change image on hover using gwt and ui-binder - image

i am using the declarative/ui-binder method of adding images to a page. this is in combination with using the ImageBundle functions that GWT provides.
what i would like to do is change the image out when i hover over the image. my questions are: what are the best way to do this, and is my current method the best method in the first place?
my code looks something similar to:
<ui:with field='res' type='path.to.my.app.AppResources' />
...
<g:HorizontalPanel ui:field='horizPanel' >
<g:Image ui:field='image1' resource='{res.image1}'/>
</g:HorizontalPanel>
that is then tied into an ImageBundle class via the AbstractImagePrototype.
then, in my main handler, i have something like:
#UiHandler("image1")
public void onMouseOver(MouseOverEvent event)
{
/* What do I do here? */
}
say i want to replace image1 with image2 when the user hovers over image1 (and put image1 back when the pointer leaves the image). do i replace the image1 object? do i use the setUrl function for that image? do i create a whole new image, and use the add/remove functions for the horizontal panel to add it on? that seems awfully inefficient. do i not even need an ImageBundle; can i add images via something like <g:Image .... url='path/to/image1.png' /> and then use CSS and the hover attribute to swap out the image?
some guidance would be great. the GWT documentation is seriously lacking in this area. thanks.

PushButton is good for this kind of behavior. You can go father than :hover - you can specify arbitrary html and widgets for different faces of the buttons.
See gwt pushButton in UiBinder for an example in uibinder.
There will be more overhead in this approach, since it does register mouse handlers and set up a whole widget - if you really only need the rollover image and not any other event handling, a :hover css selector (maybe with a #sprite?) is probably best.

Using mouse handlers here seems a little overhead. I would use css and the hover selector
.foo {
background: url('path/to/image1.png');
/* height, width, etc. */
}
.foo:hover {
background: url('path/to/image2.png');
/* ... */
}
then use a widget that renders a div element (e.g. SimplePanel) instead of an image and set the style foo as stylePrimaryName
<g:HorizontalPanel ui:field='horizPanel' >
<g:SimplePanel ui:field='image1' stylePrimaryName='foo'/>
</g:HorizontalPanel>

Related

Stretch Cover Image to Browser, Lift When Scrolled

So, the new Exposure site is wonderful and got me wondering how they've achieved something like this. Basically, it's a cover image that's stretched to the browser window (even if you resize), what's lovely about is that only when you scroll do you get to see the content below.
I guess you could use something like backstretch.js for the dynamically-resized image. How are they achieving the rest, though?
I've set up a pen here: http://codepen.io/realph/pen/luwdJ
Which seems to do the job, but the content is being covered when you scroll rather than falling below the cover image.
Any idea what I'm doing wrong, or any tips for achieving something like this?
Thanks in advance!
I think this is what your looking for and css can do the whole thing
http://codepen.io/anon/pen/rajDJ
Just add this rule to your images or image class
img {
width: 100%;
}
What exposure is doing there is creating onclick modal window that contains the image but you can do that with js or jquery or there are many jquery plugins that do that.
Also to get the nice grid structure you can use a grid template. Here is one to get you started http://960.gs/

After drag-and-drop an image inside Canvas of HTML 5, how can I display it's ID?

I am having 4 images inside Canvas in HTML5. When I drop the image somewhere in the Canvas, I want to display the name of the image inside my Canvas .
Is it possible? If yes, please tell me how can it be done?
The source code can be found here. KineticJS is used to handle the canvas.
I've never used KineticJS before, but from what I read in the doc :
To detect drag and drop events with KineticJS, we can use the on() method to detect dragstart , dragmove, or dragend events. The on() method requires an event type and a function to be executed when the event occurs.
It'll end up beign something like this
rajiniGroup.on('dragend', function(evt) {
// add your text somewhere using a shape text
};
Shape text are detailed in the doc as well.

