Wednesday Feb 29, 2012

CSS Animations - The Panel Flip

In the my final (for now) discussion on CSS3 animations with ADF Faces Rich Client  UI I wanted to discuss the most complex, but fundamentally useful (from a technique perspective) of the three animations shown in the introduction posting. The first two animations that I showcased were simply triggered by the browser's inherent mouse-over functionality. I didn't actually need to do anything to make the animation happen apart from assigning the correct styleClass to the panel or button.  In this final animation I'm triggering the animation from code and what's more I'm actually chaining together two animations with a server side call made in the middle. To break it down here's the logical flow:

Initiate a rotation of 90 degrees --> Change the contents of the panel -->  Return rotation to 0 degrees.

So the question is, how do we chain all of these actions together, given that the initial rotation will itself take a certain amount of time (2 seconds)?  Well, to handle this we have to write a little bit of JavaScript  that will first of all set the styleClass to provide the first 90deg animation and also register a listener function which will execute once the rotation is finished.  This callback function then executes the Server code we need and then kicks off the reverse animation. 

The Animations  

So first of all, the two styles that define the animations. This should be fairly obvious and understandable by now:

.rotateOut {
    -webkit-transition-property: -webkit-transform;
    -webkit-transform: rotateY(90deg);
    -webkit-transition-timing-function: ease-in-out;
    -webkit-transition-duration: 2s;
.rotateReturn {
    -webkit-transition-property: -webkit-transform;
    -webkit-transform: rotateY(0deg);
    -webkit-transition-timing-function: ease-in-out;
    -webkit-transition-duration: 2s;

The JSF components

In this example I'm using a switcher which is controlled by a managed bean  called uiManager. This switcher will either display the panelHeader that contains the inputForm or the comments screen. Contrary to your expectation though, it's not these panels managed by the switcher that we'll actually be animating, but rather a parent of the switcher, another panelGroupLayout. So the hierarchy looks a  like this:

  1. Panel group layout that will be animated
  2. Decorative box that will apparently rotate  
  3. Panel group layout that will be refreshed to show the change in contents
  4. Switcher 
<af:panelGroupLayout layout="vertical" 
<af:decorativeBox theme="dark">
  <f:facet name="center">
      <af:panelGroupLayout id="refresh" 
        <af:switcher defaultFacet="ASide" 
                     facetName="#{uiManager.flipAnimationSelectedSide}" >
          <f:facet name="ASide">
            <af:panelHeader text="Basic Information"> 
          <f:facet name="BSide"> 
            <af:panelHeader text="Comments">

Notice that the outer panelGroupLayout id="flip" has a binding to a backing bean for the page, this is so we can get the correct clientId back for it (look back at my Visual Notifications During Long Running Transactions article for details of this technique). The inner pgl, id="refresh", also has a binding to the backing bean which we will use later in the serverListener to force a refresh on that panel and the switcher inside it.

 Within each of the switcher "panels" is a button (not shown above) that will actually trigger the animation.  Here's the code for the button on the A-Side:

<af:commandButton text="More..." 
  <af:clientAttribute name="flipPanel"
  <af:clientListener method="animateFlipPanel"
  <af:serverListener type="flipEvent"

The code for the B-Side button is identical. To break that down we have three things of interest:

  1. A clientAttribute that is used to send the client id of the panel that we want to spin to JavaScript
  2. A clientListener to actually wire up a JavaScript  event to the button press
  3. A serverListener which identifies the server side method that will be called half way through the animation to tell the switcher to change contents.

So let's look at each of those:

The Client Attribute

The client attribute is bound to the page backing bean where there is a simple function that asks the panel that will be "flipped" for it's client ID, in this case the flipPanel variable contains the reference to the RichPanelGroupLayout which is bound to that outer panel:

 * Gets the correct client component ID for this panel in the context in which the 
 * panel is placed. This provides a safe way of getting the client ID if the component
 * is embedded in a region or similar where the computed path may change depending on the use.
 * @return clientID for use in JavaScript 
 public String  getFlipClientId() {
   return flipPanel.getClientId(FacesContext.getCurrentInstance());

The JavaScript

The clientListener on the button calls the animateFlipPanel method. This is stored in a .js file referenced using the <af:resource> tag in the metaContainer facet of the document:

function animateFlipPanel(event) {
    //Get the ID of the panel to flip. 
    //This has been passed in via the clientAttribute 
    var fpId = event.getSource().getProperty('flipPanel');
    //Grab a reference to this button that raised the 
    //event. we need this to register the callback against
    var raisingComponent = event.getSource();

