How can I make the width of a Constraint Layout negative? - java

I'm not sure if this is possible, or If I am approaching this challenge wrong. I am making a 2D Platformer, so when you hit the edge of the screen(Width), a new portion of the map would appear. Currently, I made single Images for each Portion of the map. Problem is, on larger devices, this would leave a lot of blank screen, and the Image would only fit a specific device.
Now I am wondering, can I make my ImageView (MAP) at a negative X value then when the character hits the edge, the map would move right (X would go higher).
I am using XML (Java is also fine), and I have NO CLUE how to approach this.

Since you are using constraint layout, you need to set android:layout_width="0dip".
This will fit any image to its screen width.(Image width should be greater than screen horizontal width).
Apply some conditions something like,
If image width < screen width then call next image to remaining screen, else call next image for entire screen.
Hope it helps for code-flow.
:)

You could use android:translationX or Android:translationY which actually support negative values. But in your particular case I think you are trying to use a nail clipper to cut your hair... You are using stuff that are not designed for that purpose. Using multiple big Image views can become a performance issue (I don't know about your particular case), I recommended you instead to be brave and make your own wiew and paint it dynamically (it can sound difficult but I'm sure will be easier than what you are trying), or make a comprehensive googling for a view meant for what you want.
Specifically for games you should try andengine lib or something like that, believe me... It would be easier in the end and you may earn something new :)

An alternative solution is to draw a layout (e.g. RelativeLayout) larger than your screen size, with an equal amount of padding on all sides.
For example, if you want to make a 50dp x 50dp ImageView appear from off the right hand side of the screen, your RelativeLayout would be 100dp taller and wider than your screen (50dp on each side). You could then position your ImageView at the far right of the RelativeLayout, and move it onto the visible area at will. So drawing something at -20dp, would actually be drawing it at 30dp in this example.
Programmatically getting the screen size and resizing a layout is very straightforward, and this approach would let you control your map loading in the manner you described.

Related

How do I expand a Libgdx image from 2 rectangles

I am working on a game using LibGDX, and right now, I am working on the menu screen. What I want to do, is have a small image, set a bounding box, and expand however large I need it. What I think would be optimal, would be to set 2 rectangles. One for width and one for height. If it needs to get bigger or smaller, it would take that rectangle, and duplicate it beside, or beneath the current one, depending if it is for the width or height. I believe there is a builtin class for this, but I cannot seem to find it.
You might want to take a look at NinePatch if I'm not misunderstanding your question. Link here: https://github.com/libgdx/libgdx/wiki/Ninepatches

Android - Text positioning

I have a very, very, very simple application that I'm working on (been trying my luck at writing an app in Java instead of Unity) and I have a background image that is fullscreen, this image has a lot of design and scales well with every device, and looks great (tested on every resolution we can think of).
However the text doesn't want to stay where it belongs, and that's not permissible. We have a basic setup, similar to this (however with about 6 hours of design work put into it):
and we need text to be centered in the squares at all times. How can we do this? Do we have to manually position and size it for each resolution? That seems like hell.
With a relative layout, if I understand correctly, the boxes will be parents and the text that goes into the boxes will be the children. You can put your TextViews into the boxes and then use things like android:layout_centerVertical or android:layout_centerHorizontal in order to make sure they are centered. Make sure to use sp for your font size so that it scales correctly with the density of the display.

Scale drawable in Android to support multiple screens

Currently I seek a solution to simple situation, which appeares to become tricky. I need 7 togglebuttons in android app, which are a simple black circles, but I need them to be in the row and fill parent (screen) horizontally. As a resource I use big .jpeg image of a circle. To make them fill all screens in the same mode, I put them into LinearLayout with
#android:layout_width = "fill_parent";
#android:layout_height = "wrap_content";
#android:weight="70";
Weight is 70, so each button received 10. The problem is that source image is too big, which unfortunately results in...this:
(because I dont have enough reputation for posting images, here is the link
http://postimg.org/image/f8wvs5si1/ )
Sorry for small amount of code and this picture taken via phone, I do not have an internet access on the computer with eclipse and this project for some time. I tried of course to change layout_height on other possibilites, but it didnt work. I could put a weight sum also on the vertical position, but on different screens it wouldn't look same.
I also tried to change the height programmatically in onCreate method,
buttonX.setHeight(buttonX.getWidth());
or do the same with a layout, but nothing helped
Perhaps the question is dumm, but I would be glad to hear some ideas.
This is due to screen density variations. There are several things you can do to fix this:
Use different images for each density (but I'm assuming you're looking for another solution)
Use DisplayMetrics to get the actual width of the screen and then set width/height accordingly.
This code:
buttonX.setHeight(buttonX.getWidth());
probably doesn't work because you are calling it before the layout is drawn, and therefore the width is not the drawn width. You can fix this using ViewTreeObserver like here:
How can you tell when a layout has been drawn?
Use an XML attribute like scaleType="centerFit" Personally, I find these confusing because scaleType attributes don't always seem to behave the same way to me. You might have to try different ones, but sometimes they come in handy if you need an XML only solution.

java android - fit items on a image background with different screen size

This is my first post and i have (i think) a uncommon request...
I'm programming on the last Eclipse Mac, for every android SDK, and i'm using more XML for layout than runtime... So i search a solution in XML if possible.
Here is the situation: i work with an image background wich simulate item like buttons, image, text... etc. On this image, i put buttons, image, and text (buttonview textview etc...) and place it precisely on their places on the image. This solution is very powerful to have good design BUT, if i change the resolution of the screen, and/or its size, each item won't be at its place, and will be translated (horiz and/or vertic) for some "dp"... (and yes i use dp, not mm or px or whatever)
I'm really embarrased because i think thanks to "dp" it keep proportionnality but.. not !
My question is how can i fix my items at their places on the image background, for different screen size/resolution !!
Thanks in advance everyone,
My Best From Lyon,France
First realise that if you want to make it pixel perfect for all screen sizes your out of luck.
Second accept that you can't make it perfect for all screen sizes.
Third you can get far with creating different layout for different screen sizes. You can read a lot about supporting multiple screen sizes here. One important thing to take from here is that you can make layout for the different screen sizes or different density sizes.

how to create universal UI design?

I would like to learn from experienced developers Android, as you develop a UI for different screens? For example, now I have this problem:
I have an element (TextView), which should be placed as nearly aligned to the left, but not back to back, but with a slight indentation. Accordingly, the bigger the screen, so this should become more padding. If it is set fixed (px / dp), as layout_marginLeft, it will remain so for all screens.
Or, like I have a button, which should take approximately the width of the percent of 60, while the remaining 40 percent are left blank. How can this be done without specifying a fixed size?
Is it possible to design a universal screen, which will stretch to compress the distance between the elements (as in my case), and do other similar things? Or is it necessary for each screen to create a resource directory and a separate design for each screen? How do you usually do that?
Thank you in advance for your reply, it is very important to me.
Some tips :
Use RelativeLayout when you want Views to be aligned with respect to each other.
Use LinearLayout with weight when you want that 60% - 40% thing
Use Custom Layouts when none of the above layouts work for you, i.e you want to customize its look and feel
It is alright to use different layouts for different screen sizes
Always use dip, - device independant pixels - instead of px
Read this article - Think like a web designer
Lastly read this article about supporting multiple screens.

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