Created
December 4, 2019 12:18
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Image view to perform pinch and drag operation
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class DelhiveryZoomDragImageView( | |
internal var context: Context, | |
attr: AttributeSet | |
) : AppCompatImageView(context, attr) { | |
var lastEvent: FloatArray? = null | |
var d = 0f | |
var newRot = 0f | |
private var isZoomAndRotate: Boolean = false | |
private var isOutSide: Boolean = false | |
private val NONE = 0 | |
private val DRAG = 1 | |
private val ZOOM = 2 | |
private var mode = NONE | |
private var start = PointF() | |
private var mid = PointF() | |
var oldDist = 1f | |
private var xCoOrdinate: Float = 0.toFloat() | |
private var yCoOrdinate: Float = 0.toFloat() | |
init { | |
super.setClickable(true) | |
setOnTouchListener { v, event -> | |
val view = v as AppCompatImageView | |
view.bringToFront() | |
viewTransformation(view, event) | |
true | |
} | |
} | |
private fun viewTransformation( | |
view: View, | |
event: MotionEvent | |
) { | |
when (event.action and MotionEvent.ACTION_MASK) { | |
MotionEvent.ACTION_DOWN -> { | |
xCoOrdinate = view.x - event.rawX | |
yCoOrdinate = view.y - event.rawY | |
start.set(event.x, event.y) | |
isOutSide = false | |
mode = DRAG | |
lastEvent = null | |
} | |
MotionEvent.ACTION_POINTER_DOWN -> { | |
oldDist = spacing(event) | |
if (oldDist > 10f) { | |
midPoint(mid, event) | |
mode = ZOOM | |
} | |
lastEvent = FloatArray(4) | |
lastEvent!![0] = event.getX(0) | |
lastEvent!![1] = event.getX(1) | |
lastEvent!![2] = event.getY(0) | |
lastEvent!![3] = event.getY(1) | |
d = rotation(event) | |
} | |
MotionEvent.ACTION_UP -> { | |
isZoomAndRotate = false | |
if (mode == DRAG) { | |
val x = event.x | |
val y = event.y | |
} | |
isOutSide = true | |
mode = NONE | |
lastEvent = null | |
mode = NONE | |
lastEvent = null | |
} | |
MotionEvent.ACTION_OUTSIDE -> { | |
isOutSide = true | |
mode = NONE | |
lastEvent = null | |
mode = NONE | |
lastEvent = null | |
} | |
MotionEvent.ACTION_POINTER_UP -> { | |
mode = NONE | |
lastEvent = null | |
} | |
MotionEvent.ACTION_MOVE -> if (!isOutSide) { | |
if (mode == DRAG) { | |
isZoomAndRotate = false | |
view.animate() | |
.x(event.rawX + xCoOrdinate) | |
.y(event.rawY + yCoOrdinate) | |
.setDuration(0) | |
.start() | |
} | |
if (mode == ZOOM && event.pointerCount == 2) { | |
val newDist1 = spacing(event) | |
if (newDist1 > 10f) { | |
val scale = newDist1 / oldDist * view.scaleX | |
view.scaleX = scale | |
view.scaleY = scale | |
} | |
if (lastEvent != null) { | |
newRot = rotation(event) | |
view.rotation = (view.rotation + (newRot - d)) | |
} | |
} | |
} | |
} | |
} | |
private fun rotation(event: MotionEvent): Float { | |
val delta_x = (event.getX(0) - event.getX(1)).toDouble() | |
val delta_y = (event.getY(0) - event.getY(1)).toDouble() | |
val radians = Math.atan2(delta_y, delta_x) | |
return Math.toDegrees(radians) | |
.toFloat() | |
} | |
private fun spacing(event: MotionEvent): Float { | |
val x = event.getX(0) - event.getX(1) | |
val y = event.getY(0) - event.getY(1) | |
return Math.sqrt((x * x + y * y).toDouble()) | |
.toInt() | |
.toFloat() | |
} | |
private fun midPoint( | |
point: PointF, | |
event: MotionEvent | |
) { | |
val x = event.getX(0) + event.getX(1) | |
val y = event.getY(0) + event.getY(1) | |
point.set(x / 2, y / 2) | |
} | |
} |
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