HTML5 and JavaScript Projects: Build on your Basic Knowledge of HTML5 and JavaScript to Create Substantial HTML5 Applications

© Jeanine Meyer 2018

Jeanine MeyerHTML5 and JavaScript Projectshttps://doi.org/10.1007/978-1-4842-3864-6_2

2. Family Collage: Manipulating Programmer-Defined Objects on a Canvas

Jeanine Meyer¹ 

(1)

New York, USA

 

In this chapter, you will learn the following:

• Creating and manipulating object oriented programming for drawing on canvas

• Handling mouse events, including double-clicks

• Saving the canvas to an image

• Using try and catch to trap errors

• Browser differences involving the location of the code

• Using algebra and geometry to construct shapes and determine when the cursor is over a specific object

• Controlling the icon used for the cursor

Introduction

The project for this chapter is a utility for manipulating objects on a canvas to produce a picture. I call ...