I'm targeting android but I don't know how to layout the UI so it works for all devices. How do I do this?
I have a TextField with a Button for searching and the search results are displayed below in a TableView below. So I have a table view but the bottom is cut off.
this.searchResults = Ti.UI.createTableView({
top:'70px',
height:'450dp'
});
As you can see from the code above I clearly dont know how to do this. How do you lay things out for android?
You can set top/bottom/left/right values. If you want the table to stop at the bottom edge of the screen, you could set bottom: 0. It's the same for iOS.
If I'm working on Android stuff, and I want it to resize proportionate to the size of the screen I often use percentages. So
this.searchResults = Ti.UI.createTableView({
top:'10%',
height:'90%'
});
Alternatively, If you want pin point accurate calculations, you can ask appcelerator for the platform width and height, and resize things proportionately yourself. Like so:
var height = Ti.Platform.DisplayCaps.platformHeight; //Screen height in pixels
this.searchResults = Ti.UI.createTableView({
top:'75dp',
height: (height - (75 * Ti.Platform.DisplayCaps.logicalDensityFactor)) //height - 75dp converted to pixels
});
Related
I´m setting up my view programmatically to show up when a button is pressed. My question is what's the difference between positioning a View programmatically with CGRect or with Constraints in storyboard/programmatic constraints?
I tried to set it programmatically and it works fine.
Simplified:
With CGRect you give certain values and UIView will have size and position depending on these values
With constraints you give instructions how these values should be created
CGRect will not fit all screen sizes as Constraints will. for example. CGRect x: 100, y: 500 may fit a large screen, but for an iPhone SE it will not work because the Item will be off screen. however with constraints like maybe Centre X & Y with a width and height constraint will centre something in the centre of the screen on all devices.
I'm using the
Item.grabToImage()
But I'm getting the following error.
QML ItemX: grabToImage: item has invalid dimensions
This is because I'm using height and width properties like so:
width: {
// return with * 0.4; based for some condition
// for eg
return parent.width * 0.4;
}
// and something similar with height
The only time that I can get the following code working is when I put in a static heigth and width:
grabToImage(
function(result)
{
result.saveToFile("/path/project-name/tmp/something.png");
}
);
Any ideas of why and how do I get around this problem?
Thank you
I'm not a 100% sure why, But it was something about the dynamic width of the parent.
In the program I wrote I has set the anchors of the image to the left and right of the preview container.
So when I tried to get the image capture from another item that was overlaying the image to cut out smaller parts of the image it was not letting me.
How I fixed this was to set a fixed image size of the source image and then just anchor it to the center of the preview section.
The only thing is now it will not size up if you scale the window.
I'm sure I could implement and on size change to the main program window and then set the width of the image (Not tested).
Last thing I should mention is that if the image is small then the cut out images from sections of the source image will be blurry and not good quality.
I fixed this by setting the "sourceSize.width" to a very large image and then used the "scale" property to scale down the image to fit within the preview item.
The problem to be solved here is how to zoom in a UIScrollView while staying centered. If you don't take some sort of precautions, the default is that as we zoom out, the zoomed view slides up to the top left corner of the scroll view, like this:
So how to prevent this, and keep the zoomed view in the center as we zoom? As you probably know, there are traditional ways of handling this by messing with the scroll view's layout, as described by Josh and Eliza in the brilliant classic WWDC video 104 from 2010. This can be done by using a delegate or by subclassing UIScrollView, and gives the desired result:
Now comes WWDC 2017 video 201 (https://developer.apple.com/videos/play/wwdc2017/201/?time=1496), and there's Eliza making a claim that the new (iOS 11) contentLayoutGuide solves the problem of zooming while staying centered in a new way: she says to center the content view at the center of the content layout guide.
But she doesn't demonstrate. And when I try it for myself, I find it isn't solving the problem. I'm zooming in just fine, but when zooming out, so that the zoom scale is smaller than 1, the content view moves up to the top left, just as it always has.
Has anyone figured out what this claim in the video actually means? How does iOS 11 make it easier to zoom centered than in the past?
EDIT I actually received a sample project from Apple in response to my bug report, which they claimed illustrated how to solve this, and it didn't! So I conclude that even Apple doesn't know what they're talking about here.
The view goes to the top left because the contentSize of the scroll view is not defined. When using the new Auto Layout guides in iOS 11, it's still necessary to define the contentSize.
Add the following constraints:
scrollView.contentLayoutGuide.widthAnchor.constraint(equalTo: scrollView.frameLayoutGuide.widthAnchor),
scrollView.contentLayoutGuide.heightAnchor.constraint(equalTo: scrollView.frameLayoutGuide.heightAnchor)
This worked for me, when I had a contentView with a fixed width/height and the following additional constraints:
// give the centerView explicit height and width constraints
centerView.widthAnchor.constraint(equalToConstant: 500),
centerView.heightAnchor.constraint(equalToConstant: 500),
// pin the center of the centerView to the center of the scrollView's contentLayoutGuide
centerView.centerXAnchor.constraint(equalTo: scrollView.contentLayoutGuide.centerXAnchor),
centerView.centerYAnchor.constraint(equalTo: scrollView.contentLayoutGuide.centerYAnchor)
This is the solution you are / everybody is looking for. In my case I want to center a view inside a table view scroll view. So if the table view scrolls the custom view will always be in the center of the scroll view content.
// create a view
let v:UIView = UIView(frame:CGRect.zero) // use zero if using constraints
ibTableView.addSubview(v)
ibTableView.bringSubview(toFront:v)
v.translatesAutoresizingMaskIntoConstraints = no
v.backgroundColor = .yellow
v.widthAnchor.constraint(equalToConstant:100).isActive = yes
v.heightAnchor.constraint(equalToConstant:100).isActive = yes
// set scrollview guides
ibTableView.contentLayoutGuide.widthAnchor.constraint(equalTo:ibTableView.frameLayoutGuide.widthAnchor).isActive = yes
ibTableView.contentLayoutGuide.heightAnchor.constraint(equalTo:ibTableView.frameLayoutGuide.heightAnchor).isActive = yes
// anchor view
v.centerXAnchor.constraint(equalTo:ibTableView.contentLayoutGuide.centerXAnchor).isActive = yes
v.centerYAnchor.constraint(equalTo:ibTableView.contentLayoutGuide.centerYAnchor).isActive = yes
I have an image view that will get this awesome tvOS focus effect when the containing view gets focused.
The problem is - it should have rounded corners. Now this is easily done:
imageView.layer.cornerRadius = 5
imageView.layer.masksToBounds = true
I have to set either masksToBounds of the layer or clipsToBounds of the image view to true (which is basically the same), in order to clip the edges of the image - but as soon as I do this, the focus effect won't work any more, because it will get clipped as well.
I had more or less the same problem with buttons, but since the focus effect is much simpler than for the image view (only scaling and shadow), I just implemented it myself, but that is not an option for the image view, with all the effects applied (moving, shimmering, and so on...)
Is there an easier way? Did I miss something? I can't be the only trying to figure out how this works!? :)
I have found out an alternative solution. What one may do is to actually draw the image, clipping out the corners with an alpha channel. The image then gets scaled correctly when focused. That applied to the layer. Then, to have the alpha channel added to the other layers (like the one for the glowing effect) we need to set; "masksFocusEffectToContents = true".
I made an extension for it, based on this answer:
Swift 4.2
extension UIImageView {
func roundedImage(corners: UIRectCorner, radius: CGFloat) {
let rect = CGRect(origin:CGPoint(x: 0, y: 0), size: self.frame.size)
UIGraphicsBeginImageContextWithOptions(self.frame.size, false, 1)
UIBezierPath(
roundedRect: rect,
byRoundingCorners: corners,
cornerRadii: CGSize(width: radius, height: radius)
).addClip()
self.draw(rect)
self.image = UIGraphicsGetImageFromCurrentImageContext()!
// Shadows - Change shadowOpacity to value > 0 to enable the shadows
self.layer.shadowOpacity = 0
self.layer.shadowColor = UIColor.black.cgColor
self.layer.shadowOffset = CGSize(width: 10, height: 15)
self.layer.shadowRadius = 3
// This propagate the transparency to the the overlay layers,
// like the one for the glowing effect.
self.masksFocusEffectToContents = true
}
}
Then to apply the rounded corners call:
myImageView.adjustsImageWhenAncestorFocused = true
myImageView.clipToBounds = false
// masks all corners with a radius of 25 in myImageView
myImageView.roundedImage(corners: UIRectCorner.allCorners, radius: 25)
One can obviously modify roundedImage() to add the parameters to define the shadows at the calling time.
Downsides:
Borders behave like cornerRadius (they get drawn inside the image).
But I think I made it working somewhere, then investigating further I
lost the changes
I am not exactly sure this is the right way to do it. I am quite confident there must be some methods out there doing it in a couple of lines. In tvOS 11 Apple introduced the round badges (animatable and all), shown at WWDC 2017. I just can't find a sample for them.
Otherwise, tvOS 12 (beta for now) introduced the Lockup. I managed to implement them programmatically, as shown in this answer.
https://forums.developer.apple.com/thread/20513
We are also facing this same issue. When you round the corners, you can see the "shine" still has a rectange shape.
I showed the issue to the Dev Evangelists at the Tech Talks in Toronto and they said it's a bug. It's reported and open rdar://23846376
For 2022.
Note that you can just use UICardView on tvOS for the effect.
Simply put the UIImageView inside the card view.
Don't forget to actually turn OFF "adjust on ancestor focus" and "user interaction enabled" on the image view, or else it will "doubly expand" when the card view expands!
There's also a weird issue where you have to add 20 to the height of all card views to make them work neatly with and enclosed image view.
How to programatically get an actual screen size (width and height) in Windows Phone? Normally I would use the following: How to get screen size on Windows Phone 7 Series
But Panorama control is a bit tricky, since the above code gives a PanoramaItem width and height (not Panorama width and height).
I have the following code that creates popup:
modalPopup = new Popup();
modalPopup.Child = new ModalWait() { MaxWidth = Application.Current.Host.Content.ActualWidth };
modalPopup.IsOpen = true;
As I result a popup is created a width of PanoramaItem, which is not a total width of a phone screen. There's a right margin which is not covered with the popup. See the screenshot below:
Any ideas how to overcome this right margin and get the actual phone screen size?
The MaxWidth property does not set an element's width. It gets/sets the maximum width constraint of that element. You want to use the Width property instead.
The code you showed Application.Current.Host.Content.ActualWidth will give you the correct screen width, not just the panorama item's width.