I have problem with getting information about views after calling setContentView(). I'm changing layout of activity after click on button. Here is the example of my code.
public void onClickButton1(View v) {
setContentView(R.layout.activity_main);
setScreen();
}
But durring execution setScreen() method, layout still is not rendered, so I cannot call getWidth() on some view intended in layout (respectively I can but I always get 0). How I can wait until setContentView() is finished? Please notice that using of this:
#Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
setScreen();
}
is not sufficient for me. I need to change layout independently on activity cycle.
You need to attach a ViewTreeObserver to your layout:
setContentView(R.layout.yourLayoutName);
View yourLayout = findViewById(R.id.ID_OF_YOUR_LAYOUT);
ViewTreeObserver vto = yourLayout.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
//Do your work
vto.removeOnGlobalLayoutListener(this);
}
});
There's no easy way to use setContentView() to get the result you want. You either need to entirely remove all views and then inflate the new layout, use a ViewFlipper to switch between different views, or, which is IMHO the best approach, rework your app to use Fragments
I am trying to scale the image in my linear layout to fill the available space, but I don't understand the values I'm getting for the widths of the layout. Here's the relevant part of my main.xml layout file:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/LeftButtonsLayout"
android:layout_width="0dip"
android:layout_height="fill_parent"
android:layout_weight="10"
android:orientation="vertical" >
<TextView
android:id="#+id/Jump"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/jump"
android:textStyle="bold"
android:padding="5dip"
/>
<ImageView
android:id="#+id/JumpButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:src="#drawable/jump"
android:contentDescription="#string/jump"
android:padding="5dip"
/>
<LinearLayout
Here's the onCreate() method of my activity, which has a debug print:
public void onCreate (Bundle savedInstanceState) {
setContentView(R.layout.main);
LinearLayout leftButtonsLayout = (LinearLayout) findViewById(R.id.LeftButtonsLayout);
imageView = (ImageView) findViewById(R.id.ResetButton);
Log.d("DEBUG", CLASS_NAME + "scaleLeftButtonsLayoutContents: \n" +
"linear layout height: " + leftButtonsLayout.getHeight() + "\n" +
"text height: " + ((TextView)findViewById(R.id.Jump)).getHeight() + "\n" +
"image height: " + imageView.getLayoutParams().height);
}
1) If I place the setContentVew() call after the Log.d() debug print, I get a Null Pointer Exception. Why? Is memory not allocated for the LinearLayout before it's used on the view?
2) The prints I see are:
linear layout height: 0
text height: 0
image height: -2
What am I doing wrong here? I expected to see sane values here, since I can see the imageView on the device screen.
3) I was planning to scale the image using:
imageView.getLayoutParams().height = newHeight. Is that right to do? Will doing this automatically update the imageView on the screen, or will I have to do a setContentView() again?
Thanks in advance for your help.
UPDATE
Thanks for your answers everyone. I've overridden the onWindowFocusChanged() method of my activity, but when I check the size of the nested ImageView below, it's reported as -2. Resizing it works, but I'm curious why it's -2 when it should've had a sane value. My code's as follows:
#Override
public void onWindowFocusChanged (boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
if (hasFocus)
scaleLeftButtonsLayoutContents();
}
private void scaleLeftButtonsLayoutContents () {
LinearLayout leftButtonsLayout = (LinearLayout)findViewById(R.id.LeftButtonsLayout);
imageView = (ImageView) findViewById(R.id.JumpButton);
Log.d("TAG", CLASS_NAME + "JumpButton.height " + imageView.getLayoutParams().height);
imageView.getLayoutParams().height = verticalSpaceAvailable;
imageView.getLayoutParams().width = verticalSpaceAvailable;
leftButtonsLayout.requestLayout();
}
This produces the print:
JumpButton.height -2
The resize produces a sane image, but why is the initial height -2?
