Sasha Koshka
b08cbea320
Instead of the previous parenting model where parents would set child callbacks during adoption by probing for callback setters, child elements will instead probe their parents for notify methods listed in the standard parent interfaces. This means that an element cannot be half-parented to something, nor can it be parented to two things at once. Parent elements may themselves fulfill these interfaces, or they can pass a hook that fulfills them to the child.
48 lines
1.7 KiB
Go
48 lines
1.7 KiB
Go
package element
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import "git.tebibyte.media/sashakoshka/tomo/input"
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// Parent represents a type capable of containing child elements.
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type Parent interface {
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// NotifyMinimumSizeChange notifies the container that a child element's
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// minimum size has changed. This method is expected to be called by
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// child elements when their minimum size changes.
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NotifyMinimumSizeChange (child Element)
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}
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// FocusableParent represents a parent with keyboard navigation support.
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type FocusableParent interface {
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Parent
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// RequestFocus notifies the parent that a child element is requesting
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// keyboard focus. If the parent grants the request, the method will
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// return true and the child element should behave as if a HandleFocus
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// call was made.
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RequestFocus (child Focusable, direction input.KeynavDirection) (granted bool)
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}
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// FlexibleParent represents a parent that accounts for elements with
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// flexible height.
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type FlexibleParent interface {
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Parent
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// NotifyFlexibleHeightChange notifies the parent that the parameters
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// affecting a child's flexible height have changed. This method is
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// expected to be called by flexible child element when their content
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// changes.
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NotifyFlexibleHeightChange (child Flexible)
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}
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// ScrollableParent represents a parent that can change the scroll
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// position of its child element(s).
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type ScrollableParent interface {
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Parent
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// NotifyScrollBoundsChange notifies the parent that a child's scroll
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// content bounds or viewport bounds have changed. This is expected to
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// be called by child elements when they change their supported scroll
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// axes, their scroll position (either autonomously or as a result of a
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// call to ScrollTo()), or their content size.
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NotifyScrollBoundsChange (child Scrollable)
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}
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