I am learning Windows 8 metro style app development, I want to set a background photo in my app, it will fit the full screen, should I provide different sizes of this image so that it can fit all devices? If i should, which detailed sizes should I provide?
Should I provide different sizes so that it can file all devices?
Yes
which detailed sizes:
You should provide images that scale for different resolutions as well as sizes. Common sizes include (these come from the Windows 8 simulator - you can test you app with these sizes):
1024 x 768
1366 x 768
1920 x 1080
There are also recommendations for providing images at different resolutions (100, 140, 180 dpi).
Please make sure you check out:
Guidelines for scaling to screens
Guidlines for scaling to pixel density
Related
I'm working on a react native application in a company and my manager asked me what is the best image size in pexels to upload from API (dashboard) to fit the View in the application ?
And I'm using percentage units not numbers: (width: '80%', height: '50%') I don't know what is the best sized of images to fit or the aspect ratio of the image and react native is unitless!
What should we add 'Hint' for the client in the dashboard when he upload any image ?
Or how could I know the best image dimensions to fit all screens ?
In our organisation, we usually follow the following convensions to make an image fully responsive.
Get the dimentions of the image using: const {width, height} = Image.resolveAssetSource('path-to-your-image');
Get the ratio factor of width and height by using: const ratioFactor = height/width;
Whenever you set the width of your screen by 'n' digit, set the height to 'n*ratioFactor'
In this ways the image can never be stretched or compressed. It will be fully responsive according to it's dimensions.
Preferably use image with standard dimentions as 1024 x 768 pixels.
In case the app target both iOS and Android, there is a multitude of devices with various resolutions and pixel densities from high-end iPads to low-end androids devices with smaller resolutions.
The General rule of thumb is to find the average image size which will not pixelated (look blurry) on the high-end devices but does not have a large download size in case some users will have slow internet.
You should start with 1024 x 768 pixels which is a standard dimension for iPad
Consider using resizeMode prop of react native image. With resizeMode you can manage to render image based on available space in screen.
Check it here : https://reactnative.dev/docs/image#resizemode
How can i set font Size in pixels?
Hello,
Designer send me sizes of app components. Header must be 60 pixels
, but if i put font size 60, it is very big. How can i adjust it for pixels. Thank you. (IOS DEVICE)
You cannot do pixels on mobile. You do DPI. Tell your designer to get with the tech. He's designing for web. While you can figure out how many DPI correlate to how many pixels for the current device (its a device specific thing) with the PixelRatio API - https://facebook.github.io/react-native/docs/pixelratio.html - it's putting in effort to make your design worse. DPI works great across different screens/sizes.
I want to set a screen size for my view (Making it for iPhone 6). Problem is, I don't know if the input scale in point or pixel
Is it 600 pixel or 600 point?
Thank
It is in point. In retina devices, 1 point equals two pixels (or 1 point equals three pixels for #3x supported device). In non-retina devices, 1 points equals 1 pixel.
To answer your question, these are points, not pixels.
I am not sure why you want to set a fixed size only for iPhone but I think you might be interested in checking out some Auto Layout tutorials like this one. It will help you build interfaces for multiple devices at a time !
Like KDeogharkar said, there are different factor between points and pixel depending on the device. Usually you don't want to work with pixels.
When one looks at the Guidelines for fonts, we see that fonts are specified in points. A point is 1/72 of an inch so it is an absolute measure: a 10 points character should show at the exact same absolute size on any monitor at any resolution. That would make sense to me as I want to be able to read text -at the same size- whether on a 10 in tablet or a 23 in monitor. In other words, I want my text to be readable on a tablet, but I do not want it to be too big on a monitor.
On the other hand, I can understand that some UI elements could be specified in pixels, as in the Page layout guidelines.
However, in XAML font size is specified in pixels which is device dependent (to my understanding). Hence the fonts size will look tiny on a monitor with a higher resolution! See this post for more details. The answer in that post says "this way, you are getting a consistent font size". I can't see how I am getting a consistent size when it changes when the resolution changes?!?
Should I load different font size programmatically depending on the resolution of the device?
I see here that Windows does some scaling adjustment depending on the DPI. Will this adjustment be enough for my users to have a great experience on a tablet and on, say, a 20 inch monitor (or should I programmatically change the font size depending on the device resolution)?
Bonus question: WHY are the Font Guidelines written using points when the software tools do not use points (like, what were they thinking)?
"What were they thinking" is extensively covered in this blog post.
You'll also see described how scaling for pixel density is automatic:
For those who buy these higher pixel-density screens, we want to ensure that their apps, text, and images will look both beautiful and usable on these devices. Early on, we explored continuous scaling to the pixel density, which would maintain the size of an object in inches, but we found that most apps use bitmap images, which could look blurry when scaled up or down to an unpredictable size. Instead, Windows 8 uses predictable scale percentages to ensure that Windows will look great on these devices. There are three scale percentages in Windows 8:
100% when no scaling is applied
140% for HD tablets
180% for quad-XGA tablets
The percentages are optimized for real devices in the ecosystem. 140% and 180% may seem like odd scale percentage choices, but they make sense when you think about how this will work on real hardware.
For example, the 140% scale is optimized for 1920x1080 HD tablets, which has 140% of the baseline tablet resolution of 1366x768. These optimized scale factors maintain consistent layouts between the baseline tablet and the HD tablet, because the effective resolution is the same on the two devices. Each scale percentage was chosen to ensure that a layout that was designed for 100% 1366x768 tablets has content that is the same physical size and the same layout on 140% HD tablets or 180% quad-XGA tablets.
I have noticed that the Surface Pro and I believe the Sony Vaio Duo 11 are reporting maximum touch coordinates of 1366x768, which is surprising to me since their native display resolution is 1920x1080.
Does anyone know of a way to find out at runtime what the maximum touch coordinates are? I'm running a DirectX app underneath the XAML, so I have to scale the touch coordinates into my own world coordinates and I cannot do this without knowing what the scale factor is.
Here is the code that I'm running that looks at the touch coordinates:
From DirectXPage.xaml
<Grid PointerPressed="OnPointerPressed"></Grid>
From DirectXPage.xaml.cpp
void DirectXPage::OnPointerPressed(Platform::Object^ sender, Windows::UI::Xaml::Input::PointerRoutedEventArgs^ args)
{
auto pointerPoint = args->GetCurrentPoint(nullptr);
// the x value ranges between 0 and 1366
auto x = pointerPoint->Position.X;
// the y value ranges between 0 and 768
auto y = pointerPoint->Position.Y;
}
Also, here is a sample project setup that can demonstrate this issue if run on a Surface Pro:
http://andrewgarrison.com/files/TouchTester.zip
Everything on XAML side is measured in device independent pixels. Ideally you should never have to worry about actual physical pixels and let winrt do its magic in the background.
If for some season you do need to find you current scale factor you can use DisplayProperties.ResolutionScale and use it to convert DIPs into screen pixels.
their native display resolution is 1920x1080
That makes the display fit the HD Tablet profile, everything is automatically scaled by 140%. With of course the opposite un-scaling occurring for any reported touch positions. You should never get a position beyond 1371,771. This ensures that any Store app works on any device, regardless of the quality of its display and without the application code having to help, beyond providing bitmaps that still look sharp when the app is rescaled to 140 and 180%. You should therefore not do anything at all. It is unclear what problem you are trying to fix.
An excellent article that describes the automatic scaling feature is here.