    //First animation sends us to 90deg
    var transition = "rotateOut";
    flipPanel = AdfPage.PAGE.findComponentByAbsoluteId(fpId);
    initiateClientFlip(raisingComponent, flipPanel, transition);

 And here's the method that assigns the animation:

 * Kick off the animation - rotate the panel to 90 degrees which will make it  
 * disappear as it's sideways on to us.
 * Then register the callback to rotate back once the animation is finished
 * @param raisingComponent - the button that kicked things off
 * @param flipPanel - the PGL to animate (assign style to) 
 * @param transition - the style to apply
function initiateClientFlip(raisingComponent, flipPanel, transition) {
  //Set the style to animate the rotation
  /* Setup a callback to reverse the animation once the transition is finished.
   * Note that we remove the transition listener once it's executed so that 
   *   it is not called by the flipBack transition as well 
   * Note also that we have to attach the listener to the underlying DOM object
  // Get the DOM object that represents this panelGroupLayout
  var flipPanelReal = AdfAgent.AGENT.getElementById(flipPanel.getClientId());
  //Define the callback 
  var reverseTransition = "rotateReturn"
  var flipBackFunction = function (event) 
           {animateFlipBack(raisingComponent, flipPanel, reverseTransition); 
  // Add the transition listener to queue up both the animation back  
  // and the server side change which will apparently flip the
  // contents of the panel 
  flipPanelReal.addEventListener("webkitTransitionEnd", flipBackFunction,false);

So the actual animation part of the above code is trivial, we just set the new style to kick that off.  The exciting part comes in the definition of the eventListener (webkitTransitionEnd) which is set up to execute once the animation has finished. Like everything that I have covered in this short series, the code here is webkit (Chrome & Safari) specific. Similar events exist both in generic terms for the future and in specific versions for FireFox and IE.

And finally the animateFlipBack() function and a convenience method that it uses:

 * Once the initial animation is done this method is invoked to change the contents of the panel and then
 * animate back to the starting point giving the illusion of a full 180 degree flip
 * @param raisingComponent - reference to the button so we can invoke the serverListener
 * @param flipPanel - pgl to animate
 * @param reverseTransition - animation style
function animateFlipBack(raisingComponent, flipPanel, reverseTransition) {
  // Call the event on the server which will cause the switcher to 
  // change it's contents and issue a PPR event

  //Now start the return animation

 * Simple function to queue up the server side event on the button that 
 * instigated the flip. This event does not need to send a payload
 * @param raisingComponent - the button 
function raiseServerFlipEvent(raisingComponent){
    var flipEvent = new AdfCustomEvent(raisingComponent,"flipEvent",{},false);

The serverListener 

The role of the serverListener code is to toggle the facet that the switcher is currently displaying and then force the panel containing the switcher to refresh with a PPR event:

 * Event raised from JavaScript to tell us that the flip animation is underway and we 
 * need to change the content on the panel 
 * @param clientEvent
public void handlePanelFipEvent(ClientEvent clientEvent) {
  String currentSide = _uiManager.getFlipAnimationSelectedSide();
  String targetSide = UIManager.A_SIDE;
  if (currentSide.equals(UIManager.A_SIDE)){
      targetSide = UIManager.B_SIDE;
  }"Flipping to " + targetSide);
  // And queue the client refresh

 This function as you can see is a toggle based on the current value stored in the uiManager.  The UIManager itself is a session scoped bean that just holds the current side value.  It is injected into this backing bean using a managed property in the managed bean definition. The function getRefreshPanel() returns a reference to the pgl that surrounds the switcher (id="refresh" in the hierarchy above). 

Wrap Up 

The technique that I've discussed within this article may seem a little complex but in fact it's all quite logical and can be quite easily extended and made generic. You can see how more complex animations may be achieved by stringing together a whole sequence of callbacks to execute after the previous animation has completed and how you can wire in server side calls into the mix. 

Tuesday Feb 21, 2012

CSS Animations - Slide Out Panel

In this second the detailed articles on the animation prototype I'm going to look at the animation of a whole group of components at once in the form of a slide out panel menu effect. This animation combines two effects (if you look closely),  The actual slide-out, and, in parallel, a shadow around the panel.  Just like the first example, no Java or JavaScript code is required for this example, we can just use default CSS hover functionality to trigger the animation.

