handler and emits done() signal with DoneWith::Cancel. All queued tasks are removed.

### void QSequentialTaskTreeRunner::cancelCurrent()

Cancels the running task tree. Calls task tree' done handler and emits done() signal with DoneWith::Cancel. If there are any enqueued recipes, the dequeued recipe is started.

### template <typename SetupHandler = QAbstractTaskTreeRunner::TreeSetupHandler, typename DoneHandler = QAbstractTaskTreeRunner::TreeDoneHandler> void QSequentialTaskTreeRunner::enqueue(const QtTaskTree::Group &recipe, SetupHandler &&setupHandler = {}, DoneHandler &&doneHandler = {}, QtTaskTree::CallDoneFlags callDone = QtTaskTree::CallDone::Always)

Schedules the recipe execution. If no task tree is executing, the runner starts a new task tree synchronously, otherwise the recipe is enqueued. When the currently executing task tree finished, the runner starts a new task tree with a dequeued recipe. Calls setupHandler when new task tree is about to be started. Calls doneHandler when the task tree is finished. The doneHandler is called according to the passed callDone.

### `[override virtual]` bool QSequentialTaskTreeRunner::isRunning() const

Reimplements: QAbstractTaskTreeRunner::isRunning() const.

Returns whether the sequential task tree runner is currently executing a task tree.

### `[override virtual]` void QSequentialTaskTreeRunner::reset()

Reimplements: QAbstractTaskTreeRunner::reset().

Resets the running task tree. No task tree's done handler is called nor done() signal is emitted. All queued tasks are removed.

### void QSequentialTaskTreeRunner::resetCurrent()

Resets the running task tree. No task tree's done handler is called nor done() signal is emitted. If there are any enqueued recipes, the dequeued recipe is started.