I am working on a web application using Google Maps. Occasionally, when one zooms using the scroll wheel, an overlay (KML data) is not re-sized correctly. Except for using the scroll wheel, I have not been able to consistently reproduce this behavior.
A Google search on Google Maps and scroll wheel is returning several items on disabling zoom for the scroll wheel.
Some related map settings:
//Map Functionality
map.enableScrollWheelZoom();
map.enableDoubleClickZoom();
map.enableContinuousZoom();
Is the mouse wheel zoom so erratic that one should disable as a best practice?
I finally was able to repeat this behavior consistently. Once the map loaded, use the scroll wheel and aggressively zoom in. And do mean aggressively. If I zoom in at a moderate or slow pace there's no problem.
I commented out map.enableContinuousZoom(); and the problem went away.
Another issue I found related to this (for me anyway) was in Chrome (Windows 7) and compatibility with a Logitech extension for Chrome : Logitech Flow Scroll 4.0.33.
As soon as I disabled the extension, using the scroll wheel to zoom in/out started working correctly.
Related
I have a forge viewer instance taking up a small portion of my page. when the mouse pointer is on the forge's canvas and I use the touch pad 2 finger scroll, the model zooms in and out as expected but the page also scrolls up and down. how can i prevent the page from scrolling while still retaining the zooming functionality.
I seem to have figured out the issue, the viewer controls bind to the DOMMouseScroll and the mousewheel on the .canvas-wrap element. this is not enough for newer versions of firefox. The controls need to also bind to the "wheel" event which seems to be the standard event for handling mouse wheel action. the following acts as a temporary fix.
document.getElementsByClassName("canvas-wrap")[0].addEventListener( 'wheel', NOP_VIEWER.impl.controls.mousewheel, false);
We are using Chrome in kiosk mode and accidentally users are causing the application to zoom with the recent addition of pinch zoom support.
They then think they've broken it and simply walk away leaving the application (and subsequently a 55" touch screen) in a broken state.
Now the only thing to work has been stopping event propagation for touch events over 2 points. Issues with that are we can't do multitouch apps in that case and if you act fast the browser reacts before javascript. Which in our tests still happen on accident by users.
I've done the Meta tags, they do not work. Honestly I wish I could disable chrome zooming at all but I cant find a way to do that.
How can I stop the browser from zooming?
We've had a similar problem, it manifests as the browser zooming but javascript receiving no touch event (or sometimes just a single point before zooming starts).
We've found these possible (but possibly not long-term) solutions:
1. Disable the pinch / swipe features when using kiosk mode
If these command-line settings remain in Chrome, you can do the following:
chrome.exe --kiosk --incognito --disable-pinch --overscroll-history-navigation=0
--disable-pinch - disables the pinch-to-zoom functionality
--overscroll-history-navigation=0 - disables the swipe-to-navigate functionality
2. Disable pinch zoom using the Chrome flags chrome://flags/#enable-pinch
Navigate to the URL chrome://flags/#enable-pinch in your browser and disable the feature.
The pinch zoom feature is currently experimental but turned on by default which probably means it will be force-enabled in future versions. If you're in kiosk mode (and control the hardware/software) you could probably toggle this setting upon installation and then prevent Chrome updates going forward.
There is already a roadmap ticket for removing this setting at Chromium Issue 304869.
The fact that the browser reacts before javascript can prevent it is definitely a bug and has been logged at the Chromium bug tracker. Hopefully it will be fixed before the feature is permanently enabled or fingers-crossed they'll leave it as a setting.
3. Disable all touches, whitelist for elements and events matching your app
In all tests that we've conducted, adding preventDefault() to the document stops the zooming (and all other swipe/touch events) in Chrome:
document.addEventListener('touchstart', function(event){
event.preventDefault();
}, {passive: false});
If you attach your touch-based functionality higher up in the DOM, it'll activate before it bubbles to the document's preventDefault() call. In Chrome it is also important to include the eventListenerOptions parameter because as of Chrome 51 a document-level event listener is set to {passive: true} by default.
This disables normal browser features like swipe to scroll though, you would probably have to implement those yourself. If it's a full-screen, non-scrollable kiosk app, maybe these features won't be important.
html {
touch-action:none;
}
This will disable browser handling of all panning and zooming gestures. The gesture will still be available for handling by javascript code.
https://developer.mozilla.org/en-US/docs/Web/CSS/touch-action
Just so anyone stumbling across this page is aware the flag in Chrome to disable 'pinch to zoom' is now:
Google Chrome/Chromium/Canary version above 50:
chrome://flags/#touch-events
Google Chrome/Chromium/Canary version less then 50 or old versions:
chrome://flags/#enable-pinch.
I'm dealing with the same issue. I think I can handle it reasonably well with the following approach
determine the css pixel width of the html element: document.documentElement.clientWidth
compare this measurement to the known pixel width of the kiosk screen
if the html element is wider, in css pixels than the screen is, in physical pixels, that means it's scaled
if the html element is scaled, apply a zoom to the body element to compensate. The formula is `body.style.zoom = htmlElementClientWidth / screenPhysicalPixelWidth
This techique has the beneficial side effect of automatically scaling the UI to whatever size the current window is, which is helpful for development if I'm developing on a screen smaller than the target screen.
More on screen pixels vs css pixels, and a discussion of how the html element expands to fill the available space at quirksmode.org.
Another solution that currently works in Chrome (54) is to add an event listener for the 'touchstart' event and call preventDefault() based on the length of the targetTouches or touches on the event.
This solution prevents a pinch (any two fingered gesture for that matter), but still provides flexibility with how you want to respond to the event. It's a nice solution because it doesn't require you to disable touch events altogether (as required if you want to disable pinch using the chrome flags, since chrome://flags/#enable-pinch no longer exists).
window.addEventListener('touchstart', function(e) {
if (e.targetTouches.length === 2) {
e.preventDefault();
}
}, false);
Some text that you can't pinch zoom on Chrome (tested in 54)
As of Version 51.0.2704.84 m, chrome://flags/#touch-events disables all the touch-events not only the pinch function. FYI. Hopefully, Google will return this functionality in future release.
After a recent update to Google Chrome (currently I'm at 30.0.1599.101), the Sources window of the Developer Tools now has the scrollbar lag as I drag it down. The effect is kind of like Facebook's 'infinite scroll', in that if I drag the scrollbar to the bottom, it doesn't actually scroll to the very end of the source. Instead goes only part of the way, and the scrollbar position then pops back up toward the middle. In order to get to the end or even middle of a longer document, I have to drag the scrollbar down multiple times. The only workaround I see is to hit Ctrl-End (Windows) and then scroll back upwards, which seems like unnecessary extra keystrokes.
This lag effect is appropriate for applications like Facebook, but it's very irritating here. Is there any way to disable this effect?
This is an issue https://code.google.com/p/chromium/issues/detail?id=269941 that is fixed in M31. You could wait for it to reach stable or try using dev/beta/canary channel as a workaround for now.
I have a Windows 7 tablet (an ASUS EP121), and I am using a web browser to display a Google Maps-based web application that I have created. Basically, I want the pinch gesture to zoom the Google Map (similar to using the scroll wheel to zoom a Google Map when using a mouse), rather than zooming the entire web page.
In Opera, Firefox, and Chrome, the pinch gesture simply zooms in the entire page. This behavior makes perfect sense for most use cases, but I'm wondering if there is any setting, in any of these browsers (e.g., Opera, FF, Chrome) that can cause the pinch gesture to behave like a mousewheel instead of zooming in the entire page?
Interestingly enough, in Arora, the pinch gesture can be used to zoom in/out a Google Map; however, other issues are preventing me from using Arora effectively that I think will be more difficult to address than the issues I am raising in this question.
Another option would be to disable pinch gestures (I know this is possible in Firefox, I'm sure the other browsers have some means to do the same), and then try to let the application take care of it. Are there any thoughts on going this route? Would something like jQuery mobile be able to accomplish this?
As a last resort, I could use Qt's webkit and implement my own event handling (basically creating a stripped down Arora), but I'm really hoping there's an easier way that utilizes currently available browsers.
Thanks.
If anyone ever runs into the same problem that I had here, I have created a very simple WebKit-based web browser using Qt that implements a pinch gesture and uses it to fire off a scroll wheel event.
It works quite well (especially for Google Maps) and the source is available on github here. I've tested the code on Windows 7 and Ubuntu Linux 12.04; it works without any problems.
I've disabled dragging on my Google Maps component, here's an example:
http://jsfiddle.net/qr2BJ/7053/
However when I'm browsing on my iPhone I can't swipe down "on" the map. So, when the map is taking up most of the screen, mobile users won't be able to swipe (scroll) down to view the rest of the page.
Is there a way to fix this, apart from sticking an extra empty div on top of Google Maps?
I had the same problem on android devices. As they are running on webkit I guess the cause is the same as for iphone. Anyways, a post on the following link addressed the issue and the first answer worked for me: Embed Google Maps on page without overriding iPhone scroll behavior