Imagine an app in which a scroll or fling gesture is recognized after the user’s finger has moved by at least 16 pixels. On a baseline screen, a user’s must move by 16 pixels / 160 dpi , which equals 1/10th of an inch (or 2.5 mm) before the gesture is recognized. On a device with a high-density display (240dpi), the user’s must move by 16 pixels / 240 dpi , which equals 1/15th of an inch (or 1.7 mm). To fix this issue, the gesture threshold must be expressed in code in dp and then converted to actual pixels.
This figure is the factor by which you should multiply the dp units in order to get the actual pixel count for the current screen. You can use the ViewConfiguration class to access common distances, speeds, and times used by the Android system.
For instance, the distance in pixels used by the framework as the scroll threshold can be obtained with getScaledTouchSlop() : Table 1 describes the different configuration qualifiers available and what screen types they apply to. The system does not scale resources tagged with this qualifier, regardless of the current screen’s density.
Then, place the generated image files in the appropriate subdirectory under res/ and the system will pick the correct one automatically based on the pixel density of the device your app is running on: Then, any time you reference @drawable/awesomeimage , the system selects the appropriate bitmap based on the screen’s dpi. If you don’t provide a density-specific resource for that density, the system picks the next best match and scales it to fit the screen.
Tip: If you have some drawable resources that the system should never scale (perhaps because you perform some adjustments to the image yourself at runtime), you should place them in a directory with the nodpi configuration qualifier. Like all other bitmap assets, you need to provide density-specific versions of your app icon. So you should provide an even higher density launcher icon in the mipmap-xxxhdpi directory.
This allows launcher apps to pick the best resolution icon to display on the home screen.
Vector graphics create an image using XML to define paths and colors, instead of using pixel bitmaps. In the Project window, right-click on the res directory and select New > Vector Asset.
On the next screen, confirm the source set where you want the file in your project and click Finish. Unless your app manipulates graphics or you have encountered problems when running on different pixel densities, you can ignore this section.
The system assumes that default resources (those from a directory without configuration qualifiers) are designed for the baseline pixel density (mdpi) and will resize those bitmaps to the appropriate size for the current pixel density. For example: res/drawable-nodpi/icon.png When the system uses the icon.png bitmap from this folder, it does not scale it based on the current device density.
Auto-scaling of pixel dimensions and coordinates You can disable pre-scaling dimensions and images by setting android:anyDensity to “false” in the manifest or programmatically for a Bitmap by setting inScaled to “false” . It does this to ensure that pixel-defined screen elements are still displayed at approximately the same physical size as they would be at the baseline pixel density (mdpi).
In this case, the system will “lie” to the app when it queries for screen dimensions, and report 320×533 (the approximate mdpi translation for the pixel density). The best way to support multiple screens is to follow the basic techniques described in this document. It’s important to test your app on multiple devices with different pixel densities so you can ensure your UI scales correctly.
How To Change DPI (Dots Per Inch) of the Screen On Android? – pCloudy – Question and Answers
private void changeDPI( AppiumDriver < WebElement > driver, int value) { try { driver.executeScript(“pCloudy_executeAdbCommand”, “adb shell wm density ” + value).toString(); } catch (Exception e) { System.out.println(“Something wrong while changing DPI:” + e.getMessage()); } }
Tablets with the highest-quality display
Tablets combine the best of smartphone technology and laptop features in one portable package powered by enough RAM to allow you to work remotely, play games, and browse the internet with ease. And, thanks to advancements in technology, most tablets now feature displays that are just as bright and beautiful as your TV or laptop screen. However, if you need a larger screen and more power, it’s best to opt for a 10-inch tablet; most can handle graphics-heavy games, productivity software, and streaming. Thumb-typing with a 10-inch tablet is still feasible as well, making them portable enough to use with one hand and easy to handle when playing games. Top tablets now have refresh rates of at least 120Hz, making it easy to find accessible laptops with buttery smooth displays.
Common Viewport Sizes for Mobile
Using the meta viewport value width=device-width instructs the page to match the screen’s width in device independent pixels. This allows the page to reflow content to match different screen sizes, whether rendered on a small mobile phone or a large desktop monitor. minimum-scale The minimum amount the visitor can zoom on the page. maximum-scale The maximum amount the visitor can zoom on the page.
Blogging and Social media bring mobile visitors In late 2012, Google conducted an independent survey titled “What Users Want Most From Mobile Sites Today.” Of the 1,088 smartphone users that were surveyed, about 67 percent indicated they would be more likely to purchase a product or service from a business that built a mobile-friendly website.
Mobile Screen Sizes
And it’s more important than ever to understand key device characteristics from a development and testing standpoint. A Comparison of Mobile Screen Sizes, Resolution, and PPI Device Name Mobile Screen Sizes Screen Resolution PPI iPhone 6 4.7” 750 x 1334 326 (XHDPI) Samsung Galaxy Note 5 5.7″ 1440 x 2560 515 (XXXHDPI) iPhone 6 Plus 5.5″ 1080 x 1920 401 (XHDPI) iPad Air 2 9.7″ 1536 x 2048 264 (HDPI) Samsung Galaxy S6 5.1″ 1440 x 2560 515 (XXXHDPI) iPhone 6S 4.7″ 750 x 1334 326 (XHDPI) Blackberry Passport 4.5″ 1440 x 1440 452 (XXHDPI) iPhone 6S Plus 5.5″ 1080 x 1920 401 (XHDPI) Google Motorola Nexus 6 6.0″ 1440 x 2560 515 (XXXHDPI) HTC One M9 5.0″ 1080 x 1920 440 (XXHDPI) For example, two Samsung devices with the same screen size but different resolutions might show different visuals to the user. Or they will consume more CPU and battery to process the various app visuals on these devices.