To answer your points,
1) It is because you haven't initailaized your Button or ImageView. Since you call your Log before doing this, obviously the Button and ImageView are null and hence you get the exception.
2)And initializing doesn't mean that your view are completely drawn to provide you with width and height. So you have to provide the time to get itself drawn. But unfortuanately we don't know the exact time it takes to get drawn. So Android provides this method,
#Override
public void onWindowFocusChanged(boolean hasFocus)
{
// which gets called when your view is drawn.
}
Just now answered a similar question here.
So what you have to do is, add your Log inside this method in your Activity and then check the resulting width and height.
3) To answer your third question, you definitely should not call setContentView() once again, which might throw you some other exception. But when considering scaling you might make use of some bitmaps to do this.
Here are some answers for you:
1) If you place the setContentView after calling view.getHeight() you will get null pointer because that view is not set on the Activity content therefore you can't get a reference to it before setting it to the content of the Activity
2) You see that because the view doesn't had time to layout.. if you want to see the height/width of a view it's better to use a ViewTreeObserver listener like this:
view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
/* don't forget to remove the listener after you use it once */
view.getViewTreeObserver().removeGlobalOnLayoutListener(this);
Log.d("MY VIEW WIDTH","width:"+view.getWidth());
}
});
3) After you set the layout params of a view don't forget to call view.requestLayout() to make sure that your view will refresh. You don't have to call setContentView() again.
EDIT: Also the width of your LinearLayout has to be at least wrap_content if not fill_parent or a value greater than 0 if you want to see the child views of the Linear Layout..
You cannot do like this. Because the linearlayout is the main container of your activity. You cannot provide android:layout_weight="10" and android:layout_width="0dip" to the main layout. create one Linear layout outside this android:id="#+id/LeftButtonsLayout" and give the layout height and width to fill_parent or match_parent. This will work in your case.
And one more thing, You cannot allow to call elements of layout before the setContentView.
I've run into what I can only categorize as a memory leak for ScrollView elements when using the Gallery component.
A short background. I've got an existing app that is a photo slideshow app.
It uses the Gallery component, but each element in the adapter is displayed in full-screen.
(full source is available at this link)
The adapter View element consist of an ImageView, and two TextViews for title and description.
As the photos are of a quite high-resolution, the app uses quite a lot of memory but the Gallery has in general manage to recycle them well.
However, when I am now implementing a ScrollView for the description TextView, I almost immediately run into memory problems. This the only change I made
<ScrollView
android:id="#+id/description_scroller"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fillViewport="true">
<TextView
android:id="#+id/slideshow_description"
android:textSize="#dimen/description_font_size"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/white"
android:layout_below="#id/slideshow_title"
android:singleLine="false"
android:maxLines="4"/>
</ScrollView>
I did a heap dump and could clearly see that it was the Scrollview which was the root of the memory problems.
Here are two screenshots from the heap dump analysis. Note that the ScrollView retains a reference to mParent which includes the large photo I use
PS same problem occurs if I use the TextView's scrolling (android:scrollbars = "vertical" and .setMovementMethod(new ScrollingMovementMethod());
PSS Tried switching off persistent drawing cache, but no different dreaandroid:persistentDrawingCache="none"
Have you tried removing the scroll view whenever it's container view scrolls off the screen? I'm not sure if that works for you but its worth a shot? Alternatively, try calling setScrollContainer(false) on the scroll view when it leaves the screen. That seems to remove the view from the mScrollContainers set.
Also, this question, answered by Dianne Hackborn (android engineer), explicitly states not to use scrollable views inside of a Gallery. Maybe this issue is why?
