class Fl_Window


Class Hierarchy

Include Files

Description

This widget produces an actual window. This can either be a main window, with a border and title and all the window management controls, or a "subwindow" inside a window. This is controlled by whether or not the window has a parent().

Once you create a window, you usually add children Fl_Widget's to it by using window->add(child) for each new widget. See Fl_Group for more information on how to add and remove children.

There are several subclasses of Fl_Window that provide double-buffering, overlay, menu, and OpenGL support.

The window's callback is done if the user tries to close a window using the window manager and Fl::modal() is zero or equal to the window. Fl_Window has a default callback that calls Fl_Window::hide() and calls exit(0) if this is the last top-level window.

Methods

Fl_Window::Fl_Window(int w, int h, const char *title = 0)

The first form of the constructor should be used for a "top-level" window (that is, one that is not inside another window). It correctly sets visible() to false and parent() to NULL. By not specifying the position of the window, the window system will pick a place to show the window or allow the user to pick a location. If you want to force a position you should call position(x,y) or hotspot() before calling show().

Fl_Widget::box() is set to FL_FLAT_BOX. If you plan to completely fill the window with children widgets you should change this to FL_NO_BOX. If you turn the window border off you may want to change this to FL_UP_BOX.

Fl_Window::Fl_Window(int x, int y, int w, int h, const char *title = 0)

The second form of the constructor is for creating child windows. It leaves visible() set to true.

virtual Fl_Window::~Fl_Window()

Calls destroy(). 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. A kludge has been done so the Fl_Window and all of it's children can be automatic (local) variables, but you must declare the Fl_Window first so that it is destroyed last.

void Fl_Window::size_range(int minw, int minh, int maxw=0, int maxh=0, int dw=0, int dh=0, int aspect=0)

Set the allowable range the user can resize this window to. This only works for top-level windows. It is undefined what happens if the current size does not fit in the constraints passed to size_range().

If this function is not called, FLTK tries to figure out the range from the setting of resizeable():

void Fl_Window::show()

Put the window on the screen. Usually this has the side effect of opening the display.

It is harmless to call show() multiple times. If the window is already shown then it is deiconized and raised to the top.

int Fl_Window::show(int argc, char **argv, int i);

This must be called after
Fl::args(argc,argv) to show the "main" window, this indicates which window should be affected by any -geometry switch. In addition if Fl::args() has not been called yet this does so, this is a useful shortcut for the main window in a small program.

void Fl_Window::modal_for(const Fl_Window* parent);
const Fl_Window* modal_for() const;

Tell the system that this window will not have an icon, it will dissappear and reappear when the parent window is iconized or shown, and it is forced to always be above the parent window. On X this is called a "Transient" window, and Windows sometimes calls this a "overlapping child" window. This value is not to be confused with Fl_Widget::parent(), which must be zero).

On both X and win32 changing this value causes the window to be removed from the screen.

On X this requires the window manager to support "TransisentForHint", not all do, in which case the window will appear normally.

Win32 and some X window managers have an annoying bug where calling show() on this window will also raise the parent window to right below this. This makes this ability far less useful than it could be...

int Fl_Window::show(const Fl_Window* parent);

Same as modal_for(parent); show();.

void Fl_Window::set_modal()
bool Fl_Window::modal() const;

Marks the window so that when show(parent) is called this window will remain on top and block events to other windows in this application. While the window is up the function
Fl::modal() returns true.

You probably want to use exec(), unless you wish to put up a modal window but retain control of the program loop.

Notice that there is no way to turn off the modal() setting.

bool Fl_Window::exec(const Fl_Window* parent = 0);

Does set_modal(); show(parent); then enters a loop of handling events until the window is hidden again by the program (usually by the user closing it, or from a callback from some widget inside the window, such as an OK button). During this time events to other windows in this application are either thrown away or redirected to this window.

The return value is true only if some callback does window->set(). To use this, make an OK button with a callback that does this.

If parent is null the window that last received an event is used as the parent. This is convenient for popups that appear in response to a mouse or key click.

bool Fl_Window::show_inside(const Fl_Window* frame);

Make the window with a normal system border and behavior, but place it inside the frame as though that was the desktop. This is what Windows calls "MDI". Typically the other window (which must already be shown) is a child window so that space can remain around it for a menu/tool bar.

Notice that parent() of the window must be zero and it will remain zero after this is called. Fltk uses a zero parent to indicate that the system is managing the window.

