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p5.Element.js
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p5.Element.js
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/**
* @module DOM
* @submodule DOM
* @for p5.Element
*/
import p5 from './main';
/**
* A class to describe an
* <a href="https://developer.mozilla.org/en-US/docs/Learn/HTML/Introduction_to_HTML/Getting_started" target="_blank">HTML element</a>.
*
* Sketches can use many elements. Common elements include the drawing canvas,
* buttons, sliders, webcam feeds, and so on.
*
* All elements share the methods of the `p5.Element` class. They're created
* with functions such as <a href="#/p5/createCanvas">createCanvas()</a> and
* <a href="#/p5/createButton">createButton()</a>.
*
* @class p5.Element
* @constructor
* @param {HTMLElement} elt wrapped DOM element.
* @param {p5} [pInst] pointer to p5 instance.
*
* @example
* <div>
* <code>
* function setup() {
* createCanvas(100, 100);
*
* background(200);
*
* // Create a button element and
* // place it beneath the canvas.
* let btn = createButton('change');
* btn.position(0, 100);
*
* // Call randomColor() when
* // the button is pressed.
* btn.mousePressed(randomColor);
*
* describe('A gray square with a button that says "change" beneath it. The square changes color when the user presses the button.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
p5.Element = class {
constructor(elt, pInst) {
/**
* The element's underlying `HTMLElement` object.
*
* The
* <a href="https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement" target="_blank">HTMLElement</a>
* object's properties and methods can be used directly.
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Set the border style for the
* // canvas.
* cnv.elt.style.border = '5px dashed deeppink';
*
* describe('A gray square with a pink border drawn with dashed lines.');
* }
* </code>
* </div>
*
* @property elt
* @name elt
* @readOnly
*/
this.elt = elt;
/**
* @private
* @type {p5.Element}
* @name _pInst
*/
this._pInst = this._pixelsState = pInst;
this._events = {};
/**
* A `Number` property that stores the element's width.
*
* @type {Number}
* @property width
* @name width
*/
this.width = this.elt.offsetWidth;
/**
* A `Number` property that stores the element's height.
*
* @type {Number}
* @property height
* @name height
*/
this.height = this.elt.offsetHeight;
}
/**
* Attaches the element to a parent element.
*
* For example, a `<div></div>` element may be used as a box to
* hold two pieces of text, a header and a paragraph. The
* `<div></div>` is the parent element of both the header and
* paragraph.
*
* The parameter `parent` can have one of three types. `parent` can be a
* string with the parent element's ID, as in
* `myElement.parent('container')`. It can also be another
* <a href="#/p5.Element">p5.Element</a> object, as in
* `myElement.parent(myDiv)`. Finally, `parent` can be an `HTMLElement`
* object, as in `myElement.parent(anotherElement)`.
*
* Calling `myElement.parent()` without an argument returns the element's
* parent.
*
* @method parent
* @param {String|p5.Element|Object} parent ID, <a href="#/p5.Element">p5.Element</a>,
* or HTMLElement of desired parent element.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* background(200);
*
* // Create a div element.
* let div = createDiv();
*
* // Place the div in the top-left corner.
* div.position(10, 20);
*
* // Set its width and height.
* div.size(80, 60);
*
* // Set its background color to white
* div.style('background-color', 'white');
*
* // Align any text to the center.
* div.style('text-align', 'center');
*
* // Set its ID to "container".
* div.id('container');
*
* // Create a paragraph element.
* let p = createP('p5*js');
*
* // Make the div its parent
* // using its ID "container".
* p.parent('container');
*
* describe('The text "p5*js" written in black at the center of a white rectangle. The rectangle is inside a gray square.');
* }
* </code>
* </div>
*
* <div>
* <code>
* function setup() {
* background(200);
*
* // Create rectangular div element.
* let div = createDiv();
*
* // Place the div in the top-left corner.
* div.position(10, 20);
*
* // Set its width and height.
* div.size(80, 60);
*
* // Set its background color and align
* // any text to the center.
* div.style('background-color', 'white');
* div.style('text-align', 'center');
*
* // Create a paragraph element.
* let p = createP('p5*js');
*
* // Make the div its parent.