Just add this -> android:isScrollContainer="false"
<ScrollView
android:id="#+id/description_scroller"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fillViewport="true"
android:isScrollContainer="false">
There is some source why this is appear:
http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.0.1_r1/android/view/View.java
the problem is:
setScrollContainer(boolean isScrollContainer)
by default:
boolean setScrollContainer = false;
but in some cases like this
if (!setScrollContainer && (viewFlagValues&SCROLLBARS_VERTICAL) != 0) {
setScrollContainer(true);
}
it can be true, and when it happends
/**
* Change whether this view is one of the set of scrollable containers in
* its window. This will be used to determine whether the window can
* resize or must pan when a soft input area is open -- scrollable
* containers allow the window to use resize mode since the container
* will appropriately shrink.
*/
public void setScrollContainer(boolean isScrollContainer) {
if (isScrollContainer) {
if (mAttachInfo != null && (mPrivateFlags&SCROLL_CONTAINER_ADDED) == 0) {
mAttachInfo.mScrollContainers.add(this);
mPrivateFlags |= SCROLL_CONTAINER_ADDED;
}
mPrivateFlags |= SCROLL_CONTAINER;
} else {
if ((mPrivateFlags&SCROLL_CONTAINER_ADDED) != 0) {
mAttachInfo.mScrollContainers.remove(this);
}
mPrivateFlags &= ~(SCROLL_CONTAINER|SCROLL_CONTAINER_ADDED);
}
}
mAttachInfo.mScrollContainers.add(this) - all view put into ArrayList this lead to leak of memory sometimes
Yes i noticed the problem, sorry for my previous comment, i've tried to empty the Drawables
by setting previous Drawable.setCallBack(null); but didnt work, btw i have nearly the same project, i use ViewFlipper instead of Gallery, so i can control every thing, and i just use 2 Views in it, and switch between them, and no memory leak, and why not you resize the Image before displaying it, so it will reduce memory usage (search SO for resizing Image before reading it)
Try moving "android:layout_below="#id/slideshow_title" in TextView to ScrollView.
Ended up with implementing a workaround that uses a TextSwitcher that is automatically changed to the remaining substring every x seconds.
Here is the relevant xml definition from the layout
<TextSwitcher
android:id="#+id/slideshow_description"
android:textSize="#dimen/description_font_size"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<TextView
android:id="#+id/slideshow_description_anim1"
android:textSize="#dimen/description_font_size"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxLines="2"
android:textColor="#color/white"
android:singleLine="false"/>
<TextView
android:id="#+id/slideshow_description_anim2"
android:textSize="#dimen/description_font_size"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxLines="2"
android:textColor="#color/white"
android:singleLine="false"/>
</TextSwitcher>
Here I add the transition animation to the TextSwitcher (in the adapter's getView method)
final TextSwitcher slideshowDescription = (TextSwitcher)slideshowView.findViewById(R.id.slideshow_description);
Animation outAnim = AnimationUtils.loadAnimation(context,
R.anim.slide_out_down);
Animation inAnim = AnimationUtils.loadAnimation(context,
R.anim.slide_in_up);
slideshowDescription.setInAnimation(inAnim);
slideshowDescription.setOutAnimation(outAnim);
Here is how I swap to the part of the description
private void updateScrollingDescription(SlideshowPhoto currentSlideshowPhoto, TextSwitcher switcherDescription){
String description = currentSlideshowPhoto.getDescription();
TextView descriptionView = ((TextView)switcherDescription.getCurrentView());
//note currentDescription may contain more text that is shown (but is always a substring
String currentDescription = descriptionView.getText().toString();
if(currentDescription == null || description==null){
return;
}
int indexEndCurrentDescription= descriptionView.getLayout().getLineEnd(1);
//if we are not displaying all characters, let swap to the not displayed substring
if(indexEndCurrentDescription>0 && indexEndCurrentDescription<currentDescription.length()){
String newDescription = currentDescription.substring(indexEndCurrentDescription);
switcherDescription.setText(newDescription);
