richdemo.css

/* Copyright (c) 2006, 2011, Oracle and/or its affiliates. All rights reserved. */
.TestRichPanelBorder {
  position: absolute;
  top: 50px;
  left: 10px;
  width: 500px;
  height: 400px;
  border-top:1px silver solid;
  border-bottom:1px silver solid;
  background-color:blue;
  cursor: default;
  font-size:11px;
  font-family: Tahoma, Verdana, Helvetica, sans-serif;
}
.TestRichOutputTextNorth {
  border: 1px Black solid;
  margin-right: 5px;
  background-color:Yellow;
}
.TestRichOutputTextSouth {
  border: 1px Black solid;
  margin: 5px;
  padding: 5px;
  background-color:Yellow;
}
.TestRichOutputText {
  border: 1px Black solid;
  margin-right: 5px;
  padding-left: 3px;
  background-color:Yellow;
}

.TestWatermark {
  background-image: url('/images/watermark.png');
}

.DemoRichPanelBorder {
  border-top:1px silver solid;
  border-bottom:1px silver solid;
  background-color:scrollbar;
  cursor:default;
  font-size:11px;
  font-family: Tahoma, Verdana, Helvetica, sans-serif;
}

.DemoCurrentLocation {
  margin:3px 3px 3px 3px;
}

.DemoPathDisplay {

  border:1px gray solid;
  background-color:white;
  padding: 1px 1px 1px 1px;
}

.DemoFileIcon:ltr {
  margin-right: 2px;
  vertical-align: middle;
}
.DemoFileIcon:rtl {
  margin-left: 2px;
  vertical-align: middle;
}

af|panelResizeNotify {
  background-color:#dddddd;
  border:2px #999999 solid;
  padding: 5px;
  margin:5px;
  font-family: Tahoma;
  font-size: 8pt;
}

af|panelAddScript {
  background-color:#dddddd;
  border:2px #999999 solid;
  padding: 5px;
  margin:5px;
  font-family: Tahoma;
  font-size: 8pt;
}

/* The following 'AttributeDeprecated' classes are used in the component attribute editor. */
af|inputText.AttributeDeprecated af|inputText::label {
  text-decoration:line-through;
}
af|selectBooleanCheckbox.AttributeDeprecated af|selectBooleanCheckbox::label {
  text-decoration:line-through;
}
/*  bug 12630300 - workaround for MS SR111072584108293 */
@agent ie and (version:9) {
  .AFDialog {
    -tr-enable-ie-rtl-toggle: true;
  }
}

8 Organizing Content on Web Pages (OFM_ADF_WUI_DG_11.1.1.6)

http://docs.oracle.com/cd/E23943_01/web.1111/b31973/af_orgpage.htm#CDEHDJEA

8.6 Arranging Content in Forms.

Right-Aligned Labels and Left-Aligned Fields in a Form.

Labels Above Fields in a Form.

8.6.1 How to Use the panelFormLayout Component.

setting no of columns and rows.

setting Label width and Field Width.

Insert the desired child components.

when to use non-input components?

when to use panelLabelAndMessage component in panelFormLayout.

when to use the group component  in panelFormLayout.

when to use footer facet in panelFormLayout.

8.6.2What You May Need to Know About Using the group Component with the panelFormLayout Component.

panelGroupLayout Inside a Group Component WITH  layout="horizontal".

panelGroupLayout Inside a Group Component WITH  layout="vertical".

footer Facet in panelFormLayout with One Root group Component.

fixed field width of panelFormLayout child Components

solution link
http://www.jobinesh.com/2011/02/customizing-width-of-ui-control-using.html
extra knoledge link
http://docs.oracle.com/cd/E23943_01/web.1111/b31973/af_orgpage.htm#CACCBCCI
solution
You can use contentStyle attribute to override the default width of specific types of UI controls. This property is applicable for single select and multiple select controls( af:selectOneChoice, af:selectManyShuttle, af:selectBooleanRadio etc.) and input controls( af:inputText, af:inputRangeSlider, af:inputListOfValues,af:richTextEditor etc. ). 

<af:selectOneChoice  contentStyle="width:200px" label="Select an Item:" id="soc1">