Struct rute::auto::application::Application

pub struct Application<'a> { /* private fields */ }

Notice these docs are heavy WIP and not very relevent yet

QApplication specializes QGuiApplication with some functionality needed for QWidget-based applications. It handles widget specific initialization, finalization.

For any GUI application using Qt, there is precisely one QApplication object, no matter whether the application has 0, 1, 2 or more windows at any given time. For non-QWidget based Qt applications, use QGuiApplication instead, as it does not depend on the QtWidgets library.

Some GUI applications provide a special batch mode ie. provide command line arguments for executing tasks without manual intervention. In such non-GUI mode, it is often sufficient to instantiate a plain QCoreApplication to avoid unnecessarily initializing resources needed for a graphical user interface. The following example shows how to dynamically create an appropriate type of application instance:

The QApplication object is accessible through the instance() function that returns a pointer equivalent to the global qApp pointer.

QApplication’s main areas of responsibility are:

• It initializes the application with the user’s desktop settings such as palette(), font() and doubleClickInterval(). It keeps track of these properties in case the user changes the desktop globally, for example through some kind of control panel.
• It performs event handling, meaning that it receives events from the underlying window system and dispatches them to the relevant widgets. By using sendEvent() and postEvent() you can send your own events to widgets.
• It parses common command line arguments and sets its internal state accordingly. See the constructor documentation below for more details.
• It defines the application’s look and feel, which is encapsulated in a QStyle object. This can be changed at runtime with setStyle().
• It specifies how the application is to allocate colors. See setColorSpec() for details.
• It provides localization of strings that are visible to the user via translate().
• It provides some magical objects like the desktop() and the clipboard().
• It knows about the application’s windows. You can ask which widget is at a certain position using widgetAt(), get a list of topLevelWidgets() and closeAllWindows(), etc.
• It manages the application’s mouse cursor handling, see setOverrideCursor()

Since the QApplication object does so much initialization, it must be created before any other objects related to the user interface are created. QApplication also deals with common command line arguments. Hence, it is usually a good idea to create it before any interpretation or modification of argv is done in the application itself.

• {2,1} Groups of functions

• System settings

• desktopSettingsAware(), setDesktopSettingsAware(), cursorFlashTime(), setCursorFlashTime(), doubleClickInterval(), setDoubleClickInterval(), setKeyboardInputInterval(), wheelScrollLines(), setWheelScrollLines(), palette(), setPalette(), font(), setFont(), fontMetrics().

• Event handling

• exec(), processEvents(), exit(), quit(). sendEvent(), postEvent(), sendPostedEvents(), removePostedEvents(), hasPendingEvents(), notify().

• GUI Styles

• style(), setStyle().

• Color usage

• colorSpec(), setColorSpec().

• Text handling

• installTranslator(), removeTranslator() translate().

• Widgets

• allWidgets(), topLevelWidgets(), desktop(), activePopupWidget(), activeModalWidget(), clipboard(), focusWidget(), activeWindow(), widgetAt().

• Advanced cursor handling

• overrideCursor(), setOverrideCursor(), restoreOverrideCursor().

• Miscellaneous

• closeAllWindows(), startingUp(), closingDown().

See also: CoreApplication [AbstractEventDispatcher] [EventLoop] [Settings]

Licence

The documentation is an adoption of the original Qt Documentation and provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation.

Implementations

impl<'a> Application<'a>

pub fn new() -> Application<'a>

pub fn style() -> Option<Style<'a>>

By default, this property returns an empty string unless the user specifies the -stylesheet option on the command line when running the application.

See also: Widget::set_style {Qt Style Sheets}

Returns the application’s style object.

See also: [set_style()] Style

pub fn set_style<S: StyleTrait<'a>>(arg0: &S)

Sets the application’s GUI style to style. Ownership of the style object is transferred to QApplication, so QApplication will delete the style object on application exit or when a new style is set and the old style is still the parent of the application object.

Example usage:

When switching application styles, the color palette is set back to the initial colors or the system defaults. This is necessary since certain styles have to adapt the color palette to be fully style-guide compliant.

Setting the style before a palette has been set, i.e., before creating QApplication, will cause the application to use QStyle::standardPalette() for the palette.

