0Logo WordpressMostra l'immagine ingrandita al passaggio del mouse in wordpress

Come parte dei recenti miglioramenti che ho apportato a vari siti Web, volevo che le immagini nelle gallerie mostrassero versioni ingrandite quando passavo sopra. Fare questo con base CSS è abbastanza banale, ma non volevo solo espandere l'immagine originale, Volevo che il browser prendesse un nuovo (più grande) anche l'immagine...

All of the images are already provid­ing a full src-set so all I needed to do was to use a little jQuery (which is already loaded by word­press any­way) to change the tar­get dis­play size to make the browser pull a lar­ger image. La cosa bella è che CSS works instantly so you get a lar­ger image using the ori­gin­al file, and then the qual­ity improves a split second later as the high­er res file gets loaded.


Il CSS I used is as fol­lows. L'ho semplicemente aggiunto allo style.css del mio tema (or rather child-theme — always a good idea to use one)

Appunto (1) — the above CSS applies to gal­lery images only. It is unlikely any­one would want this func­tion­al­ity for all images dis­played any­where on the page, but you might want it for the main con­tent sec­tion. You would need to check how your theme struc­tures this, but in my case the main con­tent area is a “sec­tion” so the fol­low­ing code would do the job

Appunto (2) — This code applies only to thumb­nail images. For medi­um images you would replace “size-thumb­nail” with “size-medi­um”, and for large with “size-large”.

Appunto (3) — Because my thumb­nails are 120x80px I want to increase them to 3x their ori­gin­al size. I already have a cus­tom image size of 360×240 that word­press cre­ates for me that is included in the src-set. For hi-dpi screens there are also even lar­ger image sizes that I have (per esempio. 720×480). Cre­at­ing addi­tion­al image sizes in word­press is easy — there are lots of good guides online if you need to do this.

Se vuoi ridimensionare a 1,5x o 2.0x, cambia semplicemente il 3.0 come desiderato

Il jQuery

Add the fol­low­ing to your (bambino) file di script del tema (assum­ing it has one). If it does­n’t have one, cre­ate your own, and ‘enqueue’ it with a cus­tom func­tion in the (bambino) funzioni del tema.php

The above code is apply­ing to images with class thumb­nail that are found inside any dt with a gal­lery-icon class — so in oth­er­words — only to images inside the word­press built-in gal­lery struc­ture. On hov­er the max-width is increased from 120 a 360 (un aumento di 3 volte per eguagliare il mio CSS!), and then the second part of the func­tion restores the ori­gin­al 120 width when the hov­er stops.

Come con il CSS sopra, you can adjust the num­bers to change how much the image enlarges, e puoi cambiare il dt.gallery-icon a img.size-thumbnail sec­tion to tar­get a dif­fer­ent ele­ment or class depend­ing on which images you want to target.

Accoda il tuo script

If your theme did­n’t have a script file and you need to enqueue your own add the fol­low­ing to your (bambino) funzioni del tema.php (assum­ing you called your script file image-zoom.js and saved it in the root folder of the theme)

Quanto sopra registrerà il tuo script, in the foot­er, mak­ing sure it is placed after jquery (so jquery should already be avail­able when it executes)

Aggiungere le dimensioni dell'immagine

For com­plete­ness here’s how to add cus­tom image sizes to word­press. Di nuovo, aggiungi questo al tuo (bambino) funzioni del tema.php

Above I’ve added a new image-size called “quarter-width” with a max­im­um width of 192px and a max­im­um height of 144px. L'immagine non verrà ritagliata (quindi il falso alla fine).

Word­Press will now cre­ate images of this size auto­mat­ic­ally when you upload images (you will need to use a thumb­nail rebuild plu­gin to recre­ate the thumb­nails for already-uploaded images).

