42 lines
1.4 KiB
Kotlin
42 lines
1.4 KiB
Kotlin
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package center.sciprog.maps.features
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import androidx.compose.ui.input.pointer.PointerEvent
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import androidx.compose.ui.input.pointer.isPrimaryPressed
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public fun interface DragHandle<in V: ViewPoint<*>> {
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/**
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* @param event - qualifiers of the event used for drag
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* @param start - is a point where drag begins, end is a point where drag ends
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* @param end - end point of the drag
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*
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* @return true if default event processors should be used after this one
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*/
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public fun handle(event: PointerEvent, start: V, end: V): Boolean
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public companion object {
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public val BYPASS: DragHandle<*> = DragHandle<ViewPoint<*>> { _, _, _ -> true }
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/**
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* Process only events with primary button pressed
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*/
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public fun <V> withPrimaryButton(
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block: (event: PointerEvent, start: V, end: V) -> Boolean,
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): DragHandle<V> = DragHandle { event, start, end ->
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if (event.buttons.isPrimaryPressed) {
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block(event, start, end)
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} else {
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true
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}
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}
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/**
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* Combine several handles into one
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*/
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public fun <V> combine(vararg handles: DragHandle<V>): DragHandle<V> = DragHandle { event, start, end ->
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handles.forEach {
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if (!it.handle(event, start, end)) return@DragHandle false
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}
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return@DragHandle true
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}
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}
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}
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