Special

Introducing the “Welcome to Xojo” Bundle!

New to Xojo and looking for guidance? We've put together a terrific bundle to welcome you! Xojo Bundle

This bundle includes six back issues of the magazine -- all of year 21 in printed book and digital formats -- plus a one-year subscription (beginning with 22.1) so you'll be learning all about Xojo for the next year. It's the perfect way to get started programming with Xojo. And you save as much as $35 over the non-bundle price!

This offer is only available for a limited time as supplies are limited, so hurry today and order this special bundle before the offer goes away!

Article Preview


Buy Now

Issue 18.5 ('OOP Listbox')
Instant purchase and download via GumRoad!

FEATURE

Maps (Part 6)

A deep dive into Annotations

Issue: 18.5 (September/October 2020)
Author: Markus Winter
Author Bio: Markus is a Molecular Biologist who taught himself REALbasic programming in 2003 to let the computer deal with some exceedingly tedious lab tasks. Some call it lazy, he thinks it smart. He still thinks of himself as an advanced beginner at best.
Article Description: No description available.
Article Length (in bytes): 23,485
Starting Page Number: 79
Article Number: 18505
Resource File(s):

Download Icon project18505.zip Updated: 2020-08-31 22:37:34

Related Link(s): None

Excerpt of article text...

Last issue we learned that if we want to display an annotation on a map, then we require two distinct objects: an annotation object and an annotation view:

  • An annotation object conforms to the MKAnnotation protocol (an interface in Xojo) and manages the data for the annotation (such as the coordinate, title, and subtitle properties).

  • An annotation view is derived from the MKAnnotationView class and draws the visual representation of the annotation on the map surface.

But to understand what that means for implementing and using them, we need to know more about how annotations and annotation views relate to each other.

Relationship Counselling: Annotations Versus Views

An annotation and its annotation view are said to be only "loosely coupled"—there isn't a one-to-one relationship—and there is a very good reason for that.

...End of Excerpt. Please purchase the magazine to read the full article.