Image block: consolidate + simplify size controls

[sarahmonster]

If I want to change the size of an image, there are currently four different ways of accomplishing this:

• the image size drop-down
• editing the width and height values
• selecting 25/50/75/100%
• scaling using the blue dot handles.

This leads to a slightly cluttered-looking settings sidebar:

As a user, I don't immediately understand the difference between "Image size" and "Image dimensions", and it's not immediately clear (particularly in a default state) what the former refers to.

Some suggestions for improvement:

• Since there's so much going on with the image size, I think it might be better if it were its own section/panel here, at the very least.
• "Image size" should be renamed to something more descriptive—"predefined image size"? I'm not sure exactly what it should be called, but I'm sure there's a better way to communicate "size templates that your theme or plugins have provided."
• I think the 25/50/75/100 would be a good candidate for removal here. My guess is that they exist here to allow proportional image resizing, but I think that could be better accomplished with a "lock proportions" button here, a la graphics programs:

[ZebulanStanphill]

I think Image Size could be renamed to Image Source Size. I would be in favor of removing the proportional size shortcuts in favor of the ability to lock the image dimensions together.

I made an issue about this: #7636. See also: #7638.

[xavivars]

IMHO, the blue dots are everything but intuitive, even more when the image has a white background. (see example)

It would be great if there was some kind of "dashed/dotted border highlighting", like in some image editors, that would make it easier to realize those are actual places to scale the image. Also, having a control in the bottom-right corner (to fix ratio) would be great.

[nabrown]

Are there any plans to implement the lock aspect ratio bit of this enhancement? I agree the % selectors should be removed. It's not even clear if it indicated a percent of the image's inherent dimensions or a percent of its container.

[mtias]

The biggest part of this work (consolidation) is going to happen through the "Dimensions" panel described in #27331

[mtias]

There's a lot of improvements in the width handling and more to come. Going to close this as it's not very actionable on its own.