CSS float pixels and percent mixed - css

Question

Ok, I want this:
For that, I have this HTML code:
<div id="wrapForCenter">
<div id="title">
title
</div>
<div id="contentFrame">
<div id="imagePlaceholder">
image
</div>
<div id="content">
content
</div>
</div>
<div id="buttonsBar">
buttonsBar
</div>
</div>
And I have this CSS code:
#wrapForCenter
{
position: absolute;
top:50%;
left: 50%;
margin-top: -160px;
margin-left: -240px;
width: 480px;
height: 320px;
border: 1px solid black;
}
#title
{
width: 100%;
height: 40px;
background-color: Blue;
}
#contentFrame
{
height: 240px;
width: 480px;
}
#imagePlaceholder
{
float: left;
width: 100px;
height: 100%;
background-color: Green;
}
#content
{
float: left;
width: 380px; /*<-- look at this*/
height: 100%;
background-color: Yellow;
overflow: auto;
}
#buttonsBar
{
clear: left;
width: 100%;
height: 40px;
background-color: Silver;
}
If I change the contents width to 100%, why occurs this?
What I spect is that content width would be contentFrame minus imagePlacehoder width in pixels, but when I specify float:left for both, imagePlacehoder and content, content gets its parent container width. Why?
Is there another way to get the same result without using float (maybe display:inline)? And using width:100% for content?
Thank you very much. CSS is not my strenght.

Answer 1

This is called a float drop. Floats work such that they'll fit side-by-side as long as there's enough room for each, but a float will bump down below the previous one if there's not enough room for it to fit.
width:100% means make it 100% as wide as its container (#wrapForCenter). Naturally, if you tell something to be the entire width of it's container, nothing can fit along either side inside of that container, so as a float it must move down below whatever is before it (an earlier "sibling") to fit.

Answer 2

A question similar to this was asked by me myself in stackoverflow before.
How to auto adjust (stretch) div height and width using jQuery or CSS
You can set HTML like;
<div id="container">
<div id="top"></div>
<div id="left"></div>
<div id="right"></div>
<div id="bottom"></div>
</div>
And CSS like;
#container {
position: relative;
width: 300px;
height: 200px;
}
#top, #left, #right, #bottom {
position: absolute
}
#top {
top: 0;
width: 100%;
height: 50px;
background: #00b7f0
}
#left {
top: 50px;
width: 50px;
bottom: 50px;
background: #787878
}
#right {
top: 50px;
left: 50px;
right: 0;
bottom: 50px;
background: #ff7e00
}
#bottom {
bottom: 0;
width: 100%;
height: 50px;
background: #9dbb61
}
Here is the working demo.
Hope this helps..
Note: I recommend (not forcing) you to do a search in stackoverflow before asking questions.

Answer 3

You should set your image holder to 25% and your content to 75%, or if you know how much space you have allocated for your entire content area(picture and content) then subtract 100 from that and use that many pixels. but overall this should work
#wrapForCenter {
position: absolute;
top: 50%;
left: 50%;
margin-top: -160px;
margin-left: -240px;
width: 480px;
height: 320px;
border: 1px solid black;
}
#title {
width: 100%;
height: 40px;
background-color: Blue;
}
#contentFrame {
height: 240px;
width: 480px;
}
#imagePlaceholder {
float: left;
width: 25%; /* See Here */
height: 100%;
background-color: Green;
}
#content {
float:right;
width: 75%; /* And here */
height: 100%;
background-color:Yellow;
}