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phetsims / acid-base-solutions

"Acid-Base Solutions" is an educational simulation in HTML5, by PhET Interactive Simulations.
http://phet.colorado.edu/sims/html/acid-base-solutions/latest/acid-base-solutions_en.html
GNU General Public License v3.0
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pH paper can become obscured #153

Closed pixelzoom closed 3 years ago

pixelzoom commented 7 years ago

This issue was migrated (and adapted) from Unfuddle https://phet.unfuddle.com/a#/projects/9404/tickets/by_number/2513?cycle=true. It was reported for the Java version, and is still a problem in the HTML5 version.

If the user drags the pH paper behind the magnifying glass or graph, then lets go of it, the pH paper is no longer visible. If you mouse over where it is, the cursor will change, and you can grab it. But you can't see it. The user needs to select "Hide Views" in order to see it.

As a possible fix, it was proposed to constrain dragging of the pH paper - don't allow the pH paper to be dragged below the top of the beaker (like the pH meter). This seems like a reasonable way to address this issue.

pixelzoom commented 5 years ago

@arouinfar Not a big priority, but I'm looking at "low hanging fruit" to knock off, getting all of my sims in good shape for re-publication. Here's my proposal on this one.

There's no value to being able to fully submerge the pH paper. And if you do submerge the paper fully, then you won't be able to see the color to compare to the pH Color Key. So constrain vertical dragging such that some of the paper always remains above the top of the fluid level in the beaker - say 20%, like in the screenshot below. Horizontal dragging would remain unchanged; that is, the full width of the beaker.

Does that sound like a reasonable solution?

screenshot_917

pixelzoom commented 5 years ago

Ah, scratch that proposal. I said:

There's no value to being able to fully submerge the pH paper.

But that statement is fundamentally flawed. You need to submerge the pH paper in order to change it's color.

Back to the drawing board...

pixelzoom commented 5 years ago

We could make the pH paper float to the top when released?

pixelzoom commented 5 years ago

@arouinfar please review 1.3.0-dev.1.

If the pH paper is release with any portion of it above the surface of the fluid, it remains where it was released. It is it released blow the surface of the fluid, it float to the top, such that the top 1/3 of the pH paper is above the fluid. Behavior (and code used) is identical in both screens.

It's easy to modify how much of the paper floats up above the surface. I chose 1/3 of the paper because that seems to facilitate comparison with the pH Color Key. It's also easy to totally back this out, if you don't like this solution.

arouinfar commented 5 years ago

@pixelzoom I really like the floating behavior! Keeping the bottom 2/3 of the paper submerged also seems reasonable to me.

brooklynlash commented 3 years ago

pH paper does not become obscured anymore, it floats back to the top. Reassigning to @pixelzoom

pixelzoom commented 3 years ago

Thanks @brooklynlash. Closing.