I have an NSMutableArray of jpg images and I want to be able to touch and, moving my finger from right to left, move through the array of images in order. I've been reading about UIScrollView, but I'm not sure if this accomplishes what I am looking for. It seems to me that UIScrollView is more used for viewing an object that is too large to be displayed entirely on the screen and you need to be able to move to see every part of the object. I need to move to an entirely new image, the next image in my array. What is the best way to go about this?
You certainly can use a UIScrollView for what you want. A scroll view can be used, as you noted, to scroll an area that is too large for the screen. However, you can also use it to scroll through "pages". This is really the best way to do what you want, short of rolling your won scroll view.
There is a property of UIScrollView, called pagingEnabled, which you'll want to set to YES. I suggest that you give it a try. Also, have a look at the UIScrollView documentation and the Scroll View programming guide. It will tell you all that you need to know about UIScrollViews. Also, remember that for proper memory management, you'll want to only load three images at any given time. See this answer that I wrote for more information on that, and on UIScrollViews in general.
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How can I create simple image carousel. Let's say I have GridView with two rows and one column. I want to create image carousel in upper row. Can I do that with ScrollView. Any sugestions?
You have the right idea. You can use gridLayout just to keep your sizing in line, and using scrollView is perfectly fine.
I do not know exactly how you imagine such a carousel working, but one option to be aware of in scrollview is the 'paginated' option. This allows you to easily define target positions for scrollview to stop and snap to, similar to a scroll picker on native. Or if you want the sources definition..
* #param {Boolean} [paginated=false] A paginated scrollview will scroll through items discretely
* rather than continously.
The next thing you may want to think about is how a carousel goes round and round and never reaches an end like scrollview would. There is no option for this by default, but I found a way it can easily be done. It may be a bit trickier with smaller images, but here is an example I did for a infinite panorama.
Transforming Panoramas for Virtual Tours with famo.us, has it been done?
The trick was to use a second duplicate image trailing the scrollview and when scrollview was in the right position, we could jump it back to the beginning, with no visual evidence to the user.
Here is the live example..
http://higherorderhuman.com/examples/infinite.html
Hope this helps you get started!
I have built so far an application that allows the user to drag and drop images onto a NSImageView. However, I want to be able to move these images by simply clicking on any image and hold down the mouse button to move it's location.
How can I manipulate NSImageView to translate/scale after setting the images down? Is that possible? I've read about the NSAffineTransform, but it seems like that is moving the images before creating the image itself. I already have the images on the canvas, and simply want to click and hold the image and move it with my mouse. Please help anyone!
There are two sides to this.
NSImage is the model object, which you might want to display in different ways, save to disk/archive, etc. If you want to actually change the model (scaling, rotating, etc.), implying a permanent change, then you are going to probably want to look at NSAffineTransform, Quartz drawing, etc.
But you probably didn't mean that. Instead you probably are interested in NSImageView, which is a view object, displaying the contents of the NSImage model object using whatever display attributes are desired. If you only want to change how an image is displayed, not what the actual bytes in the image are, then you are going to manipulate the NSImageView at run-time. You can use NSAffineTransform here as well, but it's somewhat uncommon (and usually unnecessary).
The key thing to note that is the NSImageView inherits from NSView, so you have all its power at your disposal. Take a look at certain methods, such as:
-setFrameSize: - useful for changing the view size, and thus the image display scale
-setFrameOrigin: - useful for changing the view position, and thus the apparent image position
Note again that these have nothing to do with images per se, and apply to all Cocoa views. You may want to take a look at a book like Cocoa Programming for Mac OS X to get you past the basics. (You can then do more interesting things, like rotation, animation, etc.)
Hi I'm looking to do the following:
For a game, Create some effects based on the current view.
The code needs to grab part of a view then manipulate it.
One I need is "glass", so when the character walks behind the glass(or where the glass should be), the code will grab the image behind the glass and stretch it and reprint it where the glass should be, to give the effect of walking behind a lens.
What is the best way to do this?
I've never tried any thing like this before, so any help will be great!
I think you're asking about the image manipulation capabilities of the cocoa framework, in which case I reccomend looking into CoreImage:
http://developer.apple.com/library/mac/#documentation/graphicsimaging/Conceptual/CoreImaging/ci_intro/ci_intro.html#//apple_ref/doc/uid/TP30001185
The NSBox draws on top of the player view, the resulting composition gets a CIFilter (distortion) applied to it before drawing.
I've been banging my head about this seemingly easy task and I could really use some help.
I have a wide Image loaded in the gui (using the designer..) and I want to be able to draw only a portion of it, a rectangle.
I need to be able to change this rectangle position over the large image, in order to draw a different part of the larger image at will. In this process the rect must maintain its size.
Using the Ui::MainWindow object I'm able to access the label holding the image and a solution that involves using this option is preferred (in order to keep up with the rest of the code I've already written )
Any solution will be much appreciated :)
Thanks,
Itamar
I would definitely (for ease of use) just place an empty label as placeholder in Designer.
Then implement the paintEvent for this label (delegate it to your own method). You'll have also have to look into QPainter, QPixMap, etc... Should be doable based on these hints and the documentation.
If you want more, I suggest you provide a small code snippet to work upon.
If you want to do this more or less purely through designer, you could put a QScrollArea where you want the portion of the image to appear. If you set the scroll area's scrollbar policy to be never shown, you can then manually change what part is visible via the scroll area widget. However, this would probably be more complex that creating a derived widget and reimplementing the paint function.
I would like to create an effect than an image zooms up from a thumbnail size to full screen.
I am not sure what's the right steps to achieve this. Should I create a transparent full screen window and animate a layer on top of it?
Take a look at this CoreGraphics example. Specifically, take a look at the "grow" and "shrink" animations. That's how Apple does it, and that's what you'll want to do too.
Your solution of a transparent window with a CALayer inside is probably the best supported way to do it.
One thing that seems like it should be a good solution (at least it's the first thing I thought of when I wanted to do this) but isn't is NSView's enterFullScreenMode:withOptions:. If memory serves, it was originally meant to do what you're talking about here, but the animation was taken out and it generally doesn't work that well now.