?
Solved

drawing with mouse events

Posted on 2009-05-06
2
Medium Priority
?
890 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
  • 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 2000 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

New feature and membership benefit!

New feature! Upgrade and increase expert visibility of your issues with Priority Questions.

Question has a verified solution.

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

A while back, I ran into a situation where I was trying to use the calculated columns feature in SharePoint 2013 to do some simple math using values in two lists. Between certain data types not being accessible, and also with trying to make a one to…
Q&A with Course Creator, Mark Lassoff, on the importance of HTML5 in the career of a modern-day developer.
This tutorial demonstrates how to identify and create boundary or building outlines in Google Maps. In this example, I outline the boundaries of an enclosed skatepark within a community park.  Login to your Google Account, then  Google for "Google M…
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).
Suggested Courses
Course of the Month13 days, 8 hours left to enroll

750 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