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// Counting mouse clicks, so that a second one on the same spot means
// something different from the first.

package editor

import (
	"time"

	"codeberg.org/turbo-editors/turbo-core/buffer"
)

// doubleClickWithin is how long after a press a second one on the same cell
// still counts as a double click.
//
// Four hundred milliseconds is what most desktops settle on. Shorter and a
// deliberate double click made with an unhurried hand is read as two separate
// ones; longer and two unrelated clicks in the same place — which happens all
// the time while reading — start selecting words nobody asked for.
const doubleClickWithin = 400 * time.Millisecond

// click is where and when a press landed, and how many have landed in a row.
type click struct {
	at    buffer.Position
	when  time.Time
	count int
}

// countClick records a press and returns how many presses in a row have now
// landed on the same cell: 1 for a fresh click, 2 for a double click.
//
// The cell has to be the same, not merely near: a press one column over is a
// different word, and selecting the first one because the pointer drifted is
// worse than not selecting at all.
func (v *View) countClick(at buffer.Position) int {
	now := v.now()
	if v.lastClick.count > 0 &&
		v.lastClick.at == at &&
		now.Sub(v.lastClick.when) <= doubleClickWithin {
		v.lastClick.count++
	} else {
		v.lastClick.count = 1
	}

	v.lastClick.at = at
	v.lastClick.when = now
	return v.lastClick.count
}

// SetClock replaces the clock two clicks are timed against.
//
// Only a test has any business calling this. A double click measured against
// the real clock is a test that passes or fails by how fast the machine is.
//
//	view.SetClock(func() time.Time { return moment })
func (v *View) SetClock(now func() time.Time) { v.now = now }