}else if(indexEndCurrentDescription>=currentDescription.length() && indexEndCurrentDescription<description.length()){
//if we are displaying the last of the text, but the text has multiple sections. Display the first one again
switcherDescription.setText(description);
}else {
//do nothing (ie. leave the text)
}
}
And finally, here is where I setup the Timer which causes it to update every 3.5 seconds
public void setUpScrollingOfDescription(){
final CustomGallery gallery = (CustomGallery) findViewById(R.id.gallery);
//use the same timer. Cancel if running
if(timerDescriptionScrolling!=null){
timerDescriptionScrolling.cancel();
}
timerDescriptionScrolling = new Timer("TextScrolling");
final Activity activity = this;
long msBetweenSwaps=3500;
//schedule this to
timerDescriptionScrolling.scheduleAtFixedRate(
new TimerTask() {
int i=0;
public void run() {
activity.runOnUiThread(new Runnable() {
public void run() {
SlideshowPhoto currentSlideshowPhoto = (SlideshowPhoto)imageAdapter.getItem(gallery.getSelectedItemPosition());
View currentRootView = gallery.getSelectedView();
TextSwitcher switcherDescription = (TextSwitcher)currentRootView.findViewById(R.id.slideshow_description);
updateScrollingDescription(currentSlideshowPhoto,switcherDescription);
//this is the max times we will swap (to make sure we don't create an infinite timer by mistake
if(i>30){
timerDescriptionScrolling.cancel();
}
i++;
}
});
}
}, msBetweenSwaps, msBetweenSwaps);
}
Finally I can put this problem to a rest :)
I am working in android. I want to add functionality of seekbar in my application.
This is my xml file:-
<SeekBar
android:id="#+id/ProgressBar01"
android:layout_width="fill_parent"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_height="60dp"
android:layout_below="#+id/incentives_textViewBottemLeft"
android:max="10"
android:progressDrawable="#drawable/incentive_progress"
android:secondaryProgress="0"
android:thumb="#drawable/incentives_progress_pin" />
And this is my java code related to this seek bar.
mSkbSample = (SeekBar)findViewById(R.id.ProgressBar01);
v1 = (TextView)findViewById(R.id.incentives_textViewAbove_process_pin);
v1.setText(String.valueOf(progress).toCharArray(), 0, String.valueOf(progress).length());
mSkbSample.setProgress(progress);
int xPos = ((mSkbSample.getRight() - mSkbSample.getLeft()) * mSkbSample.getProgress()) / mSkbSample.getMax();
v1.setPadding(xPos,0,0,0);
I tried to print mSkbSample.getRight()and mSkbSample.getLeft(), this always returning zero.
help me to find out what mistake i have done.
You wont get the getRight value in onCreate because the UI hasn't been drawn on the screen so none of the UI elements are measure yet. Try this
SeekBar seekbar = (SeekBar)findViewById(R.id.YOUD VIEW ID);
ViewTreeObserver vto = seekbar.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
this.seekbar.getViewTreeObserver().removeGlobalOnLayoutListener(this);
int left = seekbar.getLeft();
}
});
Put the code in the onCreate method. This will get called after the seekbar has been laid out. You should get the left value now.
I think you are required to add
android:progress and android:secondaryProgress with some values.
you can check the example below:
http://coderzheaven.com/2011/06/how-to-use-seekbar-in-android/
Thanks,
Shafali
I have a view made up of TableLayout, TableRow and TextView. I want it to look like a grid. I need to get the height and width of this grid. The methods getHeight() and getWidth() always return 0. This happens when I format the grid dynamically and also when I use an XML version.
How to retrieve the dimensions for a view?
Here is my test program I used in Debug to check the results:
import android.app.Activity;
import android.os.Bundle;
import android.widget.TableLayout;
import android.widget.TextView;
public class appwig extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.maindemo); //<- includes the grid called "board"
int vh = 0;
int vw = 0;
//Test-1 used the xml layout (which is displayed on the screen):
TableLayout tl = (TableLayout) findViewById(R.id.board);
tl = (TableLayout) findViewById(R.id.board);
vh = tl.getHeight(); //<- getHeight returned 0, Why?
vw = tl.getWidth(); //<- getWidth returned 0, Why?
