I have a menu div that I want to slide down so it's always visible, but I want it to be positioned under my title div. I don't want it to move until the top of the menu hits the top of the screen and then stay in place. Basically I want a sliding menu with a maximum height it can slide to.
I think I understand what you're talking about—we used a similar technique on The King with jQuery. Here's how:
///// CONFIGURATION VARIABLES:
var name = "#rightsidebar";
var menu_top_limit = 241;
var menu_top_margin = 20;
var menu_shift_duration = 500;
var menuYloc = null;
///////////////////////////////////
$(window).scroll(function()
{
// Calculate the top offset, adding a limit
offset = menuYloc + $(document).scrollTop() + menu_top_margin;
// Limit the offset to 241 pixels...
// This keeps the menu out of our header area:
if(offset < menu_top_limit)
offset = menu_top_limit;
// Give it the PX for pixels:
offset += "px";
// Animate:
$(name).animate({top:offset},{duration:menu_shift_duration,queue:false});
});
(Hat tip to #soyrex who wrote this code.)
Slashdot does this. Check it out at, for example, http://tech.slashdot.org/tech/08/10/22/1246200.shtml
You may be able to lift the technique from their site.
Related
I have a video tag in my Ionic app, video element is added after click on a button.
function addVideo(videoId){
var path = $scope.getVideo(videoId).newVideoLocation.nativeURL;
path = $sce.trustAsResourceUrl(path);
var container = document.getElementById('videoContainer' + videoId);
var video = document.createElement('video');
video.src = path;
video.setAttribute('id', 'video' + videoId);
video.setAttribute('poster', $scope.getVideo(videoId).thumbnailPath);
video.setAttribute('width', '100%');
container.appendChild(video);
};
Video is added successfully but there are bottom and top white spaces / bars:
After click play button spaces are no longer there:
I set border to all elements to know what is happening. Blue border is video tag:
It could be margin o padding however I set them to 0:
* {
border: 1px solid red !important;
}
video {
border: 2px solid blue !important;
margin: 0;
padding: 0;
}
Any idea what is the problem?
After a lot of research I found a solution.
I start understanding what happened after read HTML 5 Video stretch post:
Video content should be rendered inside the element's playback area
such that the video content is shown centered in the playback area at
the largest possible size that fits completely within it, with the
video content's aspect ratio being preserved. Thus, if the aspect
ratio of the playback area does not match the aspect ratio of the
video, the video will be shown letterboxed or pillarboxed. Areas of
the element's playback area that do not contain the video represent
nothing.
Then in google books I found and explanation how works video width, the book is call The Definitive Guide to HTML5 Video
If width and height are not same aspect ratio as original video it doesn't work. Set a 100% to width doesn't mean you want video to fit the container. So I decided to calculate width and height of the container and set to video element:
function addVideo(videoId){
var path = getTrustUrl($scope.getVideo(videoId).newVideoLocation.nativeURL);
// Create container element and get padding
var container = document.getElementById('videoContainer' + videoId);
var paddingLeft = window.getComputedStyle(container, null).getPropertyValue('padding-left');
var paddingRight = window.getComputedStyle(container, null).getPropertyValue('padding-right');
// Get only numeric part and parse to integer
paddingLeft = parseInt(paddingLeft.slice(0,-2));
paddingRight = parseInt(paddingRight.slice(0,-2));
//Get internal width of container and calculate height
var width = container.offsetWidth - paddingLeft - paddingRight;
var height = (width * 9 ) / 16; // TODO, if not 16:9 error
// Create video element and set attributes
var video = document.createElement('video');
video.src = path;
video.setAttribute('id', 'video' + videoId);
video.setAttribute('poster', $scope.getVideo(videoId).thumbnailPath);
video.setAttribute('width', width);
video.setAttribute('height', height);
// Append video to container
container.appendChild(video);
};
I don't see it straightforward... if someone know another solution let me know!
Let me start with i am sorry for the long post.
