Solved

drawing with mouse events

Posted on 2009-05-06
2
877 Views
Last Modified: 2015-01-05
I have a div tag on my page with the following attributes:

<DIV onmouseup="toggleLoading(true);setEnd(event.offsetX, event.offsetY);drawPic();setData();"onmousedown="setStart(event.offsetX, event.offsetY);"
onmouseover="setIndex();setPoints(event.offsetX, event.offsetY);" id="divCanvas" >

The onmouseup function sets the end coordinates  and the onmousedown sets the start coordinates.  I want to use the onmouseover to capture all of the points inbetween.

I do that with creating two new arrays in my js file:
var Xpoints = new Array();
var YPoints = new Array();

THen in the setPoints function:

function setPoints(inpX, inpY) {

    if (CurrentTool == "DRAWPOLYLINE") {
        Xpoints[index] = inpX;
        YPoints[index] = inpY;
        index++;
    }
    else {
//do nothing
    }

THen after the mousup is called, I have something like this:
Here I want to draw each point saved in the arrays.
for (x in Xpoints)
             jg.freeform(Xpoints[x], YPoints[x], CurrentStroke, CurrentStroke);

I have two problems:

1) WIth my original div tag, I am getting an error with the mouseover event...that an object was expected.

2) When I draw the array I don't get anything...I suspect that is becuase the onmoueover is not working.  If I try to draw just one coordinate (the first or last, which I record with the mousedown and mouseup events, it draws the one point, but I want all of them drawn).

Thanks
0
Comment
Question by:wizkid2332
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
2 Comments
 
LVL 10

Expert Comment

by:bugada
ID: 24320020
You must use onmousemove event to capture each pixel while the mouse is moving. Mouseover only fires when your pointer enters the div.

A code like your is not crossbrowser but IE oriented. If this is not a problem, continue on this road, otherway try to change it like the following snippet

To get coords you must use pageX, pageY (FF/GC/Safari) or a more complex function for IE (see Mousecoords function).

This code is untested, it's just an example, may contain typos or bugs.

<script>
window.onload = function() {
   var div = document.getElementById("divCanvas");
   
   div.onmouseup = function(e) {
      e = e || window.event;
      toggleLoading(true);
      setEnd(event.offsetX, event.offsetY);
      drawPic();
      setData();
   };
   
   div.onmousedown = function(e) {
      e = e || window.event;
      var coords = mouseCoords(e);
      setStart(coords.x, coords );
   };
   
   div.onmousemove = function(e) {
      e = e || window.event;
      setIndex();
      var coords = mouseCoords(e);
      setPoints(coords.x, coords.y);
   }; 
   
   function mouseCoords(e){
      if (e.pageX || e.pageY) {
         return {x:e.pageX, y:e.pageY};
      }
      return {
         x:e.clientX + document.body.scrollLeft - document.body.clientLeft,
         y:e.clientY + document.body.scrollTop  - document.body.clientTop
      };
   };
};
 
function setPoints(inpX, inpY) {
 
    if (CurrentTool == "DRAWPOLYLINE") {
        Xpoints[index] = inpX;
        YPoints[index] = inpY;
        index++;
    } else {
//do nothing
    }
};
 
</script>
 
<div id="divcanvas"></div>

Open in new window

0
 
LVL 10

Accepted Solution

by:
bugada earned 500 total points
ID: 24320036
sorry i've made some typos, try this code

<script>
window.onload = function() {
   var div = document.getElementById("divCanvas");
   
   div.onmouseup = function(e) {
      e = e || window.event;
      toggleLoading(true);
      var coords = mouseCoords(e);
      setEnd(coords.x, coords.y);
      drawPic();
      setData();
   };
   
   div.onmousedown = function(e) {
      e = e || window.event;
      var coords = mouseCoords(e);
      setStart(coords.x, coords.y);
   };
   
   div.onmousemove = function(e) {
      e = e || window.event;
      setIndex();
      var coords = mouseCoords(e);
      setPoints(coords.x, coords.y);
   }; 
   
   function mouseCoords(e){
      if (e.pageX || e.pageY) {
         return {x:e.pageX, y:e.pageY};
      }
      return {
         x:e.clientX + document.body.scrollLeft - document.body.clientLeft,
         y:e.clientY + document.body.scrollTop  - document.body.clientTop
      };
   };
};
</script>

Open in new window

0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Get to know the ins and outs of building a web-based ERP system for your enterprise. Development timeline, technology, and costs outlined.
There’s a good reason for why it’s called a homepage – it closely resembles that of a physical house and the only real difference is that it’s online. Your website’s homepage is where people come to visit you. It’s the family room of your website wh…
Video by: Mark
This lesson goes over how to construct ordered and unordered lists and how to create hyperlinks.
Learn how to create flexible layouts using relative units in CSS.  New relative units added in CSS3 include vw(viewports width), vh(viewports height), vmin(minimum of viewports height and width), and vmax (maximum of viewports height and width).

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question