## class Fl_Double_Window

### Class Hierarchy

    Fl_Window
       |
       +----Fl_Double_Window

### Include Files

    #include <FL/Fl_Double_Window.H>

### Description

The `Fl_Double_Window` class provides a double-buffered window. If possible this will use the X double buffering extension (Xdbe). If not, it will draw the window data into an off-screen pixmap, and then copy it to the on-screen window.

It is highly recommended that you put the following code before the first `show()` of any window in your program:

    Fl::visual(FL_DOUBLE|FL_INDEX)

This makes sure you can use Xdbe on servers where double buffering does not exist for every visual.

### Methods

- Fl_Double_Window
- ~Fl_Double_Window

#### Fl_Double_Window::Fl_Double_Window(int x, int y, int w, int h, const char *label = 0)

Creates a new `Fl_Double_Window` widget using the given position, size, and label (title) string.

#### virtual Fl_Double_Window::~Fl_Double_Window()

The destructor also deletes all the children. This allows a whole tree to be deleted at once, without having to keep a pointer to all the children in the user code.