Add hyperlink support in SVG canvas: handle click events to open links

Author: IKupriyanov-HORIS

platf-awt/src/main/kotlin/org/jetbrains/letsPlot/awt/plot/component/DefaultPlotComponentProviderCanvas.kt

@@ -24,9 +24,20 @@ open class DefaultPlotComponentProviderCanvas(
     companion object {
         private val LOG = PortableLogging.logger(DefaultPlotComponentProviderCanvas::class)
 
+        private fun browseLink(href: String) {
+            try {
+                val uri = java.net.URI(href)
+                java.awt.Desktop.getDesktop().browse(uri)
+            } catch (e: Exception) {
+                LOG.info { "Failed to open link: $href (${e.message})" }
+            }
+        }
+
         private val SVG_COMPONENT_FACTORY_CANVAS = { svg: SvgSvgElement ->
             CanvasPane2().apply {
-                figure = SvgCanvasFigure2(svg)
+                figure = SvgCanvasFigure2(svg).apply {
+                    onHrefClick(::browseLink)
+                }
             }
         }
     }

plot-raster/src/commonMain/kotlin/org/jetbrains/letsPlot/raster/view/PlotCanvasFigure2.kt

@@ -50,6 +50,10 @@ class PlotCanvasFigure2 : CanvasFigure2 {
         buildPlotSvg()
     }
 
+    fun onHrefClick(handler: (href: String) -> Unit) {
+        plotSvgFigure.onHrefClick(handler)
+    }
+
     override fun paint(context2d: Context2d) {
         plotSvgFigure.paint(context2d)
     }
@@ -98,6 +102,7 @@ class PlotCanvasFigure2 : CanvasFigure2 {
         )
 
         plotSvgFigure.svgSvgElement = vm.svg
+        plotSvgFigure.eventPeer.addEventSource(eventPeer)
         eventReg = vm.eventDispatcher.addEventSource(eventPeer)
 
         viewModel = vm

plot-raster/src/commonMain/kotlin/org/jetbrains/letsPlot/raster/view/SvgCanvasFigure2.kt

@@ -5,8 +5,11 @@
 
 package org.jetbrains.letsPlot.raster.view
 
+import org.jetbrains.letsPlot.commons.event.MouseEvent
 import org.jetbrains.letsPlot.commons.event.MouseEventPeer
+import org.jetbrains.letsPlot.commons.event.MouseEventSpec
 import org.jetbrains.letsPlot.commons.geometry.Vector
+import org.jetbrains.letsPlot.commons.intern.observable.event.EventHandler
 import org.jetbrains.letsPlot.commons.registration.Registration
 import org.jetbrains.letsPlot.core.canvas.CanvasPeer
 import org.jetbrains.letsPlot.core.canvas.Context2d
@@ -20,6 +23,7 @@ import org.jetbrains.letsPlot.raster.mapping.svg.SvgCanvasPeer
 import org.jetbrains.letsPlot.raster.mapping.svg.SvgSvgElementMapper
 import org.jetbrains.letsPlot.raster.shape.Container
 import org.jetbrains.letsPlot.raster.shape.Element
+import org.jetbrains.letsPlot.raster.shape.reversedDepthFirstTraversal
 import kotlin.math.ceil
 
 class SvgCanvasFigure2(svg: SvgSvgElement = SvgSvgElement()) : CanvasFigure2 {
@@ -29,6 +33,8 @@ class SvgCanvasFigure2(svg: SvgSvgElement = SvgSvgElement()) : CanvasFigure2 {
         return Vector(contentWidth, contentHeight)
     }
 
+    override val eventPeer: MouseEventPeer = MouseEventPeer()
+
     var svgSvgElement: SvgSvgElement = svg
         set(value) {
             field = value
@@ -41,6 +47,11 @@ class SvgCanvasFigure2(svg: SvgSvgElement = SvgSvgElement()) : CanvasFigure2 {
 
     internal lateinit var rootMapper: SvgSvgElementMapper // = SvgSvgElementMapper(svgSvgElement, canvasPeer)
     private val repaintRequestListeners = mutableListOf<() -> Unit>()
+    private var onHrefClick: (String) -> Unit = { }
+
+    fun onHrefClick(handler: (String) -> Unit) {
+        onHrefClick = handler
+    }
 
     override fun mapToCanvas(canvasPeer: CanvasPeer): Registration {
         svgCanvasPeer = SvgCanvasPeer(canvasPeer)
@@ -54,7 +65,20 @@ class SvgCanvasFigure2(svg: SvgSvgElement = SvgSvgElement()) : CanvasFigure2 {
         }
     }
 
-    override val eventPeer: MouseEventPeer = MouseEventPeer()
+    init {
+        eventPeer.addEventHandler(MouseEventSpec.MOUSE_CLICKED, object : EventHandler<MouseEvent> {
+            override fun onEvent(event: MouseEvent) {
+                val coord = event.location.toDoubleVector()
+                val linkElement = reversedDepthFirstTraversal(rootMapper.target)
+                    .filter { it.href != null }
+                    .filterNot(Element::isMouseTransparent)
+                    .firstOrNull() { coord in it.screenBounds }
+
+                val href = linkElement?.href ?: return
+                onHrefClick(href)
+            }
+        })
+    }
 
     override fun paint(context2d: Context2d) {
         renderElement(rootMapper.target, context2d)