Warning: Qt style sheets are currently not supported for custom QStyle subclasses. We plan to address this in some future release.

See also: [style()] Style [set_palette()] [desktop_settings_aware()]

Overloads Requests a QStyle object for style from the QStyleFactory.

The string must be one of the QStyleFactory::keys(), typically one of , , , or . Style names are case insensitive.

Returns 0 if an unknown style is passed, otherwise the QStyle object returned is set as the application’s GUI style.

Warning: To ensure that the application’s style is set correctly, it is best to call this function before the QApplication constructor, if possible.

pub fn set_style_2(arg0: &str) -> Option<Style<'a>>

Sets the application’s GUI style to style. Ownership of the style object is transferred to QApplication, so QApplication will delete the style object on application exit or when a new style is set and the old style is still the parent of the application object.

Example usage:

When switching application styles, the color palette is set back to the initial colors or the system defaults. This is necessary since certain styles have to adapt the color palette to be fully style-guide compliant.

Setting the style before a palette has been set, i.e., before creating QApplication, will cause the application to use QStyle::standardPalette() for the palette.

Warning: Qt style sheets are currently not supported for custom QStyle subclasses. We plan to address this in some future release.

See also: [style()] Style [set_palette()] [desktop_settings_aware()]

Overloads Requests a QStyle object for style from the QStyleFactory.

The string must be one of the QStyleFactory::keys(), typically one of , , , or . Style names are case insensitive.

Returns 0 if an unknown style is passed, otherwise the QStyle object returned is set as the application’s GUI style.

Warning: To ensure that the application’s style is set correctly, it is best to call this function before the QApplication constructor, if possible.

pub fn color_spec() -> i32

Returns the color specification.

See also: Application::set_color_spec

pub fn set_color_spec(arg0: i32)

Sets the color specification for the application to spec.

This call has no effect.

The color specification controls how the application allocates colors when run on a display with a limited amount of colors, e.g. 8 bit / 256 color displays.

The color specification must be set before you create the QApplication object.

The options are:

• QApplication::NormalColor. This is the default color allocation strategy. Use this option if your application uses buttons, menus, texts and pixmaps with few colors. With this option, the application uses system global colors. This works fine for most applications under X11, but on the Windows platform, it may cause dithering of non-standard colors.
• QApplication::CustomColor. Use this option if your application needs a small number of custom colors. On X11, this option is the same as NormalColor. On Windows, Qt creates a Windows palette, and allocates colors to it on demand.
• QApplication::ManyColor. Use this option if your application is very color hungry, e.g., it requires thousands of colors. r Under X11 the effect is:
• For 256-color displays which have at best a 256 color true color visual, the default visual is used, and colors are allocated from a color cube. The color cube is the 6x6x6 (216 color) “Web palette” (the red, green, and blue components always have one of the following values: 0x00, 0x33, 0x66, 0x99, 0xCC, or 0xFF), but the number of colors can be changed by the -ncols option. The user can force the application to use the true color visual with the -visual option.
• For 256-color displays which have a true color visual with more than 256 colors, use that visual. Silicon Graphics X servers this feature, for example. They provide an 8 bit visual by default but can deliver true color when asked. On Windows, Qt creates a Windows palette, and fills it with a color cube.

Be aware that the CustomColor and ManyColor choices may lead to colormap flashing: The foreground application gets (most) of the available colors, while the background windows will look less attractive.

Example:

See also: [color_spec()]

pub fn palette<W: WidgetTrait<'a>>(arg0: &W) -> Palette<'a>

Overloads If a widget is passed, the default palette for the widget’s class is returned. This may or may not be the application palette. In most cases there is no special palette for certain types of widgets, but one notable exception is the popup menu under Windows, if the user has defined a special background color for menus in the display settings.

See also: [set_palette()] Widget::palette

Overloads Returns the palette for widgets of the given className.

See also: [set_palette()] Widget::palette

pub fn font() -> Font<'a>

Overloads If a widget is passed, the default palette for the widget’s class is returned. This may or may not be the application palette. In most cases there is no special palette for certain types of widgets, but one notable exception is the popup menu under Windows, if the user has defined a special background color for menus in the display settings.

See also: [set_palette()] Widget::palette

Overloads Returns the palette for widgets of the given className.

