Learning how to add Map into your react-native mobile application in both iOS, and Android by making a simple Thai Travel Directory app.

1. Kobkrit Viriyayudhakorn, Ph.D.
CEO of iApp Technology Limited.
kobkrit@gmail.com
http://www.kobkrit.com

2. Thai Travel Directory App

3. React-Native-Maps
• https://github.com/airbnb/react-
native-maps
• React Native Map Components
for iOS + Android
• Made by Airbnb
• iOS => Choose either
• Google Map
• Apple Map
• Android => Only Google Map

4. Installation
1. $ react-native init --version=“0.35.0” l9_map
2. $ npm install react-native-maps --save
3. $ react-native link
4. Write some code
5. $ react-native run-ios
6. For Android, we have extra steps.

5. Android Installation Extra
Steps.
1. Google Map need an API key
2. You can get your own at https://
console.developers.google.com or using my API
key. >>
AIzaSyCKspSGmpYn3GxZfIc_Sccu7x-8qXQcZkI
3. Add the Google Map’s API key at
androidappsrcmainAndroidManifest.xml
4. $ react-native run-android

6. Adding Google API key
Add meta-data tag as shown below, between <application>
tag in AndroidManifest.xml

7. Adding Basic Map Code
l9_map_1
You can see full l9_map_1 source code at the end of lecture note (A4)

8. First try!
1. $ react-native run-ios
2. Empty screen come up!?
why!?
3. Map need the width,
height. Can not use flex:1
here… :(
l9_map_1

9. Adding Width,Height to Map
l9_map_2Full l9_map_2 source code at the end of lecture note
• Dimensions return current screen’s
width and height.
• Dimensions.get(‘windows’).width
• Dimensions.get(‘windows’).height
• Thus, the map will be full screen.

10. 1. Welcome to San Francisco, the
home of tech companies in the world.
2. At the center point of the screen is
<37.78825, -122.4324>
3. The zoom of the map is specify by
*Delta.
4. At the Equator
1 LatitudeDelta => 110.57 KM
1 LongitudeDelta => 111.32 KM
0.0922 latDelta
0.0421 longDelta
(37.78825, -122.4324)
l9_map_2

11. Make it controllable by State
l9_map_3
Instead of, the fixed regions, we make it as a state.

12. Make it controllable by State #2
l9_map_3
• onRegionChange props will be called when the location/zoom
are changed, with the value of new location/zoom (region)
• Region props defined the current location/zoom in the map.

13. 1. Drag on map view to move
the map.
2. Once drag, this.state.region
was updated by
onRegionChanged().
3. Text at the lower third of the
screen is updated according
to the this.state.region
4.Try two fingers pinch, to
zoom, to rotate the map. In
simulator, press alt(option)
button to two fingers pinch.
l9_map_3

14. Configure the MapView
And much more..
https://github.com/airbnb/react-native-maps/blob/master/docs/mapview.md

15. MapEvents are also catchable
And much more..
https://github.com/airbnb/react-native-maps/blob/master/docs/mapview.md

16. Let configure some MapView
l9_map_4

17. Let’s change the mapType
mapType=“hybrid” mapType=“satellite” mapType=“terrain”
l9_map_4
Android only

18. Adding Map Markerl9_map_5
Let move the location to the Victory
Monument, Bangkok, Thailand.
MapView.Marker
coordinate => LatLng Object of that
marker
title => Title of Information popup
description => Description of popup

19. 1. MapView.Marker creates a red-
pin marker on the map (for Apple
map), and droplet shape pin on
Google map. Place it as children
of the MapView.
2.Touch the pin to show up the
popup windows, touch elsewhere
to hide it.
3. The map is draggable.
4.You can add many markers you
want.
Google Map
Apple Map l9_map_5

20. Add More Markers!
l9_map_6

21. l9_map_6

22. Don’t forget to add “key”
We found that there are warnings below…
It will occur every time, when we use JSX under loop.
To remove it, Add key props.
To distinguish each MapView.Marker
from others.
l9_map_6

23. Adding custom images to
markers
images/shopping.png images/music.png images/attention.png
W=56px / H=56px / Transparent Background
l9_map_7

24. Adding custom images to
markers l9_map_7
• Load image into state,
and display it on map
using “image” prop.
• Image shall be around
56px X 56px

25. l9_map_7

26. Nah,.. Change my mind
I want custom view to represent
markers instead… l9_map_8
Place Name
Normal Picture Group of View

27. Marker as Custom View
• Add View as the children of MapView.Marker
l9_map_8

28. l9_map_8

29. That such a boring
Popup… I want to have
a photo in it. (Custom Popup)
l9_map_9

30. Custom Popup
• Add MapView.Callout as the children of the MapView.Marker
l9_map_9

31. l9_map_9

32. Drawing Circle on Map
…
https://github.com/airbnb/react-native-maps/blob/master/docs/circle.md l9_map_10

33. Drawing Polyline on Map
…
https://github.com/airbnb/react-native-maps/blob/master/docs/polyline.md l9_map_10

34. Drawing Polygon on Map
…
https://github.com/airbnb/react-native-maps/blob/master/docs/polygon.md l9_map_10

35. Drawing Something on Map
(Code) l9_map_10

37. Travel Directory App
• Center map at the Victory
Monument
• Map can be moved.
• Tap on icon, show Title and
Description
• Push buttons to move the map
to that specific location and
zoom in and open the call out.
• Starting to modify the app from
l9_map_7
App Requirements
l9_map_travel

38. moveMapToLocation method
Once called,
moveMaptoLocation
method change the
state of region to
assigned latlng, and
zoom in by setting
latitudeDelta, and
longitudeDelta
l9_map_travel

39. Location Button Component
l9_map_travel_locationButton

40. Tap!
l9_map_travel

41. Tap!
l9_map_travel

42. Tap!
l9_map_travel

43. Tap!
l9_map_travel

44. The Change is so sudden!
• I want to make it smoothly animate to the new location!
• MapView have a method for that called “animateToRegion”
• They accept 2 arguments, i.e., Region to move to, and, How long
does the animation will need (in ms).
l9_map_travel_smooth

45. How to reference to the
MapView (Ref)
• How we can reference to our UI in react?
• Luckily, we have Ref System!
• We can have ref props in any component, e.g.,
<MapView ref=“map” … >
• We can reference to the MapView Component by
accessing this.ref.map
l9_map_travel_smooth

46. l9_map_travel_smooth
• We move to the new location as specified in latlng.
• And zoom in,
• smoothly in 3 seconds (3000 ms)

47. Smoothly Move Map
Demo
l9_map_travel_smooth

48. HW: How to automatically open
call out when pressing a button?
• There is a method call “showCallout()” in MapView.Marker
• Use Ref!
• This is your homework!
https://github.com/airbnb/react-native-maps/blob/master/docs/marker.md

49. Q/A