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Android Button different position on other devices (using setX)

I want to move several buttons, rearranging them in a different position than the original one at a specific moment, while playing the app. I used the setX() method for this purpose, to move the button to the place I want. I know that this method takes pixels as imput (and pixels depend on the density of the device), so I took the density of the device and multiplied it by a certain number (the position in density pixels), so the output is that position in pixels for each device. I thought that would give me the same button position for all devices, but it doesn´t work. The buttons appear displaced on different devices. This is the method I used to convert density pixels to the corresponding pixels for each device:
public void Converter_Dp_to_Px(){
pxX = (int) (dpX * Resources.getSystem().getDisplayMetrics().density); //Pixels in X direction
pxY = (int) (dpY * Resources.getSystem().getDisplayMetrics().density); //Pixels in Y direction
}
Now I set values for dpX and dpY, convert them into pixels for each device, and place the button in that position with setX() and setY() methods:
dpX = 254;
Converter_Dp_to_Px();
dpY = 477;
Converter_Dp_to_Px();
button1.setX(pxX);
button1.setY(pxY);
I also tried not with absolute position, but with one with percentages, as follows:
int maxX = Resources.getSystem().getDisplayMetrics().heightPixels;
int maxY = Resources.getSystem().getDisplayMetrics().widthPixels;
mov_percenX = 0.37f;
mov_percenY = 0.63f;
button1.setX(button1.getX() + maxX * mov_percenX);
button1.setY(button1.getY() + maxY * mov_percenY);
But it doesn´t work anyway. I hope you can help me, thanks in advance.

Android add imageview programmatically fix size all screen

I'm creating several ImageViews programmatically, but I'm running into an issue where there are different ImageView sizes on different displays.
I want the ImageView size to be fixed on all screens. Here is how I am generating those ImageViews:
for (int i = 0; i < myImageList.size(); i++) {
ImageView iv = new ImageView(this);
iv.setImageResource(myImageList.get(i));
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(420, 210);
lp.gravity = Gravity.CENTER;
iv.setLayoutParams(lp);
float angleDeg = i * 360.0f / myImageList.size() - 70.0f;
float angleRad = (float) (angleDeg * Math.PI / 180.0f);
iv.setTranslationX(320 * (float) Math.cos(angleRad));
iv.setTranslationY(320 * (float) Math.sin(angleRad));
iv.setRotation(angleDeg + 80.0f);
main.addView(iv);
final int finalI = i;
}

You could introduce new class derived from ImageView and make all those adjustments in that class. Then just replaces ImageView to your class implementation in layouts etc

There are multiple interpretations of your questions.
The ImageView should have same size on all the devices - use dp. You are using pixels right now in the LayoutParams.
The ImageView should look that it has same size on all screens - find the width and height of the screen, set an aspect ration, eg. 0.33 and use that factored width and height in LayoutParams.
Use MATCH_PARENT in LayoutParams for width as well as height and the ImageView will take the full size (of the parent).
This question has a lot of great explanation about dp, px, sp that could be useful - What is the difference between "px", "dip", "dp" and "sp"?

To find screen sizes
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
// these are sizes in pixels
metrics.widthPixels, metric.heightPixels
Then, you can use this
iv.setScaleType(ImageView.ScaleType.FIT_XY);
See this link for all ScaleType values
Android ImageView ScaleType: A Visual Guide

Getting the actual screen height (android)

I want to get the actual screen height of the device that runs my app. To achieve this i try the following:
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int Height = metrics.heightPixels;
TextView HeightView = (TextView) findViewById(R.id.screenHeight);
HeightView.setText("Screen Height: " + Height);
int Width = metrics.widthPixels;
TextView WidthView = (TextView) findViewById(R.id.screenWidth);
WidthView.setText("Screen Width: " + Width);
The device that I run using the emulator has a screen width of 1080 pixels and a screen height of 1920 pixels. The width is displayed correctly (1080 pixels) but the height is according to the app only 1776 pixels. What do I need to make my app display the correct screen height? Is metrics.heightPixels a bad way of getting the screen height?

see this answer
if your API level > 13 try this if you are in activity
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
If you're not in an Activity you can get the default Display via WINDOW_SERVICE:
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
getWidth and getHeight is for API level 13 or less
UPDATE
For API 17 and higher method Display.getRealSize() returns full size of screen, as mentioned in documentation:
Gets the real size of the display
without subtracting any window decor or applying any compatibility
scale factors.
The size is adjusted based on the current rotation of the display.
The real size may be smaller than the physical size of the screen when
the window manager is emulating a smaller display (using adb shell am
display-size).

int width=Resources.getSystem().getDisplayMetrics().widthPixels;
int height=Resources.getSystem().getDisplayMetrics().heightPixels;