* p.parent(div);
*
* describe('The text "p5*js" written in black at the center of a white rectangle. The rectangle is inside a gray square.');
* }
* </code>
* </div>
*
* <div>
* <code>
* function setup() {
* background(200);
*
* // Create rectangular div element.
* let div = createDiv();
*
* // Place the div in the top-left corner.
* div.position(10, 20);
*
* // Set its width and height.
* div.size(80, 60);
*
* // Set its background color and align
* // any text to the center.
* div.style('background-color', 'white');
* div.style('text-align', 'center');
*
* // Create a paragraph element.
* let p = createP('p5*js');
*
* // Make the div its parent
* // using the underlying
* // HTMLElement.
* p.parent(div.elt);
*
* describe('The text "p5*js" written in black at the center of a white rectangle. The rectangle is inside a gray square.');
* }
* </code>
* </div>
*/
/**
* @method parent
* @return {p5.Element}
*/
parent(p) {
if (typeof p === 'undefined') {
return this.elt.parentNode;
}
if (typeof p === 'string') {
if (p[0] === '#') {
p = p.substring(1);
}
p = document.getElementById(p);
} else if (p instanceof p5.Element) {
p = p.elt;
}
p.appendChild(this.elt);
return this;
}
/**
* Sets the element's ID using a given string.
*
* Calling `myElement.id()` without an argument returns its ID as a string.
*
* @method id
* @param {String} id ID of the element.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Set the canvas' ID
* // to "mycanvas".
* cnv.id('mycanvas');
*
* // Get the canvas' ID.
* let id = cnv.id();
* text(id, 24, 54);
*
* describe('The text "mycanvas" written in black on a gray background.');
* }
* </code>
* </div>
*/
/**
* @method id
* @return {String} ID of the element.
*/
id(id) {
if (typeof id === 'undefined') {
return this.elt.id;
}
this.elt.id = id;
this.width = this.elt.offsetWidth;
this.height = this.elt.offsetHeight;
return this;
}
/**
* Adds a
* <a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/class" target="_blank">class attribute</a>
* to the element using a given string.
*
* Calling `myElement.class()` without an argument returns a string with its current classes.
*
* @method class
* @param {String} class class to add.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Add the class "small" to the
* // canvas element.
* cnv.class('small');
*
* // Get the canvas element's class
* // and display it.
* let c = cnv.class();
* text(c, 35, 54);
*
* describe('The word "small" written in black on a gray canvas.');
*
* }
* </code>
* </div>
*/
/**
* @method class
* @return {String} element's classes, if any.
*/
class(c) {
if (typeof c === 'undefined') {
return this.elt.className;
}
this.elt.className = c;
return this;
}
/**
* Calls a function when the mouse is pressed over the element.
*
* Calling `myElement.mousePressed(false)` disables the function.
*
* Note: Some mobile browsers may also trigger this event when the element
* receives a quick tap.
*
* @method mousePressed
* @param {Function|Boolean} fxn function to call when the mouse is
* pressed over the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the canvas
* // is pressed.
* cnv.mousePressed(randomColor);
*
* describe('A gray square changes color when the mouse is pressed.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
mousePressed(fxn) {
// Prepend the mouse property setters to the event-listener.
// This is required so that mouseButton is set correctly prior to calling the callback (fxn).
// For details, see https://github.com/processing/p5.js/issues/3087.
const eventPrependedFxn = function (event) {
this._pInst._setProperty('mouseIsPressed', true);
this._pInst._setMouseButton(event);
// Pass along the return-value of the callback:
return fxn.call(this, event);
};
// Pass along the event-prepended form of the callback.
p5.Element._adjustListener('mousedown', eventPrependedFxn, this);
return this;
}
/**
* Calls a function when the mouse is pressed twice over the element.
*
* Calling `myElement.doubleClicked(false)` disables the function.
*
* @method doubleClicked
* @param {Function|Boolean} fxn function to call when the mouse is
* double clicked over the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // canvas is double-clicked.
* cnv.doubleClicked(randomColor);
*
* describe('A gray square changes color when the user double-clicks the canvas.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
doubleClicked(fxn) {
p5.Element._adjustListener('dblclick', fxn, this);
return this;
}
/**
* Calls a function when the mouse wheel scrolls over the element.
