blob: f3ead4f619ba13677c499a311e079641148e466d [file] [log] [blame]
/*
* Copyright (C) 2013, 2015 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
WI.Slider = class Slider extends WI.Object
{
constructor()
{
super();
this._element = document.createElement("div");
this._element.className = "slider";
this._element.tabIndex = 0;
this._knob = this._element.appendChild(document.createElement("img"));
this._value = 0;
this._knobY = 0;
this._maxY = 0;
this._element.addEventListener("mousedown", this);
this._element.addEventListener("keydown", this._handleKeyDown.bind(this));
}
// Public
get element()
{
return this._element;
}
get value()
{
return this._value;
}
set value(value)
{
value = Math.max(Math.min(value, 1), 0);
if (value === this._value)
return;
this.knobY = value;
if (this.delegate && typeof this.delegate.sliderValueDidChange === "function")
this.delegate.sliderValueDidChange(this, value);
}
set knobY(value)
{
this._value = value;
this._knobY = Math.round((1 - value) * this.maxY);
this._knob.style.setProperty("--translate-y", `${this._knobY}px`);
}
get maxY()
{
if (this._maxY <= 0 && document.body.contains(this._element))
this._maxY = Math.max(this._element.offsetHeight - Math.ceil(WI.Slider.KnobWidth / 2), 0);
return this._maxY;
}
recalculateKnobY()
{
this._maxY = 0;
this.knobY = this._value;
}
// Protected
handleEvent(event)
{
switch (event.type) {
case "mousedown":
this._handleMousedown(event);
break;
case "mousemove":
this._handleMousemove(event);
break;
case "mouseup":
this._handleMouseup(event);
break;
}
}
// Private
_handleMousedown(event)
{
if (event.button !== 0 || event.ctrlKey)
return;
if (event.target !== this._knob)
this.value = 1 - ((this._localPointForEvent(event).y - 3) / this.maxY);
this._startKnobY = this._knobY;
this._startMouseY = this._localPointForEvent(event).y;
this._element.classList.add("dragging");
window.addEventListener("mousemove", this, true);
window.addEventListener("mouseup", this, true);
this._element.focus();
}
_handleMousemove(event)
{
let dy = this._localPointForEvent(event).y - this._startMouseY;
let y = Math.max(Math.min(this._startKnobY + dy, this.maxY), 0);
this.value = 1 - (y / this.maxY);
}
_handleMouseup(event)
{
this._element.classList.remove("dragging");
window.removeEventListener("mousemove", this, true);
window.removeEventListener("mouseup", this, true);
}
_handleKeyDown(event)
{
let y = 0;
let step = event.shiftKey ? 0.1 : 0.01;
switch (event.keyIdentifier) {
case "Down":
y -= step;
break;
case "Up":
y += step;
break;
}
if (y) {
event.preventDefault();
this.value += y;
}
}
_localPointForEvent(event)
{
// We convert all event coordinates from page coordinates to local coordinates such that the slider
// may be transformed using CSS Transforms and interaction works as expected.
let rect = this._element.getBoundingClientRect();
return {
x: event.pageX - rect.x,
y: event.pageY - rect.y,
};
}
};
WI.Slider.KnobWidth = 13;