Example Start

Text Sample 1

  • Increase font size
  • Decrease font size
  • Italicize text
  • Bold text

 

 

Text Sample 2

  • Increase font size
  • Decrease font size
  • Italicize text
  • Bold text

 

Bold

Italic

Font Larger

Font Smaller

Example End

Example Description

Type: Best Practice

Simple example using inline image buttons to style and size text in a text box.

Keyboard Support

The following keyboard shortcuts are implemented for this example (based on recommended shortcuts specified by the DHTML Style Guide Working Group.):


  • Tab: move between button items.

  • ENTER or Space: toggle aria-pressed state of currently focused button. Italics and bold buttons will continuously toggle until key is released.

Example Markup

Browser Compatibility

HTML Source Code


<div role="application">

<h3>Text Sample 1</h3>

<ul class="buttons" title="Text Formating Controls 1">

    <li id="larger1"  
        role="button"
        tabindex="0"
        aria-pressed="false"
        aria-controls="text1"
        aria-labelledby="larger_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-bigger.png" alt="Increase font size" align="middle">
    </li>
            
    <li id="smaller1"  
        role="button"
        tabindex="0"
        aria-pressed="false"
        aria-controls="text1"
        aria-labelledby="smaller_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-smaller.png" alt="Decrease font size" align="middle">
    </li>
          
    <li id="italic1"  
        role="button"
        class="toggleButton italic"
        tabindex="0"
        aria-pressed="true"
        aria-controls="text1"
        aria-labelledby="italic_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-italicPressed.png" alt="Italicize text" align="middle">
    </li>
        
    <li id="bold1"  
        role="button"
        class="toggleButton"
        tabindex="0"
        aria-pressed="false"
        aria-controls="text1"
        aria-labelledby="bold_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-bold.png" alt="Bold text" align="middle">
    </li>
        
</ul>

<p style="clear: both; height: 1px">&nbsp;</p>

<label for="text1" class="hide">Text Sample 1</label>
<textarea id="text1" name="text1" class="example italic">
Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.

Now we are engaged in a great civil war, testing whether that nation, or any nation, so conceived and so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this.
</textarea>        
<p>&nbsp;</p>

<h3>Text Sample 2</h3>

<ul class="buttons" title="Text Formating Controls 2">

    <li id="larger2"  
        role="button"
        tabindex="0"
        aria-pressed="false"
        aria-controls="text2"
        aria-labelledby="larger_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-bigger.png" alt="Increase font size" align="middle">
    </li>
            
    <li id="smaller2"  
        role="button"
        tabindex="0"
        aria-pressed="false"
        aria-controls="text2"
        aria-labelledby="smaller_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-smaller.png" alt="Decrease font size" align="middle">
    </li>
          
    <li id="italic2"  
        role="button"
        class="toggleButton italic"
        tabindex="0"
        aria-pressed="false"
        aria-controls="text2"
        aria-labelledby="italic_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-italic.png" alt="Italicize text" align="middle">
    </li>
        
    <li id="bold2"  
        role="button"
        class="toggleButton"
        tabindex="0"
        aria-pressed="true"
        aria-controls="text2"
        aria-labelledby="bold_label">
        <img src="http://www.oaa-accessibility.org/media/examples/images/button-boldPressed.png" alt="Bold text" align="middle">
    </li>
        
</ul>

<p style="clear: both; height: 1px">&nbsp;</p>

<label for="text2" class="hide">Text Sample 2</label>
<textarea id="text2" name="text2" class="example bold">
But, in a larger sense, we can not dedicate - we can not consecrate - we can not hallow - this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before us - that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion - that we here highly resolve that these dead shall not have died in vain - that this nation, under God, shall have a new birth of freedom - and that government of the people, by the people, for the people, shall not perish from the earth.
</textarea>

<p class="hide" id="bold_label">Bold</p>

<p class="hide" id="italic_label">Italic</p>

<p class="hide" id="larger_label">Font Larger</p>

<p class="hide" id="smaller_label">Font Smaller</p>

</div>

CSS Code



ul.buttons {
  margin: 0;
  padding: 0;
  list-style: none;
}

ul.buttons li {
  float: left;
  text-align: center;
  margin: 1px;
  padding: 1px;
  width: 36px;
  height: 34px;
}

