System UI: Enable resizing edge for screen capture's region select box. (7039007b) · Commits · e / os / android_frameworks_base

packages/SystemUI/src/com/android/systemui/screencapture/ui/compose/RegionBox.kt

+99 −59

Original line number	Diff line number	Diff line
		@@ -43,45 +43,70 @@ import androidx.compose.ui.unit.dp
		import com.android.systemui.common.shared.model.Icon as IconModel
		import com.android.systemui.res.R

		/**
		* A common interface for all draggable zones of the resizable box. The ResizeZone is one of Corner
		* or Edge.
		*/
		sealed interface ResizeZone

		/**
		* An enum to identify each of the four corners of the rectangle.
		*
		* @param alignment The alignment of the corner within the box.
		*/
		enum class Corner(val alignment: Alignment) {
		enum class Corner(val alignment: Alignment) : ResizeZone {
		TopLeft(Alignment.TopStart),
		TopRight(Alignment.TopEnd),
		BottomLeft(Alignment.BottomStart),
		BottomRight(Alignment.BottomEnd),
		}

		/** An enum to identify each of the four edges of the rectangle. */
		enum class Edge : ResizeZone {
		Top,
		Bottom,
		Left,
		Right,
		}

		/**
		* Determines which corner of a box is being touched based on the press offset.
		* Determines which zone (corner or edge) of a box is being touched based on the press offset.
		*
		* @param boxWidth The total width of the box.
		* @param boxHeight The total height of the box.
		* @param startOffset The position of the initial press.
		* @param touchAreaPx The size of the touch area in pixels.
		* @return The Corner that was touched, or `null` if the press was not in a corner.
		* @return The ResizeZone that was pressed, or `null` if the press was not on a zone.
		*/
		private fun getDraggedCorner(
		private fun getDragZone(
		boxWidth: Float,
		boxHeight: Float,
		startOffset: Offset,
		touchAreaPx: Float,
		): Corner? {
		): ResizeZone? {
		val isTouchingTop = startOffset.y in -touchAreaPx..touchAreaPx
		val isTouchingBottom = startOffset.y in (boxHeight - touchAreaPx)..boxHeight
		val isTouchingLeft = startOffset.x in -touchAreaPx..touchAreaPx
		val isTouchingRight = startOffset.x in (boxWidth - touchAreaPx)..boxWidth

		return when {
		isTouchingTop && isTouchingLeft -> Corner.TopLeft
		isTouchingTop && isTouchingRight -> Corner.TopRight
		isTouchingBottom && isTouchingLeft -> Corner.BottomLeft
		isTouchingBottom && isTouchingRight -> Corner.BottomRight
		else -> null
		// Corners should be checked first because edges are also touched when the user touches a
		// corner.
		when {
		isTouchingTop && isTouchingLeft -> return Corner.TopLeft
		isTouchingTop && isTouchingRight -> return Corner.TopRight
		isTouchingBottom && isTouchingLeft -> return Corner.BottomLeft
		isTouchingBottom && isTouchingRight -> return Corner.BottomRight
		}

		// Edges are checked next.
		when {
		isTouchingTop -> return Edge.Top
		isTouchingBottom -> return Edge.Bottom
		isTouchingLeft -> return Edge.Left
		isTouchingRight -> return Edge.Right
		}

		return null
		}

		/**
		@@ -119,10 +144,9 @@ fun RegionBox(
		)
		}

		val onCornerDrag:
		(dragAmount: Offset, corner: Corner, maxWidth: Float, maxHeight: Float) -> Unit =
		{ dragAmount, corner, maxWidth, maxHeight ->
		// Used for calculating the new dimensions based on which corner is dragged.
		val onResizeDrag:
		(dragAmount: Offset, zone: ResizeZone, maxWidth: Float, maxHeight: Float) -> Unit =
		{ dragAmount, zone, maxWidth, maxHeight ->
		var newLeft = rect.left
		var newTop = rect.top
		var newRight = rect.right
		@@ -131,30 +155,50 @@ fun RegionBox(
		val (dragX, dragY) = dragAmount

		// Handle horizontal drag for resizing.
		if (corner == Corner.TopLeft \|\| corner == Corner.BottomLeft) {
		when (zone) {
		Corner.TopLeft,
		Corner.BottomLeft,
		Edge.Left -> {
		val potentialNewLeft = rect.left + dragX
		val rightLimitForMinWidth = rect.right - minSizePx

		newLeft = potentialNewLeft.coerceIn(0f, rightLimitForMinWidth)
		} else {
		}
		Corner.TopRight,
		Corner.BottomRight,
		Edge.Right -> {
		val potentialNewRight = rect.right + dragX
		val leftLimitForMinWidth = rect.left + minSizePx

		newRight = potentialNewRight.coerceIn(leftLimitForMinWidth, maxWidth)
		}
		else -> {
		// No horizontal change for Top or Bottom edges.
		}
		}