See also: [set_palette()] Widget::palette

Returns the default application font.

See also: [font_metrics()] Widget::font

Overloads Returns the default font for the widget.

See also: [font_metrics()] Widget::set_font

Overloads Returns the font for widgets of the given className.

See also: [set_font()] Widget::font

Returns display (screen) font metrics for the application font.

See also: [font()] [set_font()] [Widget::font_metrics] [Painter::font_metrics]

pub fn font_2<W: WidgetTrait<'a>>(arg0: &W) -> Font<'a>

Returns the default application font.

See also: [font_metrics()] Widget::font

Overloads Returns the default font for the widget.

See also: [font_metrics()] Widget::set_font

Overloads Returns the font for widgets of the given className.

See also: [set_font()] Widget::font

Returns display (screen) font metrics for the application font.

See also: [font()] [set_font()] [Widget::font_metrics] [Painter::font_metrics]

pub fn set_window_icon<I: IconTrait<'a>>(icon: &I)

pub fn window_icon() -> Icon<'a>

See also: Widget::set_window_icon {Setting the Application Icon}

pub fn desktop() -> Option<DesktopWidget<'a>>

Returns the desktop widget (also called the root window).

The desktop may be composed of multiple screens, so it would be incorrect, for example, to attempt to center some widget in the desktop’s geometry. QDesktopWidget has various functions for obtaining useful geometries upon the desktop, such as QDesktopWidget::screenGeometry() and QDesktopWidget::availableGeometry().

On X11, it is also possible to draw on the desktop.

pub fn active_popup_widget() -> Option<Widget<'a>>

Returns the active popup widget.

A popup widget is a special top-level widget that sets the Qt::WType_Popup widget flag, e.g. the QMenu widget. When the application opens a popup widget, all events are sent to the popup. Normal widgets and modal widgets cannot be accessed before the popup widget is closed.

Only other popup widgets may be opened when a popup widget is shown. The popup widgets are organized in a stack. This function returns the active popup widget at the top of the stack.

See also: [active_modal_widget()] [top_level_widgets()]

pub fn active_modal_widget() -> Option<Widget<'a>>

Returns the active modal widget.

A modal widget is a special top-level widget which is a subclass of QDialog that specifies the modal parameter of the constructor as true. A modal widget must be closed before the user can continue with other parts of the program.

Modal widgets are organized in a stack. This function returns the active modal widget at the top of the stack.

See also: [active_popup_widget()] [top_level_widgets()]

pub fn focus_widget() -> Option<Widget<'a>>

Returns the application widget that has the keyboard input focus, or 0 if no widget in this application has the focus.

See also: Widget::set_focus Widget::has_focus [active_window()] [focus_changed()]

pub fn active_window() -> Option<Widget<'a>>

Returns the application top-level window that has the keyboard input focus, or 0 if no application window has the focus. There might be an activeWindow() even if there is no focusWidget(), for example if no widget in that window accepts key events.

See also: Widget::set_focus Widget::has_focus [focus_widget()]

pub fn set_active_window<W: WidgetTrait<'a>>(act: &W)

Sets the active window to the active widget in response to a system event. The function is called from the platform specific event handlers.

Warning: This function does not set the keyboard focus to the active widget. Call QWidget::activateWindow() instead.

It sets the activeWindow() and focusWidget() attributes and sends proper WindowActivate / WindowDeactivate and FocusIn / FocusOut events to all appropriate widgets. The window will then be painted in active state (e.g. cursors in line edits will blink), and it will have tool tips enabled.

See also: [active_window()] Widget::activate_window

pub fn widget_at<P: PointTrait<'a>>(p: &P) -> Option<Widget<'a>>

Returns the widget at global screen position point, or 0 if there is no Qt widget there.

This function can be slow.

See also: Cursor::pos Widget::grab_mouse Widget::grab_keyboard

Overloads Returns the widget at global screen position ( x, y), or 0 if there is no Qt widget there.

pub fn widget_at_2(x: i32, y: i32) -> Option<Widget<'a>>

Returns the widget at global screen position point, or 0 if there is no Qt widget there.

This function can be slow.