*
* The callback function, `fxn`, is passed an `event` object. `event` has
* two numeric properties, `deltaY` and `deltaX`. `event.deltaY` is
* negative if the mouse wheel rotates away from the user. It's positive if
* the mouse wheel rotates toward the user. `event.deltaX` is positive if
* the mouse wheel moves to the right. It's negative if the mouse wheel moves
* to the left.
*
* Calling `myElement.mouseWheel(false)` disables the function.
*
* @method mouseWheel
* @param {Function|Boolean} fxn function to call when the mouse wheel is
* scrolled over the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // mouse wheel moves.
* cnv.mouseWheel(randomColor);
*
* describe('A gray square changes color when the user scrolls the mouse wheel over the canvas.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call changeBackground() when the
* // mouse wheel moves.
* cnv.mouseWheel(changeBackground);
*
* describe('A gray square. When the mouse wheel scrolls over the square, it changes color and displays shapes.');
* }
*
* function changeBackground(event) {
* // Change the background color
* // based on deltaY.
* if (event.deltaY > 0) {
* background('deeppink');
* } else if (event.deltaY < 0) {
* background('cornflowerblue');
* } else {
* background(200);
* }
*
* // Draw a shape based on deltaX.
* if (event.deltaX > 0) {
* circle(50, 50, 20);
* } else if (event.deltaX < 0) {
* square(40, 40, 20);
* }
* }
* </code>
* </div>
*/
mouseWheel(fxn) {
p5.Element._adjustListener('wheel', fxn, this);
return this;
}
/**
* Calls a function when the mouse is released over the element.
*
* Calling `myElement.mouseReleased(false)` disables the function.
*
* Note: Some mobile browsers may also trigger this event when the element
* receives a quick tap.
*
* @method mouseReleased
* @param {Function|Boolean} fxn function to call when the mouse is
* pressed over the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when a
* // mouse press ends.
* cnv.mouseReleased(randomColor);
*
* describe('A gray square changes color when the user releases a mouse press.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
mouseReleased(fxn) {
p5.Element._adjustListener('mouseup', fxn, this);
return this;
}
/**
* Calls a function when the mouse is pressed and released over the element.
*
* Calling `myElement.mouseReleased(false)` disables the function.
*
* Note: Some mobile browsers may also trigger this event when the element
* receives a quick tap.
*
* @method mouseClicked
* @param {Function|Boolean} fxn function to call when the mouse is
* pressed and released over the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when a
* // mouse press ends.
* cnv.mouseClicked(randomColor);
*
* describe('A gray square changes color when the user releases a mouse press.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
mouseClicked(fxn) {
p5.Element._adjustListener('click', fxn, this);
return this;
}
/**
* Calls a function when the mouse moves over the element.
*
* Calling `myElement.mouseMoved(false)` disables the function.
*
* @method mouseMoved
* @param {Function|Boolean} fxn function to call when the mouse
* moves over the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // mouse moves.
* cnv.mouseMoved(randomColor);
*
* describe('A gray square changes color when the mouse moves over the canvas.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
mouseMoved(fxn) {
p5.Element._adjustListener('mousemove', fxn, this);
return this;
}
/**
* Calls a function when the mouse moves onto the element.
*
* Calling `myElement.mouseOver(false)` disables the function.
*
* @method mouseOver
* @param {Function|Boolean} fxn function to call when the mouse
* moves onto the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // mouse moves onto the canvas.
* cnv.mouseOver(randomColor);
*
* describe('A gray square changes color when the mouse moves onto the canvas.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
mouseOver(fxn) {
p5.Element._adjustListener('mouseover', fxn, this);
return this;
}
/**
* Calls a function when the mouse moves off the element.
*
* Calling `myElement.mouseOut(false)` disables the function.
*
* @method mouseOut
* @param {Function|Boolean} fxn function to call when the mouse
* moves off the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // mouse moves off the canvas.
* cnv.mouseOut(randomColor);
*
* describe('A gray square changes color when the mouse moves off the canvas.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
mouseOut(fxn) {
p5.Element._adjustListener('mouseout', fxn, this);
return this;
}
/**
* Calls a function when the element is touched.
*
* Calling `myElement.touchStarted(false)` disables the function.
*
* Note: Touch functions only work on mobile devices.
