Prevent default Press but not default Drag in iOS MobileSafari?

Question

Context: Web app on MobileSafari/iPad, both full-screen and embedded in iframe

Goal: Technique that provides custom event handlers

Answer 1

Success: Prevent "default press" behavior entirely through CSS instead of preventDefault. This answer was provided by Safari Technologies Evangelist Vicki Murley over here (registration required)

I see in your stackoverflow post that you say your ultimate goal is that:

"We never want the default MobileSafari Press behavior of "Copy Image" or selecting text."

These behaviors can be disabled in CSS (+ one bonus property, since people often want to turn off the highlight if they're turning off these other behaviors):

/* behavior */
-webkit-user-select: none;                /* disable cut copy paste */
-webkit-touch-callout: none;              /* disable callout, image save panel */
-webkit-tap-highlight-color: transparent; /* "turn off" link highlight */

Commentary: We assumed that Safari's Press behavior was event-based, not driven by CSS. Calling preventDefault ontouchstart does cancel the press behavior (which is what led us astray, really), but that seems to be an unintended side-effect. Really, Mobile Safari does not execute a "press event" so much as "CSS on press".

Disabling the Press behavior with CSS has allowed us to once again call preventDefault only where and when we actually need it.