cacao/appkit/view/traits.rs

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//! Various traits used for Views.
use crate::dragdrop::{DragInfo, DragOperation};
use crate::view::View;
pub trait ViewDelegate {
/// Called when the View is ready to work with. You're passed a `ViewHandle` - this is safe to
/// store and use repeatedly, but it's not thread safe - any UI calls must be made from the
/// main thread!
fn did_load(&mut self, _view: View) {}
/// Called when this is about to be added to the view heirarchy.
fn will_appear(&self) {}
/// Called after this has been added to the view heirarchy.
fn did_appear(&self) {}
/// Called when this is about to be removed from the view heirarchy.
fn will_disappear(&self) {}
/// Called when this has been removed from the view heirarchy.
fn did_disappear(&self) {}
/// Invoked when the dragged image enters destination bounds or frame; returns dragging operation to perform.
fn dragging_entered(&self, _info: DragInfo) -> DragOperation { DragOperation::None }
/// Invoked when the image is released, allowing the receiver to agree to or refuse drag operation.
fn prepare_for_drag_operation(&self, _info: DragInfo) -> bool { false }
/// Invoked after the released image has been removed from the screen, signaling the receiver to import the pasteboard data.
fn perform_drag_operation(&self, _info: DragInfo) -> bool { false }
/// Invoked when the dragging operation is complete, signaling the receiver to perform any necessary clean-up.
fn conclude_drag_operation(&self, _info: DragInfo) {}
/// Invoked when the dragged image exits the destinations bounds rectangle (in the case of a view) or its frame
/// rectangle (in the case of a window object).
fn dragging_exited(&self, _info: DragInfo) {}
}