Learning – Page 31 – Xojo Programming Blog

What’s important in a programming language?

Published November 6, 2018 by Geoff Perlman

I started learning how to code as a teenager. Back then there weren’t very many programming languages. I remember BASIC, Pascal, Fortran, COBOL, C and a handful of others that were highly specialized. Why so few? Because in the 1970’s, computers just couldn’t do very much compared to today. The available languages were sufficient for the limited tasks computers had been assigned to manage.

Over the last several decades, computer technology has exploded. The smartphone I carry around in my pocket is far more powerful than the fastest computers of my youth. As a teenager, I rarely encountered anything where a computer had played a part. Today the rare encounter would be with things where computers had played no part. Computers handle so many tasks now that, as a natural consequence, there are thousands of programming languages with more appearing every year.

With so many languages, it can be difficult to choose one. What is important in a programming language?

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Drawing Objects in a Canvas with the Paint Event

Published November 2, 2018 by Paul Lefebvre

The Canvas control is a great way to draw pretty much anything to a window. With a Canvas, do all your drawing in its Paint event handler for the best quality and performance.

I’ve had many people ask for an example for how to create a Canvas that allows you to:

Draw pictures within it (as objects)
Move these objects
Remove them
Add labels to them
Programmatically select one

This example demonstrates how to do all these things. It has a large Canvas on the window with several buttons that let you add and manage the objects on the Canvas.

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IDE changes in Xojo 2018r3 and more

Published October 23, 2018 by Greg O'Lone

About three years ago, we added HiDPI/Retina support to our framework which was released to users as part of Xojo 2016r1 when we also shipped our first HiDPI IDE.

With Apple’s announcements at WWDC 2018 and the introduction of dark mode it was time to revisit our graphics and the overall appearance of the IDE again. Here are some things which contribute to the changes that have been made and ones that you will see in the coming months.

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Adventures in Regular Expressions

Published October 22, 2018 by Paul Lefebvre

As you probably know, every version of Xojo includes an extensive list of release notes that is included in the Documentation folder as an HTML file called ReleaseNotes.htm.

To make these even easier to access, I needed a way to get these into the wiki. It would be easiest if I could just copy and paste the HTML contents onto a wiki page, but MediaWiki can’t quite process all the HTML in that file so I needed a way to clean it up a bit.

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Tutorial: Saving WebCanvas Images to Disk

Published October 11, 2018 by Javier Menendez

The WebCanvas control is used for drawing graphics in web apps. It takes advantage of the HTML5 Canvas making it fast and powerful. Sometimes is can be useful to be able to save the graphics drawn in the WebCanvas to an image file, but unfortunately there is no built-in Xojo method to do this.

However, by using a little JavaScript you can easily add this capability to Xojo.

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Web Services: Xojo Web, at your service

Web Services: Xojo Web, at your service

Published September 26, 2018 by Javier Menendez

Using Xojo Web to create complete web apps and solutions means not having to learn a bunch of interpreted languages and dozens of ever-changing frameworks. I’m looking at you: HTML, CSS (is that even a language?), JavaScript, PHP, et al. Of course, Xojo Web not only makes it possible to create your own web apps, but it also acts as the perfect middleware that your desktop and iOS apps can communicate with. Learn about APIs and web services with Xojo in the tutorial blog post.

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Localize Your Edit Menu on Mac

Published September 19, 2018 by Paul Lefebvre

On macOS you may have noticed two special menu items that appear at the bottom of the Edit menu: “Start Dictation” and “Emoji & Symbols”. These menu items are added automatically by macOS provided your Xojo app follows a few simple rules.

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Quick Control Library Tips

Published September 17, 2018 by Paul Lefebvre

When you start using Xojo one of the first things you’ll see is that there are many, many types of built-in controls. The area where you see all the controls is called the Library and each project type (desktop, web or iOS) has its own set of controls.

No matter the what type of project you are creating, learn these tips to make using the Library and finding controls fast and easy.

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#JustCode Challenge Week 11 – Xojo Dojo for Pi

#JustCode Challenge Week 11 – Xojo Dojo for Pi

Published August 31, 2018 by Paul Lefebvre

For #JustCode week 11, I’ve finished a project I’ve been working on for several months. This project is a simple app that you can use to write and run your own scripts using Xojo code on the Raspberry Pi. I call it Xojo Dojo.

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Formatting Your XML

Published August 21, 2018 by Paul Lefebvre

Although Xojo does not have a built-in method to format XML text, you can use XSLT to do this for you. XSLT stands for eXtensible Stylesheet Language. This XSLT can be used to format XML:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:transform version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes" />
<xsl:template match="/">
<xsl:copy-of select="/" />
</xsl:template>
</xsl:transform>

To use this with Xojo, add a module to your project (name it XMLExtensions), add a String constant to the module (call it kXSLTFormat) and copy the above XSLT into the constant.

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Category: Learning