HTML5 canvas Painting Clock

Last Update:2016-03-01 Source: Internet

Author: User

Tags drawtext time and seconds

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This example uses HTML5 's canvas label and JavaScript script to simulate the display of a clock, using a browser preview effect that supports HTML5:

HTML section:

<!DOCTYPE HTML><HTMLLang= "en"><Head>    <MetaCharSet= "UTF-8">    <Metaname= "Viewport"content= "Width=device-width, initial-scale=1.0,minimum-scale=1.0,maximum-scale=1.0">    <title>Canvas Drawing</title></Head><Bodyonload= "init ()"><CanvasID= "Canvas"width= "200px"Height= "200px"></Canvas></Body></HTML>

JavaScript section:

functioninit () {varCanvas = document.getElementById ("Canvas"), Context= Canvas.getcontext ("2d"); SetInterval (function() {Draw (canvas, context)},1000);}functionDraw (canvas, context) {varx =canvas.width, y=Canvas.height, R= Math.min (X/2, Y/2); Context.clearrect (0, 0, x, y);//Clear Painting History    //Painting Clock BoxContext.fillstyle = "#f1f1f1";    Drawcircle (context, x, Y, R); //Painting Text    vartx = X/2,ty = Y/2,TR = 0.8*R; Context.font= "Bold 12px Microsoft Jas Black"; Context.fillstyle= "#000"; DrawText (Context,"1", TX + 0.5*tr,ty-0.866*tr); DrawText (Context,"2", TX + 0.866*TR, ty-0.5*tr); DrawText (Context,"3", TX +tr, Ty); DrawText (Context,"4", TX + 0.866*tr, Ty + 0.5*tr); DrawText (Context,"5", TX + 0.5*tr, Ty + 0.866*tr); DrawText (Context,"6", TX, Ty +tr); DrawText (Context,"7", tx-0.5*tr, Ty + 0.866*tr); DrawText (Context,"8", tx-0.866*tr, Ty + 0.5*tr); DrawText (Context,"9", TX-tr, Ty); DrawText (Context,"Ten", Tx-0.866*tr, ty-0.5*tr); DrawText (Context,"One", Tx-0.5*tr, ty-0.866*tr); DrawText (Context,"A", TX, Ty-tr); //Get current Time    varDate =NewDate (), H=date.gethours (), M=date.getminutes (), S=date.getseconds (), Angleh= (360/12) *math.pi/180, Anglem= (360/60) *math.pi/180Context.strokesyle= "#000"; //draw a time degreeDrawscale (context, x, Y, R, Angleh, -0.88*r, -0.96*r, 3); //draw a sub-scaleDrawscale (context, x, Y, R, Anglem, -0.93*r, -0.96*r, 1); //drawing time and seconds needlesDrawcircle (context, x, Y, 3); Drawneedle (context, x, Y, R, H*angleh + M*ANGLEM/12, -0.5*r);    Drawneedle (context, x, Y, R, M*anglem + S*ANGLEM/60, -0.6*r); Drawneedle (context, x, Y, R, S*anglem, -0.75*r);}//Painting Circlefunctiondrawcircle (context, x, Y, R) {context.save ();    Context.beginpath (); Context.arc (x/2, Y/2, R, 0, math.pi*2, 0);    Context.fill ();    Context.closepath (); Context.restore ();}//Drawing Text MethodfunctionDrawText (context, text, x, y) {context.save (); X-= (Context.measuretext (text). WIDTH/2); Y + = 4;    Context.translate (x, y); Context.filltext (text,0, 0); Context.restore ();}//draw a scale methodfunctionDrawscale (context, x, Y, R, rotate, start, end, linewidth) {context.save ();    Context.beginpath (); Context.translate (x/2,y/2); Context.linewidth=linewidth;  for(vari = 0; I < 60; i++) {context.rotate (rotate); Context.moveto (0, start); Context.lineto (0, end);    } context.closepath ();    Context.stroke (); Context.restore ();}//how to draw a needlefunctionDrawneedle (context, x, Y, R, rotate, line) {Context.save (); Context.translate (x/2,y/2);    Context.beginpath ();    Context.rotate (rotate); Context.moveto (0, 0.1*R); Context.lineto (0, line);    Context.closepath ();    Context.stroke (); Context.restore ();}

HTML5 canvas Painting Clock

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