1/7/2023 0 Comments Js new simpleimage![]() It then tries to set to offButton.src (or onButton.src, as the case may be). If you have a JavaScript-savvy browser that doesn’t understand images, it will still catch those event handlers. As you’d expect by now, it sets to offButton.src, the blue (off) version of the button image. ![]() That causes the line of code =offButton.src to run. When the cursor moves off the image, the onMouseout event handler is triggered. Because this is the moused-over version, we set to onButton.src, the red (on) version of the button image. In order to change the image that’s displayed, we need to update the src property of this image. Remember that because we named our image myButton, we created a new image object document.myButton. That causes the line of code =onButton.src to run. When the cursor moves over the image, the onMouseover event handler is triggered. ![]() (An event is any action that triggers a JavaScript.) More event handlers will be covered in subsequent articles. These are JavaScript event handlers, which means that when an event happens, such as moving the cursor over an image, JavaScript will catch it and do whatever you’ve asked it to do. It has two new attributes: onMouseover and onMouseout. This is the last piece of the puzzle: the anchor tag around the img tag. As long as you refer to those images by the names of the image objects that JavaScript recognizes, the new images will display immediately. These two lines handle the precaching for you. Then, if the user moves the cursor over a button, the new version will display immediately. Have you ever been to a Web site where you move the cursor over an image, and suddenly a new image starts to download? A properly written image rollover won’t do that: it will precache the images, which means the JavaScript will be written so it downloads all the images that might be displayed into the browser’s cache when the page first loads. So now, I’ve showed you how to map the onButton image to the redButton.gif, and the offButton image to the blueButton.gif. In this example, the off version of the button is set to the blue version of the image, and the on version of the button is set to the red version of the image. In each case, set the src (read: “source”) property of the image object to the folder in which the image is located. This is where the image objects stored for later on learn about the actual physical files they’re associated with. This line checks to see if the JavaScript code can detect any images on the page. Some older browsers knew a little about JavaScript but couldn’t handle image effects. In order for a browser to display image rollovers, it needs to be able to understand JavaScript, and how to manipulate images. This line sets up the whole rollover magic. Up at the top of the page, inside the section, is a section that contains the JavaScript code that sets up our rollover effect. Names can’t have spaces or start with numbers beyond those limitations, you can call them just about anything you’d like. In this case, you’re going to name this image myButton, which will later be referred to as document.myButton. JavaScript uses the value of the name attribute (in quotes directly after name= ) so it can refer to this image later. In CSS, we will set the display property to none and the width to 100% of the img selector.The only differences you should see between this and the garden-variety image tags you’ve been adding to your HTML all along is a new attribute: name. Next, we will hide all the images by default using CSS and make them appear one by one in order using JavaScript. There are three static images wrapped inside a div element.Įach image has a src attribute with a random image URL from the picsum website. However, you’ll have a strong understanding of building one from scratch by the end of this tutorial. In this article, you’re going to learn how to create a simple image slider on your own, but it’s not going to be fancy. If you’re new to JavaScript, you’ve most likely used some sort of library for an image slider.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |