I think this is rather easy achieved, but I couldn't find out how to- and couldn't find much documentary about it.
I hate those 'scroll to top' buttons that appear after you already scrolled just 300px. Like I'm that lazy to scroll to top on myself. Therefor I would like to have a scroll to top button that only appears when you reached the bottom of the page (minus 100vh (100% viewport height).
Let's take in account the button is called .scrollTopButton and it's CSS is opacity: 0 and it's position: fixed on default.
How would I make the button appear when you reached the bottom of the page, minus 100vh and scroll along?
I was thinking of comparing the body height minus 100vh with (window).scrollTop().
var vH = $(window).height(),
bodyMinus100vh = ($('body').height() - vH);
if (bodyMinus100VH < $(window).scrollTop) {
$('.scrollTopButton').toggle();
};
Fixed it myself. Quite easy, honestly.
$(window).scroll(function () {
var vH = $(window).height(),
bodyHeight = ($(document).height() - (vH * 2)),
// When you open a page, you already see the website as big
// as your own screen (viewport). Therefor you need to reduce
// the page by two times the viewport
scrolledPX = $(window).scrollTop();
if (scrolledPX > bodyHeight) {
$('.scrollTopButton').css('opacity', '1');
} else {
$('.scrollTopButton').css('opacity', '0')
};
});
I'm using FPPopover to present a pop over view for my iPhone app. I'm having an issue, however, where when I present it, it will only allow me to present it so low or it will jump to the top. And this is well before it gets cut off anyway.
For example:
[self.speedOptionsPopover presentPopoverFromPoint:CGPointMake(0, 235)];
Works fine, but if I put it a 255 instead of 235 (as it's a good 40px from the bottom) it jumps back up to the top.
Does anyone have any experience with this or how I could fix it?
Also, bonus points if you can explain why the content for the popover always starts like 50px from the top, when I want it to start up higher. How can I change this also?
More code from the creation:
- (void)speedOptionsTapped:(UIBarButtonItem *)sender {
// Set the delegate in the controller that acts as the popover's view to be self so that the controls on the popover can manipulate the WPM and number of words shown
self.speedOptionsController.delegate = self;
self.speedOptionsPopover.arrowDirection = FPPopoverNoArrow;
self.speedOptionsPopover.border = NO;
self.speedOptionsPopover.contentSize = CGSizeMake(320, 190);
[self.speedOptionsPopover presentPopoverFromPoint:CGPointMake(0, 235)];
}
Try replacing this part of the code in FPPopoverController.m:
//ok, will be vertical
if(ht == best_h || self.arrowDirection == FPPopoverArrowDirectionDown)
with this code:
//ok, will be vertical
if (self.arrowDirection == FPPopoverNoArrow)
{
r.origin.x = p.x;
r.origin.y = p.y;
}
else if(ht == best_h || self.arrowDirection == FPPopoverArrowDirectionDown)
The reason you might be having this issue is that the macro FPPopoverArrowDirectionIsVertical considers a popover with no arrows as having a vertical arrow. So, the result is that is tries to best position your popover as close as possible to the view that triggered the popover.
If you replace the code as indicated above, you'll be creating a special case for popovers with no arrows and asking that the original points be respected without repositioning.
What I have currently is a very simple div that has a flexcroll scroll bar. This simple div contains some draggable itmes inside of it. My goal is to be able to drag one of the items and and move it about without the flexcroll scroll bar moving.
As it stands right now if I were to drag one of the items below the viewable area the simple div will scroll down. I would like to prevent this.
I'm using jQuery UI for the draggable items. I've already tried using the option "scroll:false" but this does not work for flexcroll.
I'm sorry I don't have any example code, I'm currently away from my work computer.
flexcroll: http://www.hesido.com/web.php?page=customscrollbar
I don't know if you have already resolved this problem. This morning, I have the same problem and I found your post. After that, I have googled a lot to find a solution without any lucky. So finally, I decided to do someting myself, I hope my idea will help you.
After read the Programming Guid, I found that in this version (2.0) of flexcroll, we could register a function for onfleXcroll whose description could be found by searching the keyword "Pseudo-event: onfleXcroll". This is to say that the method will be executed after a scroll is done. So here, what I restore the "top" style with the value before you drag an element.
Here are the code
var $assetswrapper; // This variable indicates the contentwrapper of you div.
var $assetsscrollbar; // This variable indicates the vscroller of you div.
window.onfleXcrollRun = function () { // This method will be executed as soon as the div has been rendered with the help of flexcroll
// You could find these two divs by using firebug, because the top value of these two divs will be changed when we scroll the div which use the class .flexcroll.
$assetswrapper = $('#contentwrapper');
$assetsscrollbar = $('#vscrollerbar');
}
var wrapperTopPosition = 0; // This is used to stock the top value of the wrapperContent before dragging.
var scrollbarTopPosition = 0; // This is used to stock the top value of the scrollbar before dragging.
var dragged; // This is a boolean variable which is used for indicating whether the draggable element has been dragged.
var dropped = false; // This is a boolean variable which used to say whether the draggable element has been dropped.
$('.draggable').draggable({ // you could change .draggable with any element.
start: function (event, ui) {
// Your code here.
wrapperTopPosition = $assetswrapper.position().top;
scrollbarTopPosition = $assetsscrollbar.position().top
dragged = true;
},
stop: function (event, ui) {
// Your code here.
dragged = false;
dropped = true;
}
});
$('your drag div')[0].onfleXcroll = function () { // This method will be called each time when a scroll has been done.
if (dragged) {
$assetswrapper.css('top', wrapperTopPosition);
$assetsscrollbar.css('top', scrollbarTopPosition);
} else {
// Code here is used for keeping the top position as before even though you have dragged an element out of this div for a long time.
// You could test the scrollbar without this piece of code, if you drag an element out of the div for a long time, the scrollbar will keep its position,
// but after you dropped this element and try to scroll the div, then the scrollbar will reach the end of the div. To solve this problem,
// I have introduced the method setScrollPos with the old top position plus 72. 72 here is to set the scroll increment for this scroll, I know
// this value is not fit for any size of windows, but I don't know how to get the scroll-increment automatically.
if (dropped) {
dropped = false;
$('your drag div')[0].fleXcroll.setScrollPos(false, Math.abs(wrapperTopPosition) + 72);
$('your drag div')[0].fleXcroll.setScrollPos(false, Math.abs(wrapperTopPosition) + 72);
}
}
};
I hope this could give you a help if you haven't found any solution yet.
I have an asp.net web site I am building to be supported on ipad. When I focus on an input element and the keyboard pops up, the position fixed header div(which normally scrolls along with the page) will pop up the page a distance equivalent to the amount the keyboard takes up and freeze there for the duration of the input process. Once the keyboard is dropped back down, the div snaps back into place and behaves normally again. I am testing on iOS5 so position: fixed should be supported.
Is this a known issue? Has someone come across this and dealt with it before? I can't seem to find anything on this.
Fixed positioning is broken on iOS5/iOS6/iOS7.
Edit 3: See link to a working fix near end of this answer for iOS8.
Position:fixed is broken when either:
a) the page is zoomed
or
b) the keyboard shows on the iPad/iPhone (due to an input getting focus).
You can view the bugs yourself in jsbin.com/icibaz/3 by opening the link and zooming, or giving the input focus. You can edit the edit the html yourself.
Notes about bugs (a) and (b):
A fixed div with top: 0px; left: 0px; will show in the wrong position (above or below the top of the screen) when an input gets focus and the keyboard shows.
The problem seems to have something to do with the auto-centering of the input on the screen (changing window.pageYOffset).
It appears to be a calculation fault, and not a redraw fault: if you force the top: to change (e.g. switching between 0px and 1px) on the onScroll event, you can see the fixed div move by a pixel, but it remains in the wrong place.
One solution I used previously is to hide the fixed div when an input gets focus - see the other Answer I wrote.
The fixed div seems to becomes stuck at the same absolute position on the page it was at at the time when the keyboard opened.
So perhaps change the div to absolute positioning when an input has focus? Edit 3: see comment at bottom using this solution. Or perhaps save the pageXOffset/pageYOffset values before the keyboard is opened, and in an onScroll event calculate the difference between those values and the current pageXOffset/pageYOffset values (current once the keyboard is opened), and offset the fixed div by that difference.
