I 've a big png which has some buttons "drawn" on it as images. Can I use it in a way that it can be shared as both background and buttons?
For example, I can load it as a background which will have "buttons" in , say, position X 5 Y 5 to position X 100 Y 100, and "button" in position X 110 Y 110 to X 200 Y 200.
If this is possible, can I also have "two state" buttons? Different image for "pressed" etc.
Best Regards.
Based on what you've said, it sounds like a good solution might be separating the buttons from the rest of the png. Set the button-less image as the background of your parent layout, then add your buttons on top of it. If the buttons cannot be decoupled from the rest of the background, you'll probably need to use completely transparent buttons.
Something to keep in mind would be that, because screen sizes differ, what your intend to do probably best achieved by adding the buttons programatically and setting their size and position relative to the current screen size. Also good to remember is that, due to this fragmentation, setting an image with the android:background attribute could possibly resize and distort your image, changing the target location for your buttons.
As for multi-state buttons, here's the part of the dev guide that can help you: (What you'll need is the android:state_pressed attribute)
http://developer.android.com/guide/topics/resources/drawable-resource.html#StateList
If you need further help, it might be easier if you give it a try yourself and see what issues arise, so that you can focus your question, post some code, and get a more detailed response. What you're asking is pretty broad. Good luck!
Related
I am trying to replicate the below layout (Boxes with Text and a line going outwards on a dedicated section) on Android
As evident, these boxes can be implemented as individual views (or drawable) to have the shape as
.
It is apparent that these boxes need to have some flexibility for the "wires" going out of them, most importantly deciding the "turning" point of the line. I have thought of a few approaches to achieve this:
Achieve the entire layout just by using image drawable and positioning the text boxes at exact places
Implement this with a dedicated view to have full flexibility of positioning the text boxes at any position and be compatible with all screen sizes.
I am inclined towards trying #2, but can't get my head around where to start. At first, I am not able to decide on whether I should be using a ViewGroup as the base class and add a TextView and a plain view as a child or should I be using a single View to implement this? The second thing I am concerned about, is whether I am overthinking it and there is an easy way to achieve the same thing (Just to save time, nothing else)?
Any help/guiding material is deeply appreciated. Thanks in advance.
I think that approach #2 will be better longer term. Because of the nature of the image, you will have to maintain the aspect ratio; otherwise, the person is stretched. Because you are maintaining the aspect ratio (at least the person-part), the placement of each text box and end point can be expressed as a percentage distance from an edge or the center lines.
Assuming the image you show is the entire image, the belly end point can be set at, say, 45% of of distance from the left edge and, also let's say, 42% of the distance from the top. The text boxes can be placed likewise. Once the text boxes and end point are place, the lines simply connect them. Now the image can stretch to any size to support multiple screen sizes and, as long as the aspect ratio is respected, and look good.
Take a look at ConstraintLayout and its percentage guidelines and barriers. There is also some radial placement which may help. You may still have to support the layout with a little code, but ConstraintLayout should be able to get you 95% of the way to a solution.
Edit: I meant to mention biases as well which may be the most helpful to you. Here is an example of using biases for a checkerboard solution that may be useful.
I have read all about supporting different screens and I understand the concept of Density Pixels (DP). However one thing I am not sure about. Lets say I have an image file which is 200 by 200 pixels and I loaded it using xml with wrap_content attributes at the top left of the screen (0,0). Now let's say I want to place a textview programmatically beside it.
If I put the text view at coordinates (250,0). Does that mean that the text view will never overlap the image and will always be to the right no matter what the device density/screen size is.
I understand the distance ( gap) will be different but I am hoping my theory of not overlapping will hold.
I tried it on 2 device and no issues but I am not sure if this is coincendence
Thanks
If you are using px unit it will always remain the same. But if you are using dp unit instead of pixel you cannot definitely be sure.
By the way you should use toRightOf property instead of this approach if you only want this.
I am learning about Android UI and am unclear why people use nine-patch, when you could use vector graphics, because those are scalable without any pixel degradation. I am a beginner in Android, so I hope I am not missing anything here, but it seems like it would be easier to build vector graphics and use those. You would not need the special editor to build them.
Can anyone explain the advantages to using nine-patch over vector? (Don't just explain advantages of nine-patch, as that is already done on StackO., but rather the advantages that vector does not have). Because it seems like Android recommends nine-patch. Thanks.