See also: Cursor::pos Widget::grab_mouse Widget::grab_keyboard

Overloads Returns the widget at global screen position ( x, y), or 0 if there is no Qt widget there.

pub fn top_level_at<P: PointTrait<'a>>(p: &P) -> Option<Widget<'a>>

Returns the top-level widget at the given point; returns 0 if there is no such widget.

Overloads Returns the top-level widget at the point ( x , y ); returns 0 if there is no such widget.

pub fn top_level_at_2(x: i32, y: i32) -> Option<Widget<'a>>

Returns the top-level widget at the given point; returns 0 if there is no such widget.

Overloads Returns the top-level widget at the point ( x , y ); returns 0 if there is no such widget.

pub fn beep()

Sounds the bell, using the default volume and sound. The function is not available in Qt for Embedded Linux.

pub fn alert<W: WidgetTrait<'a>>(widget: &W, duration: i32)

Causes an alert to be shown for widget if the window is not the active window. The alert is shown for msec miliseconds. If msec is zero (the default), then the alert is shown indefinitely until the window becomes active again.

Currently this function does nothing on Qt for Embedded Linux.

On MacOS , this works more at the application level and will cause the application icon to bounce in the dock.

On Windows, this causes the window’s taskbar entry to flash for a time. If msec is zero, the flashing will stop and the taskbar entry will turn a different color (currently orange).

On X11, this will cause the window to be marked as , the window must not be hidden (i.e. not have hide() called on it, but be visible in some sort of way) in order for this to work.

pub fn set_cursor_flash_time(arg0: i32)

pub fn cursor_flash_time() -> i32

The flash time is the time required to display, invert and restore the caret display. Usually the text cursor is displayed for half the cursor flash time, then hidden for the same amount of time, but this may vary.

The default value on X11 is 1000 milliseconds. On Windows, the {Control Panel} value is used and setting this property sets the cursor flash time for all applications.

We recommend that widgets do not cache this value as it may change at any time if the user changes the global desktop settings.

Note: This property may hold a negative value, for instance if cursor blinking is disabled.

pub fn set_double_click_interval(arg0: i32)

pub fn double_click_interval() -> i32

The default value on X11 is 400 milliseconds. On Windows and Mac OS, the operating system’s value is used.

pub fn set_keyboard_input_interval(arg0: i32)

pub fn keyboard_input_interval() -> i32

The default value on X11 is 400 milliseconds. On Windows and Mac OS, the operating system’s value is used.

pub fn set_wheel_scroll_lines(arg0: i32)

pub fn wheel_scroll_lines() -> i32

If the value exceeds the widget’s number of visible lines, the widget should interpret the scroll operation as a single page up or page down . If the widget is an item view class

then the result of scrolling one line depends on the setting of the widget’s scroll mode . Scroll one line can mean scroll one item

or scroll one pixel

By default, this property has a value of 3.

See also: [StyleHints::wheel_scroll_lines]

pub fn set_start_drag_time(ms: i32)

pub fn start_drag_time() -> i32

If you support drag and drop in your application, and want to start a drag and drop operation after the user has held down a mouse button for a certain amount of time, you should use this property’s value as the delay.

Qt also uses this delay internally, e.g. in QTextEdit and QLineEdit, for starting a drag.

The default value is 500 ms.

See also: [start_drag_distance()] {Drag and Drop}

pub fn set_start_drag_distance(l: i32)

pub fn start_drag_distance() -> i32

If you support drag and drop in your application, and want to start a drag and drop operation after the user has moved the cursor a certain distance with a button held down, you should use this property’s value as the minimum distance required.

For example, if the mouse position of the click is stored in startPos and the current position (e.g. in the mouse move event) is currentPos, you can find out if a drag should be started with code like this:

Qt uses this value internally, e.g. in QFileDialog.

The default value (if the platform doesn’t provide a different default) is 10 pixels.

See also: [start_drag_time()] Point::manhattan_length {Drag and Drop}

pub fn is_effect_enabled(arg0: UIEffect) -> bool

Returns true if effect is enabled; otherwise returns false.

By default, Qt will try to use the desktop settings. To prevent this, call setDesktopSettingsAware(false).

Note: All effects are disabled on screens running at less than 16-bit color depth.

See also: [set_effect_enabled()] [t::ui_effect()]

pub fn set_effect_enabled(arg0: UIEffect, enable: bool)

Enables the UI effect effect if enable is true, otherwise the effect will not be used.