//Test-2 used a simple dynamically generated view:
TextView tv = new TextView(this);
tv.setHeight(20);
tv.setWidth(20);
vh = tv.getHeight(); //<- getHeight returned 0, Why?
vw = tv.getWidth(); //<- getWidth returned 0, Why?
} //eof method
} //eof class
I believe the OP is long gone, but in case this answer is able to help future searchers, I thought I'd post a solution that I have found. I have added this code into my onCreate() method:
EDITED: 07/05/11 to include code from comments:
final TextView tv = (TextView)findViewById(R.id.image_test);
ViewTreeObserver vto = tv.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
LayerDrawable ld = (LayerDrawable)tv.getBackground();
ld.setLayerInset(1, 0, tv.getHeight() / 2, 0, 0);
ViewTreeObserver obs = tv.getViewTreeObserver();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
obs.removeOnGlobalLayoutListener(this);
} else {
obs.removeGlobalOnLayoutListener(this);
}
}
});
First I get a final reference to my TextView (to access in the onGlobalLayout() method). Next, I get the ViewTreeObserver from my TextView, and add an OnGlobalLayoutListener, overriding onGLobalLayout (there does not seem to be a superclass method to invoke here...) and adding my code which requires knowing the measurements of the view into this listener. All works as expected for me, so I hope that this is able to help.
I'll just add an alternative solution, override your activity's onWindowFocusChanged method and you will be able to get the values of getHeight(), getWidth() from there.
#Override
public void onWindowFocusChanged (boolean hasFocus) {
// the height will be set at this point
int height = myEverySoTallView.getMeasuredHeight();
}
You are trying to get width and height of an elements, that weren't drawn yet.
If you use debug and stop at some point, you'll see, that your device screen is still empty, that's because your elements weren't drawn yet, so you can't get width and height of something, that doesn't yet exist.
And, I might be wrong, but setWidth() is not always respected, Layout lays out it's children and decides how to measure them (calling child.measure()), so If you set setWidth(), you are not guaranteed to get this width after element will be drawn.
What you need, is to use getMeasuredWidth() (the most recent measure of your View) somewhere after the view was actually drawn.
Look into Activity lifecycle for finding the best moment.
http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle
I believe a good practice is to use OnGlobalLayoutListener like this:
yourView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
if (!mMeasured) {
// Here your view is already layed out and measured for the first time
mMeasured = true; // Some optional flag to mark, that we already got the sizes
}
}
});
You can place this code directly in onCreate(), and it will be invoked when views will be laid out.
Use the View's post method like this
post(new Runnable() {
#Override
public void run() {
Log.d(TAG, "width " + MyView.this.getMeasuredWidth());
}
});
I tried to use onGlobalLayout() to do some custom formatting of a TextView, but as #George Bailey noticed, onGlobalLayout() is indeed called twice: once on the initial layout path, and second time after modifying the text.
View.onSizeChanged() works better for me because if I modify the text there, the method is called only once (during the layout pass). This required sub-classing of TextView, but on API Level 11+ View. addOnLayoutChangeListener() can be used to avoid sub-classing.
One more thing, in order to get correct width of the view in View.onSizeChanged(), the layout_width should be set to match_parent, not wrap_content.
Are you trying to get sizes in a constructor, or any other method that is run BEFORE you get the actual picture?
You won't be getting any dimensions before all components are actually measured (since your xml doesn't know about your display size, parents positions and whatever)
Try getting values after onSizeChanged() (though it can be called with zero), or just simply waiting when you'll get an actual image.
As F.X. mentioned, you can use an OnLayoutChangeListener to the view that you want to track itself
view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
#Override
public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
// Make changes
}
});
You can remove the listener in the callback if you only want the initial layout.