Again, just a warning.  This prototype was only set up for the WebKit based browsers (Safari and Chrome). So where I talk about -webkit* styles below be aware that these will have different names on FireFox (usually -moz*) and IE. A stylesheet that handles more browsers will have to include these versions as well. 

The start point for this article assumes that your style sheet (via a custom skin) already exists (go back to the first article if you've not read this yet).

However, before we get too excited about the animations we need to think a little about layout.  The last thing we want to do with these funky effects is to mess up the rest of the screen, and so at this stage, where we've not got any scripting involved, we need to make sure that space is available in the UI for the slide out. To do this I started out by laying out my components thus:

<af:panelGroupLayout (Horizontal)>
  <af:panelGroupLayout (Vertical)> - will be animated
  <af:spacer .../>  
  <af:panelGroupLayout (Vertical)>
    [Decorative Box etc.] 

So basically the panelGroupLayout that will be animated already has space "reserved" for it on the screen and, at design time, it occupies that slot. At this stage you also need to work out how wide the panel that you are animating will be once populated. This is so you can push it off screen, but still expose enough for the mouse to hover over. In my case the pgl comes out at around 100px once populated.

Hint: To keep things simple with these "container" animations I recommend that you attach effects to a vertical panelGroupLayout. In HTML terms these components get rendered as a simple html <div> which is perfect and makes things much easier to debug if the styles don't seem to be working.

On to the animation. When I started this animation I was not sure what components I would be animating so, rather than defining a specific sub-type as I did for the button in the last article, I'm defining a generic styleClass that could be used with any components. Again we need the base class(.slideout) and the :hover selector for it.


Again concentrating on the base selector first, let's look at the transitions. This time I'm kicking it up a notch (to coin a phrase) by desiring two concurrent animations, the slide out and the shadow.  Just like the last example with the commandButton we want to pair effects so that any effect I put on the hover needs to be mirrored and reversed by the base selector. This way, both the mouse-over and mouse-out will be smoothly animated.

So here's the base selector.  This "parks" the panel off screen with a little bit hanging out for the mouse to hover over and start the animation:

  position: relative;
  -webkit-transition-property: left, -webkit-box-shadow; ;  
  -webkit-transition-timing-function: linear, ease-out;
  -webkit-transition-duration: 1s, 1s;  
  -webkit-box-shadow: 0px 0px 0px;
  left: -80px; 

The story here is going to be similar to the simple button scaling discussed in part 1, but there are some differences worthy of mention.  First of all the position property. As part of this animation we're actually moving a <div> and all it's contents around the screen. I want to do that in relation to it's initial position (remember that we started out with the panel in a conventional layout). So the relative keyword is used for this. The other option here is absolute. Try setting this to absolute if you give this a go, you'll notice that the results can be, shall we say unpredictable. You need to be really careful if you're trying to move things around out of context and could end up fighting with the ADF layout algorythms. So stick to relative for now!

Next the -webkit-transition-property - this time it contains two properties, separated by a comma: left and -webkit-box-shadow. So I'm declaring here that those are the two properties I'll be animating the change in. As I'm now dealing with two properties the other -webkit-transition* properties also contain two values separated by a comma and those refer to each property transition. Thus if you look at the timing function, you'll see how the animation in the change of the left value will be linear whereas the shadow will use the ease-in-out rate of change just like the button did.  Again have a play with this and see what the difference is between the timing effects, you have total control. 

Both animations take place concurrently and take place over the same 1s duration although they could be of different durations.  In the next article I'll be looking at how animations can be queued up to provide more complex effects. 

Finally we have the endpoints for  the shadow (basically no shadow) and left. Notice with the left property, it is set to -80px. Recall that the positioning for this style is relative, so this really just tells the panel to shift 80px to the left from its starting position, which happens, in this case, to place it mostly, but not quite all, off screen.

Next the hover selector, it is, as you would expect pretty similar except that we move the pgl back to where it belongs at 0px (relative) and introduces some shadow:

  position: relative;
  -webkit-transition-property: left, -webkit-box-shadow;  
  -webkit-transition-timing-function: linear, ease-in;
  -webkit-transition-duration: 1s, 1s;  
  -webkit-box-shadow: 10px 10px 5px #888;
  left: 0px;

The final step is, of course, to assign this style to the pgl itself. Again this is done with the styleClass property 

<af:panelGroupLayout id="pglmenu" layout="vertical" styleClass="slideout"> 

There you have it.  In the final article in this series I'll be investigating a more complex animation involving JavaScript and other goodies - stay tuned! 

