QSplitterHandle Class | Qt Widgets 5.6

Qt 5.6 | Qt Widgets | C++ Classes | QSplitterHandle

Qt 5.6.2 Reference Documentation

# QSplitterHandle Class

The QSplitterHandle class provides handle functionality for the splitter. More...

Header: | #include <QSplitterHandle>
qmake: | QT += widgets
Inherits: | QWidget

- List of all members, including inherited members

## Public Functions

| QSplitterHandle(Qt::Orientation orientation, QSplitter *parent)
| ~QSplitterHandle()
bool | opaqueResize() const
Qt::Orientation | orientation() const
void | setOrientation(Qt::Orientation orientation)
QSplitter * | splitter() const

## Reimplemented Public Functions

virtual QSize | sizeHint() const

- 211 public functions inherited from QWidget

## Protected Functions

int | closestLegalPosition(int pos)
bool | event(QEvent *event)
void | moveSplitter(int pos)

## Reimplemented Protected Functions

virtual void | mouseMoveEvent(QMouseEvent *e)
virtual void | mousePressEvent(QMouseEvent *e)
virtual void | mouseReleaseEvent(QMouseEvent *e)
virtual void | paintEvent(QPaintEvent *)
virtual void | resizeEvent(QResizeEvent *event)

- 35 protected functions inherited from QWidget

### Additional Inherited Members

- 58 properties inherited from QWidget
- 19 public slots inherited from QWidget
- 3 signals inherited from QWidget
- 5 static public members inherited from QWidget
- 1 protected slot inherited from QWidget

## Detailed Description

The QSplitterHandle class provides handle functionality for the splitter.

QSplitterHandle is typically what people think about when they think about a splitter. It is the handle that is used to resize the widgets.

A typical developer using QSplitter will never have to worry about QSplitterHandle. It is provided for developers who want splitter handles that provide extra features, such as popup menus.

The typical way one would create splitter handles is to subclass QSplitter and then reimplement QSplitter::createHandle() to instantiate the custom splitter handle. For example, a minimum QSplitter subclass might look like this:

      class Splitter : public QSplitter
      {
      public:
          Splitter(Qt::Orientation orientation, QWidget *parent = 0);

      protected:
          QSplitterHandle *createHandle();
      };

The createHandle() implementation simply constructs a custom splitter handle, called `Splitter` in this example:

      QSplitterHandle *Splitter::createHandle()
      {
          return new SplitterHandle(orientation(), this);
      }

Information about a given handle can be obtained using functions like orientation() and opaqueResize(), and is retrieved from its parent splitter. Details like these can be used to give custom handles different appearances depending on the splitter's orientation.

The complexity of a custom handle subclass depends on the tasks that it needs to perform. A simple subclass might only provide a paintEvent() implementation:

      void SplitterHandle::paintEvent(QPaintEvent *event)
      {
          QPainter painter(this);
          if (orientation() == Qt::Horizontal) {
              gradient.setStart(rect().left(), rect().height()/2);
              gradient.setFinalStop(rect().right(), rect().height()/2);
          } else {
              gradient.setStart(rect().width()/2, rect().top());
              gradient.setFinalStop(rect().width()/2, rect().bottom());
          }
          painter.fillRect(event->rect(), QBrush(gradient));
      }

In this example, a predefined gradient is set up differently depending on the orientation of the handle. QSplitterHandle provides a reasonable size hint for the handle, so the subclass does not need to provide a reimplementation of sizeHint() unless the handle has special size requirements.

See also QSplitter.

## Member Function Documentation

### QSplitterHandle::QSplitterHandle(Qt::Orientation orientation, QSplitter *parent)

Creates a QSplitter handle with the given orientation and parent.

### QSplitterHandle::~QSplitterHandle()

Destructor.

### `[protected]` int QSplitterHandle::closestLegalPosition(int pos)

Returns the closest legal position to pos of the splitter handle. The positions are measured from the left or top edge of the splitter, even for right-to-left languages.

See also QSplitter::closestLegalPosition() and moveSplitter().

### `[protected]` bool QSplitterHandle::event(QEvent *event)

### `[virtual protected]` void QSplitterHandle::mouseMoveEvent(QMouseEvent *e)

Reimplemented from QWidget::mouseMoveEvent().

### `[virtual protected]` void QSplitterHandle::mousePressEvent(QMouseEvent *e)

Reimplemented from QWidget::mousePressEvent().

### `[virtual protected]` void QSplitterHandle::mouseReleaseEvent(QMouseEvent *e)

Reimplemented from QWidget::mouseReleaseEvent().

### `[protected]` void QSplitterHandle::moveSplitter(int pos)

Tells the splitter to move this handle to position pos, which is the distance from the left or top edge of the widget.

Note that pos is also measured from the left (or top) for right-to-left languages. This function will map pos to the appropriate position before calling QSplitter::moveSplitter().

See also QSplitter::moveSplitter() and closestLegalPosition().

### bool QSplitterHandle::opaqueResize() const

Returns `true` if widgets are resized dynamically (opaquely), otherwise returns `false`. This value is controlled by the QSplitter.

See also QSplitter::opaqueResize().

### Qt::Orientation QSplitterHandle::orientation() const

Returns the handle's orientation. This is usually propagated from the QSplitter.

See also setOrientation() and QSplitter::orientation().

### `[virtual protected]` void QSplitterHandle::paintEvent(QPaintEvent *)

Reimplemented from QWidget::paintEvent().

### `[virtual protected]` void QSplitterHandle::resizeEvent(QResizeEvent *event)

Reimplemented from QWidget::resizeEvent().

### void QSplitterHandle::setOrientation(Qt::Orientation orientation)

Sets the orientation of the splitter handle to orientation. This is usually propagated from the QSplitter.

See also orientation() and QSplitter::setOrientation().

### `[virtual]` QSize QSplitterHandle::sizeHint() const

Reimplemented from QWidget::sizeHint().

### QSplitter *QSplitterHandle::splitter() const

Returns the splitter associated with this splitter handle.

See also QSplitter::handle().