getBoundingClientRect Method

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getClientRects Method

DHTML Methods

Web Workshop | DHTML, HTML & CSS

getBoundingClientRect Method

Retrieves an object specifying the bounds of a collection of TextRectangle objects.

Syntax

[ oRect ] = object.getBoundingClientRect()

Return Value

oRect. Returns a TextRectangle object. Each rectangle has four integer properties (top, left, right, and bottom) that represent a coordinate of the rectangle, in pixels.

Remarks

This method retrieves an object that exposes the left, top, right, and bottom coordinates of the union of rectangles relative to the client's upper-left corner. In Microsoft® Internet Explorer 5, the window's upper-left is at 2,2 (pixels) with respect to the true client.

Example

This example uses the getClientRects and getBoundingClientRect methods to highlight text lines in an object.

Sample Code

<HEAD>
<SCRIPT>
var rcts;
var keyCount=0;

function Highlight(obj) {            
    rcts = obj.getClientRects();
    rctLength= rcts.length;

    if (keyCount > rctLength-1) {
        idBeige.style.display="none";
        keyCount = 0
    }

    // set the rendering properties for the yellow DIV
    cdRight = rcts[keyCount].right + idBody.scrollLeft;
    cdLeft = rcts[keyCount].left + idBody.scrollLeft;
    cdTop = rcts[keyCount].top + idBody.scrollTop;
    cdBottom = rcts[keyCount].bottom + idBody.scrollTop;
    idYellow.style.top = cdTop;
    idYellow.style.width = (cdRight-cdLeft) - 5;
    idYellow.style.display = 'inline';

    // set the rendering properties for the beige DIV
    bndRight = obj.getBoundingClientRect().right +
	    idBody.scrollLeft;
    bndLeft = obj.getBoundingClientRect().left +
	    idBody.scrollLeft;
    bndTop = obj.getBoundingClientRect().top +
	    idBody.scrollTop;
    idBeige.style.top = bndTop;
    idBeige.style.width = (bndRight-bndLeft) - 5;
    idBeige.style.height = cdTop - bndTop;
    if (keyCount>0){
        idBeige.style.display = 'inline';
    }
    keyCount++;
}
</SCRIPT>
</HEAD>

<BODY ID="idBody">
<DIV ID="oID_1" onclick="Highlight(this)"
    onkeydown="Highlight(this)">
A large block of text should go here. Click on this
block of text multiple times to see each line
highlight with every click of the mouse button.
Once each line has been highlighted, the process
will begin again starting with the first line.
</DIV>
<DIV STYLE="position:absolute; left:5; top:400;
z-index:-1; background-color:yellow; display:none"
ID="idYellow"></DIV>
<DIV STYLE="position:absolute; left:5; top:400;
z-index:-1; background-color:beige; display:none"
ID="idBeige"></DIV>
</BODY>

This feature requires Internet Explorer 5 or later. Click the icon below to install the latest version. Then reload this page to view the sample.

This example uses the TextRectangle collection with the getClientRects and getBoundingClientRect methods to determine the position of the text rectangle within an element. In each line, the left-justified text does not extend to the right margin of the box that contains the text. Using the collection, you can determine the coordinates of the rectangle that surrounds only the content in each line. The example code reads these rectangle coordinates and instructs the ball to move over the text only, and not to the end of the line.

Sample Code

<HEAD>
<SCRIPT>
var timid = -1;
var timoID_2 = -1;
var nLine;
var nPosInLine;
var oRcts;
var nDivLen;
var nEraser;

function LoadDone() {
    oTextRange = document.body.createTextRange();              
    // Get bounding rect of the range
    oRcts = oTextRange.getClientRects();
    nLine = 0;
    oBndRct = obj.getBoundingClientRect();
    nDivLen = oBndRct.right - oBndRct.left + 1;    
    MoveTo();
}

function MoveTo() {
    if (nLine >= oRcts.length) {
	    nLine = 0;
	}
    obj.style.top = oRcts[nLine].top;
    nPosInLine = oRcts[nLine].left;
    nEraser = 0;
    timoID_2 = setInterval("MoveToInLine()",60);    
}

function MoveToInLine() {
    if (nPosInLine >= oRcts[nLine].right - nDivLen) {
        clearInterval(timoID_2);
        timoID_2 = -1;
        obj.style.left = oRcts[nLine].right - nDivLen;
        nLine++;
        timid = setTimeout("MoveTo()", 100);
        return;
    }
    if (nEraser == 0) {
	    nEraser = 1;
	}
    else {
	    nEraser = 0;
	}
	im.src = "/workshop/graphics/dot.gif";
    obj.style.left = nPosInLine;
    nPosInLine += 3;
}

function End() {
    if(timid != -1) {
	    clearInterval(timid);
        timid = -1;
	}
    if(timoID_2 != -1) {
	    clearInterval(timoID_2);
        timoID_2 = -1;
	}
}
</SCRIPT>
</HEAD>

<BODY ID="bodyid" onload="LoadDone()"
    onresize="End();LoadDone();" onunload="End()">
<P STYLE="text-align:center">
<B>The quick brown fox jumps over the lazy dog.</B>
</P>
<DIV ID="obj" STYLE="position:absolute">
<IMG ID="im" SRC="/workshop/graphics/dot.gif"
    BORDER=0 HEIGHT=16 WIDTH=16>
</DIV>
</BODY>

This feature requires Internet Explorer 5 or later. Click the icon below to install the latest version. Then reload this page to view the sample.

Applies To

[ Object Name ]

Platform Version

Win16:

Win32:

Mac:

Unix:

WinCE:

Version data is listed when the mouse hovers over a link, or the link has focus.

A, ACRONYM, ADDRESS, APPLET, AREA, B, BASE, BASEFONT, BIG, BLOCKQUOTE, BODY, BUTTON, CAPTION, CENTER, CITE, CODE, COL, COLGROUP, COMMENT, custom, DD, DEL, DFN, DIR, DIV, DL, DT, EM, EMBED, FIELDSET, FONT, FORM, Hn, I, IMG, INPUT type=button, INPUT type=checkbox, INPUT type=file, INPUT type=image, INPUT type=password, INPUT type=radio, INPUT type=reset, INPUT type=submit, INPUT type=text, INS, ISINDEX, KBD, LABEL, LEGEND, LI, LINK, LISTING, MAP, MARQUEE, MENU, NEXTID, NOBR, OBJECT, OL, OPTION, P, PRE, Q, S, SAMP, SELECT, SMALL, SPAN, STRIKE, STRONG, SUB, SUP, TABLE, TBODY, TD, TEXTAREA, TextRange, TFOOT, TH, THEAD, TR, TT, U, UL, VAR, XMP

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