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javascript function to stop show

Posted on 2012-03-22
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Medium Priority
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Last Modified: 2012-03-28
I modified some code I found to display a slide show and have it working exactly as I want.  I have run into a problem where I cannot stop the show and clear the canvas.  Here is the code to run the slideshow:


// JavaScript Document
  
var imagePaths = [
  "_sites/BBB_homepage.png",
  "_sites/CabezonKidsDental_homepage.png",
  "_sites/djer_homepage.png",
  "_sites/enchanted_homepage.png",
  "_sites/JoeSSausage_homepage.png",
  "_sites/MMCS_homepage.png",
  "_sites/mySRB.png",
  "_sites/PHCP_homepage.png",
  "_sites/smilesforkidsnm_homepage.png",
  "_sites/t2consulting_homepage.png",
  "_sites/Upward_homepage.png",
  "_sites/Webb_based_homepage.png"
];
var showCanvas = null;
var showCanvasCtx = null;
var img = document.createElement("img");
var currentImage = 0;
var revealTimer;
var stopShow = 0;
  
function slideShow() {
  if (!stopShow){
    showCanvas = document.getElementById('Canvas1');
    showCanvasCtx = showCanvas.getContext('2d');

    //clear canvas
    showCanvasCtx.clearRect(0,0,showCanvasCtx.canvas.width,showCanvasCtx.canvas.height);
  
    img.setAttribute('width','500');
    img.setAttribute('height','400');
    switchImage();
    
    //start the animation
    setInterval(switchImage,3000);
  }
}

function switchImage() {
  img.setAttribute('src',imagePaths[currentImage++]);
  if (currentImage >= imagePaths.length)
      currentImage = 0;
    
  showCanvasCtx.globalAlpha = 0.1;
  revealTimer = setInterval(revealImage,100);
}
  
function revealImage() {
  showCanvasCtx.save();
  showCanvasCtx.drawImage(img,100,0,500,400);
  showCanvasCtx.globalAlpha += 0.1;
  if (showCanvasCtx.globalAlpha >= 1.0) clearInterval(revealTimer);
  showCanvasCtx.restore();
}

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Here is the function that I wrote thinking that it would stop the slideshow:

function stopSlideShow() {
  //alert('stop show');
  clearInterval(revealTimer);
  stopShow=1;
}

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0
Comment
Question by:prostang
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4 Comments
 
LVL 82

Accepted Solution

by:
leakim971 earned 2000 total points
ID: 37756522
replace line 23  by :
		var slideTimer; 

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line 37, replace :
setInterval(switchImage,3000);

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by :
slideTimer = setInterval(switchImage,3000);

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line 47, replace :
revealTimer = setInterval(revealImage,100);

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by :
revealTimer = setTimeout(revealImage,100); 

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and use :
function stopSlideShow() {
			//alert('stop show');
			clearInterval(slideTimer);
			clearTimeout(revealTimer);
			stopShow=1;
		}

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0
 

Author Comment

by:prostang
ID: 37757195
When I launch the slideShow function, there is no fading.  All images are now stacked and the alpha is set for the entire canvas to .1.  It does stop the show and allows me to clear.
0
 
LVL 82

Assisted Solution

by:leakim971
leakim971 earned 2000 total points
ID: 37757346
Replace anywhere << Timeout >> by << Interval >>
0
 

Author Comment

by:prostang
ID: 37757453
it stops the function, but does not allow to clear the canvas and the information under the image still has an alpha of .1.

http://mjmco.com/MJMCo.html

the web design link will show -view examples when clicked.  
the -view examples runs the slide show, the stop (just for testing now) should (and does stop it).  
When I click any other link, the first command is to clear the canvas, which isn't working now.
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