As a starting point, it is easy to determine your device’s PPI and classify it as one of the density families accordingly. Mobile apps run on different devices equipped with very different hardware (systems on chip). The CPU, battery usage, and performance (responsive time) would be different for each device. Because there is such a large, fragmented market of devices, there’s a lot for developers and testers to consider.
Testing screen size, resolution, and PPI among manufacturers should be your first step in assuring good user experience across platforms. It’s clear that bug fixes around performance, battery consumption, and user interface are key. You can leverage our mobile test lab to make sure that your app runs smoothly, regardless of device.
DPI love ♥ Easily find the DPI
In general PPI is a bit more correct but DPI is more commonplace, hence its usage on this site (also ppi.lv wasn’t available :P). I got fed up with marketing speak and buzzwords often used to create the impression that a display is much better than it actually is, so I wanted to help people decide what to get with the actual numbers at hand, through an easy to use web app.
Understanding Density Independence Pixel: sp, dp, dip in Android
Understanding Density Independence Pixel: sp, dp, dip and all in android What does the French Revolution have to do with the time NASA accidentally crashed a $200 million orbiter into the surface of Mars? Crash happened due to a small mistake on the unit conversion between two measurement systems. At the time of French Revolution, France alone has a quarter million different units. Gradually, everyone accepts this new standard system except few countries like America where they follow the older imperial system where things measured in feet, inches and pounds. How the French Revolution and NASA crash orbiter is connected to this article?
Pixels — (Google Definition) a minute area of illumination on a display screen, one of many from which an image is composed. Screen Resolution — Resolution is always referred in x*y form, which means x is the number of pixels in horizontal direction and y is the number of pixels in a vertical direction.
Through this terminologies, we can say that now we can design the UI for Android based on the pixels of the displaying screen. But, this world consists of a variety of display screen sizes which is not possible for us to design with. If I define my Button’s height and width in pixel, this is going to happen in different device resolution. Scale Independent Pixels —This is same as dp, but by default, android resizes it based on the font size of the user’s phone.
This helps us to design the layout for a tablet and phone very quickly. Many times we had seen some words like MDPI, HDPI, XHDPI, XXHDPI inside our Android Studio. This is the screenshot of a StackOverflow answer explaining density bucket.
This chart can help us to understand which resolution devices comes in which bucket either mdpi or hdpi etc.
The resolution in the tablets, the weak point of the low-cost models
In recent years we have seen a trend in the screens of Android devices, the first increase in their dimensions – beyond the physical and ergonomic limits of people’s daily lives – and in a second moment of your resolution. First the high-end was at WVGA resolutions, it was about 4-inch devices or a little more and the quality was acceptable, well let’s talk in terms of pixel density per inch, specifically around 230/250 dpi. It is clear that we are talking about tablets but in some cases we find 10-inch devices with approximate prices of 200 euros, at that point they should already give something more than the HD resolution.
Designing for multiple screen densities on Android
Many companies like Samsung, Lenovo, Huawei, LG, and Google make phones, tablets, and laptops that run on the Android operating system. Having a firm grasp of this is critical in being able to create wireframes and designs in Sketch that can be implemented on actual devices (phones, tablets, laptops, TVs, wearables).
We are only going to look at phone screen densities, but the same concepts apply to tablets, TVs, and wearables running the Android OS. In digital displays / screens like monitors, phones, and tablets, density measurement unit is PPI (pixels-per-inch). Ideally, you would want to create assets as SVGs in Sketch, and that will ensure that they are “density independent”. Unlike bitmap images, SVGs can “scale” to fit any size screen of any density.
SVGs files actually contain a set of instructions that tell Android how to accurately paint an image on a screen of any size or density. SVG images, on the other hand, will look “right” no matter what the screen size / density.
If you provided bitmap assets in the highest resolution, then the Android device would have to do a lot of work to downsample or upsample it and make it look “right” on whatever screen size the app is running on. This can lead to apps that consume more network, CPU, and memory than they should, and this results in a poor UX for the user (and has a negative impact on battery life).
Logical density buckets are created by Android to help you and me to stay sane while exporting images 😛. These phones screens have different physical sizes, densities, aspect ratios and resolutions.
Currently, the best place where you can go to find out the screen density is Material Design device metrics website. I used PPI (pixels-per-inch) earlier in this article, but Android uses DPI (dots-per-inch), to describe logical density buckets.
Because Android uses DPI, then we end up with names like MDPI, HDPI, XHDPI, XXHDPI, and XXXHDPI, rather than MPPI, HPPI, XHPPI, XXHPPI and XXXHPPI 😄. If you look at the image above, all of the “buy” buttons appear the same physical size in different density screens.
In 1.5x screen (~240 DPI) it takes 1.5 times as many pixels (132 x 54 PX) to fill the area of 88 x 36 density-independent-pixels. In 3x screen (~480 DPI) it takes three times as many pixels (264 x 108 PX) to fill the area of 88 x 36 density-independent-pixels.
In 4x screen (~640 DPI) it takes four times as many pixels (352 x 144 PX) to fill the area of 88 x 36 density-independent-pixels. if you download the Sketch file (from the high fidelity mockup section), you will find that the size of each artboard is 411 x 731 px.
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