On systems that don't support nested desktops (i.e. X) this does show(frame), which produces a normal overlapping window that is tied to remain atop and iconize with the frame window (IMHO this is a great improvement over MDI!).

virtual void Fl_Window::hide()

Remove the window from the screen. If the window is already hidden or has not been shown then this does nothing and is harmless.

virtual void Fl_Window::destroy();

Hides the window and also deletes all window system information about the window, and thus returns if back to the state it was in before the first show(). It is harmless to call this if the window is already destroyed.

Subclasses can override this, if you do this you must also override the destructor and make it call destroy().

int Fl_Window::shown() const

Returns non-zero if show() has been called, but destroy() has not been called.

int Fl_Window::iconic() const

Returns true if the window is currently displayed as an icon. Returns false if the window is not shown() or hide() has been called. On X this will return true for a short time after show() is called the first time.

void Fl_Window::iconize()

Iconifies the window. If you call this when shown() is false it will show() it as an icon. If the window is already iconified this does nothing.

Call show() to restore the window.

Currently there are only system-specific ways to control what is drawn in the icon. You should not rely on window managers displaying the icons.

Fl_Window *Fl::first_window()

Returns the first shown() window in the widget hierarchy. If no windows are displayed first_window returns NULL.

void *Fl::first_window(Fl_Window*)

Change which window is returned by Fl::first_window(). This window must have shown() true. This is useful for making an
exec(0) inside some inner code make the window a child of the correct window.

Fl_Window *Fl::next_window(const Fl_Window*)

Returns the next shown() window in the hierarchy. You can use this call to iterate through all the windows that are shown().

void Fl_Window::resize(int,int,int,int)

Change the size and position of the window. If shown() is true, these changes are communicated to the window server (which may refuse that size and cause a further resize). If shown() is false, the size and position are used when show() is called. See
Fl_Group for the effect of resizing on the child widgets.

You can also call the Fl_Widget methods size(x,y) and position(w,h), which are inline wrappers for this virtual function.

The special value FL_USEDEFAULT may be used for x and y indicate that the system should choose the window's position.

void Fl_Window::hotspot(int x, int y, int offscreen = 0)
void Fl_Window::hotspot(const Fl_Widget*, int offscreen = 0)
void Fl_Window::hotspot(const Fl_Widgetp, int offscreen = 0)

position() the window so that the mouse is pointing at the given position, or at the center of the given widget, which may be the window itself. If the optional offscreen parameter is non-zero, then the window is allowed to extend off the screen (this does not work with some X window managers).

void Fl_Window::fullscreen()

Makes the window completely fill the screen, without any window manager border visible. You must use fullscreen_off() to undo this. This may not work with all X window managers (and currently it is not successful at hiding the Windows taskbar).

int Fl_Window::fullscreen_off(int x, int y, int w, int h)

Turns off any side effects of fullscreen() and does resize(x,y,w,h).

void Fl_Window::clear_border()

You may turn off the window manager border before calling show() on the window the first time. This will also mean the user cannot move, iconize, or resize the window (unless your program does it). This is used by the fltk menus and tooltips.

On X this causes "override redirect". This is only good for short-lived windows as it can confuse X window managers, however this is the only reliable and fast way to do it. This also turns on "save under" which on many X servers (like XFree86) can make the window pop-down much faster.

bool Fl_Window::border() const

Returns false if clear_border() has been called.

void Fl_Window::label(const char*)
const char* Fl_Window::label() const

Gets or sets the window title bar label.

void Fl_Window::iconlabel(const char*)
const char* Fl_Window::iconlabel() const

Gets or sets the icon label.

void Fl_Window::make_current()

make_current() sets things up so that the drawing functions in
<FL/fl_draw.H> will go into this window. This is useful for incremental update of windows, such as in an idle callback, which will make your program behave much better if it draws a slow graphic. This call does not work for Fl_Double_Window!.

static Fl_Window* Fl_Window::current()

Returns the last window that was made current.

void Fl_Window::cursor(Fl_Cursor, Fl_Color = FL_WHITE, Fl_Color = FL_BLACK)

Change the cursor for this window. This always calls the system, if you are changing the cursor a lot you may want to keep track of how you set it in a static varaible and call this only if the new cursor is different.

The type Fl_Cursor is an enumeration defined in <Enumerations.H>. (Under X you can get any XC_cursor value by passing Fl_Cursor((XC_foo/2)+1)). The colors only work on X, they are not implemented on WIN32.