Resizing image

Resizing Image

A recurrent question by newbies is how to resize a window containing a Red Image. Once again, due to the elegance of Red language, this is really easy to do.

The resize flag

When creating a window, Red allows different flags such as resize flag which allows the window to be scaled in response to user's action :  view/flags/no-wait win 'resize.

insert-event-func

To be operational, your code must define a custom event handler that  handles the resize of window content when resized event occurs:

insert-event-func [

if event/type = 'resize [

win/pane/1/size: win/size - 20x20

'done

]

]

Then, it's really simple to update image size with the window/pane facet which handles the faces included in your window. In the following example, main window contains only one image face numbered 1.

Code example

Red [

    Title:   "Red Computer Vision: Resize"

    Author:  "Francois Jouen"

    File:    %resize.red

    Needs:   'View

]

; use the image you want

img1: load %lena.jpg

;creates window title

title: "Resizes "

append title form to-local-file %lena.jpg

; main windows with resize flag

win: layout [

        title title     ; window title

        image img1      ; an image face for displaying loaded image

]

view/flags/no-wait win 'resize

; A custom event handler 

; This handles the resize of window content when resized

insert-event-func [

    if event/type = 'resize [

        win/pane/1/size: win/size - 20x20

        'done

    ]

]

do-events

And the result for down and up sizing