From c15ad9ab56f5661b17ae6e97685dc0cb7ca69c91 Mon Sep 17 00:00:00 2001
From: "Phyks (Lucas Verney)" <phyks@phyks.me>
Date: Sun, 1 Jul 2018 22:02:54 +0200
Subject: [PATCH] Let users move the view around

* Let user move the view around, without automatic refocusing.
* Add a button to refocus view.
---
 src/components/Map.vue | 18 ++++++-------
 src/views/Map.vue      | 57 ++++++++++++++++++++++++++++++++++--------
 2 files changed, 56 insertions(+), 19 deletions(-)

diff --git a/src/components/Map.vue b/src/components/Map.vue
index 04e39e1..973bf60 100644
--- a/src/components/Map.vue
+++ b/src/components/Map.vue
@@ -1,10 +1,10 @@
 <template>
     <div class="fill-height fill-width">
-        <v-lmap :center="latlng" :zoom="this.zoom" :minZoom="this.minZoom" :maxZoom="this.maxZoom" :options="{ zoomControl: false }" @contextmenu="handleLongPress">
+        <v-lmap :center="latLng" :zoom="this.zoom" :minZoom="this.minZoom" :maxZoom="this.maxZoom" :options="{ zoomControl: false }" @contextmenu="handleLongPress" @moveend="onMoveEnd" @movestart="onMoveStart">
             <v-ltilelayer :url="tileServer" :attribution="attribution"></v-ltilelayer>
 
-            <v-lts v-if="heading" :lat-lng="latlng" :options="markerOptions"></v-lts>
-            <v-lcirclemarker v-else :lat-lng="latlng" :color="markerOptions.color" :fillColor="markerOptions.fillColor" :fillOpacity="1.0" :weight="markerOptions.weight" :radius="markerRadius"></v-lcirclemarker>
+            <v-lts v-if="heading" :lat-lng="positionLatLng" :options="markerOptions"></v-lts>
+            <v-lcirclemarker v-else :lat-lng="positionLatLng" :color="markerOptions.color" :fillColor="markerOptions.fillColor" :fillOpacity="1.0" :weight="markerOptions.weight" :radius="markerRadius"></v-lcirclemarker>
 
             <v-lcircle v-if="shouldDisplayAccuracy" :lat-lng="latlng" :radius="radiusFromAccuracy"></v-lcircle>
 
@@ -41,16 +41,19 @@ export default {
             default: null,
         },
         heading: Number,
-        lat: Number,
-        lng: Number,
+        latLng: Array,
         markers: Array,
         onLongPress: Function,
+        onMoveEnd: Function,
+        onMoveStart: Function,
+        positionLatLng: Array,
     },
     computed: {
         radiusFromAccuracy() {
             if (this.accuracy) {
                 return this.accuracy / (
-                    (constants.EARTH_RADIUS * 2 * Math.PI * Math.cos(this.lat * (Math.PI / 180))) /
+                    (constants.EARTH_RADIUS * 2 * Math.PI * Math.cos(this.latLng[0] *
+                        (Math.PI / 180))) /
                     (2 ** (this.zoom + 8))
                 );
             }
@@ -63,9 +66,6 @@ export default {
                 this.radiusFromAccuracy > this.markerRadius
             );
         },
-        latlng() {
-            return [this.lat, this.lng];
-        },
         markerOptions() {
             return {
                 fillColor: '#00ff00',
diff --git a/src/views/Map.vue b/src/views/Map.vue
index ea0eabe..de3ba08 100644
--- a/src/views/Map.vue
+++ b/src/views/Map.vue
@@ -1,8 +1,21 @@
 <template>
     <v-container fluid fill-height class="no-padding">
         <v-layout row wrap fill-height>
-            <v-flex xs12 fill-height v-if="lat && lng">
-                <Map :lat="lat" :lng="lng" :heading="heading" :accuracy="accuracy" :markers="reportsMarkers" :onLongPress="showReportDialog"></Map>
+            <v-flex xs12 fill-height v-if="latLng">
+                <Map :latLng="mapLatLng" :positionLatLng="latLng" :heading="heading" :accuracy="accuracy" :markers="reportsMarkers" :onLongPress="showReportDialog" :onMoveEnd="onMapMoveEnd" :onMoveStart="onMapMoveStart"></Map>
+                <v-btn
+                    fixed
+                    dark
+                    fab
+                    bottom
+                    left
+                    color="blue"
+                    class="overlayButton"
+                    v-if="hasMapMoved"
+                    @click.native.stop="recenterMap"
+                    >
+                    <v-icon>my_location</v-icon>
+                </v-btn>
                 <v-btn
                     fixed
                     dark
@@ -64,15 +77,23 @@ export default {
                 latLng: [report.attributes.lat, report.attributes.lng],
             }));
         },
+        mapLatLng() {
+            if (this.hasMapMoved) {
+                return this.mapMovedLatLng;
+            }
+            return this.latLng;
+        },
     },
     data() {
         return {
             accuracy: null,
+            centering: false,
             dialog: false,
             error: null,
+            hasMapMoved: false,
             heading: null,
-            lat: null,
-            lng: null,
+            latLng: null,
+            mapMovedLatLng: null,
             noSleep: null,
             reportLat: null,
             reportLng: null,
@@ -119,17 +140,16 @@ export default {
             this.error = `Error ${error.code}: ${error.message}`;
         },
         setPosition(position) {
-            if (this.lat && this.lng) {
+            if (this.latLng) {
                 const distanceFromPreviousPoint = distance(
-                    [this.lat, this.lng],
+                    [this.latLng[0], this.latLng[1]],
                     [position.coords.latitude, position.coords.longitude],
                 );
                 if (distanceFromPreviousPoint > constants.UPDATE_REPORTS_DISTANCE_THRESHOLD) {
                     this.$store.dispatch('fetchReports');
                 }
             }
-            this.lat = position.coords.latitude;
-            this.lng = position.coords.longitude;
+            this.latLng = [position.coords.latitude, position.coords.longitude];
             this.heading = position.coords.heading ? position.coords.heading : null;
             this.accuracy = position.coords.accuracy ? position.coords.accuracy : null;
         },
@@ -147,8 +167,8 @@ export default {
                 this.reportLat = latlng.lat;
                 this.reportLng = latlng.lng;
             } else {
-                this.reportLat = this.lat;
-                this.reportLng = this.lng;
+                this.reportLat = this.latLng[0];
+                this.reportLng = this.latLng[1];
             }
             this.dialog = !this.dialog;
         },
@@ -183,6 +203,23 @@ export default {
             window.addEventListener('touchmove', this.handleFirstUserInteraction, false);
             window.addEventListener('MSPointerMove', this.handleFirstUserInteraction, false);
         },
+        recenterMap() {
+            this.mapMovedLatLng = null;
+            this.centering = true;
+            this.hasMapMoved = false;
+        },
+        onMapMoveStart() {
+            if (!this.centering) {
+                this.hasMapMoved = true;
+            }
+        },
+        onMapMoveEnd(ev) {
+            const latLng = ev.target.getCenter();
+            if (!this.hasMapMoved) {
+                this.mapMovedLatLng = [latLng.lat, latLng.lng];
+            }
+            this.centering = false;
+        },
     },
 };
 </script>