refactor: extract MapView extensions from MapFragment

app/src/main/java/com/geeksville/mesh/util/MapViewExtensions.kt

@@ -0,0 +1,61 @@
+package com.geeksville.mesh.util
+
+import android.graphics.Color
+import android.graphics.Paint
+import org.osmdroid.events.DelayedMapListener
+import org.osmdroid.events.MapListener
+import org.osmdroid.events.ScrollEvent
+import org.osmdroid.events.ZoomEvent
+import org.osmdroid.views.MapView
+import org.osmdroid.views.overlay.CopyrightOverlay
+import org.osmdroid.views.overlay.gridlines.LatLonGridlineOverlay2
+
+/**
+ * Adds copyright to map depending on what source is showing
+ */
+fun MapView.addCopyright() {
+    if (overlays.none { it is CopyrightOverlay }) {
+        val copyrightNotice: String = tileProvider.tileSource.copyrightNotice ?: return
+        val copyrightOverlay = CopyrightOverlay(context)
+        copyrightOverlay.setCopyrightNotice(copyrightNotice)
+        overlays.add(copyrightOverlay)
+    }
+}
+
+/**
+ * Create LatLong Grid line overlay
+ * @param enabled: turn on/off gridlines
+ */
+fun MapView.createLatLongGrid(enabled: Boolean) {
+    val latLongGridOverlay = LatLonGridlineOverlay2()
+    latLongGridOverlay.isEnabled = enabled
+    if (latLongGridOverlay.isEnabled) {
+        val textPaint = Paint().apply {
+            textSize = 40f
+            color = Color.GRAY
+            isAntiAlias = true
+            isFakeBoldText = true
+            textAlign = Paint.Align.CENTER
+        }
+        latLongGridOverlay.textPaint = textPaint
+        latLongGridOverlay.setBackgroundColor(Color.TRANSPARENT)
+        latLongGridOverlay.setLineWidth(3.0f)
+        latLongGridOverlay.setLineColor(Color.GRAY)
+        overlays.add(latLongGridOverlay)
+    }
+}
+
+private const val INACTIVITY_DELAY_MILLIS = 500L
+fun MapView.addMapEventListener(onEvent: () -> Unit) {
+    addMapListener(DelayedMapListener(object : MapListener {
+        override fun onScroll(event: ScrollEvent): Boolean {
+            onEvent()
+            return true
+        }
+
+        override fun onZoom(event: ZoomEvent): Boolean {
+            onEvent()
+            return true
+        }
+    }, INACTIVITY_DELAY_MILLIS))
+}