.italic {
  font-style: italic;
}

.bold {
  font-weight: bold;
}

textarea.example {
  clear: both;
  padding: .25em;
  width: 50%;
  height: 200px;
}

.hide {
position: absolute;
top: -20em;
left: -200em;
}

Javascript Source Code


var KEY_ENTER = 13;
var KEY_SPACE = 32;

$(document).ready(function() {

  $('ul.buttons li').mousedown(function(event) {

    var ariaControls = '#' + $(this).attr('aria-controls');

    // Update state of the other buttons to their appropriate unfocused state
    $(this).siblings().each(function() {
      updateButton(this);
    });

    switch($(this).attr('aria-labelledby')) {
      case 'italic_label': {
        $(ariaControls).toggleClass('italic');

        if ($(ariaControls).hasClass('italic') == true) {
          $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-italicPressed-focus.png");
        }
        else
        {
          $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-italic-focus.png");
        }
        break;
      }
      case 'bold_label': {
        $(ariaControls).toggleClass('bold');

        if ($(ariaControls).hasClass('bold') == true) {
          $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-boldPressed-focus.png");
        }
        else
        {
          $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bold-focus.png");
        }
        break;
      }
      case 'larger_label': {
        increaseFontSize(ariaControls);
        $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-biggerPressed-focus.png");
        break;
      }
      case 'smaller_label': {
        decreaseFontSize(ariaControls);
        $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-smallerPressed-focus.png");
        break;
      }
    } // end switch

    if ($(this).hasClass('toggleButton') == true) {

        // This is a toggle button: toggle aria-pressed state
        togglePressed(this);
    }
    else
    {
        // This is a momentary pushbutton: Set aria-pressed to true
        $(this).attr('aria-pressed', 'true');
    }

    // Give the current button focus
    $(this).focus();

    event.stopPropagation();
    return false;
  }); // end button click handler

  // bind a mouseup handler to the buttons to enable momentary pushbuttons
  // to return to unpressed state and toggle buttons to remain pressed
  //
  $('ul.buttons li').mouseup(function(event) {

    if ($(this).hasClass('toggleButton') == false) {

      // Set aria-pressed to false
      $(this).attr('aria-pressed', 'false');

      // change button image to reflect unpressed state
      switch ($(this).attr('aria-labelledby')) {
        case 'larger_label': {
          $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bigger-focus.png");
          break;
        }
        case 'smaller_label': {
          $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-smaller-focus.png");
          break;
        }
      } // end switch
    }

    event.stopPropagation();
    return false;
  }); // end mouseup handler

  // keypress handler
  //
  // The Opera browser detects keystrokes to perform window manipulation during the keypress event,
  // not keydown like IE, Firefox, and Safari. Relevant keypresses are consumed by this handler to
  // make the browser behave properly when the user is manipulating the buttons.
  //
  $('ul.buttons li').keypress(function(event) {

    switch (event.which) {
      case KEY_ENTER:
      case KEY_SPACE: {
        event.stopPropagation;
        return false;
        break;
      }
    } //end switch
    return true;
  });

  $('ul.buttons li').keydown(function(event) {

    var ariaControls = '#' + $(this).attr('aria-controls');

    switch (event.which) {
      case KEY_ENTER:
      case KEY_SPACE: {
        switch($(this).attr('aria-labelledby')) {
          case 'italic_label': {
            $(ariaControls).toggleClass('italic');

            if ($(ariaControls).hasClass('italic') == true) {
              $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-italicPressed-focus.png");
            }
            else
            {
              $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-italic-focus.png");
            }
            break;
          }
          case 'bold_label': {
            $(ariaControls).toggleClass('bold');

            if ($(ariaControls).hasClass('bold') == true) {
              $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-boldPressed-focus.png");
            }
            else
            {
              $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bold-focus.png");
            }
            break;
          }
          case 'larger_label': {
            increaseFontSize(ariaControls);
            $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-biggerPressed-focus.png");
            break;
          }
          case 'smaller_label': {
            decreaseFontSize(ariaControls);
            $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-smallerPressed-focus.png");
            break;
          }
        } // end switch

        if ($(this).hasClass('toggleButton') == true) {

            // This is a toggle button: toggle aria-pressed state
            togglePressed(this);
        }
        else
        {
            // This is a momentary pushbutton: Set aria-pressed to true
            $(this).attr('aria-pressed', 'true');
        }

        event.stopPropagation();
        return false;

