#include <Wt/WBoxLayout>
Public Types | |
enum | Direction { LeftToRight, RightToLeft, TopToBottom, BottomToTop } |
Enumeration of the direction in which widgets are layed out. More... | |
Public Member Functions | |
WBoxLayout (Direction dir, WWidget *parent=0) | |
Create a new box layout. | |
virtual void | addItem (WLayoutItem *item) |
Add a layout item. | |
virtual void | removeItem (WLayoutItem *item) |
Remove a layout item (widget or nested layout). | |
virtual WLayoutItem * | itemAt (int index) const |
Return the layout item at a specific index. | |
virtual int | count () const |
Return the number of items in this layout. | |
void | setDirection (Direction direction) |
Set the layout direction. | |
Direction | direction () const |
Returns the layout direction. | |
void | setSpacing (int size) |
Set spacing between each item. | |
int | spacing () const |
Returns the spacing between each item. | |
void | addWidget (WWidget *widget, int stretch=0, WFlags< AlignmentFlag > alignment=0) |
Adds a widget to the layout. | |
void | addLayout (WLayout *layout, int stretch=0, WFlags< AlignmentFlag > alignment=0) |
Adds a nested layout to the layout. | |
void | addSpacing (const WLength &size) |
Adds extra spacing. | |
void | addStretch (int stretch=0) |
Adds a stretch element. | |
void | insertWidget (int index, WWidget *widget, int stretch=0, WFlags< AlignmentFlag > alignment=0) |
Inserts a widget in the layout. | |
void | insertLayout (int index, WLayout *layout, int stretch=0, WFlags< AlignmentFlag > alignment=0) |
Inserts a nested layout in the layout. | |
void | insertSpacing (int index, const WLength &size) |
Inserts extra spacing in the layout. | |
void | insertStretch (int index, int stretch=0) |
Inserts a stretch element in the layout. | |
bool | setStretchFactor (WLayout *layout, int stretch) |
Set the stretch factor for a nested layout. | |
bool | setStretchFactor (WWidget *widget, int stretch) |
Set the stretch factor for a nested layout. |
This layout manager arranges widgets horizontally or vertically inside the parent container. The space is divided so that each widgets is given its minimum size, and remaining space is divided according to stretch factors among the widgets. The widget minimum height or width is used for sizing each widget, whose default values may be overridden using WWidget::setMinimumSize().
You can use WContainerWidget::setOverflow(OverflowAuto) to automatically show scrollbars on a container widget which you inserted into the layout. In some cases, you will want to wrap another widget (like a WTable) into WContainerWidget to have the scrollbars, since not all widgets allow for scrollbars.
Each item is separated using a constant spacing, which defaults to 6 pixels, and can be changed using setSpacing(). In addition, when this layout is a top-level layout (i.e. is not nested inside another layout), a margin is set around the contents, which thus replaces padding defined for the container. This margin defaults to 9 pixels, and can be changed using setContentsMargins(). It is not allowed to define padding for the container widget using its CSS 'padding' property or the WContainerWidget::setPadding(). You can add more space between two widgets using addSpacing().
For each item a stretch factor may be defined, which controls how remaining space is used. Each item is stretched using the stretch factor to fill the remaining space.
Usage example:
Wt::WContainerWidget *w = new Wt::WContainerWidget(this); w->resize(WLength(), 600); Wt::WBoxLayout *layout = new Wt::WBoxLayout(Wt::WBoxLayout::TopToBottom); layout->addWidget(new Wt::WText("One")); layout->addWidget(new Wt::WText("Two")); layout->addWidget(new Wt::WText("Three")); layout->addWidget(new Wt::WText("Four")); w->setLayout(layout);
When JavaScript support is not available, only Safari and Firefox properly implement this box layout. For other browsers, only the horizontal layout is properly implemented, while vertically all widgets use their minimum size.
When set on a WContainerWidget, this layout manager accepts the following hints (see setLayoutHint()):
Enumeration of the direction in which widgets are layed out.
Create a new box layout.
This constructor is rarely used. Instead, use the convenient constructors of the specialized WHBoxLayout or WVBoxLayout classes.
Use parent=0 to created a layout manager that can be nested inside other layout managers.
void Wt::WBoxLayout::addItem | ( | WLayoutItem * | item | ) | [virtual] |
Add a layout item.
The item may be a widget or nested layout.
