viewport

问题 I am trying to set up a Picture in picture style "map" display for a graphics program that displays a car. (Just shows the view from top again in a smaller view port.) However, the second viewport seems to flicker. I thought I was doing this correctly, but I may be not conceptualizing this correctly. void display(void) { glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT); // Set Perspective glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(fov, aspect, near,

问题 Sorry, this is a long piece of sample code below, but here's the issue: I have a background that I'm actively drawing (I could probably be smart and draw it once and just scale it, but this shows the problem just as well). You can use the mouse wheel to zoom in and out on the image. The idea is to do a "google map" zoom where it zooms under the mouse pointer. What I've noticed is that it doesn't seem to actuall behave until the image is big enough to use both scroll bars. Until then, you get

问题 When someone scrolls down our page, at a certain moment a div (with a cta button) comes into view. What i am trying to achieve is that this div, from that moment on, gets 'sticky' and scrolls down with the viewport, at the bottom of the viewport , if the site is beging scrolled down. This div then basically is, but not really, sort of a sticky footer as the rest of the site keeps on scrolling behind it. Now, i am having no problem in getting the div sticky at the top of the page, but thats

问题 How can I get the first DOM element that is visible in a viewport? PS: the first DOM element in a page will not be the first "visible" element when I scroll to the middle or bottom of the page 回答1: In mind with the scroll, you'll need to query the whole document, get the elements offset positions, and match that agains the scrollTop value of the window. Then query the :eq(0) (jQuery) of those. EDIT: I think this sample will work, haven't tried it out yet tho, since I'm unable to access any

问题 How can I check if a UITableViewCell is completely visible on the screen (not cut off by the tab or nav bar)? I can get the visible cells with this code: NSArray *indexes = [_tableView indexPathsForVisibleRows]; but I want to exclude cells that are not entirely visible in the screen. 回答1: As you have, get the visible cells. The only ones that might be partial are the top and bottom ones. For each, check if its rect ( rectForRowAtIndexPath: ) is fully within the bounds of the table view (based

问题 I'm finishing my website and everything works perfectly except for one little thing. When I'm using my iPhone, the portrait mode is exactly as I want it, the problem is the landscape mode. I is like I've design it, but I don't like the final version... So I need to insert another line of code, but I don't know how to do it... This is the one I have right now <meta name="viewport" content="width=device-width,initial-scale=1"> Now I need one just for the landscape mode. I want this one ^ to

问题 This is some quite strange behaviour I experience. I want to execute a function only when the document is taller than the viewport (i.e. it overflows it and a scrollbar appears). I use this code: var docH = $("document").height(), viewPortH = $("window").height(); if (docH > viewPortH) { // execute functions } But nothing happens and console returns: Uncaught TypeError: Cannot read property 'parent' of null Does anyone know what the problem is/what code I should use to see whether the

问题 I've been doing some research about viewport issues in iPod and iPhone 4's Safari, but i can't find any answer on this matter. There are several threads about issues going from portrait to landscape, but not from landscape to portrait. The issue is the following: I used to have the normal zooming issue when going from portrait to landscape so i added the tag: <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"> So that fixed that issue. NOW, when I go back to

问题 I'm developing a website that I want to feel "appy", for users that'll access it through phones, tablets, and desktop PCs. I'm using jQuery Mobile for that. For some reason, jQuery mobile requires a viewport tag with "width=device-width, initial-scale=1". If I choose any other width, any other initial-scale, or I remove either, then jQuery mobile behaves horribly bad. (transitions look jerky, things jump up and down, it's horrible). Now, 320px is a bit narrow for my content, and I was kind of

问题 I'm trying to specify different colors for selected range of screen sizes, however I just can't seem to figure out the iPad Mini 2 with Retina Display. It does simply not follow the rules of it's pixel resolution and I wonder why. Here is my code: /** Retina iPad **/ @media screen and (-webkit-min-device-pixel-ratio: 1.5), screen and (-moz-min-device-pixel-ratio: 1.5), screen and (-o-min-device-pixel-ratio: 1.5), screen and (min-device-pixel-ratio: 1.5){ body { background-color: #486ffd; } }