In vector graphics all side are scale or stretch when we set it to any background whereas in 9-patch we can define which sides can scale or strech so at runtime only those side scale which we set it to scale in 9-patch tool.
from this
-> The advantage of using 9-patch images is that when using it as a background, for instance, the image won't stretch and loose proportions in different screen sizes. the center 'patch' will remain as is and the 'borders' patches will be stretched to fit the screen/view size.
let say you have this image.
and a button with fill parent width. if you set this image to button background it will scale completely and your image gets blur (mean t will expand to button width)and it will not look good. so what 9 - path tool do that you define that online scale some part of image let say if width is fill parent. dont scale whole image . let say we set that after t (in image). scale whole area, so t will not get blur. so this will make good your button.hope you got my point..:)
after making your image 9 patch and setting to button background. your button look like this.
instead of t(in image). whole area expand and fill the buttons width.
Imagine a button with rounded corners. How do you scale it? If you scale it only horizontally, you will have elliptic corners, which would be ugly.
This is what 9-patch is for.
i hate 9patches. i am quite attentive when doing my artwork. i don't even use photoshop. i go with illustrator.
i do everything right when exporting my artwork, i used to do my 9 patches with insane zoom on, maybe check afther that in photoshop for misplaced pixels...
** sad trumpet ** when put on a view, if i used some subtle round corners like 6px or 10px and a stroke everything looks awful at mdpi.
So I solved my problems by marrying the two. I wrote my own 9patch which uses vectors. :)
Everything looks like it's been touched by baby Jesus. Perfect corners, strokes and, best of all, you can use one asset for all the screen sizes, densities while, of course, no more transparent borders, wicked errors because 9patch won't stretch inward, so on and so forth.
I use vectors for icons too. While there sometimes are issues with various effects, these are minimal and easily avoided if you do some reading on how to avoid them.
Best of luck to all you guys!
This is a very basic example.
You can do whatever strikes your fancy. Because of the performance impact of svg's on an app, when first run [or when the user changes appearance options, i like to save the newly generated bitmaps as pngs, if possible.
You don't get any more "best of both worlds" than this.
You can define content are on a 9-patch image which means (for example) text will always be placed in that specific area, I think you cannot do this in Vector image. Android has built-in support for 9-path but for vectors you have to use a library.
9-patch rendering is easy to implement and efficient. If you have an image that can be scaled by stretching horizontal or vertical lines (e.g. buttons or rectangular icons), then use a 9-patch. If you have some icons that don't scale well, then create multiple versions at different resolutions and use Android's resource management to handle it. Both of these approaches are much easier and more efficient than vector graphics.
If you have large images or scenes to render, and you don't want to take up a ton of space with bitmaps, thats when you start thinking about vector graphics.
I'm stuck and I think wisdom (aka experience) is the only solution.
I need to be able to have boxes on a screen with data inside each box. The number of boxes on the screen needs to be able to change and the boxes need to scale accordingly (as well as the text data inside of them) to allow for the additional boxes.
Example: I might start with only 8 boxes which are evenly spaced and displaying data at a reasonable font scale.
As I add more boxes I need the rest of the boxes to scale down and allow everything on one screen.
I am currently attempting to use a TableLayout, but I'm not certain how to make everything scale correctly. Also, I'm generating everything programmatically by extending the TableLayout. Can someone point me in the right direction. Is there a better layout method that I'm not seeing? I'm sure I'm not the first person to need this, so are there examples available that I'm just not finding by searching?
The eventual solution was to build my own scaling function which took screen pixel dimensions and calculated the appropriate margin offsets to use on a relative layout. It requires a complete redraw each time the scaling factor changes, which is annoyingly resource intensive.
I am newbi in android world and working on an android app.
I have used many of buttons and image buttons in my app.
Now i want to replace them with an background image. (So i can make nice gui easily)
I know i can use view listener and i can find the clicked x and y coordinate from onclick method.
But I want to how can i find which part of the image was clicked. Because different phones have different resolutions how can i do this efficiently ?
And one more thing, Is it good to handle gui this way ?
Thanks !
You first need to set the initial window width and height before execution of other code and load an image of quality based on the screen size. so for example you can have 3 sets of images of different size. One for 5 inch screens and below. Another for 7 inch tablets. Another for 10 and possibly another super high quality image for anything above. As many devices coming on in the near future are reaching resolutions much higher then previously developed for. Just run code initially that detects the initial window size at hand and load image based on resolution of that device. From their program as you plan to.
Also to jump on answer above. Detect rotation event and adjust image accordingly. and update accordingly. You are adding more programming of course but no reason what you are asking could not be done. Just a few extra events detection and you should be good to go to accomplish exactly what you are looking to do
AFAIK it is not good practice to handle the GUI this way. Mostly because android screen size is not standard and so you can never be sure that it will work perfectly in all the devices. You can ofcourse handle the events using onTouchListener and see which part of image was clicked from the coordinates in the MotionEvent Object. But, I would not recommend doing so.
Creating layouts of different screen sizes and handling the events using Buttons and ImageButtons will be good.
you can use android:background attribute for background images in the layout xml files...
however you also can set the background of UI element programatically