It defines the XML namespace of the document. You should put it, otherwise tags like <RelativeLayout> could be not recognied by the parser. Namespaces are a way for XML documents to include tags from various vendors. By using xmlns attribute you declare, that, by default, you’re using XML elements defined here: http://schemas.android.com/apk/res/android (note that this … Read more
Nope, there is no such attribute. Currently (Mar 2021) there is: tools:context Intended for: Any root View tools:itemCount Intended for: RecyclerView tools:layout Intended for: fragment tools:listitem / tools:listheader / tools:listfooter Intended for: AdapterView (and subclasses like ListView) tools:showIn Intended for: Any root View in a layout that’s referred to by an include tools:menu Intended for: … Read more
It’s for a feature we’re working on but which isn’t part of Studio yet. This part was accidentally not put behind a flag (which normally removes it during compilation.) We just fixed it; next canary won’t show these items — until the feature is enabled when it’s done.
Try this (3 number of items) tools:itemCount=”3″
The app namespace is not specific to a library, but it is used for all attributes defined in your app, whether by your code or by libraries you import, effectively making a single global namespace for custom attributes – i.e., attributes not defined by the android system. In this case, the appcompat-v7 library uses custom … Read more
There is a new parentTag tools attribute (added in Android Studio 2.2) that you can use to specify the layout type for a merge tag, which will make the layout render correctly in the layout editor preview. So using your example: <merge xmlns:android=”http://schemas.android.com/apk/res/android” xmlns:tools=”http://schemas.android.com/tools” android:layout_width=”match_parent” android:layout_height=”match_parent” tools:parentTag=”LinearLayout” tools:orientation=”horizontal”> <TextView android:layout_width=”wrap_content” android:layout_height=”wrap_content” android:text=”Some text” android:textSize=”20sp”/> <TextView … Read more
@oRRs is right ! I’m using Android Studio 1.4 RC2 and you can now specify any custom layout. I tried a custom CardView and it works. tools:listitem=”@android:layout/simple_list_item_checked”
This is the activity the tools UI editor uses to render your layout preview. It is documented here: This attribute declares which activity this layout is associated with by default. This enables features in the editor or layout preview that require knowledge of the activity, such as what the layout theme should be in the … Read more