I needed to get the actual available height, and out of all the options this is the only thing that worked for me.
Create a rectangle, and get its dimensions:
Rect r = new Rect();
activityRootView.getWindowVisibleDisplayFrame(r);
int screenHeight = r.bottom - r.top;
where activityRootView is the root view of your layout.
If you need to extract the toolbar height:
int availableScreenHeight = screenHeight - toolbar.getHeight();
where toolbar is your toolbar view.
availableScreenHeight will now be without the statusbar, without the toolbar, and without the navigation bar (if the device is using it).

you can use this code:
val display = windowManager.defaultDisplay
val size = Point()
display.getSize(size)
val width: Int = size.x
val height: Int = size.y

You can try this:
WindowManager wm = getWindowManager();
Display d = wm.getDefaultDisplay();
Point size = new Point();
d.getSize(size);
Log.i("LOG", "W=" + size.x + " , H=" + size.y);

libGDX change my system from pixels to units

I want everyone to see the same things on their screen regardless of their screen size and aspect ratio so this is the code I am currently using. (also I am sending net data across with the coordinates of where the other players are on the screen)
int width = 1920, height = 1080;
public OrthographicCamera camera;
Viewport viewport;
//constructor
camera = new OrthographicCamera();
viewport = new ScalingViewport(Scaling.stretch, width, height, camera);
viewport.apply();
camera.position.set(camera.viewportWidth / 2, camera.viewportHeight / 2, 0);
camera.update();
public void resize(int width, int height) {
viewport.update(width, height);
camera.position.set(camera.viewportWidth / 2, camera.viewportHeight / 2, 0);
}
now for example I wanted 10 perfect squares going across the middle of the screen so I made then 192 pixels by 192 pixels so I could have 10 perfect squares going across the middle of the screen my system right now works perfect except for the fact that it is rendered internally 1920x1080 on all devices big and small. How would I convert my camera to units and get the size needed for 10 perfect squares to go across the screen? Is that even possible?
Here is my code to draw 10 squares across the screen
float size = 192;
for(int i = 0; i<10; i++){
walls.add(new Stuff(i*size,height/2-size/2,size,size,"middle",1,1,0,1));
}
How would I convert all this code to say units? Or is this an acceptable approach?

You are already using units, they just aren't very meaningful (and it certainly aren't pixels). If you want to use meaningful units (e.g. SI units), then the only thing you have to change in this code are the values. E.g. if the size of your stuff (wall?) is, say 2 meter, then use the value 2 instead of 192. And if you want your users screen to be, say 20 meters (10 walls e.g.) in width and 16:9 aspect ratio, then use that for the Viewport worldWidth and worldHeight.
float worldWidth = 20;
float worldHeight = worldWidth * 9f / 16f;
...
viewport = new StretchViewport(worldWidth, worldHeight, camera);
Make sure to understand that these "pixels" you are talking about only exist in your imagination. See also: http://blog.xoppa.com/pixels/.

You created your ScalingViewport with a width of 1920, so the width in world units will be 1920 on all screens, no matter what. Also, your scene will be distorted on any screen that is not 16:9, since you are stretching to fit whatever the screen is. (Because of the distortion, I personally would never use ScalingViewport with Scaling.stretch, aka StretchViewport.)
If you want your squares to look square on all screens with this type of viewport, you'll have to do some math to change their height (but their width should always be 192 if you want exactly ten to fit across the screen).
public void resize(int width, int height){
float viewportAspect = 1920f / 1080f;
float screenAspect = (float)width / (float)height; //Make sure you cast to floats
boxHeight = 192 * screenAspect / viewportAspect;
viewport.update(width, height, true);
}
The camera always shows the scene in world units, so there's no conversion to do.

resizing an image issue

I have a problem with resizing an image.
First of all at the start I have an image for example in 1920x1080. The user input is the percentage of resizing the current image, for example when input is 25% the final resolution of the image is 960x540.
Explanation:
1920x1080 = 2 073 600
25% from 2 073 600 = 518 400
960x540 = 518 400
I already have the function for resizing an image , but i dont know how to CALCULATE the values WIDTH and HEIGHT for an resized image.
I the example it is 960x540. (if it can help you, images has ratio 3:2,4:3,16:9 ....)
Any help ?

You have the following information given to you:
width = 1920
height = 1080
area = 2073600
ratio = width / height =~ 1.77778
Now, suppose for example that you want to calculate a new width and height when the area shrinks to 25% of its current size. Well then we know the following things:
area = 0.25 * 2073600 = 518400
height = h (Variable, because it is unknown at the moment)
width = w (Variable, because it is unknown at the moment)
ratio = 1.77778 (Ratio should stay the same or image becomes warped/stretched)
So you have
w / h = 1.77778 (Your unknown new width divided by unknown height equals ratio)
w * h = 518400 (Your unknown width times unknown height equals area)
Now you can solve it relatively easily mathematically. It is simply two equations with two variables.
w = 1.77778 * h (from first equation)
(1.77778 * h) * h) = 518400 (by plugging above into second equation)
h =~ 540
w =~ 960
Does that make sense?