jQuery DOM Insertion, Inside & Outside

Posted on 2018-08-01 by hoyo

如何控制插入內容相對於對象的位置

jQuery 插入內容時可以使用 append(), prepend(), before(), after() 四個函式，不同的函式插入的位置不同

<div id="aaa" style="border: 1px solid #aaa;">aaaaa</div>

$('#aaa').before('<div>before 1</div>');

$('#aaa').before('<div>before 2</div>');

$('#aaa').after('<div>after 1</div>');

$('#aaa').after('<div>after 2</div>');

$('#aaa').append('<div>append 1</div>');

$('#aaa').append('<div>append 2</div>');

$('#aaa').prepend('<div>prepend 1</div>');

$('#aaa').prepend('<div>prepend 2</div>');

</script>

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124 total views, no views today

網頁或網頁內元素是否作用中 (可視)

Posted on 2017-06-09 by hoyo

$(function(){

// 頁面作用才更新資料

window.onfocus = function(){

setInterval(function(){

search();

}, 10000);

};

window.onblur = function(){

for (var i = 1; i < 9; i++) window.clearInterval(i);

};

});

—

元素出現就作用

How to tell if a DOM element is visible in the current viewport?
http://jsfiddle.net/AndyE/d48Cv/1/
jquery.inview2

$('div').bind('inview', function(event, isInView) {

if (isInView) {

$(this).css('background-color', '#f00');

} else {

$(this).css('background-color', '#00f');

}

});

—

元素完整出現才作用

</div>

<hr/>

$(window).scroll(function() {

$('div:in-viewport(-320)').css({

'background-color': '#f00',

'color': '#151612'

}).find('p').text('Now in viewport.');

});

</script>

—

83 total views, no views today

Canvas framework

Posted on 2016-11-24 by hoyo

—

應用

—

hoyo 自己的應用

需求為從主機載入一張圖之後，可以增加箭頭、文字、方框等基本的繪圖需求，編輯完成按儲存後要直接回存。

技術：HTML5 Canvas

使用工具：Fabric.js

參考

Add Delete button on element in Canvas Fabric JS

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<!DOCTYPE html>

<html>

<head>

</head>

<body>

var canvas = new fabric.Canvas('c');

var HideControls = {

'tl':true,

'tr':false,

'bl':true,

'br':true,

'ml':true,

'mt':true,

'mr':true,

'mb':true,

'mtr':true

};

var image = new Image();

image.src = 'normal_3206.png';

image.onload = function() {

// create a wrapper around native canvas element (with id="c")

canvas.setHeight(image.width).setWidth(image.height);

canvas.setBackgroundImage('normal_3206.png', canvas.renderAll.bind(canvas), {

width: canvas.width,

height: canvas.height,

// Needed to position backgroundImage at 0/0

originX: 'left',

originY: 'top'

});

};

canvas.renderAll();

function addDeleteBtn(x, y){

$(".deleteBtn").remove();

var btnLeft = x-10;

var btnTop = y-10;

var deleteBtn = '<img src="../images/delete-icon.png" class="deleteBtn" style="position:absolute;top:'+btnTop+'px;left:'+btnLeft+'px;cursor:pointer;width:20px;height:20px;"/>';

$(".canvas-container").append(deleteBtn);

}

canvas.on('object:selected',function(e){

addDeleteBtn(e.target.oCoords.tr.x, e.target.oCoords.tr.y);

});

canvas.on('mouse:down',function(e){

if(!canvas.getActiveObject())

{

$(".deleteBtn").remove();

}

});

canvas.on('object:modified',function(e){

addDeleteBtn(e.target.oCoords.tr.x, e.target.oCoords.tr.y);

});

canvas.on('object:scaling',function(e){

$(".deleteBtn").remove();

});

canvas.on('object:moving',function(e){

$(".deleteBtn").remove();

});

canvas.on('object:rotating',function(e){

$(".deleteBtn").remove();

});

$(document).on('click',".deleteBtn",function(){

if(canvas.getActiveObject())

{

canvas.remove(canvas.getActiveObject());

$(".deleteBtn").remove();

}

});

// ----------------------------------------

function addBlock(){

var rect = new fabric.Rect({

stroke: 'rgb(255,0,0)',

strokeWidth: 3,

width: 100, height: 40,

fill: false, left: 50, top: 50

}).setControlsVisibility(HideControls);

canvas.add(rect);

}

function addText() {

var t = new fabric.IText('Tap and Type', {

fontFamily: 'arial black',

left: 100,

top: 100

});

var textWithBackground = new fabric.IText('輸入文字', {

left: 50,

top: 50,

textBackgroundColor: 'rgb(255,255,255)'