There appears to be a different problem with fixed positioning if the page is zoomed - try it here (Also good information here about Android support for fixed in comments).
Edit 1: To reproduce use jsbin (not jsfiddle) and use the fullscreen view of jsbin (not the edit page). Avoid jsfiddle (and edit view of jsbin) because they put the code inside an iframe which causes interference with fixed positioning and pageYOffset.
Edit 2: iOS 6 and iOS 7 Mobile Safari position:fixed; still has the same issues - presumably they are by design!.
Edit 3: A working solution for (b) is when the input get focus, change the header to absolute positioning and then set the header top on the page scroll event for example. This solution:
Uses fixed positioning when input not focused (using window.onscroll has terrible jitter).
Don't allow pinch-zoom (avoid bug (a) above).
Uses absolute positioning and window.pageYOffset once an input gets focus (so header is correctly positioned).
If scrolled while input has focus, set style.top to equal pageYOffset (header will jitter somewhat due to onscroll event delay even on iOS8).
If using UIWebView within an App on iOS8, or using <=iOS7, if scrolling when input has focus, header will be super jittery because onscroll is not fired till scroll finishes.
Go back to fixed position header once input loses focus (Example uses input.onblur, but probably tider to use
document.body.onfocus).
Beware usability fail that if header too large, the input can be occluded/covered.
I couldn't get to work for a footer due to bugs in iOS page/viewport height when the keyboard is showing.
Edit example using http://jsbin.com/xujofoze/4/edit and view using http://output.jsbin.com/xujofoze/4/quiet
For my needs, I found it easier to use an absolute positioned header, hide it before scroll and show it when finish scroll (I need the same code to support iOS4 and Android).
For my purposes, I hide the header on a touchstart event, and show it again on touchend or scroll event (plus some timers to improve responsiveness/reduce flickering). It flashes, but is the best compromise I could find. One can detect the start of scrolling using the touchmove event (jQuery does this), but I found touchmove didn't work as well for me because:
regularly the iPad fails to do a repaint before scrolling (i.e. the absolute header remains stuck - even though the top was changed before scrolling started).
when an input element gets focus, the iPad auto-centres the element, but the scrollstart event doesn't get fired (because no touchmove if just clicking an input).
Implementing a fixed header on iOS5 could be improved by using a hybrid approach of fixed and absolute positioning:
used fixed positioning for iOS5 until an input gets focus.
when an input gets focus (keyboard showing), change to the iOS4 absolute positioning code.
when the keyboard is closed, change back to fixed positioning.
Code to detect when keyboard is closed (e.g. using keyboard hide key) is to register the DOMFocusOut event on the document element and do something like the following code. The timeout is needed because the DOMFocusOut event can fire between when one element gets the focus and another loses it.
function document_DOMFocusOut() {
clearTimeout(touchBlurTimer);
touchBlurTimer = setTimeout(function() {
if (document.activeElement == document.body) {
handleKeyboardHide();
}
}.bind(this), 400);
}
My fixed header code is something like:
{
setup: function() {
observe(window, 'scroll', this, 'onWinScroll');
observe(document, 'touchstart', this, 'onTouchStart');
observe(document, 'touchend', this, 'onTouchEnd');
if (isMobile) {
observe(document, 'DOMFocusOut', this, 'docBlurTouch');
} else if (isIE) {
// see http://ajaxian.com/archives/fixing-loss-of-focus-on-ie for code to go into this.docBlurIe()
observe(document, 'focusout', this, 'docBlurIe');
} else {
observe(isFirefox ? document : window, 'blur', this, 'docBlur');
}
},
onWinScroll: function() {
clearTimeout(this.scrollTimer);
this.scrolling = false;
this.rehomeAll();
},
rehomeAll: function() {
if ((isIOS5 && this.scrolling) || isIOS4 || isAndroid) {
this.useAbsolutePositioning();
} else {
this.useFixedPositioning();
}
},
// Important side effect that this event registered on document on iOs. Without it event.touches.length is incorrect for any elements in the document using the touchstart event!!!