		// Handle vertical drag for resizing.
		if (corner == Corner.TopLeft \|\| corner == Corner.TopRight) {
		when (zone) {
		Corner.TopLeft,
		Corner.TopRight,
		Edge.Top -> {
		val potentialNewTop = rect.top + dragY
		val bottomLimitForMinHeight = rect.bottom - minSizePx

		newTop = potentialNewTop.coerceIn(0f, bottomLimitForMinHeight)
		} else {
		}
		Corner.BottomLeft,
		Corner.BottomRight,
		Edge.Bottom -> {
		val potentialNewBottom = rect.bottom + dragY
		val topLimitForMinHeight = rect.top + minSizePx

		newBottom = potentialNewBottom.coerceIn(topLimitForMinHeight, maxHeight)
		}
		else -> {
		// No vertical change for Left or Right edges.
		}
		}

		rect = Rect(newLeft, newTop, newRight, newBottom)
		}
		@@ -176,7 +220,7 @@ fun RegionBox(

		ResizableRectangle(
		rect = rect,
		onCornerDrag = onCornerDrag,
		onResizeDrag = onResizeDrag,
		onBoxDrag = onBoxDrag,
		onDragEnd = {
		onDragEnd(
		@@ -190,10 +234,11 @@ fun RegionBox(
		}

		/**
		* A box with a border that can be resized by dragging its corners and moved by dragging its body.
		* A box with a border that can be resized by dragging its zone (corner or edge), and moved by
		* dragging its body.
		*
		* @param rect The current geometry of the region box.
		* @param onCornerDrag Callback invoked when a corner is dragged.
		* @param onResizeDrag Callback invoked when a corner or edge is dragged.
		* @param onBoxDrag Callback invoked when the main body of the box is dragged.
		* @param onDragEnd Callback invoked when a drag gesture finishes.
		* @param modifier The modifier to be applied to the composable.
		@@ -201,7 +246,7 @@ fun RegionBox(
		@Composable
		private fun ResizableRectangle(
		rect: Rect,
		onCornerDrag: (dragAmount: Offset, corner: Corner, maxWidth: Float, maxHeight: Float) -> Unit,
		onResizeDrag: (dragAmount: Offset, zone: ResizeZone, maxWidth: Float, maxHeight: Float) -> Unit,
		onBoxDrag: (dragAmount: Offset, maxWidth: Float, maxHeight: Float) -> Unit,
		onDragEnd: () -> Unit,
		modifier: Modifier = Modifier,
		@@ -213,18 +258,18 @@ private fun ResizableRectangle(

		// The width of the border stroke around the region box.
		val borderStrokeWidth = 4.dp
		// The touch area for detecting a corner resize drag.
		val cornerTouchArea = 48.dp
		// The touch area for detecting an edge or corner resize drag.
		val touchArea = 48.dp

		// Must remember the screen size for the drag logic. Initial values are set to 0.
		var screenWidth by remember { mutableStateOf(0f) }
		var screenHeight by remember { mutableStateOf(0f) }

		val density = LocalDensity.current
		val cornerTouchAreaPx = with(density) { cornerTouchArea.toPx() }
		val touchAreaPx = with(density) { touchArea.toPx() }

		// State of the corner, can be either dragged or null.
		var draggedCorner by remember { mutableStateOf<Corner?>(null) }
		// The zone being dragged for resizing, if any.
		var draggedZone by remember { mutableStateOf<ResizeZone?>(null) }

		Box(
		modifier =
		@@ -245,40 +290,35 @@ private fun ResizableRectangle(
		height = with(density) { rect.height.toDp() },
		)
		.border(borderStrokeWidth, MaterialTheme.colorScheme.onSurfaceVariant)
		.pointerInput(screenWidth, screenHeight, onCornerDrag, onBoxDrag, onDragEnd) {
		.pointerInput(screenWidth, screenHeight, onResizeDrag, onBoxDrag, onDragEnd) {
		detectDragGestures(
		onDragStart = { startOffset ->
		draggedCorner =
		getDraggedCorner(
		draggedZone =
		getDragZone(
		boxWidth = size.width.toFloat(),
		boxHeight = size.height.toFloat(),
		startOffset = startOffset,
		touchAreaPx = cornerTouchAreaPx,
		touchAreaPx = touchAreaPx,
		)
		},
		onDragEnd = {
		draggedCorner = null
		draggedZone = null
		onDragEnd()
		},
		onDrag = { change, dragAmount ->
		change.consume()

		// Create a stable and local copy of the dragged corner. This
		// ensures that the value does not change in the onCornerDrag
		// Create a stable and local copy of the draggedZone. This
		// ensures that the value does not change in the onResizeDrag
		// callback.
		val currentCorner = draggedCorner

		if (currentCorner != null) {
		// If 'currentCorner' has a value, it means we are dragging a
		// corner for resizing.
		onCornerDrag(
		dragAmount,
		currentCorner,
		screenWidth,
		screenHeight,
		)
		val currentZone = draggedZone

		if (currentZone != null) {
		// If currentZone has a value, it means we are dragging a zone
		// for resizing.
		onResizeDrag(dragAmount, currentZone, screenWidth, screenHeight)
		} else {
		// If 'currentCorner' is null, it means we are dragging the box.
		// If currentZone is null, it means we are dragging the box.
		onBoxDrag(dragAmount, screenWidth, screenHeight)
		}
		},