}).setControlsVisibility(HideControls);

canvas.add(textWithBackground);

}

function addLine2(){

var path = new fabric.Path('M512 246.16H36.504l86.98-87.43v-27.895L0 254.943v2.115l123.474 124.107h.01V353.26l-86.98-87.42H512z', {

stroke: 'rgb(255,255,255)',

strokeWidth: 8,

fill: 'rgb(255,0,0)'

}

).scaleToWidth(100).setControlsVisibility(HideControls);

canvas.add(path);

}

// 送出處理後圖像給 PHP

function saveImage() {

request = new XMLHttpRequest();

request.open('POST', 'c1.php', true);

var $Json = {};

$Json['image'] = canvas.toDataURL();

$Json['id'] = 'aa111';

request.send( JSON.stringify($Json) );

}

</script>

</body>

</html>

—

120 total views, no views today

Web Audio API – 使用

Posted on 2016-10-28 by hoyo

參考

—

實作

使用 Canvas 繪圖

<!DOCTYPE html>

<html>

</head>

<body>

</div>

</div>

$(function () {

context = new (window.AudioContext || window.webkitAudioContext)();

// Create the analyser

var analyser = context.createAnalyser();

// https://developer.mozilla.org/zh-TW/docs/Web/API/AnalyserNode/fftSize

analyser.fftSize = 64;

// Get the frequency data and update the visualisation

function update() {

var canvas = document.getElementById('canvas'),

cwidth = canvas.width,

cheight = canvas.height - 2,

meterWidth = 20, //width of the meters in the spectrum

gap = 2, //gap between meters

capHeight = 2,

capStyle = '#fff',

meterNum = 702 / (10 + 2), //count of the meters

capYPositionArray = []; //store the vertical position of hte caps for the preivous frame

ctx = canvas.getContext('2d');

gradient = ctx.createLinearGradient(0, 0, 0, 300);

gradient.addColorStop(1, '#0f0');

gradient.addColorStop(0.5, '#ff0');

gradient.addColorStop(0, '#f00');

var drawMeter = function() {

var array = new Uint8Array(analyser.frequencyBinCount);

analyser.getByteFrequencyData(array);

ctx.clearRect(0, 0, cwidth, cheight);

for (var i = 0; i < array.length; i++) {

var value = array[i];

if (capYPositionArray.length < Math.round(meterNum)) {

capYPositionArray.push(value);

}

ctx.fillStyle = gradient; //set the filllStyle to gradient for a better look

ctx.fillRect(i * 22 /*频谱条的宽度+条间间距*/ , cheight - value + capHeight, meterWidth, cheight);

}

requestAnimationFrame(drawMeter);

};

requestAnimationFrame(drawMeter);

}

// Hook up the audio routing...

// player -> analyser -> speakers

// (Do this after the player is ready to play - https://code.google.com/p/chromium/issues/detail?id=112368#c4)

$("#player").bind('canplay', function() {

var source = context.createMediaElementSource(this);

source.connect(analyser);

analyser.connect(context.destination);

update();

});

</script>

</body>

</html>

analyser.fftSize
設定值除以 2 就是陣列取樣數，預設 2048
analyser.getByteFrequencyData(Uint8Array(analyser.frequencyBinCount));
數值在 0 – 255 ，沒聲音為 0
analyser.getByteTimeDomainData(Uint8Array(analyser.frequencyBinCount));
數值在 0 – 255 ，沒聲音為 128
requestAnimationFrame 根據瀏覽器設定(一般來說是 60fps) 更新
能量條的高度是根據 0-255 所繪製，所以如果要增減就必須調整 analyser.getByteFrequencyData(array) 的 array 值

—

118 total views, no views today

RICOH THETA 網頁全景處理

Posted on 2016-05-13 by hoyo

參考

—

360 Degree Interactive Panoramas And Virtual Tours In Html 5 – Multiple Browsers / 360 Easy – Complete Tutorial On 360 Degree Photography

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<head>

* { outline : none; -moz-outline : none -moz-mac-focusring; }

#source-img { position: absolute; left: -999em; }

canvas { position: absolute; float:center; top: -90px; }

#screen { position: absolute; float:center; top: 0px; }

#screen div { position: absolute; top: 0px; left: 300px; width: 630px; height: 815px;

background: #fffff; }

div#screen-overlay { position: absolute; top: 0px; left: 0px; margin-left: 0px; height: 715px;

width: 630px; }

</style>

var YD = YAHOO.util.Dom,

YE = YAHOO.util.Event;

var canvas, ctx, img, widthSlider, scalingSlider, pw = 630, sf = .490, imgOffset = 0,

stage, stagePos, stageDim, moveInterval, moveDirection, dist = 1, data = []; function init() {

canvas = YD.get('cv');

ctx = canvas.getContext('2d');

canvas.width = 630;

canvas.height = 815;

canvas.style.width = '630px';

canvas.style.height = '815px';

stage = YD.get('screen-overlay');

