I created a custom view to arrange photos in a seamless grid, like Google Photos does (see below). My view is based on QAbstractItemView (Qt Widgets based). I would like to port this to QtQuick, in order to take advantage of hardware acceleration, animations, and touch.
QtQuick has some views inheriting from Flickable that it you can use with models, like ListView and GridView. Is there a way to create my own custom view? Things I thought about:
Create a proxy model that knows the width of the view, and lays out the images in rows. Then just use a Flickable with Repeaters to read from that model, and lay out the images. Downsides: Adding thousands of photos like this, without dynamically loading and recycling, is going to take too many resources.
Similar, but use a ListView on each "row" I put together above. Use the recycling capability of the ListView to not load too many rows. I would have to disable the selection function and roll my own on top. Could work, but seems very hacky.
Go to the source of the ListView, and implement something similar: https://code.woboq.org/qt5/qtdeclarative/src/quick/items/qquicklistview.cpp.html . QQuickListView inherits from (internal) QQuickItemView which does a lot of heavy lifting, and probably some things I don't need. This seems like the most correct way, but is a huge amount of work.
What's my best option here?
Related
I'm trying to create a menu for a local multi-player game that dynamically updates when peers become available on the network.
The interface I want to implement is a UIScrollView, where each page displays information about a peer. Ideally, these pages are added and removed when a peer's availability changes.
I have looked through several tutorials using UIScrollView, but they all seem to pull page information from a plist or pre-loaded array.
What I want must be possible; weather app behaves in a similar manner, dynamically adding or deleting location pages. I'm not sure where to turn for further help, though. How do I dynamically update my scroll view's contents as outside events occur?
I decided to go with UICollectionView instead, it seems to provide a better method of implementation for what I'm trying to accomplish. Thanks!
Have a look at this Ray Wenderlich Tutorial.
I've used it as a basis for doing a paged scroll and the mechanism is simple enough to extend to whatever dynamic scheme you would like.
You can check this site for Multiple Tutorials & examples for UIScrollview. The link:
is Here..
I am sure, you'll able to find some good code for your need. Hope it works for you.
I want to create an omnidirectional scrollview that works pretty much like the one in the "Wall of Sound" app. As in, the user should be able to pull into any direction and never get to an end. I want to keep the move to be smooth (and not see the pages change as you would in a standard scrollview). Does anyone know how that can be done? Or would I need OpenGL for that?
Create a 3x3 grid of views, each the size of the viewport. As the scrollview moves into another section, rearrange the views to constantly put the viewport in the center. In most cases 3x3 is sufficient, but if redrawing the views is expensive, you may want to use a larger grid (5x5 for instance). This requires that you have some mechanism for splitting up your full view into tiles.
You can implement the same thing using CALayer if you like. If you go that way, you should consider instead using CATiledLayer. See Matt Long's quick introduction on CIMGF.
Are there known and proven ways to manage memory with scrolling components like tables or grids other than recycling cells as is used in Cocoa? The sequence of calculations and datasource/delegation calls needed to make this way of laying out views works but also makes coordinating complex animations with the cells and a scroll view error prone as you have to pay careful attention to the sequence of calls as it reloads data, scrolls to an offset and other mechanisms of the layout that affect the target frame of your animations. I am looking for a more declarative approach to providing content to the scroll view and having it figure out a smart way to manage it's memory as is done by a browser when you load the DOM with a long vertical layout of pictures.
I found it easier to create my own custom layout classes that only do layout on my views and not to impose an elaborate protocol such as NSTableViewDataSource and the like that makes animation difficult to program. I like to know exactly where my views are at all times, the complete hierarchy of each view and I don't like to keep a model in sync with my views so I store data on the views themselves. In my mind the objects on screen are the one and only objects I like to orchestrate as a programmer. I want direct declarative control over them kind of like a game programer. By subclassing a scroll view directly and following very simple layout rules outside of the normal layoutSubviews methods of Cocoa to avoid surprise layouts, I was able to control my animations better and do more complex and fluid animations. Hope this inspires someone to do the same.
I just wanted to know how you could implement a bookcase, like in iBooks, into your iPhone app.
I presume you would need to use a UIScrollView, but then I read somewhere that you need to use a UITableView. Which is it?!
You'd use code that others have already written, such as AQGridView.
I'm not sure if there's a better way, but you could create multiple small views or images (these would represent each book) then add these small views/images to the subview of a larger view in a linear format (leaving a space between each element). Then just set the background of your larger view as an image of a bookcase. Sorry I don't know of a better way.
And for the above solution I would use a UIScrollView.
You can implement it anyway you like, but it seems to me that a UITableView would be the easiest (which will scroll anyway). All of the magic will happen in your UITableViewDataSource, which is where you will decide what books are placed on what row.
Once you have decided which books to display you will have create a custom tableview cell that draws the appropriate objects.
To be honest, while not too difficult of a task, it will take a lot of effort to get looking right. If you are not comfortable with custom drawing then be prepared to spend time learning about the various image/graphic APIs.
I have a list of images (say 180 images of sequence) to animate. If I use UIImageView with its default image sequence, I get memory issue.
I wanted to use CoreAnimation API, but really don't know how to do it?
What is the best way to do this.
Regards
iWasRobot :P
There's a very hard to google example on how to perform view transitions with Animation, here it is:
http://developer.apple.com/library/ios/#samplecode/ViewTransitions/Introduction/Intro.html
Here you would need as little as 2 views. You would load images into the hidden view, then "transition" it in. Assuming your slideshow mode is long enough, you should have no issues with loading times.
Another thing that comes to mind is paging with UIScrollView. Here you would need as little as 3 views
http://ykyuen.wordpress.com/2010/05/22/iphone-uiscrollview-with-paging-example/
I hope this helps!