How the item is layed out with respect to siblings is implementation specific to the layout manager. In some cases, a layout manager will overload this method with extra arguments that specify layout options.
Implements Wt::WLayout.
void Wt::WBoxLayout::removeItem | ( | WLayoutItem * | item | ) | [virtual] |
WLayoutItem * Wt::WBoxLayout::itemAt | ( | int | index | ) | const [virtual] |
Return the layout item at a specific index.
If there is no item at the index, 0 is returned.
Implements Wt::WLayout.
int Wt::WBoxLayout::count | ( | ) | const [virtual] |
Return the number of items in this layout.
This may be a theoretical number, which is greater than the actual number of items. It can be used to iterate over the items in the layout, in conjunction with itemAt().
Implements Wt::WLayout.
void Wt::WBoxLayout::setDirection | ( | Direction | direction | ) |
Direction Wt::WBoxLayout::direction | ( | ) | const [inline] |
void Wt::WBoxLayout::setSpacing | ( | int | size | ) |
Set spacing between each item.
The default spacing is 6 pixels.
int Wt::WBoxLayout::spacing | ( | ) | const [inline] |
void Wt::WBoxLayout::addWidget | ( | WWidget * | widget, | |
int | stretch = 0 , |
|||
WFlags< AlignmentFlag > | alignment = 0 | |||
) |
Adds a widget to the layout.
Adds a widget to the layout, with given stretch factor. The alignemnt parameter is a combination of a horizontal and/or a vertical AlignmentFlag OR'ed together.
The alignment specifies the vertical and horizontal alignment of the item. The default value 0 indicates that the item is stretched to fill the entire column or row. The alignment can be specified as a logical combination of a horizontal alignment (Wt::AlignLeft, Wt::AlignCenter, or Wt::AlignRight) and a vertical alignment (Wt::AlignTop, Wt::AlignMiddle, or Wt::AlignBottom).
void Wt::WBoxLayout::addLayout | ( | WLayout * | layout, | |
int | stretch = 0 , |
|||
WFlags< AlignmentFlag > | alignment = 0 | |||
) |
Adds a nested layout to the layout.
Adds a nested layout, with given stretch factor.
void Wt::WBoxLayout::addSpacing | ( | const WLength & | size | ) |
void Wt::WBoxLayout::addStretch | ( | int | stretch = 0 |
) |
Adds a stretch element.
Adds a stretch element to the layout. This adds an empty space that stretches as needed.
void Wt::WBoxLayout::insertWidget | ( | int | index, | |
WWidget * | widget, | |||
int | stretch = 0 , |
|||
WFlags< AlignmentFlag > | alignment = 0 | |||
) |
Inserts a widget in the layout.
Inserts a widget in the layout at position index, with given stretch factor.
The alignment specifies the vertical and horizontal alignment of the item. The default value 0 indicates that the item is stretched to fill the entire column or row. The alignment can be specified as a logical combination of a horizontal alignment (Wt::AlignLeft, Wt::AlignCenter, or Wt::AlignRight) and a vertical alignment (Wt::AlignTop, Wt::AlignMiddle, or Wt::AlignBottom).
void Wt::WBoxLayout::insertLayout | ( | int | index, | |
WLayout * | layout, | |||
int | stretch = 0 , |
|||
WFlags< AlignmentFlag > | alignment = 0 | |||
) |
Inserts a nested layout in the layout.
Inserts a nested layout in the layout at positionindex, with given stretch factor.
void Wt::WBoxLayout::insertSpacing | ( | int | index, | |
const WLength & | size | |||
) |
Inserts extra spacing in the layout.
Inserts extra spacing in the layout at position index.
void Wt::WBoxLayout::insertStretch | ( | int | index, | |
int | stretch = 0 | |||
) |
Inserts a stretch element in the layout.
Inserts a stretch element in the layout at position index. This adds an empty space that stretches as needed.
bool Wt::WBoxLayout::setStretchFactor | ( | WLayout * | layout, | |
int | stretch | |||
) |
Set the stretch factor for a nested layout.
The layout must have previously been added to this layout using insertLayout() or addLayout().
Returns whether the stretch could be set.
bool Wt::WBoxLayout::setStretchFactor | ( | WWidget * | widget, | |
int | stretch | |||
) |
Set the stretch factor for a nested layout.
The widget must have previously been added to this layout using insertWidget() or addWidget().
Returns whether the stretch could be set.