YE.on(stage, 'mousedown', startMoveBackground);

YE.on(stage, 'mousemove', moveBackground);

YE.on(stage, 'mouseout', stopMove);

YE.on(stage, 'mouseup', stopMoveBackground);

stagePos = YD.getXY(stage);

stageDim = [ YD.getStyle(stage, 'width'), YD.getStyle(stage, 'height') ];

img = YD.get('source-img');

redraw(); }

function startMoveBackground(e) {}

function moveBackground(e) {

dist = Math.abs(e.clientX - (parseInt(stageDim[0], 10) / 2 + stagePos[0])) / 3; var timeInt = 1;

if(e.clientX - stagePos[0] > parseInt(stageDim[0], 10) / 2) {

if(moveDirection === 'left' || !moveDirection) {

clearInterval(moveInterval);

moveInterval = setInterval(function() { moveRight(); }, timeInt); moveDirection = 'right'; }}

else

{ if(moveDirection === 'right' || !moveDirection) {

clearInterval(moveInterval);

moveInterval = setInterval(function() { moveLeft(); }, timeInt);

moveDirection = 'left'; }}}

function stopMove() {

clearInterval(moveInterval);

moveDirection = null; }

function moveRight() {

imgOffset += dist;

redraw(); }

function moveLeft() {

imgOffset -= dist;

redraw(); }

function stopMoveBackground(e) {}

function precalculate(img, x, y, pixelWidth, scalingFactor, offset) {

if(typeof offset === 'undefined') offset = 0;

var h = img.height,

w = (img.width - 2) / 2.5;

var polarity = (pixelWidth > 0) ? 1 : -1;

var widthFactor = Math.abs(pixelWidth) / w;

var delta = Math.abs(pixelWidth);

var dHeight, dWidth, dy, dx;

var constant = Math.pow(100000, scalingFactor); //380;

var firstInc = ((delta / 2) * (delta / 2)) / constant;

for(var n = 0, len = delta, inc = w / delta, incScale = (1 - scalingFactor) / delta; n < len; n++) {

(function(m) {

sx = function(offset) { return ((inc * m + offset) >= 0) ? (inc * m + offset) % img.width : img.width +

((inc * m + offset) % img.width) };})(n);

sy = 0;

sWidth = inc;

sHeight = h;

firstHalf = h + 100 - firstInc + (((len / 2) - n) * ((len / 2) - n)) / constant;

secondHalf = h + 100 - firstInc + ((n - (len / 2)) * (n - (len / 2))) / constant;

dHeight = (n < len / 2) ? firstHalf : secondHalf;

dWidth = inc * widthFactor;

dy = y + (h - dHeight) / 2;

dx = x + (inc * n * widthFactor * polarity);

data.push({

sx: sx,

sy: sy,

sWidth: sWidth,

sHeight: sHeight,

dx: dx,

dy: dy,

dWidth: dWidth,

dHeight: dHeight }); } }

function redraw() {

ctx.clearRect(0, 0, canvas.width, canvas.height);

displayImage(ctx, img, 0, 140, pw, sf, imgOffset); }

function displayImage(ctx, img, x, y, pixelWidth, scalingFactor, offset) {

if(data.length === 0) {

precalculate(img, x, y, pixelWidth, scalingFactor, offset); }

var slice, sx;

for(var n = 0, len = data.length; n < len; n++) {

slice = data[n];

ctx.drawImage(img, slice.sx(offset), slice.sy, slice.sWidth, slice.sHeight,

slice.dx, slice.dy, slice.dWidth, slice.dHeight); }}

YAHOO.util.Event.on(window, 'load', init);

</script>

</head>

<body>

</body>

—

720全景图

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<!DOCTYPE html>

<head>

<style>

body {

background-color: #000000;

margin: 0px;

overflow: hidden;

}

#info {

position: absolute;

top: 0px; width: 100%;

color: #ffffff;

padding: 5px;

font-family:Monospace;

font-size:13px;

font-weight: bold;

text-align:center;

}

a {

color: #ffffff;