Note: All effects are disabled on screens running at less than 16-bit color depth.

See also: [is_effect_enabled()] [t::ui_effect()] [set_desktop_settings_aware()]

pub fn exec() -> i32

Enters the main event loop and waits until exit() is called, then returns the value that was set to exit() (which is 0 if exit() is called via quit()).

It is necessary to call this function to start event handling. The main event loop receives events from the window system and dispatches these to the application widgets.

Generally, no user interaction can take place before calling exec(). As a special case, modal widgets like QMessageBox can be used before calling exec(), because modal widgets call exec() to start a local event loop.

To make your application perform idle processing, i.e., executing a special function whenever there are no pending events, use a QTimer with 0 timeout. More advanced idle processing schemes can be achieved using processEvents().

We recommend that you connect clean-up code to the aboutToQuit() signal, instead of putting it in your application’s main() function. This is because, on some platforms the QApplication::exec() call may not return. For example, on the Windows platform, when the user logs off, the system terminates the process after Qt closes all top-level windows. Hence, there is no guarantee that the application will have time to exit its event loop and execute code at the end of the main() function, after the QApplication::exec() call.

See also: quitOnLastWindowClosed CoreApplication::quit CoreApplication::exit [CoreApplication::process_events] CoreApplication::exec

pub fn style_sheet(&self) -> String

This signal is emitted when the widget that has keyboard focus changed from old to now, i.e., because the user pressed the tab-key, clicked into a widget or changed the active window. Both old and now can be the null-pointer.

The signal is emitted after both widget have been notified about the change through QFocusEvent.

See also: Widget::set_focus Widget::clear_focus [t::focus_reason()]

By default, this property returns an empty string unless the user specifies the -stylesheet option on the command line when running the application.

See also: Widget::set_style {Qt Style Sheets}

pub fn set_style_sheet(&self, sheet: &str) -> &Self

pub fn set_auto_sip_enabled(&self, enabled: bool) -> &Self

pub fn auto_sip_enabled(&self) -> bool

Set this property to true to automatically display the SIP when entering widgets that accept keyboard input. This property only affects widgets with the WA_InputMethodEnabled attribute set, and is typically used to launch a virtual keyboard on devices which have very few or no keys.

The property only has an effect on platforms that use software input panels.

The default is platform dependent.

pub fn close_all_windows()

Closes all top-level windows.

This function is particularly useful for applications with many top-level windows. It could, for example, be connected to a {Exit} entry in the {File} menu:

The windows are closed in random order, until one window does not accept the close event. The application quits when the last window was successfully closed; this can be turned off by setting quitOnLastWindowClosed to false.

See also: quitOnLastWindowClosed [last_window_closed()] Widget::close [Widget::close_event] [last_window_closed()] CoreApplication::quit [top_level_widgets()] Widget::is_window

pub fn about_qt()

Displays a simple message box about Qt. The message includes the version number of Qt being used by the application.

This is useful for inclusion in the Help menu of an application, as shown in the Menus example.

This function is a convenience slot for QMessageBox::aboutQt().

pub fn set_about_to_quit_event_ud<F, T>(&self, data: &'a T, func: F) -> &Selfwhere
    F: Fn(&T) + 'a,
    T: 'a,

This signal is emitted when the application is about to quit the main event loop, e.g. when the event loop level drops to zero. This may happen either after a call to quit() from inside the application or when the user shuts down the entire desktop session.

The signal is particularly useful if your application has to do some last-second cleanup. Note that no user interaction is possible in this state.

See also: [quit()]

pub fn set_about_to_quit_event<F>(&self, func: F) -> &Selfwhere
    F: Fn() + 'a,

pub fn set_custom_event<F>(&self, func: F) -> &Selfwhere
    F: Fn(&Event<'_>) + 'a,

pub fn build(self) -> Self

Trait Implementations

impl<'a> Clone for Application<'a>

fn clone(&self) -> Application<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> ApplicationTrait<'a> for Application<'a>

impl<'a> CoreApplicationTrait<'a> for Application<'a>

impl<'a> GuiApplicationTrait<'a> for Application<'a>

impl<'a> ObjectTrait<'a> for Application<'a>