Desaturate effect with jQuery and Pixastic

Does anyone know how to use the Pixastic plugin and jQuery to where I could have an image fade from color to completely desaturated?
I am trying to avoid saving out two images and fading one out..
i did the inverse... having desaturated images fade in to color. achieved w/ only 1 image in conjuction w/ pixastic and livequery. i basically cloned the images, desaturated one of the copies, and stacked them on top of each other.... fading the top (desaturated) layer out on hover. i'm sure it could be more elegant, but it mostly works. you can see the effect at chicagointerhandball.org on all the "sponsor" logos
$('.sponsors').load(function() {
$('.sponsors').pixastic("desaturate");
}).each(function(index) {
var clone = $(this).clone().removeClass('sponsors').addClass('sponsors-color').css('opacity',.25);
$(this).parent().append(clone);
});
$('.sponsors-color').livequery(function(){
// use the helper function hover to bind a mouseover and mouseout event
$(this).hover(function() {
$(this).stop().animate({"opacity": 1});
}, function() {
$(this).stop().animate({"opacity": 0});
});
}, function() {
// unbind the mouseover and mouseout events
$(this)
.unbind('mouseover')
.unbind('mouseout');
});
Since all those pixastic image effects are generated on the fly I don't think it would be feasible to fade between saturated and desaturated. The saturation level of the image would have to be redrawn at each step of the fade. Your best bet would probably be to have two images, one saturated and one desaturated, and have them placed on top of one another. Then when you hover over one, fade in the other image.
Edit:
Just saw that you were trying to avoid having two images. Well, that's the only solution I can think of but I'd love to see if there were others. Depending on how many images there are, you could generate all the desaturated images on page load, place them on top of saturated images, hide them, and then fade them in on hover. Just a possibility.
you could get the best of both worlds by dynamically creating a duplication and desaturating that image with pixastic. Position the new desaturated image under the original and fade the original out.
You should be able to, it is in their jQuery documentation section.
// convert all images with class="photo" to greyscale
$(".photo").pixastic("desaturate");
Looks like this is possible with the canvas element.
With this you need to mix jQuery and the standard DOM calls. I was having the same issue just today about this. I couldn't get the hover to work cross platform from the examples given here and on their site. So I decided to think for myself on this one. Came up with a solution, hope it works for you:
http://you.arenot.me/2012/03/26/pixastic-desaturate-on-mouseover-mouseenter-mouseleave/

Can you preload images in a dojo animation

I have a dojo animation object of about 15 images. I'm also using dojo.fx.chain to link them all together.
Right before I create all my dojo.fadeIn's and dojo.fadeOut's I added in some basic javascript to preload each image.
My question is: Am I doing this the hard way or is there some function/attr I can set in the animation object to do this?
I do not think there is a predefined method in dojo to preload these images for your animation.
I guess you are listening image.onload and image.onerror events to preload images, it is a common method. If you feel it is too difficult and hard to control, you can try a simple clean css way that is to put an invisible div into your page and set background images with these animation images. When the page load, the images are automatically loaded.
dojo Animations are not specifically geared around images, they work on an abstract level and may operate on DOM nodes. So, there's no built-in support for IMG nodes specifically.
There is dojox.image.preload (http://api.dojotoolkit.org/jsdoc/HEAD/dojox.image.preload) which will do the work virsir suggested of loading images into an offscreen div, but it does not (currently) arrange an onLoad event hook for you to detect when they're loaded and thus play your animation.
I imagine you could use preload()'s return value and use it to hook into onLoad, but that's an exercise for the reader. Have a look at the source code, dojox/image/_base.js.

Disabling interstitial graphic when using cfdiv binding

Is there a way to keep the "Loading..." graphic from appearing when cfdiv refreshes? I'd like to prevent the flicker of loading the graphic then loading the new html.
By adding these lines at the bottom of the header, it overwrites the "Loading..." html and seems to prevent the flickering effect in both IE and FireFox:
<script language="JavaScript">
_cf_loadingtexthtml="";
</script>
While this seems to do the trick, it would be nice if there was an officially supported way to customize the loading animation on a per page or per control basis. Hopefully they add support for that in ColdFusion9.
I don't think there is currently a way to do this programmatically within the cfdiv tag. If you really want to get rid of that "Loading..." message and the image, there are a couple places you can look.
You can rename or delete the image, which is located at: CFIDE\scripts\ajax\resources\cf\images\loading.gif
That only gets rid of the animation. The "Loading..." text can be blanked out to an empty string, and is defined in: CFIDE\scripts\ajax\messages\cfmessage.js
Making these changes will obviously have an impact on tags other than cfdiv, but if you are looking to eliminate this behavior in one place, I'm sure you won't mind killing it everywhere else too. :)
I'd love to see a cleaner way to do this if anybody else has any ideas.
This is by no means a comprehensive or an elegant solution, but I found using negative margins on adjacent elements can "cover" the animation. I don't know if this method works in all cases, but for my particular case it worked. The animation appeared next to a binded text field, to the right of which was a submit button. The layer was floated to the right. I used negative margin on the submit button and it covered the animation without affecting the layer alignment.
Another measure I did was to check the layer structure, and added the following code to my css be sure:
#TitleNameloadingicon {visibility:hidden;}
#TitleName_cf_button {visibility:hidden;}
#TitleNameautosuggest {background-color:#ffffff;}
You can create functions to change the message prior calling the ajax load that can set the message and image to a new value.
function loadingOrder(){
_cf_loadingtexthtml="Loading Order Form <image src='/CFIDE/scripts/ajax/resources/cf/images/loading.gif'>";
}
function loadingNavigation(){
_cf_loadingtexthtml="Loading Menu <image src='/CFIDE/scripts/ajax/resources/cf/images/loading_nav.gif'>";
}
(these will eventually be rolled into a single function that will take both a text_value and an image_path parameter)
In some of my processes that load both a main and left nav cfdiv I use a function like this:
function locateCreateOrder(){
loadingOrder();
ColdFusion.navigate('/functional_areas/orders/orders_actions/cf9_act_orders_index.cfm','main_content');
loadingNavigation();
ColdFusion.navigate('/functional_areas/products/products_actions/cf9_products_menu.cfm','left_menu');
}

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