}

</style>

</head>

<body>

<div id="info">单张图片全景.</div>

var camera, scene, renderer;

var fov = 70,

texture_placeholder,

isUserInteracting = false,

onMouseDownMouseX = 0, onMouseDownMouseY = 0,

lon = 0, onMouseDownLon = 0,

lat = 0, onMouseDownLat = 0,

phi = 0, theta = 0;

init();

animate();

function init() {

var container, mesh;

container = document.getElementById( 'container' );

camera = new THREE.PerspectiveCamera( fov, window.innerWidth / window.innerHeight, 1, 1100 );

camera.target = new THREE.Vector3( 0, 0, 0 );

scene = new THREE.Scene();

mesh = new THREE.Mesh( new THREE.SphereGeometry( 500, 60, 40 ), new THREE.MeshBasicMaterial( { map: THREE.ImageUtils.loadTexture( 'http://sandbox.runjs.cn/uploads/rs/232/bpgpj5uv/123.jpg' ) } ) );

mesh.scale.x = -1;

scene.add( mesh );

renderer = new THREE.WebGLRenderer();

renderer.setSize( window.innerWidth, window.innerHeight );

container.appendChild( renderer.domElement );

document.addEventListener( 'mousedown', onDocumentMouseDown, false );

document.addEventListener( 'mousemove', onDocumentMouseMove, false );

document.addEventListener( 'mouseup', onDocumentMouseUp, false );

document.addEventListener( 'mousewheel', onDocumentMouseWheel, false );

document.addEventListener( 'DOMMouseScroll', onDocumentMouseWheel, false);

window.addEventListener( 'resize', onWindowResize, false );

}

function onWindowResize() {

camera.aspect = window.innerWidth / window.innerHeight;

camera.updateProjectionMatrix();

renderer.setSize( window.innerWidth, window.innerHeight );

}

function onDocumentMouseDown( event ) {

event.preventDefault();

isUserInteracting = true;

onPointerDownPointerX = event.clientX;

onPointerDownPointerY = event.clientY;

onPointerDownLon = lon;

onPointerDownLat = lat;

}

function onDocumentMouseMove( event ) {

if ( isUserInteracting ) {

lon = ( onPointerDownPointerX - event.clientX ) * 0.1 + onPointerDownLon;

lat = ( event.clientY - onPointerDownPointerY ) * 0.1 + onPointerDownLat;

}

function onDocumentMouseUp( event ) {

isUserInteracting = false;

}

function onDocumentMouseWheel( event ) {

// WebKit

if ( event.wheelDeltaY ) {

fov -= event.wheelDeltaY * 0.05;

// Opera / Explorer 9

} else if ( event.wheelDelta ) {

fov -= event.wheelDelta * 0.05;

// Firefox

} else if ( event.detail ) {

fov += event.detail * 1.0;

}

camera.projectionMatrix.makePerspective( fov, window.innerWidth / window.innerHeight, 1, 1100 );

render();

}

function animate() {

requestAnimationFrame( animate );

render();

}

function render() {

lat = Math.max( - 85, Math.min( 85, lat ) );

phi = THREE.Math.degToRad( 90 - lat );

theta = THREE.Math.degToRad( lon );

camera.target.x = 500 * Math.sin( phi ) * Math.cos( theta );

camera.target.y = 500 * Math.cos( phi );

camera.target.z = 500 * Math.sin( phi ) * Math.sin( theta );

camera.lookAt( camera.target );

// distortion

camera.position.x = - camera.target.x;

camera.position.y = - camera.target.y;

camera.position.z = - camera.target.z;

renderer.render( scene, camera );

}

</script>

</body>

</html>

—

135 total views, no views today

jBox 第一次載入圖片無法顯示

Posted on 2016-03-04 by hoyo

jBox 使用 background image 來顯示圖片，在第一次點選圖片時都無法顯示

DIV background images not showing on first load. Only happens when first loading app on FB using Chrome

解決的方式是在第一次載入顯示時，加上 setTimeout()

// JBox-image-gallery1-0

if (next_id == 0 ) {

var $this = this;

setTimeout(function(){

(!jQuery('#JBox-image-' + gallery + '-' + next_id).length) && jQuery('<img src="' + $this.images[gallery][next_id].src + '">').load(function () {

appendImage(gallery, next_id, true);

});

}, 500);

}

else {

(!jQuery('#JBox-image-' + gallery + '-' + next_id).length) && jQuery('<img src="' + this.images[gallery][next_id].src + '">').load(function () {

appendImage(gallery, next_id, true);

});

}

—

69 total views, no views today

hoyo 學習紀錄

PHP 網頁應用 IOT 物聯網自動化

Category Archives: 網頁前端

jQuery DOM Insertion, Inside & Outside

如何控制插入內容相對於對象的位置

網頁或網頁內元素是否作用中 (可視)

元素出現就作用

元素完整出現才作用

Canvas framework

hoyo 自己的應用

Web Audio API – 使用

參考

實作

RICOH THETA 網頁全景處理

jBox 第一次載入圖片無法顯示