onTouchStart: function(event) {
clearTimeout(this.scrollTimer);
if (!this.scrolling && event.touches.length == 1) {
this.scrolling = true;
this.touchStartTime = inputOrOtherKeyboardShowingElement(event.target) ? 0 : (new Date).getTime();
// Needs to be in touchStart so happens before iPad automatic scrolling to input, also not reliable using touchMove (although jQuery touch uses touchMove to unreliably detect scrolling).
this.rehomeAll();
}
},
onTouchEnd: function(event) {
clearTimeout(this.scrollTimer);
if (this.scrolling && !event.touches.length) {
var touchedDuration = (new Date).getTime() - this.touchStartTime;
// Need delay so iPad can scroll to the input before we reshow the header.
var showQuick = this.touchStartTime && touchedDuration < 400;
this.scrollTimer = setTimeout(function() {
if (this.scrolling) {
this.scrolling = false;
this.rehomeAll();
}
}.bind(this), showQuick ? 0 : 400);
}
},
// ... more code
}
jQuery mobile supports scrollstart and scrollstop events:
var supportTouch = $.support.touch,
scrollEvent = "touchmove scroll",
touchStartEvent = supportTouch ? "touchstart" : "mousedown",
touchStopEvent = supportTouch ? "touchend" : "mouseup",
touchMoveEvent = supportTouch ? "touchmove" : "mousemove";
function triggerCustomEvent( obj, eventType, event ) {
var originalType = event.type;
event.type = eventType;
$.event.handle.call( obj, event );
event.type = originalType;
}
// also handles scrollstop
$.event.special.scrollstart = {
enabled: true,
setup: function() {
var thisObject = this,
$this = $( thisObject ),
scrolling,
timer;
function trigger( event, state ) {
scrolling = state;
triggerCustomEvent( thisObject, scrolling ? "scrollstart" : "scrollstop", event );
}
// iPhone triggers scroll after a small delay; use touchmove instead
$this.bind( scrollEvent, function( event ) {
if ( !$.event.special.scrollstart.enabled ) {
return;
}
if ( !scrolling ) {
trigger( event, true );
}
clearTimeout( timer );
timer = setTimeout(function() {
trigger( event, false );
}, 50 );
});
}
};
This is somewhat still a problem in iOS13 (when a long text gets deleted in the 'textarea' field, fixed header jumps to the start of that 'textarea' field, obstructing the view), therefore, I thought I share my quick fix:
Since my footer is rather large, I went about without any JS and just adding a greater z-index to the footer than what the fixed header has. Out of sight, out of mind.
I want to trigger an event that causes the ScrollPane to start scrolling up or down.
Ideally the ScrollPane would scroll continue to scroll all the way up or down unless canceled by another event.
Would be something like this:
this.createClassObject(mx.containers.ScrollPane, "my_sp", 10);
my_sp.setSize(360, 280);
this.createEmptyMovieClip("button_up",this.getNextHighestDepth());
this.createEmptyMovieClip("button_down",this.getNextHighestDepth());
this.createEmptyMovieClip("button_left",this.getNextHighestDepth());
this.createEmptyMovieClip("button_right",this.getNextHighestDepth());
button_up.onPress=function(){
my_sp.onEnterFrame=function(){
this.vPosition -= 5;
}
}
button_down.onPress=function(){
my_sp.onEnterFrame=function(){
this.vPosition += 5;
}
}
button_left.onPress=function(){
my_sp.onEnterFrame=function(){
this.hPosition -= 5;
}
}
button_right.onPress=function(){
my_sp.onEnterFrame=function(){
this.hPosition += 5;
}
}
//replace this with whatever event you want to use to make the scrolling stop
button_right.onRollOut = button_left.onRollOut = button_up.onRollOut = button_down.onRollOut = function(){
my_sp.onEnterFrame=undefined;
}
You'll have to check the _hmax and _vmax to make sure you don't scroll past the end of the content, where the scrollbar would naturally stop at. I don't remember off the top of my head what the names of these variables are, but if you run your program in debug mode and poke around the scrollpane instance, you should find it. It'll probably be easier if you move the built-in scrollbar to the bottom and see what variable changes, then find the one that matches and is static.