Cancel DrawRectFeedback when selection is too small

plot-base/src/commonMain/kotlin/org/jetbrains/letsPlot/core/interact/DrawRectFeedback.kt

@@ -6,76 +6,127 @@
 package org.jetbrains.letsPlot.core.interact
 
 import org.jetbrains.letsPlot.commons.geometry.DoubleRectangle
+import org.jetbrains.letsPlot.commons.geometry.DoubleVector
 import org.jetbrains.letsPlot.commons.registration.Disposable
 import org.jetbrains.letsPlot.commons.values.Color
+import org.jetbrains.letsPlot.datamodel.svg.dom.SvgGraphicsElement
+import org.jetbrains.letsPlot.datamodel.svg.dom.SvgPathDataBuilder
+import org.jetbrains.letsPlot.datamodel.svg.dom.SvgPathElement
 import org.jetbrains.letsPlot.datamodel.svg.dom.SvgRectElement
 
 class DrawRectFeedback(
  private val onCompleted: ((DoubleRectangle) -> Unit)
 ) : DragFeedback {
- private val selectionRectSvg = SvgRectElement().apply {
- strokeColor().set(Color.GRAY)
+ private val dragRectSvg = SvgRectElement().apply {
+ strokeColor().set(Color.BLACK)
  fillColor().set(Color.TRANSPARENT)
- strokeWidth().set(2.0)
+ strokeWidth().set(1.5)
+ strokeDashArray().set("5,5")
  x().set(0.0)
  y().set(0.0)
  width().set(0.0)
  height().set(0.0)
  }
 
- private fun drawRects(r: SvgRectElement, rect: DoubleRectangle) {
- r.x().set(rect.left)
- r.y().set(rect.top)
- r.width().set(rect.width)
- r.height().set(rect.height)
+ private val selectionSvg = SvgPathElement().apply {
+ fillColor().set(Color.LIGHT_GRAY)
+ opacity().set(0.5)
+ fillRule().set(SvgPathElement.FillRule.EVEN_ODD)
  }
 
- override fun start(ctx: InteractionContext): Disposable {
+ private fun drawSelection(geomBounds: DoubleRectangle, selection: DoubleRectangle) {
+ dragRectSvg.apply {
+ visibility().set(SvgGraphicsElement.Visibility.VISIBLE)
+ x().set(selection.left)
+ y().set(selection.top)
+ width().set(selection.width)
+ height().set(selection.height)
+ }
 
+ if (isSelectionAcceptable(selection)) {
+ selectionSvg.apply {
+ visibility().set(SvgGraphicsElement.Visibility.VISIBLE)
+ d().set(SvgPathDataBuilder().apply {
+ moveTo(geomBounds.left, geomBounds.top)
+ lineTo(geomBounds.right, geomBounds.top)
+ lineTo(geomBounds.right, geomBounds.bottom)
+ lineTo(geomBounds.left, geomBounds.bottom)
+ closePath()
+ moveTo(selection.left, selection.top)
+ lineTo(selection.right, selection.top)
+ lineTo(selection.right, selection.bottom)
+ lineTo(selection.left, selection.bottom)
+ closePath()
+ }.build())
+ }
+ } else {
+ selectionSvg.visibility().set(SvgGraphicsElement.Visibility.HIDDEN)
+ }
+ }
+
+ override fun start(ctx: InteractionContext): Disposable {
  val decorationsLayer = ctx.decorationsLayer
  val interaction = MouseDragInteraction(ctx)
 
  interaction.loop(
  onStarted = {
- println("DrawRectFeedback start.")
- decorationsLayer.children().add(selectionRectSvg)
+ val (target, dragFrom, dragTo, _) = it
+ decorationsLayer.children().add(dragRectSvg)
+ decorationsLayer.children().add(selectionSvg)
+
+ val selection = getSelection(dragFrom, dragTo, target)
+ drawSelection(
+ geomBounds = target.geomBounds,
+ selection = selection
+ )
  },
  onDragged = {
- println("DrawRectFeedback drag.")
  val (target, dragFrom, dragTo, _) = it
 
- val dragPlotRect = DoubleRectangle.span(dragFrom, dragTo)
- val selectionPlotRect = target.geomBounds.intersect(dragPlotRect) ?: return@loop
-
- drawRects(selectionRectSvg, selectionPlotRect)
+ val selection = getSelection(dragFrom, dragTo, target)
+ drawSelection(
+ geomBounds = target.geomBounds,
+ selection = selection
+ )
  },
  onCompleted = {
- println("DrawRectFeedback complete.")
  val (target, dragFrom, dragTo, _) = it
- decorationsLayer.children().remove(selectionRectSvg)
 
- val dragRect = DoubleRectangle.span(dragFrom, dragTo)
- val viewport = target.geomBounds.intersect(dragRect) ?: return@loop
+ val selection = getSelection(dragFrom, dragTo, target)
 
- val dataBounds = target.applyViewport(viewport)
+ if (isSelectionAcceptable(selection)) {
+ val dataBounds = target.applyViewport(selection)
+ onCompleted(dataBounds)
+ }
+
+ decorationsLayer.children().remove(dragRectSvg)
+ decorationsLayer.children().remove(selectionSvg)
 
- onCompleted(dataBounds)
  it.reset()
  },
  onAborted = {
- println("DrawRectFeedback abort.")
- decorationsLayer.children().remove(selectionRectSvg)
  it.reset()
  }
  )
 
  return object : Disposable {
  override fun dispose() {
- println("DrawRectFeedback dispose.")
- decorationsLayer.children().remove(selectionRectSvg)
+ decorationsLayer.children().remove(dragRectSvg)
+ decorationsLayer.children().remove(selectionSvg)
  interaction.dispose()
  }
  }
  }
 
+ private fun getSelection(
+ dragFrom: DoubleVector,
+ dragTo: DoubleVector,
+ target: InteractionTarget
+ ) = DoubleRectangle.span(dragFrom, dragTo)
+ .intersect(target.geomBounds)
+ ?: DoubleRectangle(dragFrom, DoubleVector.ZERO) // at least move the selection rect to the drag start point
+
+ private fun isSelectionAcceptable(selection: DoubleRectangle): Boolean {
+ return selection.width > 25 || selection.height > 25
+ }
 }