I'm attempting to use the bootstrap carousel and unfortunately the pictures i have been given are NOT uniform. for example some are 100x200, doe are 150x100, etc. The aspect ratios are different, letter vs landscape. Ive attempted a number of things, including the using the following helper function on load of each of my images in the Carousel:
function ScaleImage(srcwidth, srcheight, targetwidth, targetheight, fLetterBox) {
var result = { width: 0, height: 0, fScaleToTargetWidth: true };
if ((srcwidth <= 0) || (srcheight <= 0) || (targetwidth <= 0) || (targetheight <= 0)) {
return result;
}
// scale to the target width
var scaleX1 = targetwidth;
var scaleY1 = (srcheight * targetwidth) / srcwidth;
// scale to the target height
var scaleX2 = (srcwidth * targetheight) / srcheight;
var scaleY2 = targetheight;
// now figure out which one we should use
var fScaleOnWidth = (scaleX2 > targetwidth);
if (fScaleOnWidth) {
fScaleOnWidth = fLetterBox;
}
else {
fScaleOnWidth = !fLetterBox;
}
if (fScaleOnWidth) {
result.width = Math.floor(scaleX1);
result.height = Math.floor(scaleY1);
result.fScaleToTargetWidth = true;
}
else {
result.width = Math.floor(scaleX2);
result.height = Math.floor(scaleY2);
result.fScaleToTargetWidth = false;
}
result.targetleft = Math.floor((targetwidth - result.width) / 2);
result.targettop = Math.floor((targetheight - result.height) / 2);
return result;
}
function OnImageLoad(evt) {
var img = evt.currentTarget;
// what's the size of this image and it's parent
var w = $(img).prop('naturalWidth');
var h = $(img).prop('naturalHeight');
//var tw = $(img).parent().width();
//var th = $(img).parent().height();
var tw = $(img).parent().parent().parent().parent().width();
var th = $(img).parent().parent().parent().parent().height();
// compute the new size and offsets
var result = ScaleImage(w, h, tw, th, true);
// adjust the image coordinates and size
img.width = result.width;
img.height = result.height;
$(img).css("left", result.targetleft);
$(img).css("top", result.targettop);
}
and using the following for each of my images for the carousel
<img src="~/Images/Img1_Tall.jpg" alt="Tall" id="firstImage" onload="OnImageLoad(event);" />
and for the FIRST image in the carousel it works great, but each one after that they seem to just end up their natural size and are horizontally centered but are just against the top boarder of the carousel.
I've even changed the "onload" to pass the values of the length and width of the image but that didn't work either, in debug it seems only the first image kicks off the "onload" event.
the effect i am going for is if the ratio of the container is 3:4 and the ratio of the image is 1:2, the image stretch to meet the left and right edges and would center vertically and have letter box above and below, but the container does not change so that the navigation buttons of the carousel do not move. if the image is 2:1, the image would stretch to meet the top and bottom centered horizontally with letterboxes on the right and left, again keeping the navigation buttons unmoved.
any help would be appreciated... including:
what you are trying to do is crazy
do you want to do something like http://jsbin.com/zotelasa/1 . With that code I can get the active items w,h or any other variables you used in your code to run scale image. Because of parent.parent codes it applies to carousels main divs but you can set your own container.
The quick and dirty solution would be to resize the images using an image editor, and save the properly-sized images to a folder named eg carousel_images. Then whenever you get new content you simply run the image through your editor. With a carousel you're most likely dealing with a number of images in the several to dozens range and not hundreds or thousands.
A more complicated solution is explain to your image provider that you need everything one size. The images aren't going to look right if you're stretching and skewing them on the fly, and you can show them an image with the aspect ratios wrong to explain what you mean.
Finally, as a technical solution, I would try to find out why your image resizer is only being run on the first image. From the sound of it, other images just aren't being run through your function. I think that the technical solution should be a last resort in this case because, like I said, the end results are just not going to be as good. You should at a minimum, if possible, handle each image by hand to make sure the result is adequate.
...And the answer is a little long too...
• I assume that the width’s image’s parent is a constant, and while you don’t change the width’s viewport that must remain.
A-. Get the width’s image’s parent…
(Because the id attribute I took the grand parent’s parameter, that is (must be) the same than the parent’s one).
B-. With the below value deduce the height’s image’s parent, including the preferred ratio (in this case 16x9…
C-. … And with this, set the images’ parents height collection (all the elements with class=”item”).
D-. In order to conserve your carousel’s responsive characteristic, you must add the $F_getAdjustImagesParents function to the window resize event.
E-. Set the slide’s images position to absolute (Note: That must be via JQuery because if you do it in Css the bootstrap carousel will not display correctly. I did it with a new class for the images ('myCarouselImgs').
• Bootstrap carousel’s event 'slide.bs.carousel' and 'slid.bs.carousel'.
As you know, after the ‘click’ event, the slide.bs.carousel event is one of the firsts events that imply the change from the present slide to the next one; while the 'slid.bs.carousel' one is the end of the process.
F-. In the first one (slide.bs.carousel event), using the ‘relatedTarget’ variable of the Bootstrap’s plugin, the item’s id attribute and a item’s data attribute, get the number of the next item (ensure that these last ones -id attribute and data attribute- be present).
G-. In the second one, 'slid.bs.carousel', get the image’s size. For that you need to identify the implied image. I gave an id to each one. With this and the value obtained in previus step, it can do it.
H-. Well, now you already have the four values required for the ScaleImage function. You can call it…
I-. … And apply the result with some effect
var $parentImgW = ' '
var $parentImgH = ' ';
var $myCarousel = $('#myCarousel')
var $carouseItems = $('.item');
function $F_getAdjustImagesParents(){
$parentImgW = $myCarousel.width(); // A
$parentImgH = ($parentImgW*9)/16; // B
$carouseItems.height($parentImgH+'px').css('max-height',$parentImgH+'px'); //C
console.log('$parentImgW ====> '+$parentImgW);
console.log('$parentImgH ====> '+$parentImgH)
};
$F_getAdjustImagesParents();
$(window).on('resize',function(){ // D
$F_getAdjustImagesParents();
});
$('.myCarouselImgs').css('position','absolute'); // E
$myCarousel.on('slide.bs.carousel', function(event) {// The slide’s change process starts
var $slideNum = $("#"+event.relatedTarget.id).data('slide_num'); // F
console.log('$lideNum ====> '+$slideNum)
$myCarousel.on('slid.bs.carousel', function(event) {//The slide’s change process ends
var $imgW = $('#myCarouselSlideImage'+$slideNum).width(); //G
var $imgH = $('#myCarouselSlideImage'+$slideNum).height(); //G
console.log('$imgW ====> '+$imgW);
console.log('$imgH ====> '+$imgH);
var $result = '';
$result = ScaleImage($imgW, $imgH, $parentImgW, $parentImgH, true); //H
console.log('$result.width ====> '+$result.width);
console.log('$result.height ====> '+$result.height);
console.log('$result.targetleft ====> '+$result.targetleft);
console.log('$result.targettop ====> '+$result.targettop);
$('#myCarouselSlideImage'+$slideNum).animate({ // I
width:$result.width+'px',
height:$result.height+'px',
left:$result.targetleft+'px',
top:$result.targettop+'px' },
300);
});
});
See it runnig at https://jsfiddle.net/nd90r1ht/57/ or at https://jsfiddle.net/omarlin25/nd90r1ht/59/
See the following post for a picture highlighting my question and a potential solution:
CSS overflow-y:visible, overflow-x:scroll
However, this strategy breaks when you actually move the scrollbar. In the suggested implementation (position: fixed;), the tooltips display next to child div in its position pre-scroll. So, as you scroll new child-divs into view, the tooltips begin falling off the bottom of the page.
See here for a demo of the bug: http://jsfiddle.net/narcV/4/
Any ideas how I can make the tooltips display next to the child div at all times?
I ended up implementing this using javascript, using the getPos function from this question.
The end product looks like:
var scrollPanel = ...;
var tooltip = ...;
function nodeHovered(e) {
var hovered = e.srcElement;
var pos = getPos(hovered);
pos.x += hovered.offsetWidth;
pos.y -= scrollPanel.scrollTop;
tooltip.style.setProperty('left', pos.x);
tooltip.style.setProperty('top', pos.y);
}
Basically, I calculate where on the page the node is currently displayed (taking into account the scrollbar position), and manually place the tooltip in the right spot on the page.
Too bad there's no elegant/CSS way to do this, but at least this works.
I have a Flex 3 app that has elements that a user can add to the main canvas then resize and reposition.
There are 3 key functions I am using for the resize which are as follows:
When the resize begins:
private function startResize(event:MouseEvent):void
{
RESIZE_START_MOUSE_X = event.localX;
RESIZE_START_MOUSE_Y = event.localY;
RESIZE_START_WIDTH = this.width;
RESIZE_START_HEIGHT = this.height;
RESIZE_START_X = this.x;
RESIZE_START_Y = this.y;
RESIZE_BOUND = calculateResizeBound(event);
addEventListener(MouseEvent.MOUSE_MOVE, resizeMouseHandler);
isResizing = true;
}
When the resize is complete:
private function endResize():void
{
RESIZE_START_MOUSE_X = -1;
RESIZE_START_MOUSE_Y = -1;
RESIZE_START_WIDTH = this.width;
RESIZE_START_HEIGHT = this.height;
RESIZE_START_X = -1;
RESIZE_START_Y = -1;
RESIZE_BOUND = '';
removeEventListener(MouseEvent.MOUSE_MOVE, resizeMouseHandler);
isResizing = false;
}
Whilst the user is resizing:
private function resizeMouseHandler(event:MouseEvent):void
{
var deltaX:Number = event.localX - RESIZE_START_MOUSE_X;
var deltaY:Number = event.localY - RESIZE_START_MOUSE_Y;
if (RESIZE_BOUND.indexOf('T') > -1)
//We are fixing the top so move the bottom edge
{
this.height = RESIZE_START_HEIGHT + deltaY;
}
if (RESIZE_BOUND.indexOf('B') > -1)
//We are fixing the bottom so move the top edge
{
this.y = RESIZE_START_Y + deltaY;
this.height = RESIZE_START_HEIGHT - deltaY;
}
if (RESIZE_BOUND.indexOf('L') > -1)
//We are fixing the left so move the right edge
{
this.width = RESIZE_START_WIDTH + deltaX;
}
if (RESIZE_BOUND.indexOf('R') > -1)
//We are fixing the right so move the left edge
{
this.x = RESIZE_START_X + deltaX;
this.width = RESIZE_START_WIDTH - deltaX;
}
}
There is another function referenced in these called calculateResizeBound(). What this does is return a string indicating which edge / corner should remain fixed during the resize. Eg 'TL' means that the top left corner should stay fixed, 'BR' means bottom right, 'L' means just the left edge etc etc
When the resize starts from the 'normal' position, ie the top left corner stays fixed, everything works great. Similarly with the left or top edges fixed. However for the bottom and right cases, I need to reposition the element at the same time as resizing it since all the co-ordinates are calculated from the top left.
The problem that I have is that when it does this, the resize is not smooth, it keeps jumping up and down slightly as you resize it. Not only that but when you resize from the 'normal' edges the cursor position remains fixed relative to the fixed edge / corner however from one of the other edges, you can see it start to drift away from the edge / corner as you resize.
With this kind of thing, it is easy to get the + / - of the different bits of the calculation muddled but since the resize is working in the correct direction each time, I assume I have these correct.
So presumably the problem is coming from the simultaneous moving and resizing but I can't find a work-around for it. Any thoughts / suggestions would be much appreciated
Doug McCune has an awesome Resize wrapper that you can use to resize elements. Then you just need to add a mover on it. See the blog post for code/sample: http://dougmccune.com/blog/2007/08/17/my-360flex-slides-and-code/
The Flex Canvas container is limited to 10,000x10,000 pixels. Yet, I've seen Flex apps that are scrolling way more than 10,000 pixels. Any idea how this can be done?
The content I want to scroll is in pieces already, but I need to add those pieces to something that can scroll vertically more than 10,000 pixels.
Depending on what you actually want to display you may be able to split your content into tiles. This is how Google Maps works, every time the map is moved the program determines which tiles are visible on the screen and loads them in. Any markers or overlays that are on the map are notified that the map has moved and determine where their new location is. If their location is off the screen they can be removed from the canvas. For example, the width of all the tiles at zoom level 20 on Google Maps is (256 pixels * 2^20) which equals 268,435,456 total pixels.
Essentially you just need to create a special Sprite that keeps track of the actual x,y location it is supposed to be positioned at. Any time the container moves you simply iterate through all of the child objects and determine where to put them.
function onCanvasScroll() {
//determine the top left coordinates of the canvas
//you will figure out how to do this depending on how the scrolling window
//is implemented
var canvas_scroll_x;
var canvas_scroll_y;
//create a bounding box for the canvas
var view_bounds = new Rectangle(canvas_scroll_x, canvas_scroll_y, canvas.width, canvas.height);
for (child in canvas) {
var x = child.actual_x - view_bounds.x;
var y = child.actual_y - view_bounds.y;
var childBounds = new Rectangle(x, y, child.width, child.height);
//determine if the component is visible on screen
if (view_bounds.intersects(child_bounds)) {
child.visible = true;
child.x = x;
child.y = y;
}
else {
child.visible = false;
}
}
}
So if you have a canvas that is positioned at (100, 20000), a sprite that is positioned at (300, 20100), and a window that is (640,408), you would place it at (200, 100) and it would be visible on the screen.
Instead of just setting visible to true or false a better approach would be to remove the items from the canvas entirely when they are not within the bounds of the view.