Function drag

src/default_theme/assets/split.js:293–330

(e)

        // ---------------------------------------------------------------------
        // | <- this.start                                        this.size -> |
        function drag(e) {
            var offset;
            var a = elements[this.a];
            var b = elements[this.b];

            if (!this.dragging) { return }

            // Get the offset of the event from the first side of the
            // pair `this.start`. Then offset by the initial position of the
            // mouse compared to the gutter size.
            offset =
                getMousePosition(e) -
                this.start +
                (this[aGutterSize] - this.dragOffset);

            if (dragInterval > 1) {
                offset = Math.round(offset / dragInterval) * dragInterval;
            }

            // If within snapOffset of min or max, set offset to min or max.
            // snapOffset buffers a.minSize and b.minSize, so logic is opposite for both.
            // Include the appropriate gutter sizes to prevent overflows.
            if (offset <= a.minSize + snapOffset + this[aGutterSize]) {
                offset = a.minSize + this[aGutterSize];
            } else if (
                offset >=
                this.size - (b.minSize + snapOffset + this[bGutterSize])
            ) {
                offset = this.size - (b.minSize + this[bGutterSize]);
            }

            // Actually adjust the size.
            adjust.call(this, offset);

            // Call the drag callback continously. Don't do anything too intensive
            // in this callback.
            getOption(options, 'onDrag', NOOP)();
        }

        // Cache some important sizes when drag starts, so we don't have to do that
        // continously: