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class SF::Window
inherits Reference #

Window that serves as a target for OpenGL rendering

SF::Window is the main class of the Window module. It defines an OS window that is able to receive an OpenGL rendering.

A SF::Window can create its own new window, or be embedded into an already existing control using the create(handle) function. This can be useful for embedding an OpenGL rendering area into a view which is part of a bigger GUI with existing windows, controls, etc. It can also serve as embedding an OpenGL rendering area into a window created by another (probably richer) GUI library like Qt or wx_widgets.

The SF::Window class provides a simple interface for manipulating the window: move, resize, show/hide, control mouse cursor, etc. It also provides event handling through its poll_event() and wait_event() functions.

Note that OpenGL experts can pass their own parameters (antialiasing level, bits for the depth and stencil buffers, etc.) to the OpenGL context attached to the window, with the SF::ContextSettings structure which is passed as an optional argument when creating the window.

On dual-graphics systems consisting of a low-power integrated GPU and a powerful discrete GPU, the driver picks which GPU will run an SFML application. In order to inform the driver that an SFML application can benefit from being run on the more powerful discrete GPU, #SFML_DEFINE_DISCRETE_GPU_PREFERENCE can be placed in a source file that is compiled and linked into the final application. The macro should be placed outside of any scopes in the global namespace.

Usage example:

# Declare and create a new window
window = SF::Window.new(SF::VideoMode.new(800, 600), "SFML window")

# Limit the framerate to 60 frames per second (this step is optional)
window.framerate_limit = 60

# The main loop - ends as soon as the window is closed
while window.open?
  # Event processing
  while (event = window.poll_event())
    # Request for closing the window
    if event.is_a?(SF::Event::Closed)
      window.close()
    end
  end

  # Activate the window for OpenGL rendering
  window.active = true

  # OpenGL drawing commands go here...

  # End the current frame and display its contents on screen
  window.display()
end

Included modules

SF::GlResource SF::NonCopyable

Direct known subclasses

SF::RenderWindow

Class methods#

.new(mode : VideoMode, title : String, style : Style = Style::Default, settings : ContextSettings = ContextSettings.new) #

Construct a new window

This constructor creates the window with the size and pixel depth defined in mode. An optional style can be passed to customize the look and behavior of the window (borders, title bar, resizable, closable, ...). If style contains Style::Fullscreen, then mode must be a valid video mode.

The fourth parameter is an optional structure specifying advanced OpenGL context settings such as antialiasing, depth-buffer bits, etc.

  • mode - Video mode to use (defines the width, height and depth of the rendering area of the window)
  • title - Title of the window
  • style - Window style, a bitwise OR combination of SF::Style enumerators
  • settings - Additional settings for the underlying OpenGL context
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.new(handle : WindowHandle, settings : ContextSettings = ContextSettings.new) #

Construct the window from an existing control

Use this constructor if you want to create an OpenGL rendering area into an already existing control.

The second parameter is an optional structure specifying advanced OpenGL context settings such as antialiasing, depth-buffer bits, etc.

  • handle - Platform-specific handle of the control
  • settings - Additional settings for the underlying OpenGL context
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.new #

Default constructor

This constructor doesn't actually create the window, use the other constructors or call create() to do so.

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.new(*args, **kwargs) : self #

Shorthand for window = Window.new; window.create(...); window

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Methods#

#active=(active : Bool = true) : Bool #

Activate or deactivate the window as the current target for OpenGL rendering

A window is active only on the current thread, if you want to make it active on another thread you have to deactivate it on the previous thread first if it was active. Only one window can be active on a thread at a time, thus the window previously active (if any) automatically gets deactivated. This is not to be confused with request_focus().

  • active - True to activate, false to deactivate

Returns: True if operation was successful, false otherwise

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#close #

Close the window and destroy all the attached resources

After calling this function, the SF::Window instance remains valid and you can call create() to recreate the window. All other functions such as poll_event() or display() will still work (i.e. you don't have to test open?() every time), and will have no effect on closed windows.

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#create(mode : VideoMode, title : String, style : Style = Style::Default, settings : ContextSettings = ContextSettings.new) #

Create (or recreate) the window

If the window was already created, it closes it first. If style contains Style::Fullscreen, then mode must be a valid video mode.

The fourth parameter is an optional structure specifying advanced OpenGL context settings such as antialiasing, depth-buffer bits, etc.

  • mode - Video mode to use (defines the width, height and depth of the rendering area of the window)
  • title - Title of the window
  • style - Window style, a bitwise OR combination of SF::Style enumerators
  • settings - Additional settings for the underlying OpenGL context
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#create(handle : WindowHandle, settings : ContextSettings = ContextSettings.new) #

Create (or recreate) the window from an existing control

Use this function if you want to create an OpenGL rendering area into an already existing control. If the window was already created, it closes it first.

The second parameter is an optional structure specifying advanced OpenGL context settings such as antialiasing, depth-buffer bits, etc.

  • handle - Platform-specific handle of the control
  • settings - Additional settings for the underlying OpenGL context
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#display #

Display on screen what has been rendered to the window so far

This function is typically called after all OpenGL rendering has been done for the current frame, in order to show it on screen.

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#finalize #

Destructor

Closes the window and frees all the resources attached to it.

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#focus? : Bool #

Check whether the window has the input focus

At any given time, only one window may have the input focus to receive input events such as keystrokes or most mouse events.

Returns: True if window has focus, false otherwise See also: request_focus

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#framerate_limit=(limit : Int) #

Limit the framerate to a maximum fixed frequency

If a limit is set, the window will use a small delay after each call to display() to ensure that the current frame lasted long enough to match the framerate limit. SFML will try to match the given limit as much as it can, but since it internally uses SF.sleep, whose precision depends on the underlying OS, the results may be a little unprecise as well (for example, you can get 65 FPS when requesting 60).

  • limit - Framerate limit, in frames per seconds (use 0 to disable limit)
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#joystick_threshold=(threshold : Number) #

Change the joystick threshold

The joystick threshold is the value below which no JoystickMoved event will be generated.

The threshold value is 0.1 by default.

  • threshold - New threshold, in the range 0.0 .. 100.0
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#key_repeat_enabled=(enabled : Bool) #

Enable or disable automatic key-repeat

If key repeat is enabled, you will receive repeated KeyPressed events while keeping a key pressed. If it is disabled, you will only get a single event when the key is pressed.

Key repeat is enabled by default.

  • enabled - True to enable, false to disable
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#mouse_cursor=(cursor : Cursor) #

Set the displayed cursor to a native system cursor

Upon window creation, the arrow cursor is used by default.

Warning: The cursor must not be destroyed while in use by the window.

Warning: Features related to Cursor are not supported on iOS and Android.

  • cursor - Native system cursor type to display

See also: SF::Cursor.load_from_system See also: SF::Cursor.load_from_pixels

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#mouse_cursor_grabbed=(grabbed : Bool) #

Grab or release the mouse cursor

If set, grabs the mouse cursor inside this window's client area so it may no longer be moved outside its bounds. Note that grabbing is only active while the window has focus.

  • grabbed - True to enable, false to disable
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#mouse_cursor_visible=(visible : Bool) #

Show or hide the mouse cursor

The mouse cursor is visible by default.

  • visible - True to show the mouse cursor, false to hide it
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#open? : Bool #

Tell whether or not the window is open

This function returns whether or not the window exists. Note that a hidden window (visible=(false)) is open (therefore this function would return true).

Returns: True if the window is open, false if it has been closed

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#poll_event : Event? #

Pop the event on top of the event queue, if any, and return it

This function is not blocking: if there's no pending event then it will return false and leave event unmodified. Note that more than one event may be present in the event queue, thus you should always call this function in a loop to make sure that you process every pending event.

while (event = window.poll_event())
  # process event...
end

  • event - Event to be returned

Returns: True if an event was returned, or false if the event queue was empty

See also: wait_event

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#position : Vector2i #

Get the position of the window

Returns: Position of the window, in pixels

See also: position=

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#position=(position : Vector2 | Tuple) #

Change the position of the window on screen

This function only works for top-level windows (i.e. it will be ignored for windows created from the handle of a child window/control).

  • position - New position, in pixels

See also: position

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#request_focus #

Request the current window to be made the active foreground window

At any given time, only one window may have the input focus to receive input events such as keystrokes or mouse events. If a window requests focus, it only hints to the operating system, that it would like to be focused. The operating system is free to deny the request. This is not to be confused with active=().

See also: focus?

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#set_icon(width : Int, height : Int, pixels : Pointer(UInt8)) #

Change the window's icon

pixels must be an array of width x height pixels in 32-bits RGBA format.

The OS default icon is used by default.

  • width - Icon's width, in pixels
  • height - Icon's height, in pixels
  • pixels - Pointer to the array of pixels in memory. The pixels are copied, so you need not keep the source alive after calling this function.

See also: title=

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#settings : ContextSettings #

Get the settings of the OpenGL context of the window

Note that these settings may be different from what was passed to the constructor or the create() function, if one or more settings were not supported. In this case, SFML chose the closest match.

Returns: Structure containing the OpenGL context settings

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#size : Vector2u #

Get the size of the rendering region of the window

The size doesn't include the titlebar and borders of the window.

Returns: Size in pixels

See also: size=

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#size=(size : Vector2 | Tuple) #

Change the size of the rendering region of the window

  • size - New size, in pixels

See also: size

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#system_handle : WindowHandle #

Get the OS-specific handle of the window

The type of the returned handle is SF::WindowHandle, which is a typedef to the handle type defined by the OS. You shouldn't need to use this function, unless you have very specific stuff to implement that SFML doesn't support, or implement a temporary workaround until a bug is fixed.

Returns: System handle of the window

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#title=(title : String) #

Change the title of the window

  • title - New title

See also: icon=

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#vertical_sync_enabled=(enabled : Bool) #

Enable or disable vertical synchronization

Activating vertical synchronization will limit the number of frames displayed to the refresh rate of the monitor. This can avoid some visual artifacts, and limit the framerate to a good value (but not constant across different computers).

Vertical synchronization is disabled by default.

  • enabled - True to enable v-sync, false to deactivate it
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#visible=(visible : Bool) #

Show or hide the window

The window is shown by default.

  • visible - True to show the window, false to hide it
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#wait_event : Event? #

Wait for an event and return it

This function is blocking: if there's no pending event then it will wait until an event is received. After this function returns (and no error occurred), the event object is always valid and filled properly. This function is typically used when you have a thread that is dedicated to events handling: you want to make this thread sleep as long as no new event is received.

if (event = window.wait_event())
  # process event...
end

  • event - Event to be returned

Returns: False if any error occurred

See also: poll_event

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