HTML Canvas & JavaScript - Selection Menu - Setting Initial and Sustaining Current Selection

Question

In the HTML canvas below I have a selection menu which triggers the drawing of an image beside it dependent on what is selected (numbers 1-5 in the example below). The JavaScrip

Answer 1

you must make the paint class (in your code) once,

function Game (elementID,width,height){
	this.elementID = elementID;
	this.element   = document.getElementById(elementID);
	this.width = width;
	this.height = height;

	this.palette = {
		color1:'#fff',
		color2:'#000',
		color3:'#9F3A9B',
		color4:'#a84ea5',
		color5:'#b56ab2',
		color6:'#bf7dbd',
		color7:'#d5a8d2'
	}; 

	this.element.style.width = width + 'px';
	this.element.style.height= height + 'px';
	this.element.style.border='solid thin ' + this.palette.color2;
	this.element.style.display= 'block';
	//this.element.style.margin='1em auto';
	this.element.style.background=this.palette.color3;


	this.initialGame();
}

Game.prototype.initialGame = function(){
	this.canvas  = document.createElement("canvas");
	this.canvas.width  =  this.width;
	this.canvas.height =  this.height;
	this.element.appendChild(this.canvas);

	this.initialTitle();
	this.initialSideButtons();
	this.initialBoard();
	this.initialFooter();

    // initial selection
    this.sideButtons.select(this.sideButtons.buttons[0]);

	this.resize(this.width,this.height);
	this.render();
	this.attachEvents();
}

Game.prototype.attachEvents = function(){
	var element = this.element;
	
	var getX = function(evt){return evt.offsetX || evt.layerX || (evt.clientX - element.offsetLeft);};
	var getY = function(evt){return evt.offsetY || evt.layerY || (evt.clientY - element.offsetTop);};
 
	var game = this;
	this.element.addEventListener('mousemove',function(evt){
		game.hover(getX(evt),getY(evt));
		game.render();
	});

	this.element.addEventListener('click',function(evt){
		game.sideButtons.click();
		game.render();
	});
}

Game.prototype.onSelect = function(button){
	this.selected = button;
};

Game.prototype.hover=function(x,y){
	this.hoverX = x;
	this.hoverY = y;
};

Game.prototype.initialBoard = function(){
	var game = this;
	var Board = function(){
		this.left = 0;
		this.top  = 0;
		this.width =0;
		this.height=0;
	};

	Board.prototype.render = function(ctx){
		if(game.selected){

			var shapeWidth = this.width/3;

			ctx.fillStyle = game.palette.color1;
			ctx.strokeStyle = game.palette.color1;
			var fontSize =  14;
			ctx.font = 'bold '+ fontSize +'px Noto Sans';
			ctx.textAlign='center';
			ctx.lineWidth=8;
			ctx.lineJoin = 'round';
			ctx.strokeRect(this.left + this.width/2 - (shapeWidth/2),this.height/2-(shapeWidth/2) + this.top,shapeWidth,shapeWidth);
			ctx.fillText(game.selected.text,this.left + this.width/2,this.height/2 + this.top );
		}
	};

	this.board =  new Board();
};

Game.prototype.initialSideButtons = function(){
	var game = this;
	var ButtonBar =function(text){
		this.text = text;
		this.left = 0;
		this.top  = 0;
		this.width = 1;
		this.height= 1;
		this.selected=false;
	};

	ButtonBar.prototype.hitTest=function(x,y){
		return 	(this.left < x) && (x < (this.left + this.width)) &&
				(this.top  this.width / 2
	this.board.height= this.height - this.title.height - this.footer.height;

	this.sideButtons.left= this.board.width;
	this.sideButtons.top = this.board.top;
	this.sideButtons.width = this.width - this.board.width;
	this.sideButtons.height = this.board.height;

	this.render();
};


var game = new Game('game',window.innerWidth -50,window.innerWidth * 2/3);

window.addEventListener('resize', function(){
	game.resize(window.innerWidth -50,window.innerWidth * 2/3);
});