Class Window

Class Documentation

class Window

This class represents a window towards the windowing system, that’s used to render the scene of a component. It provides API to control windowing system specific aspects such as the position on the screen.

Public Functions

Window(const Window &other) = delete
Window &operator=(const Window &other) = delete
Window(Window &&other) = delete
Window &operator=(Window &&other) = delete
~Window() = default

Destroys this window. Window instances are explicitly shared and reference counted. If this window instance is the last one referencing the window towards the windowing system, then it will also become hidden and destroyed.

inline void show()

Shows the window on the screen. An additional strong reference on the associated component is maintained while the window is visible.

Call hide() to make the window invisible again, and drop the additional strong reference.

inline void hide()

Hides the window, so that it is not visible anymore. The additional strong reference on the associated component, that was created when show() was called, is dropped.

inline bool is_visible() const

Returns the visibility state of the window. This function can return false even if you previously called show() on it, for example if the user minimized the window.

template<std::invocable<RenderingState, GraphicsAPI> F>
inline std::optional<SetRenderingNotifierError> set_rendering_notifier(F &&callback) const

This function allows registering a callback that’s invoked during the different phases of rendering. This allows custom rendering on top or below of the scene.

The provided callback must be callable with a slint::RenderingState and the slint::GraphicsAPI argument.

On success, the function returns a std::optional without value. On error, the function returns the error code as value in the std::optional.

template<std::invocable F>
inline void on_close_requested(F &&callback) const

This function allows registering a callback that’s invoked when the user tries to close a window. The callback has to return a CloseRequestResponse.

inline void request_redraw() const

This function issues a request to the windowing system to redraw the contents of the window.

inline slint::PhysicalPosition position() const

Returns the position of the window on the screen, in physical screen coordinates and including a window frame (if present).

inline void set_position(const slint::LogicalPosition &pos)

Sets the position of the window on the screen, in physical screen coordinates and including a window frame (if present). Note that on some windowing systems, such as Wayland, this functionality is not available.

inline void set_position(const slint::PhysicalPosition &pos)

Sets the position of the window on the screen, in physical screen coordinates and including a window frame (if present). Note that on some windowing systems, such as Wayland, this functionality is not available.

inline slint::PhysicalSize size() const

Returns the size of the window on the screen, in physical screen coordinates and excluding a window frame (if present).

inline void set_size(const slint::LogicalSize &size)

Resizes the window to the specified size on the screen, in logical pixels and excluding a window frame (if present).

inline void set_size(const slint::PhysicalSize &size)

Resizes the window to the specified size on the screen, in physical pixels and excluding a window frame (if present).

inline float scale_factor() const

This function returns the scale factor that allows converting between logical and physical pixels.

inline bool is_fullscreen() const

Returns if the window is currently fullscreen.

inline void set_fullscreen(bool fullscreen)

Set or unset the window to display fullscreen.

inline bool is_maximized() const

Returns if the window is currently maximized.

inline void set_maximized(bool maximized)

Maximize or unmaximize the window.

inline bool is_minimized() const

Returns if the window is currently minimized.

inline void set_minimized(bool minimized)

Minimize or unminimze the window.

inline void dispatch_key_press_event(const SharedString &text)

Dispatch a key press event to the scene.

Use this when you’re implementing your own backend and want to forward user input events.

The text is the unicode representation of the key.

inline void dispatch_key_press_repeat_event(const SharedString &text)

Dispatch an auto-repeated key press event to the scene.

Use this when you’re implementing your own backend and want to forward user input events.

The text is the unicode representation of the key.

inline void dispatch_key_release_event(const SharedString &text)

Dispatch a key release event to the scene.

Use this when you’re implementing your own backend and want to forward user input events.

The text is the unicode representation of the key.

inline void dispatch_pointer_press_event(LogicalPosition pos, PointerEventButton button)

Dispatches a pointer or mouse press event to the scene.

Use this function when you’re implementing your own backend and want to forward user pointer/mouse events.

pos represents the logical position of the pointer relative to the window. button is the button that was pressed.

inline void dispatch_pointer_release_event(LogicalPosition pos, PointerEventButton button)

Dispatches a pointer or mouse release event to the scene.

Use this function when you’re implementing your own backend and want to forward user pointer/mouse events.

pos represents the logical position of the pointer relative to the window. button is the button that was released.

inline void dispatch_pointer_exit_event()

Dispatches a pointer exit event to the scene.

Use this function when you’re implementing your own backend and want to forward user pointer/mouse events.

This event is triggered when the pointer exits the window.

inline void dispatch_pointer_move_event(LogicalPosition pos)

Dispatches a pointer move event to the scene.

Use this function when you’re implementing your own backend and want to forward user pointer/mouse events.

pos represents the logical position of the pointer relative to the window.

inline void dispatch_pointer_scroll_event(LogicalPosition pos, float delta_x, float delta_y)

Dispatches a scroll (or wheel) event to the scene.

Use this function when you’re implementing your own backend and want to forward user wheel events.

parameter represents the logical position of the pointer relative to the window. delta_x and delta_y represent the scroll delta values in the X and Y directions in logical pixels.

inline void dispatch_resize_event(slint::LogicalSize s)

Set the logical size of this window after a resize event

The backend must send this event to ensure that the width and height property of the root Window element are properly set.

inline void dispatch_scale_factor_change_event(float factor)

The window’s scale factor has changed. This can happen for example when the display’s resolution changes, the user selects a new scale factor in the system settings, or the window is moved to a different screen. Platform implementations should dispatch this event also right after the initial window creation, to set the initial scale factor the windowing system provided for the window.

inline void dispatch_window_active_changed_event(bool active)

The Window was activated or de-activated.

The backend should dispatch this event with true when the window gains focus and false when the window loses focus.

inline void dispatch_close_requested_event()

The user requested to close the window.

The backend should send this event when the user tries to close the window,for example by pressing the close button.

This will have the effect of invoking the callback set in Window::on_close_requested() and then hiding the window depending on the return value of the callback.

inline bool has_active_animations() const

Returns true if there is an animation currently active on any property in the Window.