This new image size will NOT show up for inser­tion in the edit­or though. To make it avail­able also add the fol­low­ing code to your functions.php

Rispettare le impostazioni esistenti

Un'altra cosa che potresti voler fare (to ensure respons­ive images work well) is to cre­ate lar­ger (i.e. ciao dpi) thumb­nail sizes that respect the GUI of wheth­er to crop thumb­nails or not. To do that use the code below which as you will see is slightly mod­i­fied from the more basic one above

Il codice sopra verifica la presenza di 2 things — firstly it checks to see if the crop option is set, e se lo è, it mir­rors it for our new respons­ive size. Controlla anche se la larghezza è impostata su 0 (i.e. no max­im­um) in which case our new image will also have no max­im­um either. I called the new image size “resp-thumb-2x” as it is a ‘respons­ive’ copy of the thumb­nail that is twice as large (for hi-dpi screens with double the nor­mal pixel dens­ity). I have also cre­ated a num­ber of oth­er sizes to make a fairly com­plete set.

Note — Since my ori­gin­al thumb­nails were 120×80 I want my new ones to be 240×160 so those are the sizes I have spe­cified (hardcoded). It would be pos­sible to get both the height and width spe­cified for the ori­gin­al thumb­nail and mul­tiply both by 2 to make this func­tion fully gen­er­ic, but I did­n’t do so when I was devel­op­ing it so I will leave that to you to fig­ure out!

Un ultimo consiglio

Se, come me, you cre­ate your own full set of new image sizes, you may not want word­press to cre­ate it’s own extra hid­den sizes. In addi­tion to the ori­gin­al image, and the thumb­nail, the medi­um, e l'immagine grande, word­press also cre­ate a “post-thumb­nail”, a “medi­um-large”, a 1536×1536 and a 2048×2048. These are dis­abled in 2 dif­fer­ent ways…

Per rimuovere il 1536 e 2048 le immagini sono dirette

The post-thumb and medi­um-large are slightly more complicated

Note that remov­ing the post-thumb­nail seems to some­times have strange effects on the image lib­rary in the editor.

Un'ultima nota finale

When decid­ing on image sizes (for lar­ger images, less so thumb­nails) you ideally want a size that com­mon aspect ratio images will always res­ize nicely to. For that reas­on I recom­mend the fol­low­ing sizes

DimensioneLarghezzaAltezza (4:3)Altezza (16:9)Altezza (3:2)

Note how the widths spe­cified pro­duce whole num­ber heights for all 3 of the most com­mon aspect ratios. Non lo otterrai con larghezze come 150 or 200.

Also note the pat­tern in increases. Saltare 2 righe nella tabella e la dimensione raddoppia! Le righe pari (288,576,1152 e 1535) are also 1.5x the pre­vi­ous size so these work well on semi-hi-dpi screens using a 50% aumento dpi. Usando questo set di 7 sizes you have a good range of usable options for most view­ports AND a good set of respons­ive images that word­press will auto­mat­ic­ally add to the src-set since they will have con­sist­ent aspect ratios with no frac­tions that would lead to qual­ity loss or cropping.

Cur­rently for thumb­nails I tend to either have unlim­ited width allowed OR I hard crop to a fixed 3:2 ratio so I use whole num­ber sizes for thumb­nails but I may even­tu­ally tweak my theme and extend the above sys­tem back­wards by hav­ing options 48px and 96px wide (nota che non c'è alcun valore tra questi 2 that would work unfor­tu­nately — and since I use 60px wide mini thumb­nails I haven’t opted to extend back­wards). 72px funzionerebbe per entrambi 4:3 e 3:2 (e 64px funzionerebbero con 4:3 e 16:9). Since a major­ity of my images are taken on my dSLR these are typ­ic­ally 3:2 (the same as the aspect ratio of tra­di­tion­al 35mm film) quindi potrei usare anche questa dimensione, che poi funzionerebbe con le taglie grandi fino in fondo, but the lar­ger sizes are not cropped where­as my thumb­nails are — I’m happy for lar­ger images to be both land­scape and por­trait, but I want thumb­nails to typ­ic­ally be land­scape only to fit with my design, so that’s why I haven’t exten­ded back­wards. Hope­fully as more and more logos are avail­able as SVG'S, e una volta JPEG-XL arriverà nei browser nel prossimo futuro, molto di questo sarà risolto.

Credo che abbiamo perso qualcosa? Fateci sapere commentando qui sotto. Se si desidera iscriversi si prega di utilizzare il link iscriviti sul menu in alto a destra. È inoltre possibile condividere con i tuoi amici usando i link sottostanti sociali. Saluti.

lascia un commento