Why new created constraintLayout does not have android:id="#+id/constraint_layout_file_name"?
After creating new constraintLayout we suppose to go to Design view and start creating our layout. But when we do so and we add to our layout for example a TextView, place it where we like and provide constraints so it stays like this after pushing layout on a device it will not stay where we want it to be. It will appear on left top corner on a device because constraints we provided have error
The id "constraintLayout" is not defined anywhere.
What we have to do is to manually add android:id="#+id/constraint_layout_file_name" and edit all constraints. Example:
wrong constraint:
app:layout_constraintLeft_toLeftOf="#+id/constraintLayout"
corect one:
app:layout_constraintLeft_toLeftOf="#+id/constraint_layout_file_name"
Reason why I do ask is that it took me too much time to figure out what I'm doing wrong and I think I'm not the only one.
i had the same problem.
and when i turned on the Autoconnect (on the top | left side) it fixed it by changing it
from:
app:layout_constraintLeft_toLeftOf="#+id/constraintLayout"
to:
app:layout_constraintLeft_toLeftOf="parent"
first,compile 'com.android.support.constraint:constraint-layout:1.0.0-beta4';
second,sync your project!
I have a TextView that has 10 lines as a property and two variables, Alpha and Beta.
I want Alpha to use the first two lines of the TextView and Beta use the remainder of the lines or 3-10.
How do I code my Java? I cannot find a way to directly address the Lines collection.
This does not work:
TextView.setText.Lines[1]("This is a test\n for Alpha");
TextView.setText.Lines[3]("This is a test\n for Beta\n that has more lines\n than Alpha");
TiA Trey
You can't do that, the lines depend on the width of the TextView. If you want, you can use two TextViews, one with 2 lines and another one with 8.
The question is pretty much exactly what I want, lets say i have this text:
"{W}, {T}: Tap target creature."
I have to replace the {W} and the {T} for 2 tiny little images pretty much the same size of the 3 letters(in case {W} and {T})... Is that possible in some way?
Just to say, the TextView is inside a Listview...
the Position for {W} and {T} are not always the same...
the images are in my resource...
The one workaround you can try is to place your TextView and ImageView inside a FrameLayout, one on top of the other. Now when you want to change them, just make one of them invisible and initialize the other. This will probably work. Hope this helps.
Did you try the attribute drawableLeft of the text view? But since you have two images, you will have to use a single image file which consists of both {w}{t}. so you will have to put the images with all combinations of {w}{t} in your resources.
then use the following method in your code:
textView.setCompoundDrawables(leftDrawable, null, null, null);
I have been working in android for past few months. The problem for me is now related to Z index value. I am having a layout with a textview,edittext and imageview.
Suppose i have a xml file something like this..
<Layout1>
<edittext><zindex>3</zindex></edittext>
<textview><zindex>2</zindex></textview>
<imageview><zindex>1</zindex></imageview>
</Layout1>
So my question is that am reading this xml file by DOM parser and i want to set the z index value for all these by the values defined in the xml. Now is there any function or property that i can use to do it.
I have learnt about coding it with xml, but that will make it hardcoded. I want a dynamic display so how do i adjust layout with the zindex values.... HELP PLZ
there is no Z-index in android layouts. You'll need to use FrameLayout or RelativeLayout if you need to place elements on top of each other in reverse order.
see Placing/Overlapping(z-index) a view above another view in android
You can use view.setZ(float) starting from API level 21. Here you can find more info.
I would like to define the z order of the views of a RelativeLayout in Android.
I know one way of doing this is calling bringToFront.
Is there are better way of doing this? It would be great if I could define the z order in the layout xml.
The easiest way is simply to pay attention to the order in which the Views are added to your XML file. Lower down in the file means higher up in the Z-axis.
Edit:
This is documented here and here on the Android developer site. (Thanks #flightplanner)
If you want to do this in code
you can do
View.bringToFront();
see docs
Please note, buttons and other elements in API 21 and greater have a high elevation, and therefore ignore the xml order of elements regardless of parent layout. Took me a while to figure that one out.
In Android starting from API level 21, items in the layout file get their Z order both from how they are ordered within the file, as described in correct answer, and from their elevation, a higher elevation value means the item gets a higher Z order.
This can sometimes cause problems, especially with buttons that often appear on top of items that according to the order of the XML should be below them in Z order. To fix this just set the android:elevation of the the items in your layout XML to match the Z order you want to achieve.
I you set an elevation of an element in the layout it will start to cast a shadow. If you don't want this effect you can remove the shadow with code like so:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
myView.setOutlineProvider(null);
}
I haven't found any way to remove the shadow of a elevated view through the layout xml.
I encountered the same issues: In a relative layout parentView, I have 2 children childView1 and childView2. At first, I put childView1 above childView2 and I want childView1 to be on top of childView2. Changing the order of children views did not solve the problem for me. What worked for me is to set android:clipChildren="false" on parentView and in the code I set:
childView1.bringToFront();
parentView.invalidate();
Please note that you can use view.setZ(float) starting from API level 21. Here you can find more info.
Thought I'd add an answer since the introduction of the
android:translationZ
XML field changed things a tad. The other answers that suggest running
childView1.bringToFront();
parentView.invalidate();
are totally spot on EXCEPT for that this code will NOT bring childView1 in front of any view with a hardcoded android:translationZ in the XML file. I was having problems with this, and once I removed this field from the other views, bringToFront() worked just fine.
API 21 has view.setElevation(float) build-in
Use ViewCompat.setElevation(view, float); for backward compatibility
More methods ViewCompat.setZ(v, pixels) and ViewCompat.setTranslationZ(v, pixels)
Another way collect buttons or view array and use addView to add to RelativeLayout
childView.bringToFront() didn't work for me, so I set the Z translation of the least recently added item (the one that was overlaying all other children) to a negative value like so:
lastView.setTranslationZ(-10);
see https://developer.android.com/reference/android/view/View.html#setTranslationZ(float) for more
Or put the overlapping button or views inside a FrameLayout. Then, the RelativeLayout in the xml file will respect the order of child layouts as they added.
You can use custom RelativeLayout with redefined
protected int getChildDrawingOrder (int childCount, int i)
Be aware - this method takes param i as "which view should I draw i'th".
This is how ViewPager works. It sets custom drawing order in conjuction with PageTransformer.
Check if you have any elevation on one of the Views in XML. If so, add elevation to the other item or remove the elevation to solve the issue. From there, it's the order of the views that dictates what comes above the other.
You can use below code sample also for achieving the same
ViewCompat.setElevation(sourceView, ViewCompat.getElevation(mCardView)+1);
This is backward compatible.
Here mCardView is a view which should be below sourceView.