Monday Feb 20, 2012

CSS Animations - Basic Hover Scaling

In this first of the detailed articles on the animation prototype I wanted to look at the basic setup of application and the simplest of the animations - the Pick Me! button.  The Pick Me! button animates to draw attention to itself as the mouse moves over it.  The actual animation itself is a simple scaling so it's a good place to start. 

Again, just a warning.  This prototype was only set up for the WebKit based browsers (Safari and Chrome). So where I talk about -webkit* styles below be aware that these will have different names on FireFox (usually -moz*) and IE. A stylesheet that handles more browsers will have to include these versions as well. 

The basis of all of this work is a custom skin so that's the first thing to create. In 11.1.2 this is really as simple as going to the New Gallery and creating a new skin in the project.  Here I've extended the fusionFx-simple-v2.desktop skin as I want to keep the standard look and feel.  If you've not created a skin for your applications before, there are plenty of articles out there to help you, so I won't dwell on that.

Now in the skin itself I want to create a sub-type of button which will do the animation.  I don't want to animate every button, that would probably make the users seasick.  So the first step is to create a sub-type of the button thus:


This sub-type can then  applied to the selected buttons using the styleClass property:

<af:commandButton text="Pick Me!" styleClass="zoomOnFocus" ...>

Now to implement the  zoom behaviour, fortunately this does not involve writing any code apart from the actual CSS to provide the style. To do this we define a :hover selector for the zoomOnFocus in the skin:


Now we fill that in with the desired animation, I'll explain each of the lines next:

  -webkit-transition-property: -webkit-transform;
  -webkit-transform: scale(2,2); 
  -webkit-transition-timing-function: ease-in-out;
  -webkit-transition-duration: 1s;  

The first line,  -webkit-transition-property defines which property, -webkit-transform, should be animated. The second line -webkit-transform itself defines the end result of the animation which is a scale function. This takes two arguments for the x and y scaling respectively, so scale(2,2) doubles the size of the button in both directions.

The third line  -webkit-transition-timing-function, defines the progression of the animation in time. There are various options for this, the ease-in-out function starts the animation slowly, then speeds up and then slows down again towards the end. This provides a pleasing effect to the eye.

Finally -webkit-transition-duration defines how long the animation should take.

If you do all of this, the zoom will work nicely as you move the mouse over the button, however, as you move the mouse out the style will snap back instantly, so we need to complete the recipe with an animation the other way on the base style:

  -webkit-transition-property: -webkit-transform;
  -webkit-transform: scale(1,1); 
  -webkit-transition-timing-function: ease-in-out;
   -webkit-transition-duration: 1s;  

This style is pretty much identical to the :hover version.  The only difference is the scale() factor which is changed to 1,1 to return the button to it's normal size.  With this all in place, the button will gracefully shrink back to its normal size. 

So that's the first, very simple animation, in the next article in the series I'll look at the only slightly more complex slide-out panel animation. 

Friday Feb 17, 2012

Experiments with CSS animations in ADF Applications - Introduction

We have had several ADF users experimenting with JQuery to achieve animation effects and that made me wonder how feasible it would be to work with pure CSS3 animations within the context of an ADF application.  From the point of view of the product, we're thinking about how we might express a broader range of animations in a declaritive way, but for now I wanted to see what was possible with the product as it stands.  To wet your appetite, here's a short video of my initial prototype.  I'll explain all of the effects in follow up articles - so be patient with me and, of course, keep coming back to the blog for more!

This prototype was written in, but there is nothing there that would not work in 11.1.1.n. Also I've only worked with WebKit browsers (Chrome / Safari so far),  this is still an area where the different browser families need different treatment. This will be an exercise for you the reader. 

If you have an up to date version of Chrome, Safari or IE9 you can play the following short video in-line, Firefox users, sorry I had problems with encoding to ogg format, you'll have to download:

If not download it from here (Size: 374k) 

I've used three sets of animations here:

  1. Simple animated zoom on the Pick Me! button. It grows and then shrinks as the mouse moves over and out.
  2. Panel slide-out effect with shadow for the "menu" panel.
  3. Panel flip effect where the panel rotates through 180 degrees to show some different content, the kind of effect you'll see on your phone fairly often. (I'll admit that this one is very cool)

Hawaii, Yes! Duncan has been around Oracle technology way too long but occasionally has interesting things to say. He works in the Development Tools Division at Oracle, but you guessed that right? In his spare time he contributes to the Hudson CI Server Project at Eclipse
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