      } // end case
    } // end switch

    return true;
  }); // end button click handler

  // bind a keyup handler to the buttons to enable momentary pushbuttons
  // to return to unpressed state and toggle buttons to remain pressed
  //
  $('ul.buttons li').keyup(function(event) {
    
    id = this;

    switch (event.which) {
      case KEY_ENTER:
      case KEY_SPACE: {
        if ($(this).hasClass('toggleButton') == false) {
        
          // set aria-pressed to false
          $(id).attr('aria-pressed', 'false');

          // change button image to reflect unpressed state
          switch ($(this).attr('aria-labelledby')) {
            case 'larger_label': {
              $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bigger-focus.png");
              break;
            }
            case 'smaller_label': {
              $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-smaller-focus.png");
              break;
            }
          } // end switch
        }

        event.stopPropagation();
        return false;
      } // end case
    } // end switch

    return true;
  }); // end mouseup handler

  // bind a focus handler to set button image to show focus
  //
  $('ul.buttons li').focus(function(event) {

    var pressed = "Pressed";

    if ($(this).attr('aria-pressed') == 'false') {
      pressed = '';
    }
    
    switch ($(this).attr('aria-labelledby')) {
      case 'larger_label': {
        $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bigger" + pressed + "-focus.png");
        break;
      }
      case 'smaller_label': {
        $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-smaller" + pressed + "-focus.png");
        break;
      }
      case 'italic_label': {
        $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-italic" + pressed + "-focus.png");
        break;
      }
      case 'bold_label': {
        $(this).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bold" + pressed + "-focus.png");
        break;
      }
    } //end switch

  }); // end focus handler

  // bind a blur handler to set remove focus image from button
  //
  $('ul.buttons li').blur(function(event) {

    // update the button
    updateButton(this);

  }); // end blur handler

  /**
   * updateButton() updates the button image to its appropriate unfocused state
   *
   * @param (ariaControls) id of button to update
   *
   * @return N/A
   */
  function updateButton(id) {

    var pressed = "Pressed";

    if ($(id).attr('aria-pressed') == 'false') {
      pressed = '';
    }
    
    switch ($(id).attr('aria-labelledby')) {
      case 'larger_label': {
        $(id).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bigger" + pressed + ".png");
        break;
      }
      case 'smaller_label': {
        $(id).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-smaller" + pressed + ".png");
        break;
      }
      case 'italic_label': {
        $(id).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-italic" + pressed + ".png");
        break;
      }
      case 'bold_label': {
        $(id).children('img').attr('src', "http://www.oaa-accessibility.org/media/examples/images/button-bold" + pressed + ".png");
        break;
      }
    } //end switch
  } // end updateButton


  /**
   * increaseFontSize() increases the font size for the controlled area
   *
   * @param (ariaControls) id of text area to modify
   *
   * @return N/A
   */
  function increaseFontSize(ariaControls) {
  
    var $text = $(ariaControls);
    var fontSize = parseFloat($text.css('fontSize'), 10);
  
    // increase the font size
    fontSize *= 1.4;
  
    if (fontSize > 120) {
      return;
    }
    // write the new value to the css property
    // note: 'px' must be appended for valid css
    $text.css('fontSize', fontSize+'px');
  } // end increaseFontSize()
  
  /**
   * decreaseFontSize() decreases the font size for the controlled area
   *
   * @param (ariaControls) id of text area to modify
   *
   * @return N/A
   */
  function decreaseFontSize(ariaControls) {
  
    var $text = $(ariaControls);
    var fontSize = parseFloat($text.css('fontSize'), 10);
  
    // increase the font size
    fontSize /= 1.4;
  
    if (fontSize < 4) {
      return;
    }
  
    // write the new value to the css property
    // note: 'px' must be appended for valid css
    $text.css('fontSize', fontSize+'px');
  
  } // end decreaseFontSize
  
  /**
   * togglePressed() toggles the aria-pressed atribute between true or false
   *
   * @param ( id object) button to be operated on
   *
   * @return N/A
   */
  function togglePressed(id) {
  
    // reverse the aria-pressed state
    if ($(id).attr('aria-pressed') == 'true') {
      $(id).attr('aria-pressed', 'false');
    }
    else {
      $(id).attr('aria-pressed', 'true');
    }
  }

}); // end ready