*
* @method touchStarted
* @param {Function|Boolean} fxn function to call when the touch
* starts.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // user touches the canvas.
* cnv.touchStarted(randomColor);
*
* describe('A gray square changes color when the user touches the canvas.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
touchStarted(fxn) {
p5.Element._adjustListener('touchstart', fxn, this);
return this;
}
/**
* Calls a function when the user touches the element and moves.
*
* Calling `myElement.touchMoved(false)` disables the function.
*
* Note: Touch functions only work on mobile devices.
*
* @method touchMoved
* @param {Function|Boolean} fxn function to call when the touch
* moves over the element.
* `false` disables the function.
* @chainable
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // user touches the canvas
* // and moves.
* cnv.touchMoved(randomColor);
*
* describe('A gray square changes color when the user touches the canvas and moves.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
touchMoved(fxn) {
p5.Element._adjustListener('touchmove', fxn, this);
return this;
}
/**
* Calls a function when the user stops touching the element.
*
* Calling `myElement.touchMoved(false)` disables the function.
*
* Note: Touch functions only work on mobile devices.
*
* @method touchEnded
* @param {Function|Boolean} fxn function to call when the touch
* ends.
* `false` disables the function.
* @chainable
* @example
* <div>
* <code>
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call randomColor() when the
* // user touches the canvas,
* // then lifts their finger.
* cnv.touchEnded(randomColor);
*
* describe('A gray square changes color when the user touches the canvas, then lifts their finger.');
* }
*
* // Paint the background either
* // red, yellow, blue, or green.
* function randomColor() {
* let c = random(['red', 'yellow', 'blue', 'green']);
* background(c);
* }
* </code>
* </div>
*/
touchEnded(fxn) {
p5.Element._adjustListener('touchend', fxn, this);
return this;
}
/**
* Calls a function when a file is dragged over the element.
*
* Calling `myElement.dragOver(false)` disables the function.
*
* @method dragOver
* @param {Function|Boolean} fxn function to call when the file is
* dragged over the element.
* `false` disables the function.
* @chainable
*
* @example
* <div>
* <code>
* // Drag a file over the canvas to test.
*
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call helloFile() when a
* // file is dragged over
* // the canvas.
* cnv.dragOver(helloFile);
*
* describe('A gray square. The text "hello, file" appears when a file is dragged over the square.');
* }
*
* function helloFile() {
* text('hello, file', 50, 50);
* }
* </code>
* </div>
*/
dragOver(fxn) {
p5.Element._adjustListener('dragover', fxn, this);
return this;
}
/**
* Calls a function when a file is dragged off the element.
*
* Calling `myElement.dragLeave(false)` disables the function.
*
* @method dragLeave
* @param {Function|Boolean} fxn function to call when the file is
* dragged off the element.
* `false` disables the function.
* @chainable
* @example
* <div>
* <code>
* // Drag a file over, then off
* // the canvas to test.
*
* function setup() {
* // Create a canvas element and
* // assign it to cnv.
* let cnv = createCanvas(100, 100);
*
* background(200);
*
* // Call byeFile() when a
* // file is dragged over,
* // then off the canvas.
* cnv.dragLeave(byeFile);
*
* describe('A gray square. The text "bye, file" appears when a file is dragged over, then off the square.');
* }
*
* function byeFile() {
* text('bye, file', 50, 50);
* }
* </code>
* </div>
*/
dragLeave(fxn) {
p5.Element._adjustListener('dragleave', fxn, this);
return this;
}
/**
*
* @private
* @static
* @param {String} ev
* @param {Boolean|Function} fxn
* @param {Element} ctx
* @chainable
* @alt
* General handler for event attaching and detaching
*/
static _adjustListener(ev, fxn, ctx) {
if (fxn === false) {
p5.Element._detachListener(ev, ctx);
} else {
p5.Element._attachListener(ev, fxn, ctx);
}
return this;
}
/**
*
* @private
* @static
* @param {String} ev
* @param {Function} fxn
* @param {Element} ctx
*/
static _attachListener(ev, fxn, ctx) {
// detach the old listener if there was one
if (ctx._events[ev]) {
p5.Element._detachListener(ev, ctx);
}
const f = fxn.bind(ctx);
ctx.elt.addEventListener(ev, f, false);
ctx._events[ev] = f;