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I cant move any elements in the layout (Android Studio)

I cant move any elements in the layout (android studio) for some reason..
I searched alot and nothing worked with me.
All text views or buttons (all elements) stays top-left and I cant move them or even resize them...
Whats the solution for that?
And if I tried to resize the button it fills up the whole screen.
thats the code view

This is happening as you have used constraint layout in your XML file.
and the constraints as you have given in your file that makes your elements stay up at the top left.
Solution 1:
When you give start to start constraint to the parent and end to end constraint to the parent it makes your view to stick to the both side of the screen.
Even if you have given your view's height and width to wrap content it will be considered as match parent.
<androidx.constraintlayout.widget.ConstraintLayout ...>
<Button android:id="#+id/button" ...
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"/>
</>
as This will make your view to stretch to the both side of the screen and will take whole space horizontally.
all you need to do is remove the constraints mentioned below:
if you want to let your view to stick to the left side of the screen-
Remove EndtoEndof = parent constraint
if you want to let your view to stick to the right side of the screen-
Remove StarttoStartof = parent constraint
The issue with resizing the button is that you have given the constraints to the view to stick to bottom and top of the screen so it will take up whole screen vertically.
if you want to make your button to stay to the bottom
Remove toptotopof = parent
if you want to make your button to stay to the top
Remove bottomtoBottomof= parent
all you need is to understand how constraint layout works .
Look into this link it will help you understand the constraint layout from broad perspective.

Custom view on status bar

Facebook Messenger shows this view for a few seconds when resuming the app (it also hides the status bar icons). Does anyone know how to do this?

You will need to use the WindowInsets (SDK >= 20) to get the StatusBar's height. Create a FrameLayout, apply the LayoutParams(MATCH_PARENT, statusBarHeight). Set the layout background color to colorPrimaryDark.
Hide de Status Bar by using the method setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN).
To add the status text, create a LinearLayout, apply the LayoutParams(WRAP_CONTENT, MATCH_PARENT, Gravity.CENTER_HORIZONTAL), Orientation = HORIZONTAL and add a Canvas and TextView.
Finally, add the LinearLayout as the child of the FrameLayout and add the FrameLayout as the first child of the main layout.

Shadow on curved image view on toolbar

I have a bottom toolbar that has a fab like button in the center.
I am trying to add shadow to this bar. It consists of :
Parent RelativeLayout
RelativeLayout with 4 image views.
ImageView centered in the toolbar(the circle button)
I want to add shadow effect to this toolbar. If I elevate the bottom bar then it hides the ImageView that is not included in the RelativeLayout.
If I also elevate that ImageView I get a Circular shadow effect like below on that ImagView. I only want the top curved portion of the icon to have a shadow effect.

Android top left button

I want to make an about button in the top left. I tried:
android:layout_gravity:"top|left"
but it doesn't work , I searched and all what I found was using RelativeLayout and if I use that I'll have to make all my layout from beginning and it's not that good like the linear layout.
Couldn't post the code here. So this is my code on pastebin
http://pastebin.com/5EjgyB0K

Here you have given android:layout_gravity="center" to the Linear Layout so it is going to set gravity of the layout and as center and your About Button is child of layout its to going to set in center and you have given Margin_top also.Try to remove gravity amd Margin_top and you can see the result, the button will be top|left of the screen.

Stretch the image dynamically depending on row height of listview

I have a row in a list view with 3 fields. Icon to the left, a header and a description about 3-4 lines below the header. Initially description is hidden. On click of the header the visibility is changed from Gone to Visible or vice versa. When the description is visible, I want to stretch image view (icon) to the height of the expanded row. How do I do this ? I have given
android:layout_height="fill_parent"
android:scaleType="fitXY" to <ImageView />
If I change, height of icon to LayoutParams.FILL_PARENT in the program, the images stretches more than necessary.

You can try using gravity's FILL, FILL_HORIZONTAL, and FILL_VERTICAL feature. Take a look a this for further detail on this.