ClientRect object

Article
03/21/2017

Specifies a rectangle that contains a line of text in either an element or a TextRange object.

Members

The ClientRect object has these types of members:

Methods
Properties

Methods

The ClientRect object has these methods.

Method	Description
item	Retrieves an object from a TextRectangle collection.
namedItem	Retrieves an object or a collection from a specified collection.

Properties

The ClientRect object has these properties.

Property	Description
bottom	Set or retrieves the bottom coordinate of the rectangle surrounding the object content.
height	Gets the height of the rectangle that surrounds the object content.
left	Sets or retrieves the left coordinate of the rectangle surrounding the object content.
length	Sets or retrieves the number of objects in a collection.
right	Sets or retrieves the right coordinate of the rectangle surrounding the object content.
top	Sets or retrieves the top coordinate of the rectangle surrounding the object content.
width	Gets the width of the rectangle that surrounds the object content.

Remarks

Apply the getClientRects method to an element or text range object to get a collection of ClientRect objects. The getClientRects method returns a collection of rectangles, exposing for each rectangle the left, top, right, and bottom coordinates relative to the client.

The following sentences contain each letter of the English alphabet. Each sentence contains a ClientRect object defined by a em element.

<p>The quick <em>brown fox</em> jumps over the lazy dog.
<em>Bright vixens</em> jump; dozy fowl quack.
<em>Deft zebras</em> jump quickly; how vexing!
Verily! Bad quacks might jinx a <em>zippy fowl</em>.</p>

The four ClientRect objects are:

"brown fox"
"Bright vixens"
"Deft zebras"
"zippy fowl"

If you resize the window that contains this text, the ClientRect objects do not update. Because the objects are a snapshot of the layout, the objects should update after an onresize event occurs.

The width of the ClientRect may not be identical to the width of the TextRange it contains. A ClientRect is only as wide as the text, but a ClientRect width is as wide as the element that contains that text.

The ClientRect object supports properties that return the height and the width of the object.

Examples

The following example shows how to use the getClientRects and getBoundingClientRect methods to highlight text lines in an object.

<head>
<script type="text/javascript">
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 this block of text multiple times 
    to see each line highlight with every click of the mouse button. After each line 
    has been highlighted, the process will begin again starting with the first line.
</div>
<div style="position: absolute; 
    left: 5px; 
    top: 400px; 
    z-index: -1; 
    background-color: yellow; 
    display: none" 
    id="idYellow">
</div>
<div style="position: absolute; 
    left: 5px; 
    top: 400px; 
    z-index: -1; 
    background-color: #FFFFCC; 
    display: none" 
    id="idBeige">
</div>

</body>

This example uses the ClientRect, getClientRects and getBoundingClientRect collection with the 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 this 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.

<head>
<script type="text/javascript">
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" alt="dot" height="16" width="16">
</div>

</body>

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