I guess this is what you need to look at: use onSizeChanged() of your view. Here is an EXTENDED code snippet on how to use onSizeChanged() to get your layout's or view's height and width dynamically http://syedrakibalhasan.blogspot.com/2011/02/how-to-get-width-and-height-dimensions.html
ViewTreeObserver and onWindowFocusChanged() are not so necessary at all.
If you inflate the TextView as layout and/or put some content in it and set LayoutParams then you can use getMeasuredHeight() and getMeasuredWidth().
BUT you have to be careful with LinearLayouts (maybe also other ViewGroups). The issue there is, that you can get the width and height after onWindowFocusChanged() but if you try to add some views in it, then you can't get that information until everything have been drawn. I was trying to add multiple TextViews to LinearLayouts to mimic a FlowLayout (wrapping style) and so couldn't use Listeners. Once the process is started, it should continue synchronously. So in such case, you might want to keep the width in a variable to use it later, as during adding views to layout, you might need it.
Even though the proposed solution works, it might not be the best solution for every case because based on the documentation for ViewTreeObserver.OnGlobalLayoutListener
Interface definition for a callback to be invoked when the global layout state or the visibility of views within the view tree changes.
which means it gets called many times and not always the view is measured (it has its height and width determined)
An alternative is to use ViewTreeObserver.OnPreDrawListener which gets called only when the view is ready to be drawn and has all of its measurements.
final TextView tv = (TextView)findViewById(R.id.image_test);
ViewTreeObserver vto = tv.getViewTreeObserver();
vto.addOnPreDrawListener(new OnPreDrawListener() {
#Override
public void onPreDraw() {
tv.getViewTreeObserver().removeOnPreDrawListener(this);
// Your view will have valid height and width at this point
tv.getHeight();
tv.getWidth();
}
});
Height and width are zero because view has not been created by the time you are requesting it's height and width . One simplest solution is
view.post(new Runnable() {
#Override
public void run() {
view.getHeight(); //height is ready
view.getWidth(); //width is ready
}
});
This method is good as compared to other methods as it is short and crisp.
You should rather look at View lifecycle: http://developer.android.com/reference/android/view/View.html Generally you should not know width and height for sure until your activity comes to onResume state.
You can use a broadcast that is called in OnResume ()
For example:
int vh = 0;
int vw = 0;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.maindemo); //<- includes the grid called "board"
registerReceiver(new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
TableLayout tl = (TableLayout) findViewById(R.id.board);
tl = (TableLayout) findViewById(R.id.board);
vh = tl.getHeight();
vw = tl.getWidth();
}
}, new IntentFilter("Test"));
}
protected void onResume() {
super.onResume();
Intent it = new Intent("Test");
sendBroadcast(it);
}
You can not get the height of a view in OnCreate (), onStart (), or even in onResume () for the reason that kcoppock responded
Simple Response: This worked for me with no Problem.
It seems the key is to ensure that the View has focus before you getHeight etc. Do this by using the hasFocus() method, then using getHeight() method in that order. Just 3 lines of code required.
ImageButton myImageButton1 =(ImageButton)findViewById(R.id.imageButton1);
myImageButton1.hasFocus();
int myButtonHeight = myImageButton1.getHeight();
Log.d("Button Height: ", ""+myButtonHeight );//Not required
Hope it helps.
Use getMeasuredWidth() and getMeasuredHeight() for your view.
Developer guide: View
CORRECTION:
I found out that the above solution is terrible. Especially when your phone is slow.
And here, I found another solution:
calculate out the px value of the element, including the margins and paddings:
dp to px:
https://stackoverflow.com/a/6327095/1982712
or dimens.xml to px:
https://stackoverflow.com/a/16276351/1982712
sp to px:
https://stackoverflow.com/a/9219417/1982712 (reverse the solution)
or dimens to px:
https://stackoverflow.com/a/16276351/1982712
and that's it.