Events

This page documents various window events

Saucer offers a simple event system. Classes that offer events have the following member functions:

on<event>(listener)
once<event>(callback)
off(event)
off(event, id)

Registering an event is as simple as calling on:

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const auto id = window->on<saucer::window::event::resize>([](int width, int height) {
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    // ...
3
});

Each registered event is associated with an ID. This ID can later be used to disconnect the event:

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window->off(saucer::window::event::resize, id);

It is also possible to disconnect all events of a specific type by omitting the ID:

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window->off(saucer::window::event::resize);

There is also the possibility to register events that will not be cleared by wildcard disconnects:

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window->on<saucer::window::event::resize>({{.func = [](int width, int height) { /*...*/ }, .clearable = false}});

These events can only be cleared by explicitly disconnecting them by their ID.

Available Events

This event is emitted when a windows decorations change.

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window->on<saucer::window::event::decorated>([](saucer::window::decoration) {
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    // ...
3
});

This event is emitted when a window is (un-)maximized.

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window->on<saucer::window::event::maximize>([](bool) {
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    // ...
3
});

The passed parameter is set to true when the window was maximized and false otherwise.

This event is emitted when a window is (un-)minimized.

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window->on<saucer::window::event::minimize>([](bool) {
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    // ...
3
});

The passed parameter is set to true when the window was minimized and false otherwise.

This event is emitted when a window is closed.

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window->on<saucer::window::event::closed>([] {
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    // ...
3
});

This event is emitted when a window is resized.

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window->on<saucer::window::event::resize>([](int, int) {
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    // ...
3
});

The passed parameters are the new width and height.

This event is emitted when a window is (un-)focused.

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window->on<saucer::window::event::focus>([](bool) {
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    // ...
3
});

The passed parameter is set to true when the window was focused and false otherwise.

This event is emitted when a window is about to be closed.

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window->on<saucer::window::event::close>([] -> saucer::policy {
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    // ...
3
});

Subscribers of this event can block (saucer::policy::block) or allow (saucer::policy::allow) the close operation by returning the respective policy decision.